summaryrefslogtreecommitdiffstats
path: root/tools/lib/bpf
diff options
context:
space:
mode:
Diffstat (limited to 'tools/lib/bpf')
-rw-r--r--tools/lib/bpf/.gitignore1
-rw-r--r--tools/lib/bpf/Build2
-rw-r--r--tools/lib/bpf/Makefile58
-rw-r--r--tools/lib/bpf/README.rst166
-rw-r--r--tools/lib/bpf/bpf.c205
-rw-r--r--tools/lib/bpf/bpf.h40
-rw-r--r--tools/lib/bpf/bpf_prog_linfo.c249
-rw-r--r--tools/lib/bpf/btf.c2441
-rw-r--r--tools/lib/bpf/btf.h78
-rw-r--r--tools/lib/bpf/libbpf.c852
-rw-r--r--tools/lib/bpf/libbpf.h86
-rw-r--r--tools/lib/bpf/libbpf.map156
-rw-r--r--tools/lib/bpf/libbpf_errno.c1
-rw-r--r--tools/lib/bpf/libbpf_probes.c242
-rw-r--r--tools/lib/bpf/libbpf_util.h30
-rw-r--r--tools/lib/bpf/netlink.c85
-rw-r--r--tools/lib/bpf/test_libbpf.cpp18
-rw-r--r--tools/lib/bpf/xsk.c723
-rw-r--r--tools/lib/bpf/xsk.h203
19 files changed, 5315 insertions, 321 deletions
diff --git a/tools/lib/bpf/.gitignore b/tools/lib/bpf/.gitignore
index f81e549ddfdb..4db74758c674 100644
--- a/tools/lib/bpf/.gitignore
+++ b/tools/lib/bpf/.gitignore
@@ -1,2 +1,3 @@
libbpf_version.h
FEATURE-DUMP.libbpf
+test_libbpf
diff --git a/tools/lib/bpf/Build b/tools/lib/bpf/Build
index 7bc31c905018..ee9d5362f35b 100644
--- a/tools/lib/bpf/Build
+++ b/tools/lib/bpf/Build
@@ -1 +1 @@
-libbpf-y := libbpf.o bpf.o nlattr.o btf.o libbpf_errno.o str_error.o netlink.o
+libbpf-y := libbpf.o bpf.o nlattr.o btf.o libbpf_errno.o str_error.o netlink.o bpf_prog_linfo.o libbpf_probes.o xsk.o
diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile
index 425b480bda75..a05c43468bd0 100644
--- a/tools/lib/bpf/Makefile
+++ b/tools/lib/bpf/Makefile
@@ -14,21 +14,6 @@ srctree := $(patsubst %/,%,$(dir $(srctree)))
#$(info Determined 'srctree' to be $(srctree))
endif
-# Makefiles suck: This macro sets a default value of $(2) for the
-# variable named by $(1), unless the variable has been set by
-# environment or command line. This is necessary for CC and AR
-# because make sets default values, so the simpler ?= approach
-# won't work as expected.
-define allow-override
- $(if $(or $(findstring environment,$(origin $(1))),\
- $(findstring command line,$(origin $(1)))),,\
- $(eval $(1) = $(2)))
-endef
-
-# Allow setting CC and AR, or setting CROSS_COMPILE as a prefix.
-$(call allow-override,CC,$(CROSS_COMPILE)gcc)
-$(call allow-override,AR,$(CROSS_COMPILE)ar)
-
INSTALL = install
# Use DESTDIR for installing into a different root directory.
@@ -54,7 +39,7 @@ man_dir_SQ = '$(subst ','\'',$(man_dir))'
export man_dir man_dir_SQ INSTALL
export DESTDIR DESTDIR_SQ
-include ../../scripts/Makefile.include
+include $(srctree)/tools/scripts/Makefile.include
# copy a bit from Linux kbuild
@@ -66,7 +51,7 @@ ifndef VERBOSE
endif
FEATURE_USER = .libbpf
-FEATURE_TESTS = libelf libelf-mmap bpf reallocarray
+FEATURE_TESTS = libelf libelf-mmap bpf reallocarray cxx
FEATURE_DISPLAY = libelf bpf
INCLUDES = -I. -I$(srctree)/tools/include -I$(srctree)/tools/arch/$(ARCH)/include/uapi -I$(srctree)/tools/include/uapi
@@ -145,14 +130,26 @@ include $(srctree)/tools/build/Makefile.include
BPF_IN := $(OUTPUT)libbpf-in.o
LIB_FILE := $(addprefix $(OUTPUT),$(LIB_FILE))
+VERSION_SCRIPT := libbpf.map
+
+GLOBAL_SYM_COUNT = $(shell readelf -s --wide $(BPF_IN) | \
+ awk '/GLOBAL/ && /DEFAULT/ && !/UND/ {s++} END{print s}')
+VERSIONED_SYM_COUNT = $(shell readelf -s --wide $(OUTPUT)libbpf.so | \
+ grep -Eo '[^ ]+@LIBBPF_' | cut -d@ -f1 | sort -u | wc -l)
CMD_TARGETS = $(LIB_FILE)
+CXX_TEST_TARGET = $(OUTPUT)test_libbpf
+
+ifeq ($(feature-cxx), 1)
+ CMD_TARGETS += $(CXX_TEST_TARGET)
+endif
+
TARGETS = $(CMD_TARGETS)
all: fixdep all_cmd
-all_cmd: $(CMD_TARGETS)
+all_cmd: $(CMD_TARGETS) check
$(BPF_IN): force elfdep bpfdep
@(test -f ../../include/uapi/linux/bpf.h -a -f ../../../include/uapi/linux/bpf.h && ( \
@@ -167,14 +164,33 @@ $(BPF_IN): force elfdep bpfdep
@(test -f ../../include/uapi/linux/if_link.h -a -f ../../../include/uapi/linux/if_link.h && ( \
(diff -B ../../include/uapi/linux/if_link.h ../../../include/uapi/linux/if_link.h >/dev/null) || \
echo "Warning: Kernel ABI header at 'tools/include/uapi/linux/if_link.h' differs from latest version at 'include/uapi/linux/if_link.h'" >&2 )) || true
+ @(test -f ../../include/uapi/linux/if_xdp.h -a -f ../../../include/uapi/linux/if_xdp.h && ( \
+ (diff -B ../../include/uapi/linux/if_xdp.h ../../../include/uapi/linux/if_xdp.h >/dev/null) || \
+ echo "Warning: Kernel ABI header at 'tools/include/uapi/linux/if_xdp.h' differs from latest version at 'include/uapi/linux/if_xdp.h'" >&2 )) || true
$(Q)$(MAKE) $(build)=libbpf
$(OUTPUT)libbpf.so: $(BPF_IN)
- $(QUIET_LINK)$(CC) --shared $^ -o $@
+ $(QUIET_LINK)$(CC) --shared -Wl,--version-script=$(VERSION_SCRIPT) \
+ $^ -o $@
$(OUTPUT)libbpf.a: $(BPF_IN)
$(QUIET_LINK)$(RM) $@; $(AR) rcs $@ $^
+$(OUTPUT)test_libbpf: test_libbpf.cpp $(OUTPUT)libbpf.a
+ $(QUIET_LINK)$(CXX) $(INCLUDES) $^ -lelf -o $@
+
+check: check_abi
+
+check_abi: $(OUTPUT)libbpf.so
+ @if [ "$(GLOBAL_SYM_COUNT)" != "$(VERSIONED_SYM_COUNT)" ]; then \
+ echo "Warning: Num of global symbols in $(BPF_IN)" \
+ "($(GLOBAL_SYM_COUNT)) does NOT match with num of" \
+ "versioned symbols in $^ ($(VERSIONED_SYM_COUNT))." \
+ "Please make sure all LIBBPF_API symbols are" \
+ "versioned in $(VERSION_SCRIPT)." >&2; \
+ exit 1; \
+ fi
+
define do_install
if [ ! -d '$(DESTDIR_SQ)$2' ]; then \
$(INSTALL) -d -m 755 '$(DESTDIR_SQ)$2'; \
@@ -201,8 +217,8 @@ config-clean:
$(Q)$(MAKE) -C $(srctree)/tools/build/feature/ clean >/dev/null
clean:
- $(call QUIET_CLEAN, libbpf) $(RM) *.o *~ $(TARGETS) *.a *.so .*.d .*.cmd \
- $(RM) LIBBPF-CFLAGS
+ $(call QUIET_CLEAN, libbpf) $(RM) $(TARGETS) $(CXX_TEST_TARGET) \
+ *.o *~ *.a *.so .*.d .*.cmd LIBBPF-CFLAGS
$(call QUIET_CLEAN, core-gen) $(RM) $(OUTPUT)FEATURE-DUMP.libbpf
diff --git a/tools/lib/bpf/README.rst b/tools/lib/bpf/README.rst
new file mode 100644
index 000000000000..5788479384ca
--- /dev/null
+++ b/tools/lib/bpf/README.rst
@@ -0,0 +1,166 @@
+.. SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
+
+libbpf API naming convention
+============================
+
+libbpf API provides access to a few logically separated groups of
+functions and types. Every group has its own naming convention
+described here. It's recommended to follow these conventions whenever a
+new function or type is added to keep libbpf API clean and consistent.
+
+All types and functions provided by libbpf API should have one of the
+following prefixes: ``bpf_``, ``btf_``, ``libbpf_``, ``xsk_``.
+
+System call wrappers
+--------------------
+
+System call wrappers are simple wrappers for commands supported by
+sys_bpf system call. These wrappers should go to ``bpf.h`` header file
+and map one-on-one to corresponding commands.
+
+For example ``bpf_map_lookup_elem`` wraps ``BPF_MAP_LOOKUP_ELEM``
+command of sys_bpf, ``bpf_prog_attach`` wraps ``BPF_PROG_ATTACH``, etc.
+
+Objects
+-------
+
+Another class of types and functions provided by libbpf API is "objects"
+and functions to work with them. Objects are high-level abstractions
+such as BPF program or BPF map. They're represented by corresponding
+structures such as ``struct bpf_object``, ``struct bpf_program``,
+``struct bpf_map``, etc.
+
+Structures are forward declared and access to their fields should be
+provided via corresponding getters and setters rather than directly.
+
+These objects are associated with corresponding parts of ELF object that
+contains compiled BPF programs.
+
+For example ``struct bpf_object`` represents ELF object itself created
+from an ELF file or from a buffer, ``struct bpf_program`` represents a
+program in ELF object and ``struct bpf_map`` is a map.
+
+Functions that work with an object have names built from object name,
+double underscore and part that describes function purpose.
+
+For example ``bpf_object__open`` consists of the name of corresponding
+object, ``bpf_object``, double underscore and ``open`` that defines the
+purpose of the function to open ELF file and create ``bpf_object`` from
+it.
+
+Another example: ``bpf_program__load`` is named for corresponding
+object, ``bpf_program``, that is separated from other part of the name
+by double underscore.
+
+All objects and corresponding functions other than BTF related should go
+to ``libbpf.h``. BTF types and functions should go to ``btf.h``.
+
+Auxiliary functions
+-------------------
+
+Auxiliary functions and types that don't fit well in any of categories
+described above should have ``libbpf_`` prefix, e.g.
+``libbpf_get_error`` or ``libbpf_prog_type_by_name``.
+
+AF_XDP functions
+-------------------
+
+AF_XDP functions should have an ``xsk_`` prefix, e.g.
+``xsk_umem__get_data`` or ``xsk_umem__create``. The interface consists
+of both low-level ring access functions and high-level configuration
+functions. These can be mixed and matched. Note that these functions
+are not reentrant for performance reasons.
+
+Please take a look at Documentation/networking/af_xdp.rst in the Linux
+kernel source tree on how to use XDP sockets and for some common
+mistakes in case you do not get any traffic up to user space.
+
+libbpf ABI
+==========
+
+libbpf can be both linked statically or used as DSO. To avoid possible
+conflicts with other libraries an application is linked with, all
+non-static libbpf symbols should have one of the prefixes mentioned in
+API documentation above. See API naming convention to choose the right
+name for a new symbol.
+
+Symbol visibility
+-----------------
+
+libbpf follow the model when all global symbols have visibility "hidden"
+by default and to make a symbol visible it has to be explicitly
+attributed with ``LIBBPF_API`` macro. For example:
+
+.. code-block:: c
+
+ LIBBPF_API int bpf_prog_get_fd_by_id(__u32 id);
+
+This prevents from accidentally exporting a symbol, that is not supposed
+to be a part of ABI what, in turn, improves both libbpf developer- and
+user-experiences.
+
+ABI versionning
+---------------
+
+To make future ABI extensions possible libbpf ABI is versioned.
+Versioning is implemented by ``libbpf.map`` version script that is
+passed to linker.
+
+Version name is ``LIBBPF_`` prefix + three-component numeric version,
+starting from ``0.0.1``.
+
+Every time ABI is being changed, e.g. because a new symbol is added or
+semantic of existing symbol is changed, ABI version should be bumped.
+
+For example, if current state of ``libbpf.map`` is:
+
+.. code-block::
+ LIBBPF_0.0.1 {
+ global:
+ bpf_func_a;
+ bpf_func_b;
+ local:
+ \*;
+ };
+
+, and a new symbol ``bpf_func_c`` is being introduced, then
+``libbpf.map`` should be changed like this:
+
+.. code-block::
+ LIBBPF_0.0.1 {
+ global:
+ bpf_func_a;
+ bpf_func_b;
+ local:
+ \*;
+ };
+ LIBBPF_0.0.2 {
+ global:
+ bpf_func_c;
+ } LIBBPF_0.0.1;
+
+, where new version ``LIBBPF_0.0.2`` depends on the previous
+``LIBBPF_0.0.1``.
+
+Format of version script and ways to handle ABI changes, including
+incompatible ones, described in details in [1].
+
+Stand-alone build
+=================
+
+Under https://github.com/libbpf/libbpf there is a (semi-)automated
+mirror of the mainline's version of libbpf for a stand-alone build.
+
+However, all changes to libbpf's code base must be upstreamed through
+the mainline kernel tree.
+
+License
+=======
+
+libbpf is dual-licensed under LGPL 2.1 and BSD 2-Clause.
+
+Links
+=====
+
+[1] https://www.akkadia.org/drepper/dsohowto.pdf
+ (Chapter 3. Maintaining APIs and ABIs).
diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index 03f9bcc4ef50..9cd015574e83 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -22,6 +22,7 @@
*/
#include <stdlib.h>
+#include <string.h>
#include <memory.h>
#include <unistd.h>
#include <asm/unistd.h>
@@ -65,6 +66,17 @@ static inline int sys_bpf(enum bpf_cmd cmd, union bpf_attr *attr,
return syscall(__NR_bpf, cmd, attr, size);
}
+static inline int sys_bpf_prog_load(union bpf_attr *attr, unsigned int size)
+{
+ int fd;
+
+ do {
+ fd = sys_bpf(BPF_PROG_LOAD, attr, size);
+ } while (fd < 0 && errno == EAGAIN);
+
+ return fd;
+}
+
int bpf_create_map_xattr(const struct bpf_create_map_attr *create_attr)
{
__u32 name_len = create_attr->name ? strlen(create_attr->name) : 0;
@@ -173,42 +185,133 @@ int bpf_create_map_in_map(enum bpf_map_type map_type, const char *name,
-1);
}
+static void *
+alloc_zero_tailing_info(const void *orecord, __u32 cnt,
+ __u32 actual_rec_size, __u32 expected_rec_size)
+{
+ __u64 info_len = actual_rec_size * cnt;
+ void *info, *nrecord;
+ int i;
+
+ info = malloc(info_len);
+ if (!info)
+ return NULL;
+
+ /* zero out bytes kernel does not understand */
+ nrecord = info;
+ for (i = 0; i < cnt; i++) {
+ memcpy(nrecord, orecord, expected_rec_size);
+ memset(nrecord + expected_rec_size, 0,
+ actual_rec_size - expected_rec_size);
+ orecord += actual_rec_size;
+ nrecord += actual_rec_size;
+ }
+
+ return info;
+}
+
int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr,
char *log_buf, size_t log_buf_sz)
{
+ void *finfo = NULL, *linfo = NULL;
union bpf_attr attr;
+ __u32 log_level;
__u32 name_len;
int fd;
- if (!load_attr)
+ if (!load_attr || !log_buf != !log_buf_sz)
+ return -EINVAL;
+
+ log_level = load_attr->log_level;
+ if (log_level > 2 || (log_level && !log_buf))
return -EINVAL;
name_len = load_attr->name ? strlen(load_attr->name) : 0;
- bzero(&attr, sizeof(attr));
+ memset(&attr, 0, sizeof(attr));
attr.prog_type = load_attr->prog_type;
attr.expected_attach_type = load_attr->expected_attach_type;
attr.insn_cnt = (__u32)load_attr->insns_cnt;
attr.insns = ptr_to_u64(load_attr->insns);
attr.license = ptr_to_u64(load_attr->license);
- attr.log_buf = ptr_to_u64(NULL);
- attr.log_size = 0;
- attr.log_level = 0;
+
+ attr.log_level = log_level;
+ if (log_level) {
+ attr.log_buf = ptr_to_u64(log_buf);
+ attr.log_size = log_buf_sz;
+ } else {
+ attr.log_buf = ptr_to_u64(NULL);
+ attr.log_size = 0;
+ }
+
attr.kern_version = load_attr->kern_version;
attr.prog_ifindex = load_attr->prog_ifindex;
+ attr.prog_btf_fd = load_attr->prog_btf_fd;
+ attr.func_info_rec_size = load_attr->func_info_rec_size;
+ attr.func_info_cnt = load_attr->func_info_cnt;
+ attr.func_info = ptr_to_u64(load_attr->func_info);
+ attr.line_info_rec_size = load_attr->line_info_rec_size;
+ attr.line_info_cnt = load_attr->line_info_cnt;
+ attr.line_info = ptr_to_u64(load_attr->line_info);
memcpy(attr.prog_name, load_attr->name,
min(name_len, BPF_OBJ_NAME_LEN - 1));
- fd = sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr));
- if (fd >= 0 || !log_buf || !log_buf_sz)
+ fd = sys_bpf_prog_load(&attr, sizeof(attr));
+ if (fd >= 0)
return fd;
+ /* After bpf_prog_load, the kernel may modify certain attributes
+ * to give user space a hint how to deal with loading failure.
+ * Check to see whether we can make some changes and load again.
+ */
+ while (errno == E2BIG && (!finfo || !linfo)) {
+ if (!finfo && attr.func_info_cnt &&
+ attr.func_info_rec_size < load_attr->func_info_rec_size) {
+ /* try with corrected func info records */
+ finfo = alloc_zero_tailing_info(load_attr->func_info,
+ load_attr->func_info_cnt,
+ load_attr->func_info_rec_size,
+ attr.func_info_rec_size);
+ if (!finfo)
+ goto done;
+
+ attr.func_info = ptr_to_u64(finfo);
+ attr.func_info_rec_size = load_attr->func_info_rec_size;
+ } else if (!linfo && attr.line_info_cnt &&
+ attr.line_info_rec_size <
+ load_attr->line_info_rec_size) {
+ linfo = alloc_zero_tailing_info(load_attr->line_info,
+ load_attr->line_info_cnt,
+ load_attr->line_info_rec_size,
+ attr.line_info_rec_size);
+ if (!linfo)
+ goto done;
+
+ attr.line_info = ptr_to_u64(linfo);
+ attr.line_info_rec_size = load_attr->line_info_rec_size;
+ } else {
+ break;
+ }
+
+ fd = sys_bpf_prog_load(&attr, sizeof(attr));
+
+ if (fd >= 0)
+ goto done;
+ }
+
+ if (log_level || !log_buf)
+ goto done;
+
/* Try again with log */
attr.log_buf = ptr_to_u64(log_buf);
attr.log_size = log_buf_sz;
attr.log_level = 1;
log_buf[0] = 0;
- return sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr));
+ fd = sys_bpf_prog_load(&attr, sizeof(attr));
+done:
+ free(finfo);
+ free(linfo);
+ return fd;
}
int bpf_load_program(enum bpf_prog_type type, const struct bpf_insn *insns,
@@ -231,13 +334,13 @@ int bpf_load_program(enum bpf_prog_type type, const struct bpf_insn *insns,
}
int bpf_verify_program(enum bpf_prog_type type, const struct bpf_insn *insns,
- size_t insns_cnt, int strict_alignment,
- const char *license, __u32 kern_version,
- char *log_buf, size_t log_buf_sz, int log_level)
+ size_t insns_cnt, __u32 prog_flags, const char *license,
+ __u32 kern_version, char *log_buf, size_t log_buf_sz,
+ int log_level)
{
union bpf_attr attr;
- bzero(&attr, sizeof(attr));
+ memset(&attr, 0, sizeof(attr));
attr.prog_type = type;
attr.insn_cnt = (__u32)insns_cnt;
attr.insns = ptr_to_u64(insns);
@@ -247,9 +350,9 @@ int bpf_verify_program(enum bpf_prog_type type, const struct bpf_insn *insns,
attr.log_level = log_level;
log_buf[0] = 0;
attr.kern_version = kern_version;
- attr.prog_flags = strict_alignment ? BPF_F_STRICT_ALIGNMENT : 0;
+ attr.prog_flags = prog_flags;
- return sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr));
+ return sys_bpf_prog_load(&attr, sizeof(attr));
}
int bpf_map_update_elem(int fd, const void *key, const void *value,
@@ -257,7 +360,7 @@ int bpf_map_update_elem(int fd, const void *key, const void *value,
{
union bpf_attr attr;
- bzero(&attr, sizeof(attr));
+ memset(&attr, 0, sizeof(attr));
attr.map_fd = fd;
attr.key = ptr_to_u64(key);
attr.value = ptr_to_u64(value);
@@ -270,10 +373,23 @@ int bpf_map_lookup_elem(int fd, const void *key, void *value)
{
union bpf_attr attr;
- bzero(&attr, sizeof(attr));
+ memset(&attr, 0, sizeof(attr));
+ attr.map_fd = fd;
+ attr.key = ptr_to_u64(key);
+ attr.value = ptr_to_u64(value);
+
+ return sys_bpf(BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr));
+}
+
+int bpf_map_lookup_elem_flags(int fd, const void *key, void *value, __u64 flags)
+{
+ union bpf_attr attr;
+
+ memset(&attr, 0, sizeof(attr));
attr.map_fd = fd;
attr.key = ptr_to_u64(key);
attr.value = ptr_to_u64(value);
+ attr.flags = flags;
return sys_bpf(BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr));
}
@@ -282,7 +398,7 @@ int bpf_map_lookup_and_delete_elem(int fd, const void *key, void *value)
{
union bpf_attr attr;
- bzero(&attr, sizeof(attr));
+ memset(&attr, 0, sizeof(attr));
attr.map_fd = fd;
attr.key = ptr_to_u64(key);
attr.value = ptr_to_u64(value);
@@ -294,7 +410,7 @@ int bpf_map_delete_elem(int fd, const void *key)
{
union bpf_attr attr;
- bzero(&attr, sizeof(attr));
+ memset(&attr, 0, sizeof(attr));
attr.map_fd = fd;
attr.key = ptr_to_u64(key);
@@ -305,7 +421,7 @@ int bpf_map_get_next_key(int fd, const void *key, void *next_key)
{
union bpf_attr attr;
- bzero(&attr, sizeof(attr));
+ memset(&attr, 0, sizeof(attr));
attr.map_fd = fd;
attr.key = ptr_to_u64(key);
attr.next_key = ptr_to_u64(next_key);
@@ -317,7 +433,7 @@ int bpf_obj_pin(int fd, const char *pathname)
{
union bpf_attr attr;
- bzero(&attr, sizeof(attr));
+ memset(&attr, 0, sizeof(attr));
attr.pathname = ptr_to_u64((void *)pathname);
attr.bpf_fd = fd;
@@ -328,7 +444,7 @@ int bpf_obj_get(const char *pathname)
{
union bpf_attr attr;
- bzero(&attr, sizeof(attr));
+ memset(&attr, 0, sizeof(attr));
attr.pathname = ptr_to_u64((void *)pathname);
return sys_bpf(BPF_OBJ_GET, &attr, sizeof(attr));
@@ -339,7 +455,7 @@ int bpf_prog_attach(int prog_fd, int target_fd, enum bpf_attach_type type,
{
union bpf_attr attr;
- bzero(&attr, sizeof(attr));
+ memset(&attr, 0, sizeof(attr));
attr.target_fd = target_fd;
attr.attach_bpf_fd = prog_fd;
attr.attach_type = type;
@@ -352,7 +468,7 @@ int bpf_prog_detach(int target_fd, enum bpf_attach_type type)
{
union bpf_attr attr;
- bzero(&attr, sizeof(attr));
+ memset(&attr, 0, sizeof(attr));
attr.target_fd = target_fd;
attr.attach_type = type;
@@ -363,7 +479,7 @@ int bpf_prog_detach2(int prog_fd, int target_fd, enum bpf_attach_type type)
{
union bpf_attr attr;
- bzero(&attr, sizeof(attr));
+ memset(&attr, 0, sizeof(attr));
attr.target_fd = target_fd;
attr.attach_bpf_fd = prog_fd;
attr.attach_type = type;
@@ -377,7 +493,7 @@ int bpf_prog_query(int target_fd, enum bpf_attach_type type, __u32 query_flags,
union bpf_attr attr;
int ret;
- bzero(&attr, sizeof(attr));
+ memset(&attr, 0, sizeof(attr));
attr.query.target_fd = target_fd;
attr.query.attach_type = type;
attr.query.query_flags = query_flags;
@@ -398,7 +514,7 @@ int bpf_prog_test_run(int prog_fd, int repeat, void *data, __u32 size,
union bpf_attr attr;
int ret;
- bzero(&attr, sizeof(attr));
+ memset(&attr, 0, sizeof(attr));
attr.test.prog_fd = prog_fd;
attr.test.data_in = ptr_to_u64(data);
attr.test.data_out = ptr_to_u64(data_out);
@@ -415,12 +531,35 @@ int bpf_prog_test_run(int prog_fd, int repeat, void *data, __u32 size,
return ret;
}
+int bpf_prog_test_run_xattr(struct bpf_prog_test_run_attr *test_attr)
+{
+ union bpf_attr attr;
+ int ret;
+
+ if (!test_attr->data_out && test_attr->data_size_out > 0)
+ return -EINVAL;
+
+ memset(&attr, 0, sizeof(attr));
+ attr.test.prog_fd = test_attr->prog_fd;
+ attr.test.data_in = ptr_to_u64(test_attr->data_in);
+ attr.test.data_out = ptr_to_u64(test_attr->data_out);
+ attr.test.data_size_in = test_attr->data_size_in;
+ attr.test.data_size_out = test_attr->data_size_out;
+ attr.test.repeat = test_attr->repeat;
+
+ ret = sys_bpf(BPF_PROG_TEST_RUN, &attr, sizeof(attr));
+ test_attr->data_size_out = attr.test.data_size_out;
+ test_attr->retval = attr.test.retval;
+ test_attr->duration = attr.test.duration;
+ return ret;
+}
+
int bpf_prog_get_next_id(__u32 start_id, __u32 *next_id)
{
union bpf_attr attr;
int err;
- bzero(&attr, sizeof(attr));
+ memset(&attr, 0, sizeof(attr));
attr.start_id = start_id;
err = sys_bpf(BPF_PROG_GET_NEXT_ID, &attr, sizeof(attr));
@@ -435,7 +574,7 @@ int bpf_map_get_next_id(__u32 start_id, __u32 *next_id)
union bpf_attr attr;
int err;
- bzero(&attr, sizeof(attr));
+ memset(&attr, 0, sizeof(attr));
attr.start_id = start_id;
err = sys_bpf(BPF_MAP_GET_NEXT_ID, &attr, sizeof(attr));
@@ -449,7 +588,7 @@ int bpf_prog_get_fd_by_id(__u32 id)
{
union bpf_attr attr;
- bzero(&attr, sizeof(attr));
+ memset(&attr, 0, sizeof(attr));
attr.prog_id = id;
return sys_bpf(BPF_PROG_GET_FD_BY_ID, &attr, sizeof(attr));
@@ -459,7 +598,7 @@ int bpf_map_get_fd_by_id(__u32 id)
{
union bpf_attr attr;
- bzero(&attr, sizeof(attr));
+ memset(&attr, 0, sizeof(attr));
attr.map_id = id;
return sys_bpf(BPF_MAP_GET_FD_BY_ID, &attr, sizeof(attr));
@@ -469,7 +608,7 @@ int bpf_btf_get_fd_by_id(__u32 id)
{
union bpf_attr attr;
- bzero(&attr, sizeof(attr));
+ memset(&attr, 0, sizeof(attr));
attr.btf_id = id;
return sys_bpf(BPF_BTF_GET_FD_BY_ID, &attr, sizeof(attr));
@@ -480,7 +619,7 @@ int bpf_obj_get_info_by_fd(int prog_fd, void *info, __u32 *info_len)
union bpf_attr attr;
int err;
- bzero(&attr, sizeof(attr));
+ memset(&attr, 0, sizeof(attr));
attr.info.bpf_fd = prog_fd;
attr.info.info_len = *info_len;
attr.info.info = ptr_to_u64(info);
@@ -496,7 +635,7 @@ int bpf_raw_tracepoint_open(const char *name, int prog_fd)
{
union bpf_attr attr;
- bzero(&attr, sizeof(attr));
+ memset(&attr, 0, sizeof(attr));
attr.raw_tracepoint.name = ptr_to_u64(name);
attr.raw_tracepoint.prog_fd = prog_fd;
diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
index 26a51538213c..6ffdd79bea89 100644
--- a/tools/lib/bpf/bpf.h
+++ b/tools/lib/bpf/bpf.h
@@ -27,6 +27,10 @@
#include <stdbool.h>
#include <stddef.h>
+#ifdef __cplusplus
+extern "C" {
+#endif
+
#ifndef LIBBPF_API
#define LIBBPF_API __attribute__((visibility("default")))
#endif
@@ -74,6 +78,14 @@ struct bpf_load_program_attr {
const char *license;
__u32 kern_version;
__u32 prog_ifindex;
+ __u32 prog_btf_fd;
+ __u32 func_info_rec_size;
+ const void *func_info;
+ __u32 func_info_cnt;
+ __u32 line_info_rec_size;
+ const void *line_info;
+ __u32 line_info_cnt;
+ __u32 log_level;
};
/* Flags to direct loading requirements */
@@ -90,7 +102,7 @@ LIBBPF_API int bpf_load_program(enum bpf_prog_type type,
char *log_buf, size_t log_buf_sz);
LIBBPF_API int bpf_verify_program(enum bpf_prog_type type,
const struct bpf_insn *insns,
- size_t insns_cnt, int strict_alignment,
+ size_t insns_cnt, __u32 prog_flags,
const char *license, __u32 kern_version,
char *log_buf, size_t log_buf_sz,
int log_level);
@@ -99,6 +111,8 @@ LIBBPF_API int bpf_map_update_elem(int fd, const void *key, const void *value,
__u64 flags);
LIBBPF_API int bpf_map_lookup_elem(int fd, const void *key, void *value);
+LIBBPF_API int bpf_map_lookup_elem_flags(int fd, const void *key, void *value,
+ __u64 flags);
LIBBPF_API int bpf_map_lookup_and_delete_elem(int fd, const void *key,
void *value);
LIBBPF_API int bpf_map_delete_elem(int fd, const void *key);
@@ -110,6 +124,25 @@ LIBBPF_API int bpf_prog_attach(int prog_fd, int attachable_fd,
LIBBPF_API int bpf_prog_detach(int attachable_fd, enum bpf_attach_type type);
LIBBPF_API int bpf_prog_detach2(int prog_fd, int attachable_fd,
enum bpf_attach_type type);
+
+struct bpf_prog_test_run_attr {
+ int prog_fd;
+ int repeat;
+ const void *data_in;
+ __u32 data_size_in;
+ void *data_out; /* optional */
+ __u32 data_size_out; /* in: max length of data_out
+ * out: length of data_out */
+ __u32 retval; /* out: return code of the BPF program */
+ __u32 duration; /* out: average per repetition in ns */
+};
+
+LIBBPF_API int bpf_prog_test_run_xattr(struct bpf_prog_test_run_attr *test_attr);
+
+/*
+ * bpf_prog_test_run does not check that data_out is large enough. Consider
+ * using bpf_prog_test_run_xattr instead.
+ */
LIBBPF_API int bpf_prog_test_run(int prog_fd, int repeat, void *data,
__u32 size, void *data_out, __u32 *size_out,
__u32 *retval, __u32 *duration);
@@ -128,4 +161,9 @@ LIBBPF_API int bpf_load_btf(void *btf, __u32 btf_size, char *log_buf,
LIBBPF_API int bpf_task_fd_query(int pid, int fd, __u32 flags, char *buf,
__u32 *buf_len, __u32 *prog_id, __u32 *fd_type,
__u64 *probe_offset, __u64 *probe_addr);
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
#endif /* __LIBBPF_BPF_H */
diff --git a/tools/lib/bpf/bpf_prog_linfo.c b/tools/lib/bpf/bpf_prog_linfo.c
new file mode 100644
index 000000000000..6978314ea7f6
--- /dev/null
+++ b/tools/lib/bpf/bpf_prog_linfo.c
@@ -0,0 +1,249 @@
+// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
+/* Copyright (c) 2018 Facebook */
+
+#include <string.h>
+#include <stdlib.h>
+#include <linux/err.h>
+#include <linux/bpf.h>
+#include "libbpf.h"
+
+#ifndef min
+#define min(x, y) ((x) < (y) ? (x) : (y))
+#endif
+
+struct bpf_prog_linfo {
+ void *raw_linfo;
+ void *raw_jited_linfo;
+ __u32 *nr_jited_linfo_per_func;
+ __u32 *jited_linfo_func_idx;
+ __u32 nr_linfo;
+ __u32 nr_jited_func;
+ __u32 rec_size;
+ __u32 jited_rec_size;
+};
+
+static int dissect_jited_func(struct bpf_prog_linfo *prog_linfo,
+ const __u64 *ksym_func, const __u32 *ksym_len)
+{
+ __u32 nr_jited_func, nr_linfo;
+ const void *raw_jited_linfo;
+ const __u64 *jited_linfo;
+ __u64 last_jited_linfo;
+ /*
+ * Index to raw_jited_linfo:
+ * i: Index for searching the next ksym_func
+ * prev_i: Index to the last found ksym_func
+ */
+ __u32 i, prev_i;
+ __u32 f; /* Index to ksym_func */
+
+ raw_jited_linfo = prog_linfo->raw_jited_linfo;
+ jited_linfo = raw_jited_linfo;
+ if (ksym_func[0] != *jited_linfo)
+ goto errout;
+
+ prog_linfo->jited_linfo_func_idx[0] = 0;
+ nr_jited_func = prog_linfo->nr_jited_func;
+ nr_linfo = prog_linfo->nr_linfo;
+
+ for (prev_i = 0, i = 1, f = 1;
+ i < nr_linfo && f < nr_jited_func;
+ i++) {
+ raw_jited_linfo += prog_linfo->jited_rec_size;
+ last_jited_linfo = *jited_linfo;
+ jited_linfo = raw_jited_linfo;
+
+ if (ksym_func[f] == *jited_linfo) {
+ prog_linfo->jited_linfo_func_idx[f] = i;
+
+ /* Sanity check */
+ if (last_jited_linfo - ksym_func[f - 1] + 1 >
+ ksym_len[f - 1])
+ goto errout;
+
+ prog_linfo->nr_jited_linfo_per_func[f - 1] =
+ i - prev_i;
+ prev_i = i;
+
+ /*
+ * The ksym_func[f] is found in jited_linfo.
+ * Look for the next one.
+ */
+ f++;
+ } else if (*jited_linfo <= last_jited_linfo) {
+ /* Ensure the addr is increasing _within_ a func */
+ goto errout;
+ }
+ }
+
+ if (f != nr_jited_func)
+ goto errout;
+
+ prog_linfo->nr_jited_linfo_per_func[nr_jited_func - 1] =
+ nr_linfo - prev_i;
+
+ return 0;
+
+errout:
+ return -EINVAL;
+}
+
+void bpf_prog_linfo__free(struct bpf_prog_linfo *prog_linfo)
+{
+ if (!prog_linfo)
+ return;
+
+ free(prog_linfo->raw_linfo);
+ free(prog_linfo->raw_jited_linfo);
+ free(prog_linfo->nr_jited_linfo_per_func);
+ free(prog_linfo->jited_linfo_func_idx);
+ free(prog_linfo);
+}
+
+struct bpf_prog_linfo *bpf_prog_linfo__new(const struct bpf_prog_info *info)
+{
+ struct bpf_prog_linfo *prog_linfo;
+ __u32 nr_linfo, nr_jited_func;
+
+ nr_linfo = info->nr_line_info;
+
+ if (!nr_linfo)
+ return NULL;
+
+ /*
+ * The min size that bpf_prog_linfo has to access for
+ * searching purpose.
+ */
+ if (info->line_info_rec_size <
+ offsetof(struct bpf_line_info, file_name_off))
+ return NULL;
+
+ prog_linfo = calloc(1, sizeof(*prog_linfo));
+ if (!prog_linfo)
+ return NULL;
+
+ /* Copy xlated line_info */
+ prog_linfo->nr_linfo = nr_linfo;
+ prog_linfo->rec_size = info->line_info_rec_size;
+ prog_linfo->raw_linfo = malloc(nr_linfo * prog_linfo->rec_size);
+ if (!prog_linfo->raw_linfo)
+ goto err_free;
+ memcpy(prog_linfo->raw_linfo, (void *)(long)info->line_info,
+ nr_linfo * prog_linfo->rec_size);
+
+ nr_jited_func = info->nr_jited_ksyms;
+ if (!nr_jited_func ||
+ !info->jited_line_info ||
+ info->nr_jited_line_info != nr_linfo ||
+ info->jited_line_info_rec_size < sizeof(__u64) ||
+ info->nr_jited_func_lens != nr_jited_func ||
+ !info->jited_ksyms ||
+ !info->jited_func_lens)
+ /* Not enough info to provide jited_line_info */
+ return prog_linfo;
+
+ /* Copy jited_line_info */
+ prog_linfo->nr_jited_func = nr_jited_func;
+ prog_linfo->jited_rec_size = info->jited_line_info_rec_size;
+ prog_linfo->raw_jited_linfo = malloc(nr_linfo *
+ prog_linfo->jited_rec_size);
+ if (!prog_linfo->raw_jited_linfo)
+ goto err_free;
+ memcpy(prog_linfo->raw_jited_linfo,
+ (void *)(long)info->jited_line_info,
+ nr_linfo * prog_linfo->jited_rec_size);
+
+ /* Number of jited_line_info per jited func */
+ prog_linfo->nr_jited_linfo_per_func = malloc(nr_jited_func *
+ sizeof(__u32));
+ if (!prog_linfo->nr_jited_linfo_per_func)
+ goto err_free;
+
+ /*
+ * For each jited func,
+ * the start idx to the "linfo" and "jited_linfo" array,
+ */
+ prog_linfo->jited_linfo_func_idx = malloc(nr_jited_func *
+ sizeof(__u32));
+ if (!prog_linfo->jited_linfo_func_idx)
+ goto err_free;
+
+ if (dissect_jited_func(prog_linfo,
+ (__u64 *)(long)info->jited_ksyms,
+ (__u32 *)(long)info->jited_func_lens))
+ goto err_free;
+
+ return prog_linfo;
+
+err_free:
+ bpf_prog_linfo__free(prog_linfo);
+ return NULL;
+}
+
+const struct bpf_line_info *
+bpf_prog_linfo__lfind_addr_func(const struct bpf_prog_linfo *prog_linfo,
+ __u64 addr, __u32 func_idx, __u32 nr_skip)
+{
+ __u32 jited_rec_size, rec_size, nr_linfo, start, i;
+ const void *raw_jited_linfo, *raw_linfo;
+ const __u64 *jited_linfo;
+
+ if (func_idx >= prog_linfo->nr_jited_func)
+ return NULL;
+
+ nr_linfo = prog_linfo->nr_jited_linfo_per_func[func_idx];
+ if (nr_skip >= nr_linfo)
+ return NULL;
+
+ start = prog_linfo->jited_linfo_func_idx[func_idx] + nr_skip;
+ jited_rec_size = prog_linfo->jited_rec_size;
+ raw_jited_linfo = prog_linfo->raw_jited_linfo +
+ (start * jited_rec_size);
+ jited_linfo = raw_jited_linfo;
+ if (addr < *jited_linfo)
+ return NULL;
+
+ nr_linfo -= nr_skip;
+ rec_size = prog_linfo->rec_size;
+ raw_linfo = prog_linfo->raw_linfo + (start * rec_size);
+ for (i = 0; i < nr_linfo; i++) {
+ if (addr < *jited_linfo)
+ break;
+
+ raw_linfo += rec_size;
+ raw_jited_linfo += jited_rec_size;
+ jited_linfo = raw_jited_linfo;
+ }
+
+ return raw_linfo - rec_size;
+}
+
+const struct bpf_line_info *
+bpf_prog_linfo__lfind(const struct bpf_prog_linfo *prog_linfo,
+ __u32 insn_off, __u32 nr_skip)
+{
+ const struct bpf_line_info *linfo;
+ __u32 rec_size, nr_linfo, i;
+ const void *raw_linfo;
+
+ nr_linfo = prog_linfo->nr_linfo;
+ if (nr_skip >= nr_linfo)
+ return NULL;
+
+ rec_size = prog_linfo->rec_size;
+ raw_linfo = prog_linfo->raw_linfo + (nr_skip * rec_size);
+ linfo = raw_linfo;
+ if (insn_off < linfo->insn_off)
+ return NULL;
+
+ nr_linfo -= nr_skip;
+ for (i = 0; i < nr_linfo; i++) {
+ if (insn_off < linfo->insn_off)
+ break;
+
+ raw_linfo += rec_size;
+ linfo = raw_linfo;
+ }
+
+ return raw_linfo - rec_size;
+}
diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index 449591aa9900..1b8d8cdd3575 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -1,6 +1,7 @@
// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
/* Copyright (c) 2018 Facebook */
+#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
@@ -9,12 +10,14 @@
#include <linux/btf.h>
#include "btf.h"
#include "bpf.h"
+#include "libbpf.h"
+#include "libbpf_util.h"
-#define elog(fmt, ...) { if (err_log) err_log(fmt, ##__VA_ARGS__); }
#define max(a, b) ((a) > (b) ? (a) : (b))
#define min(a, b) ((a) < (b) ? (a) : (b))
-#define BTF_MAX_NR_TYPES 65535
+#define BTF_MAX_NR_TYPES 0x7fffffff
+#define BTF_MAX_STR_OFFSET 0x7fffffff
#define IS_MODIFIER(k) (((k) == BTF_KIND_TYPEDEF) || \
((k) == BTF_KIND_VOLATILE) || \
@@ -37,6 +40,52 @@ struct btf {
int fd;
};
+struct btf_ext_info {
+ /*
+ * info points to the individual info section (e.g. func_info and
+ * line_info) from the .BTF.ext. It does not include the __u32 rec_size.
+ */
+ void *info;
+ __u32 rec_size;
+ __u32 len;
+};
+
+struct btf_ext {
+ union {
+ struct btf_ext_header *hdr;
+ void *data;
+ };
+ struct btf_ext_info func_info;
+ struct btf_ext_info line_info;
+ __u32 data_size;
+};
+
+struct btf_ext_info_sec {
+ __u32 sec_name_off;
+ __u32 num_info;
+ /* Followed by num_info * record_size number of bytes */
+ __u8 data[0];
+};
+
+/* The minimum bpf_func_info checked by the loader */
+struct bpf_func_info_min {
+ __u32 insn_off;
+ __u32 type_id;
+};
+
+/* The minimum bpf_line_info checked by the loader */
+struct bpf_line_info_min {
+ __u32 insn_off;
+ __u32 file_name_off;
+ __u32 line_off;
+ __u32 line_col;
+};
+
+static inline __u64 ptr_to_u64(const void *ptr)
+{
+ return (__u64) (unsigned long) ptr;
+}
+
static int btf_add_type(struct btf *btf, struct btf_type *t)
{
if (btf->types_size - btf->nr_types < 2) {
@@ -65,54 +114,54 @@ static int btf_add_type(struct btf *btf, struct btf_type *t)
return 0;
}
-static int btf_parse_hdr(struct btf *btf, btf_print_fn_t err_log)
+static int btf_parse_hdr(struct btf *btf)
{
const struct btf_header *hdr = btf->hdr;
__u32 meta_left;
if (btf->data_size < sizeof(struct btf_header)) {
- elog("BTF header not found\n");
+ pr_debug("BTF header not found\n");
return -EINVAL;
}
if (hdr->magic != BTF_MAGIC) {
- elog("Invalid BTF magic:%x\n", hdr->magic);
+ pr_debug("Invalid BTF magic:%x\n", hdr->magic);
return -EINVAL;
}
if (hdr->version != BTF_VERSION) {
- elog("Unsupported BTF version:%u\n", hdr->version);
+ pr_debug("Unsupported BTF version:%u\n", hdr->version);
return -ENOTSUP;
}
if (hdr->flags) {
- elog("Unsupported BTF flags:%x\n", hdr->flags);
+ pr_debug("Unsupported BTF flags:%x\n", hdr->flags);
return -ENOTSUP;
}
meta_left = btf->data_size - sizeof(*hdr);
if (!meta_left) {
- elog("BTF has no data\n");
+ pr_debug("BTF has no data\n");
return -EINVAL;
}
if (meta_left < hdr->type_off) {
- elog("Invalid BTF type section offset:%u\n", hdr->type_off);
+ pr_debug("Invalid BTF type section offset:%u\n", hdr->type_off);
return -EINVAL;
}
if (meta_left < hdr->str_off) {
- elog("Invalid BTF string section offset:%u\n", hdr->str_off);
+ pr_debug("Invalid BTF string section offset:%u\n", hdr->str_off);
return -EINVAL;
}
if (hdr->type_off >= hdr->str_off) {
- elog("BTF type section offset >= string section offset. No type?\n");
+ pr_debug("BTF type section offset >= string section offset. No type?\n");
return -EINVAL;
}
if (hdr->type_off & 0x02) {
- elog("BTF type section is not aligned to 4 bytes\n");
+ pr_debug("BTF type section is not aligned to 4 bytes\n");
return -EINVAL;
}
@@ -121,15 +170,15 @@ static int btf_parse_hdr(struct btf *btf, btf_print_fn_t err_log)
return 0;
}
-static int btf_parse_str_sec(struct btf *btf, btf_print_fn_t err_log)
+static int btf_parse_str_sec(struct btf *btf)
{
const struct btf_header *hdr = btf->hdr;
const char *start = btf->nohdr_data + hdr->str_off;
const char *end = start + btf->hdr->str_len;
- if (!hdr->str_len || hdr->str_len - 1 > BTF_MAX_NAME_OFFSET ||
+ if (!hdr->str_len || hdr->str_len - 1 > BTF_MAX_STR_OFFSET ||
start[0] || end[-1]) {
- elog("Invalid BTF string section\n");
+ pr_debug("Invalid BTF string section\n");
return -EINVAL;
}
@@ -138,7 +187,38 @@ static int btf_parse_str_sec(struct btf *btf, btf_print_fn_t err_log)
return 0;
}
-static int btf_parse_type_sec(struct btf *btf, btf_print_fn_t err_log)
+static int btf_type_size(struct btf_type *t)
+{
+ int base_size = sizeof(struct btf_type);
+ __u16 vlen = BTF_INFO_VLEN(t->info);
+
+ switch (BTF_INFO_KIND(t->info)) {
+ case BTF_KIND_FWD:
+ case BTF_KIND_CONST:
+ case BTF_KIND_VOLATILE:
+ case BTF_KIND_RESTRICT:
+ case BTF_KIND_PTR:
+ case BTF_KIND_TYPEDEF:
+ case BTF_KIND_FUNC:
+ return base_size;
+ case BTF_KIND_INT:
+ return base_size + sizeof(__u32);
+ case BTF_KIND_ENUM:
+ return base_size + vlen * sizeof(struct btf_enum);
+ case BTF_KIND_ARRAY:
+ return base_size + sizeof(struct btf_array);
+ case BTF_KIND_STRUCT:
+ case BTF_KIND_UNION:
+ return base_size + vlen * sizeof(struct btf_member);
+ case BTF_KIND_FUNC_PROTO:
+ return base_size + vlen * sizeof(struct btf_param);
+ default:
+ pr_debug("Unsupported BTF_KIND:%u\n", BTF_INFO_KIND(t->info));
+ return -EINVAL;
+ }
+}
+
+static int btf_parse_type_sec(struct btf *btf)
{
struct btf_header *hdr = btf->hdr;
void *nohdr_data = btf->nohdr_data;
@@ -147,37 +227,13 @@ static int btf_parse_type_sec(struct btf *btf, btf_print_fn_t err_log)
while (next_type < end_type) {
struct btf_type *t = next_type;
- __u16 vlen = BTF_INFO_VLEN(t->info);
+ int type_size;
int err;
- next_type += sizeof(*t);
- switch (BTF_INFO_KIND(t->info)) {
- case BTF_KIND_INT:
- next_type += sizeof(int);
- break;
- case BTF_KIND_ARRAY:
- next_type += sizeof(struct btf_array);
- break;
- case BTF_KIND_STRUCT:
- case BTF_KIND_UNION:
- next_type += vlen * sizeof(struct btf_member);
- break;
- case BTF_KIND_ENUM:
- next_type += vlen * sizeof(struct btf_enum);
- break;
- case BTF_KIND_TYPEDEF:
- case BTF_KIND_PTR:
- case BTF_KIND_FWD:
- case BTF_KIND_VOLATILE:
- case BTF_KIND_CONST:
- case BTF_KIND_RESTRICT:
- break;
- default:
- elog("Unsupported BTF_KIND:%u\n",
- BTF_INFO_KIND(t->info));
- return -EINVAL;
- }
-
+ type_size = btf_type_size(t);
+ if (type_size < 0)
+ return type_size;
+ next_type += type_size;
err = btf_add_type(btf, t);
if (err)
return err;
@@ -186,6 +242,11 @@ static int btf_parse_type_sec(struct btf *btf, btf_print_fn_t err_log)
return 0;
}
+__u32 btf__get_nr_types(const struct btf *btf)
+{
+ return btf->nr_types;
+}
+
const struct btf_type *btf__type_by_id(const struct btf *btf, __u32 type_id)
{
if (type_id > btf->nr_types)
@@ -204,21 +265,6 @@ static bool btf_type_is_void_or_null(const struct btf_type *t)
return !t || btf_type_is_void(t);
}
-static __s64 btf_type_size(const struct btf_type *t)
-{
- switch (BTF_INFO_KIND(t->info)) {
- case BTF_KIND_INT:
- case BTF_KIND_STRUCT:
- case BTF_KIND_UNION:
- case BTF_KIND_ENUM:
- return t->size;
- case BTF_KIND_PTR:
- return sizeof(void *);
- default:
- return -EINVAL;
- }
-}
-
#define MAX_RESOLVE_DEPTH 32
__s64 btf__resolve_size(const struct btf *btf, __u32 type_id)
@@ -232,11 +278,16 @@ __s64 btf__resolve_size(const struct btf *btf, __u32 type_id)
t = btf__type_by_id(btf, type_id);
for (i = 0; i < MAX_RESOLVE_DEPTH && !btf_type_is_void_or_null(t);
i++) {
- size = btf_type_size(t);
- if (size >= 0)
- break;
-
switch (BTF_INFO_KIND(t->info)) {
+ case BTF_KIND_INT:
+ case BTF_KIND_STRUCT:
+ case BTF_KIND_UNION:
+ case BTF_KIND_ENUM:
+ size = t->size;
+ goto done;
+ case BTF_KIND_PTR:
+ size = sizeof(void *);
+ goto done;
case BTF_KIND_TYPEDEF:
case BTF_KIND_VOLATILE:
case BTF_KIND_CONST:
@@ -260,6 +311,7 @@ __s64 btf__resolve_size(const struct btf *btf, __u32 type_id)
if (size < 0)
return -EINVAL;
+done:
if (nelems && size > UINT32_MAX / nelems)
return -E2BIG;
@@ -317,10 +369,8 @@ void btf__free(struct btf *btf)
free(btf);
}
-struct btf *btf__new(__u8 *data, __u32 size, btf_print_fn_t err_log)
+struct btf *btf__new(__u8 *data, __u32 size)
{
- __u32 log_buf_size = 0;
- char *log_buf = NULL;
struct btf *btf;
int err;
@@ -330,16 +380,6 @@ struct btf *btf__new(__u8 *data, __u32 size, btf_print_fn_t err_log)
btf->fd = -1;
- if (err_log) {
- log_buf = malloc(BPF_LOG_BUF_SIZE);
- if (!log_buf) {
- err = -ENOMEM;
- goto done;
- }
- *log_buf = 0;
- log_buf_size = BPF_LOG_BUF_SIZE;
- }
-
btf->data = malloc(size);
if (!btf->data) {
err = -ENOMEM;
@@ -349,30 +389,17 @@ struct btf *btf__new(__u8 *data, __u32 size, btf_print_fn_t err_log)
memcpy(btf->data, data, size);
btf->data_size = size;
- btf->fd = bpf_load_btf(btf->data, btf->data_size,
- log_buf, log_buf_size, false);
-
- if (btf->fd == -1) {
- err = -errno;
- elog("Error loading BTF: %s(%d)\n", strerror(errno), errno);
- if (log_buf && *log_buf)
- elog("%s\n", log_buf);
- goto done;
- }
-
- err = btf_parse_hdr(btf, err_log);
+ err = btf_parse_hdr(btf);
if (err)
goto done;
- err = btf_parse_str_sec(btf, err_log);
+ err = btf_parse_str_sec(btf);
if (err)
goto done;
- err = btf_parse_type_sec(btf, err_log);
+ err = btf_parse_type_sec(btf);
done:
- free(log_buf);
-
if (err) {
btf__free(btf);
return ERR_PTR(err);
@@ -381,11 +408,47 @@ done:
return btf;
}
+int btf__load(struct btf *btf)
+{
+ __u32 log_buf_size = BPF_LOG_BUF_SIZE;
+ char *log_buf = NULL;
+ int err = 0;
+
+ if (btf->fd >= 0)
+ return -EEXIST;
+
+ log_buf = malloc(log_buf_size);
+ if (!log_buf)
+ return -ENOMEM;
+
+ *log_buf = 0;
+
+ btf->fd = bpf_load_btf(btf->data, btf->data_size,
+ log_buf, log_buf_size, false);
+ if (btf->fd < 0) {
+ err = -errno;
+ pr_warning("Error loading BTF: %s(%d)\n", strerror(errno), errno);
+ if (*log_buf)
+ pr_warning("%s\n", log_buf);
+ goto done;
+ }
+
+done:
+ free(log_buf);
+ return err;
+}
+
int btf__fd(const struct btf *btf)
{
return btf->fd;
}
+const void *btf__get_raw_data(const struct btf *btf, __u32 *size)
+{
+ *size = btf->data_size;
+ return btf->data;
+}
+
const char *btf__name_by_offset(const struct btf *btf, __u32 offset)
{
if (offset < btf->hdr->str_len)
@@ -393,3 +456,2195 @@ const char *btf__name_by_offset(const struct btf *btf, __u32 offset)
else
return NULL;
}
+
+int btf__get_from_id(__u32 id, struct btf **btf)
+{
+ struct bpf_btf_info btf_info = { 0 };
+ __u32 len = sizeof(btf_info);
+ __u32 last_size;
+ int btf_fd;
+ void *ptr;
+ int err;
+
+ err = 0;
+ *btf = NULL;
+ btf_fd = bpf_btf_get_fd_by_id(id);
+ if (btf_fd < 0)
+ return 0;
+
+ /* we won't know btf_size until we call bpf_obj_get_info_by_fd(). so
+ * let's start with a sane default - 4KiB here - and resize it only if
+ * bpf_obj_get_info_by_fd() needs a bigger buffer.
+ */
+ btf_info.btf_size = 4096;
+ last_size = btf_info.btf_size;
+ ptr = malloc(last_size);
+ if (!ptr) {
+ err = -ENOMEM;
+ goto exit_free;
+ }
+
+ memset(ptr, 0, last_size);
+ btf_info.btf = ptr_to_u64(ptr);
+ err = bpf_obj_get_info_by_fd(btf_fd, &btf_info, &len);
+
+ if (!err && btf_info.btf_size > last_size) {
+ void *temp_ptr;
+
+ last_size = btf_info.btf_size;
+ temp_ptr = realloc(ptr, last_size);
+ if (!temp_ptr) {
+ err = -ENOMEM;
+ goto exit_free;
+ }
+ ptr = temp_ptr;
+ memset(ptr, 0, last_size);
+ btf_info.btf = ptr_to_u64(ptr);
+ err = bpf_obj_get_info_by_fd(btf_fd, &btf_info, &len);
+ }
+
+ if (err || btf_info.btf_size > last_size) {
+ err = errno;
+ goto exit_free;
+ }
+
+ *btf = btf__new((__u8 *)(long)btf_info.btf, btf_info.btf_size);
+ if (IS_ERR(*btf)) {
+ err = PTR_ERR(*btf);
+ *btf = NULL;
+ }
+
+exit_free:
+ close(btf_fd);
+ free(ptr);
+
+ return err;
+}
+
+int btf__get_map_kv_tids(const struct btf *btf, const char *map_name,
+ __u32 expected_key_size, __u32 expected_value_size,
+ __u32 *key_type_id, __u32 *value_type_id)
+{
+ const struct btf_type *container_type;
+ const struct btf_member *key, *value;
+ const size_t max_name = 256;
+ char container_name[max_name];
+ __s64 key_size, value_size;
+ __s32 container_id;
+
+ if (snprintf(container_name, max_name, "____btf_map_%s", map_name) ==
+ max_name) {
+ pr_warning("map:%s length of '____btf_map_%s' is too long\n",
+ map_name, map_name);
+ return -EINVAL;
+ }
+
+ container_id = btf__find_by_name(btf, container_name);
+ if (container_id < 0) {
+ pr_debug("map:%s container_name:%s cannot be found in BTF. Missing BPF_ANNOTATE_KV_PAIR?\n",
+ map_name, container_name);
+ return container_id;
+ }
+
+ container_type = btf__type_by_id(btf, container_id);
+ if (!container_type) {
+ pr_warning("map:%s cannot find BTF type for container_id:%u\n",
+ map_name, container_id);
+ return -EINVAL;
+ }
+
+ if (BTF_INFO_KIND(container_type->info) != BTF_KIND_STRUCT ||
+ BTF_INFO_VLEN(container_type->info) < 2) {
+ pr_warning("map:%s container_name:%s is an invalid container struct\n",
+ map_name, container_name);
+ return -EINVAL;
+ }
+
+ key = (struct btf_member *)(container_type + 1);
+ value = key + 1;
+
+ key_size = btf__resolve_size(btf, key->type);
+ if (key_size < 0) {
+ pr_warning("map:%s invalid BTF key_type_size\n", map_name);
+ return key_size;
+ }
+
+ if (expected_key_size != key_size) {
+ pr_warning("map:%s btf_key_type_size:%u != map_def_key_size:%u\n",
+ map_name, (__u32)key_size, expected_key_size);
+ return -EINVAL;
+ }
+
+ value_size = btf__resolve_size(btf, value->type);
+ if (value_size < 0) {
+ pr_warning("map:%s invalid BTF value_type_size\n", map_name);
+ return value_size;
+ }
+
+ if (expected_value_size != value_size) {
+ pr_warning("map:%s btf_value_type_size:%u != map_def_value_size:%u\n",
+ map_name, (__u32)value_size, expected_value_size);
+ return -EINVAL;
+ }
+
+ *key_type_id = key->type;
+ *value_type_id = value->type;
+
+ return 0;
+}
+
+struct btf_ext_sec_setup_param {
+ __u32 off;
+ __u32 len;
+ __u32 min_rec_size;
+ struct btf_ext_info *ext_info;
+ const char *desc;
+};
+
+static int btf_ext_setup_info(struct btf_ext *btf_ext,
+ struct btf_ext_sec_setup_param *ext_sec)
+{
+ const struct btf_ext_info_sec *sinfo;
+ struct btf_ext_info *ext_info;
+ __u32 info_left, record_size;
+ /* The start of the info sec (including the __u32 record_size). */
+ void *info;
+
+ if (ext_sec->off & 0x03) {
+ pr_debug(".BTF.ext %s section is not aligned to 4 bytes\n",
+ ext_sec->desc);
+ return -EINVAL;
+ }
+
+ info = btf_ext->data + btf_ext->hdr->hdr_len + ext_sec->off;
+ info_left = ext_sec->len;
+
+ if (btf_ext->data + btf_ext->data_size < info + ext_sec->len) {
+ pr_debug("%s section (off:%u len:%u) is beyond the end of the ELF section .BTF.ext\n",
+ ext_sec->desc, ext_sec->off, ext_sec->len);
+ return -EINVAL;
+ }
+
+ /* At least a record size */
+ if (info_left < sizeof(__u32)) {
+ pr_debug(".BTF.ext %s record size not found\n", ext_sec->desc);
+ return -EINVAL;
+ }
+
+ /* The record size needs to meet the minimum standard */
+ record_size = *(__u32 *)info;
+ if (record_size < ext_sec->min_rec_size ||
+ record_size & 0x03) {
+ pr_debug("%s section in .BTF.ext has invalid record size %u\n",
+ ext_sec->desc, record_size);
+ return -EINVAL;
+ }
+
+ sinfo = info + sizeof(__u32);
+ info_left -= sizeof(__u32);
+
+ /* If no records, return failure now so .BTF.ext won't be used. */
+ if (!info_left) {
+ pr_debug("%s section in .BTF.ext has no records", ext_sec->desc);
+ return -EINVAL;
+ }
+
+ while (info_left) {
+ unsigned int sec_hdrlen = sizeof(struct btf_ext_info_sec);
+ __u64 total_record_size;
+ __u32 num_records;
+
+ if (info_left < sec_hdrlen) {
+ pr_debug("%s section header is not found in .BTF.ext\n",
+ ext_sec->desc);
+ return -EINVAL;
+ }
+
+ num_records = sinfo->num_info;
+ if (num_records == 0) {
+ pr_debug("%s section has incorrect num_records in .BTF.ext\n",
+ ext_sec->desc);
+ return -EINVAL;
+ }
+
+ total_record_size = sec_hdrlen +
+ (__u64)num_records * record_size;
+ if (info_left < total_record_size) {
+ pr_debug("%s section has incorrect num_records in .BTF.ext\n",
+ ext_sec->desc);
+ return -EINVAL;
+ }
+
+ info_left -= total_record_size;
+ sinfo = (void *)sinfo + total_record_size;
+ }
+
+ ext_info = ext_sec->ext_info;
+ ext_info->len = ext_sec->len - sizeof(__u32);
+ ext_info->rec_size = record_size;
+ ext_info->info = info + sizeof(__u32);
+
+ return 0;
+}
+
+static int btf_ext_setup_func_info(struct btf_ext *btf_ext)
+{
+ struct btf_ext_sec_setup_param param = {
+ .off = btf_ext->hdr->func_info_off,
+ .len = btf_ext->hdr->func_info_len,
+ .min_rec_size = sizeof(struct bpf_func_info_min),
+ .ext_info = &btf_ext->func_info,
+ .desc = "func_info"
+ };
+
+ return btf_ext_setup_info(btf_ext, &param);
+}
+
+static int btf_ext_setup_line_info(struct btf_ext *btf_ext)
+{
+ struct btf_ext_sec_setup_param param = {
+ .off = btf_ext->hdr->line_info_off,
+ .len = btf_ext->hdr->line_info_len,
+ .min_rec_size = sizeof(struct bpf_line_info_min),
+ .ext_info = &btf_ext->line_info,
+ .desc = "line_info",
+ };
+
+ return btf_ext_setup_info(btf_ext, &param);
+}
+
+static int btf_ext_parse_hdr(__u8 *data, __u32 data_size)
+{
+ const struct btf_ext_header *hdr = (struct btf_ext_header *)data;
+
+ if (data_size < offsetof(struct btf_ext_header, func_info_off) ||
+ data_size < hdr->hdr_len) {
+ pr_debug("BTF.ext header not found");
+ return -EINVAL;
+ }
+
+ if (hdr->magic != BTF_MAGIC) {
+ pr_debug("Invalid BTF.ext magic:%x\n", hdr->magic);
+ return -EINVAL;
+ }
+
+ if (hdr->version != BTF_VERSION) {
+ pr_debug("Unsupported BTF.ext version:%u\n", hdr->version);
+ return -ENOTSUP;
+ }
+
+ if (hdr->flags) {
+ pr_debug("Unsupported BTF.ext flags:%x\n", hdr->flags);
+ return -ENOTSUP;
+ }
+
+ if (data_size == hdr->hdr_len) {
+ pr_debug("BTF.ext has no data\n");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+void btf_ext__free(struct btf_ext *btf_ext)
+{
+ if (!btf_ext)
+ return;
+ free(btf_ext->data);
+ free(btf_ext);
+}
+
+struct btf_ext *btf_ext__new(__u8 *data, __u32 size)
+{
+ struct btf_ext *btf_ext;
+ int err;
+
+ err = btf_ext_parse_hdr(data, size);
+ if (err)
+ return ERR_PTR(err);
+
+ btf_ext = calloc(1, sizeof(struct btf_ext));
+ if (!btf_ext)
+ return ERR_PTR(-ENOMEM);
+
+ btf_ext->data_size = size;
+ btf_ext->data = malloc(size);
+ if (!btf_ext->data) {
+ err = -ENOMEM;
+ goto done;
+ }
+ memcpy(btf_ext->data, data, size);
+
+ err = btf_ext_setup_func_info(btf_ext);
+ if (err)
+ goto done;
+
+ err = btf_ext_setup_line_info(btf_ext);
+ if (err)
+ goto done;
+
+done:
+ if (err) {
+ btf_ext__free(btf_ext);
+ return ERR_PTR(err);
+ }
+
+ return btf_ext;
+}
+
+const void *btf_ext__get_raw_data(const struct btf_ext *btf_ext, __u32 *size)
+{
+ *size = btf_ext->data_size;
+ return btf_ext->data;
+}
+
+static int btf_ext_reloc_info(const struct btf *btf,
+ const struct btf_ext_info *ext_info,
+ const char *sec_name, __u32 insns_cnt,
+ void **info, __u32 *cnt)
+{
+ __u32 sec_hdrlen = sizeof(struct btf_ext_info_sec);
+ __u32 i, record_size, existing_len, records_len;
+ struct btf_ext_info_sec *sinfo;
+ const char *info_sec_name;
+ __u64 remain_len;
+ void *data;
+
+ record_size = ext_info->rec_size;
+ sinfo = ext_info->info;
+ remain_len = ext_info->len;
+ while (remain_len > 0) {
+ records_len = sinfo->num_info * record_size;
+ info_sec_name = btf__name_by_offset(btf, sinfo->sec_name_off);
+ if (strcmp(info_sec_name, sec_name)) {
+ remain_len -= sec_hdrlen + records_len;
+ sinfo = (void *)sinfo + sec_hdrlen + records_len;
+ continue;
+ }
+
+ existing_len = (*cnt) * record_size;
+ data = realloc(*info, existing_len + records_len);
+ if (!data)
+ return -ENOMEM;
+
+ memcpy(data + existing_len, sinfo->data, records_len);
+ /* adjust insn_off only, the rest data will be passed
+ * to the kernel.
+ */
+ for (i = 0; i < sinfo->num_info; i++) {
+ __u32 *insn_off;
+
+ insn_off = data + existing_len + (i * record_size);
+ *insn_off = *insn_off / sizeof(struct bpf_insn) +
+ insns_cnt;
+ }
+ *info = data;
+ *cnt += sinfo->num_info;
+ return 0;
+ }
+
+ return -ENOENT;
+}
+
+int btf_ext__reloc_func_info(const struct btf *btf,
+ const struct btf_ext *btf_ext,
+ const char *sec_name, __u32 insns_cnt,
+ void **func_info, __u32 *cnt)
+{
+ return btf_ext_reloc_info(btf, &btf_ext->func_info, sec_name,
+ insns_cnt, func_info, cnt);
+}
+
+int btf_ext__reloc_line_info(const struct btf *btf,
+ const struct btf_ext *btf_ext,
+ const char *sec_name, __u32 insns_cnt,
+ void **line_info, __u32 *cnt)
+{
+ return btf_ext_reloc_info(btf, &btf_ext->line_info, sec_name,
+ insns_cnt, line_info, cnt);
+}
+
+__u32 btf_ext__func_info_rec_size(const struct btf_ext *btf_ext)
+{
+ return btf_ext->func_info.rec_size;
+}
+
+__u32 btf_ext__line_info_rec_size(const struct btf_ext *btf_ext)
+{
+ return btf_ext->line_info.rec_size;
+}
+
+struct btf_dedup;
+
+static struct btf_dedup *btf_dedup_new(struct btf *btf, struct btf_ext *btf_ext,
+ const struct btf_dedup_opts *opts);
+static void btf_dedup_free(struct btf_dedup *d);
+static int btf_dedup_strings(struct btf_dedup *d);
+static int btf_dedup_prim_types(struct btf_dedup *d);
+static int btf_dedup_struct_types(struct btf_dedup *d);
+static int btf_dedup_ref_types(struct btf_dedup *d);
+static int btf_dedup_compact_types(struct btf_dedup *d);
+static int btf_dedup_remap_types(struct btf_dedup *d);
+
+/*
+ * Deduplicate BTF types and strings.
+ *
+ * BTF dedup algorithm takes as an input `struct btf` representing `.BTF` ELF
+ * section with all BTF type descriptors and string data. It overwrites that
+ * memory in-place with deduplicated types and strings without any loss of
+ * information. If optional `struct btf_ext` representing '.BTF.ext' ELF section
+ * is provided, all the strings referenced from .BTF.ext section are honored
+ * and updated to point to the right offsets after deduplication.
+ *
+ * If function returns with error, type/string data might be garbled and should
+ * be discarded.
+ *
+ * More verbose and detailed description of both problem btf_dedup is solving,
+ * as well as solution could be found at:
+ * https://facebookmicrosites.github.io/bpf/blog/2018/11/14/btf-enhancement.html
+ *
+ * Problem description and justification
+ * =====================================
+ *
+ * BTF type information is typically emitted either as a result of conversion
+ * from DWARF to BTF or directly by compiler. In both cases, each compilation
+ * unit contains information about a subset of all the types that are used
+ * in an application. These subsets are frequently overlapping and contain a lot
+ * of duplicated information when later concatenated together into a single
+ * binary. This algorithm ensures that each unique type is represented by single
+ * BTF type descriptor, greatly reducing resulting size of BTF data.
+ *
+ * Compilation unit isolation and subsequent duplication of data is not the only
+ * problem. The same type hierarchy (e.g., struct and all the type that struct
+ * references) in different compilation units can be represented in BTF to
+ * various degrees of completeness (or, rather, incompleteness) due to
+ * struct/union forward declarations.
+ *
+ * Let's take a look at an example, that we'll use to better understand the
+ * problem (and solution). Suppose we have two compilation units, each using
+ * same `struct S`, but each of them having incomplete type information about
+ * struct's fields:
+ *
+ * // CU #1:
+ * struct S;
+ * struct A {
+ * int a;
+ * struct A* self;
+ * struct S* parent;
+ * };
+ * struct B;
+ * struct S {
+ * struct A* a_ptr;
+ * struct B* b_ptr;
+ * };
+ *
+ * // CU #2:
+ * struct S;
+ * struct A;
+ * struct B {
+ * int b;
+ * struct B* self;
+ * struct S* parent;
+ * };
+ * struct S {
+ * struct A* a_ptr;
+ * struct B* b_ptr;
+ * };
+ *
+ * In case of CU #1, BTF data will know only that `struct B` exist (but no
+ * more), but will know the complete type information about `struct A`. While
+ * for CU #2, it will know full type information about `struct B`, but will
+ * only know about forward declaration of `struct A` (in BTF terms, it will
+ * have `BTF_KIND_FWD` type descriptor with name `B`).
+ *
+ * This compilation unit isolation means that it's possible that there is no
+ * single CU with complete type information describing structs `S`, `A`, and
+ * `B`. Also, we might get tons of duplicated and redundant type information.
+ *
+ * Additional complication we need to keep in mind comes from the fact that
+ * types, in general, can form graphs containing cycles, not just DAGs.
+ *
+ * While algorithm does deduplication, it also merges and resolves type
+ * information (unless disabled throught `struct btf_opts`), whenever possible.
+ * E.g., in the example above with two compilation units having partial type
+ * information for structs `A` and `B`, the output of algorithm will emit
+ * a single copy of each BTF type that describes structs `A`, `B`, and `S`
+ * (as well as type information for `int` and pointers), as if they were defined
+ * in a single compilation unit as:
+ *
+ * struct A {
+ * int a;
+ * struct A* self;
+ * struct S* parent;
+ * };
+ * struct B {
+ * int b;
+ * struct B* self;
+ * struct S* parent;
+ * };
+ * struct S {
+ * struct A* a_ptr;
+ * struct B* b_ptr;
+ * };
+ *
+ * Algorithm summary
+ * =================
+ *
+ * Algorithm completes its work in 6 separate passes:
+ *
+ * 1. Strings deduplication.
+ * 2. Primitive types deduplication (int, enum, fwd).
+ * 3. Struct/union types deduplication.
+ * 4. Reference types deduplication (pointers, typedefs, arrays, funcs, func
+ * protos, and const/volatile/restrict modifiers).
+ * 5. Types compaction.
+ * 6. Types remapping.
+ *
+ * Algorithm determines canonical type descriptor, which is a single
+ * representative type for each truly unique type. This canonical type is the
+ * one that will go into final deduplicated BTF type information. For
+ * struct/unions, it is also the type that algorithm will merge additional type
+ * information into (while resolving FWDs), as it discovers it from data in
+ * other CUs. Each input BTF type eventually gets either mapped to itself, if
+ * that type is canonical, or to some other type, if that type is equivalent
+ * and was chosen as canonical representative. This mapping is stored in
+ * `btf_dedup->map` array. This map is also used to record STRUCT/UNION that
+ * FWD type got resolved to.
+ *
+ * To facilitate fast discovery of canonical types, we also maintain canonical
+ * index (`btf_dedup->dedup_table`), which maps type descriptor's signature hash
+ * (i.e., hashed kind, name, size, fields, etc) into a list of canonical types
+ * that match that signature. With sufficiently good choice of type signature
+ * hashing function, we can limit number of canonical types for each unique type
+ * signature to a very small number, allowing to find canonical type for any
+ * duplicated type very quickly.
+ *
+ * Struct/union deduplication is the most critical part and algorithm for
+ * deduplicating structs/unions is described in greater details in comments for
+ * `btf_dedup_is_equiv` function.
+ */
+int btf__dedup(struct btf *btf, struct btf_ext *btf_ext,
+ const struct btf_dedup_opts *opts)
+{
+ struct btf_dedup *d = btf_dedup_new(btf, btf_ext, opts);
+ int err;
+
+ if (IS_ERR(d)) {
+ pr_debug("btf_dedup_new failed: %ld", PTR_ERR(d));
+ return -EINVAL;
+ }
+
+ err = btf_dedup_strings(d);
+ if (err < 0) {
+ pr_debug("btf_dedup_strings failed:%d\n", err);
+ goto done;
+ }
+ err = btf_dedup_prim_types(d);
+ if (err < 0) {
+ pr_debug("btf_dedup_prim_types failed:%d\n", err);
+ goto done;
+ }
+ err = btf_dedup_struct_types(d);
+ if (err < 0) {
+ pr_debug("btf_dedup_struct_types failed:%d\n", err);
+ goto done;
+ }
+ err = btf_dedup_ref_types(d);
+ if (err < 0) {
+ pr_debug("btf_dedup_ref_types failed:%d\n", err);
+ goto done;
+ }
+ err = btf_dedup_compact_types(d);
+ if (err < 0) {
+ pr_debug("btf_dedup_compact_types failed:%d\n", err);
+ goto done;
+ }
+ err = btf_dedup_remap_types(d);
+ if (err < 0) {
+ pr_debug("btf_dedup_remap_types failed:%d\n", err);
+ goto done;
+ }
+
+done:
+ btf_dedup_free(d);
+ return err;
+}
+
+#define BTF_DEDUP_TABLE_DEFAULT_SIZE (1 << 14)
+#define BTF_DEDUP_TABLE_MAX_SIZE_LOG 31
+#define BTF_UNPROCESSED_ID ((__u32)-1)
+#define BTF_IN_PROGRESS_ID ((__u32)-2)
+
+struct btf_dedup_node {
+ struct btf_dedup_node *next;
+ __u32 type_id;
+};
+
+struct btf_dedup {
+ /* .BTF section to be deduped in-place */
+ struct btf *btf;
+ /*
+ * Optional .BTF.ext section. When provided, any strings referenced
+ * from it will be taken into account when deduping strings
+ */
+ struct btf_ext *btf_ext;
+ /*
+ * This is a map from any type's signature hash to a list of possible
+ * canonical representative type candidates. Hash collisions are
+ * ignored, so even types of various kinds can share same list of
+ * candidates, which is fine because we rely on subsequent
+ * btf_xxx_equal() checks to authoritatively verify type equality.
+ */
+ struct btf_dedup_node **dedup_table;
+ /* Canonical types map */
+ __u32 *map;
+ /* Hypothetical mapping, used during type graph equivalence checks */
+ __u32 *hypot_map;
+ __u32 *hypot_list;
+ size_t hypot_cnt;
+ size_t hypot_cap;
+ /* Various option modifying behavior of algorithm */
+ struct btf_dedup_opts opts;
+};
+
+struct btf_str_ptr {
+ const char *str;
+ __u32 new_off;
+ bool used;
+};
+
+struct btf_str_ptrs {
+ struct btf_str_ptr *ptrs;
+ const char *data;
+ __u32 cnt;
+ __u32 cap;
+};
+
+static inline __u32 hash_combine(__u32 h, __u32 value)
+{
+/* 2^31 + 2^29 - 2^25 + 2^22 - 2^19 - 2^16 + 1 */
+#define GOLDEN_RATIO_PRIME 0x9e370001UL
+ return h * 37 + value * GOLDEN_RATIO_PRIME;
+#undef GOLDEN_RATIO_PRIME
+}
+
+#define for_each_dedup_cand(d, hash, node) \
+ for (node = d->dedup_table[hash & (d->opts.dedup_table_size - 1)]; \
+ node; \
+ node = node->next)
+
+static int btf_dedup_table_add(struct btf_dedup *d, __u32 hash, __u32 type_id)
+{
+ struct btf_dedup_node *node = malloc(sizeof(struct btf_dedup_node));
+ int bucket = hash & (d->opts.dedup_table_size - 1);
+
+ if (!node)
+ return -ENOMEM;
+ node->type_id = type_id;
+ node->next = d->dedup_table[bucket];
+ d->dedup_table[bucket] = node;
+ return 0;
+}
+
+static int btf_dedup_hypot_map_add(struct btf_dedup *d,
+ __u32 from_id, __u32 to_id)
+{
+ if (d->hypot_cnt == d->hypot_cap) {
+ __u32 *new_list;
+
+ d->hypot_cap += max(16, d->hypot_cap / 2);
+ new_list = realloc(d->hypot_list, sizeof(__u32) * d->hypot_cap);
+ if (!new_list)
+ return -ENOMEM;
+ d->hypot_list = new_list;
+ }
+ d->hypot_list[d->hypot_cnt++] = from_id;
+ d->hypot_map[from_id] = to_id;
+ return 0;
+}
+
+static void btf_dedup_clear_hypot_map(struct btf_dedup *d)
+{
+ int i;
+
+ for (i = 0; i < d->hypot_cnt; i++)
+ d->hypot_map[d->hypot_list[i]] = BTF_UNPROCESSED_ID;
+ d->hypot_cnt = 0;
+}
+
+static void btf_dedup_table_free(struct btf_dedup *d)
+{
+ struct btf_dedup_node *head, *tmp;
+ int i;
+
+ if (!d->dedup_table)
+ return;
+
+ for (i = 0; i < d->opts.dedup_table_size; i++) {
+ while (d->dedup_table[i]) {
+ tmp = d->dedup_table[i];
+ d->dedup_table[i] = tmp->next;
+ free(tmp);
+ }
+
+ head = d->dedup_table[i];
+ while (head) {
+ tmp = head;
+ head = head->next;
+ free(tmp);
+ }
+ }
+
+ free(d->dedup_table);
+ d->dedup_table = NULL;
+}
+
+static void btf_dedup_free(struct btf_dedup *d)
+{
+ btf_dedup_table_free(d);
+
+ free(d->map);
+ d->map = NULL;
+
+ free(d->hypot_map);
+ d->hypot_map = NULL;
+
+ free(d->hypot_list);
+ d->hypot_list = NULL;
+
+ free(d);
+}
+
+/* Find closest power of two >= to size, capped at 2^max_size_log */
+static __u32 roundup_pow2_max(__u32 size, int max_size_log)
+{
+ int i;
+
+ for (i = 0; i < max_size_log && (1U << i) < size; i++)
+ ;
+ return 1U << i;
+}
+
+
+static struct btf_dedup *btf_dedup_new(struct btf *btf, struct btf_ext *btf_ext,
+ const struct btf_dedup_opts *opts)
+{
+ struct btf_dedup *d = calloc(1, sizeof(struct btf_dedup));
+ int i, err = 0;
+ __u32 sz;
+
+ if (!d)
+ return ERR_PTR(-ENOMEM);
+
+ d->opts.dont_resolve_fwds = opts && opts->dont_resolve_fwds;
+ sz = opts && opts->dedup_table_size ? opts->dedup_table_size
+ : BTF_DEDUP_TABLE_DEFAULT_SIZE;
+ sz = roundup_pow2_max(sz, BTF_DEDUP_TABLE_MAX_SIZE_LOG);
+ d->opts.dedup_table_size = sz;
+
+ d->btf = btf;
+ d->btf_ext = btf_ext;
+
+ d->dedup_table = calloc(d->opts.dedup_table_size,
+ sizeof(struct btf_dedup_node *));
+ if (!d->dedup_table) {
+ err = -ENOMEM;
+ goto done;
+ }
+
+ d->map = malloc(sizeof(__u32) * (1 + btf->nr_types));
+ if (!d->map) {
+ err = -ENOMEM;
+ goto done;
+ }
+ /* special BTF "void" type is made canonical immediately */
+ d->map[0] = 0;
+ for (i = 1; i <= btf->nr_types; i++)
+ d->map[i] = BTF_UNPROCESSED_ID;
+
+ d->hypot_map = malloc(sizeof(__u32) * (1 + btf->nr_types));
+ if (!d->hypot_map) {
+ err = -ENOMEM;
+ goto done;
+ }
+ for (i = 0; i <= btf->nr_types; i++)
+ d->hypot_map[i] = BTF_UNPROCESSED_ID;
+
+done:
+ if (err) {
+ btf_dedup_free(d);
+ return ERR_PTR(err);
+ }
+
+ return d;
+}
+
+typedef int (*str_off_fn_t)(__u32 *str_off_ptr, void *ctx);
+
+/*
+ * Iterate over all possible places in .BTF and .BTF.ext that can reference
+ * string and pass pointer to it to a provided callback `fn`.
+ */
+static int btf_for_each_str_off(struct btf_dedup *d, str_off_fn_t fn, void *ctx)
+{
+ void *line_data_cur, *line_data_end;
+ int i, j, r, rec_size;
+ struct btf_type *t;
+
+ for (i = 1; i <= d->btf->nr_types; i++) {
+ t = d->btf->types[i];
+ r = fn(&t->name_off, ctx);
+ if (r)
+ return r;
+
+ switch (BTF_INFO_KIND(t->info)) {
+ case BTF_KIND_STRUCT:
+ case BTF_KIND_UNION: {
+ struct btf_member *m = (struct btf_member *)(t + 1);
+ __u16 vlen = BTF_INFO_VLEN(t->info);
+
+ for (j = 0; j < vlen; j++) {
+ r = fn(&m->name_off, ctx);
+ if (r)
+ return r;
+ m++;
+ }
+ break;
+ }
+ case BTF_KIND_ENUM: {
+ struct btf_enum *m = (struct btf_enum *)(t + 1);
+ __u16 vlen = BTF_INFO_VLEN(t->info);
+
+ for (j = 0; j < vlen; j++) {
+ r = fn(&m->name_off, ctx);
+ if (r)
+ return r;
+ m++;
+ }
+ break;
+ }
+ case BTF_KIND_FUNC_PROTO: {
+ struct btf_param *m = (struct btf_param *)(t + 1);
+ __u16 vlen = BTF_INFO_VLEN(t->info);
+
+ for (j = 0; j < vlen; j++) {
+ r = fn(&m->name_off, ctx);
+ if (r)
+ return r;
+ m++;
+ }
+ break;
+ }
+ default:
+ break;
+ }
+ }
+
+ if (!d->btf_ext)
+ return 0;
+
+ line_data_cur = d->btf_ext->line_info.info;
+ line_data_end = d->btf_ext->line_info.info + d->btf_ext->line_info.len;
+ rec_size = d->btf_ext->line_info.rec_size;
+
+ while (line_data_cur < line_data_end) {
+ struct btf_ext_info_sec *sec = line_data_cur;
+ struct bpf_line_info_min *line_info;
+ __u32 num_info = sec->num_info;
+
+ r = fn(&sec->sec_name_off, ctx);
+ if (r)
+ return r;
+
+ line_data_cur += sizeof(struct btf_ext_info_sec);
+ for (i = 0; i < num_info; i++) {
+ line_info = line_data_cur;
+ r = fn(&line_info->file_name_off, ctx);
+ if (r)
+ return r;
+ r = fn(&line_info->line_off, ctx);
+ if (r)
+ return r;
+ line_data_cur += rec_size;
+ }
+ }
+
+ return 0;
+}
+
+static int str_sort_by_content(const void *a1, const void *a2)
+{
+ const struct btf_str_ptr *p1 = a1;
+ const struct btf_str_ptr *p2 = a2;
+
+ return strcmp(p1->str, p2->str);
+}
+
+static int str_sort_by_offset(const void *a1, const void *a2)
+{
+ const struct btf_str_ptr *p1 = a1;
+ const struct btf_str_ptr *p2 = a2;
+
+ if (p1->str != p2->str)
+ return p1->str < p2->str ? -1 : 1;
+ return 0;
+}
+
+static int btf_dedup_str_ptr_cmp(const void *str_ptr, const void *pelem)
+{
+ const struct btf_str_ptr *p = pelem;
+
+ if (str_ptr != p->str)
+ return (const char *)str_ptr < p->str ? -1 : 1;
+ return 0;
+}
+
+static int btf_str_mark_as_used(__u32 *str_off_ptr, void *ctx)
+{
+ struct btf_str_ptrs *strs;
+ struct btf_str_ptr *s;
+
+ if (*str_off_ptr == 0)
+ return 0;
+
+ strs = ctx;
+ s = bsearch(strs->data + *str_off_ptr, strs->ptrs, strs->cnt,
+ sizeof(struct btf_str_ptr), btf_dedup_str_ptr_cmp);
+ if (!s)
+ return -EINVAL;
+ s->used = true;
+ return 0;
+}
+
+static int btf_str_remap_offset(__u32 *str_off_ptr, void *ctx)
+{
+ struct btf_str_ptrs *strs;
+ struct btf_str_ptr *s;
+
+ if (*str_off_ptr == 0)
+ return 0;
+
+ strs = ctx;
+ s = bsearch(strs->data + *str_off_ptr, strs->ptrs, strs->cnt,
+ sizeof(struct btf_str_ptr), btf_dedup_str_ptr_cmp);
+ if (!s)
+ return -EINVAL;
+ *str_off_ptr = s->new_off;
+ return 0;
+}
+
+/*
+ * Dedup string and filter out those that are not referenced from either .BTF
+ * or .BTF.ext (if provided) sections.
+ *
+ * This is done by building index of all strings in BTF's string section,
+ * then iterating over all entities that can reference strings (e.g., type
+ * names, struct field names, .BTF.ext line info, etc) and marking corresponding
+ * strings as used. After that all used strings are deduped and compacted into
+ * sequential blob of memory and new offsets are calculated. Then all the string
+ * references are iterated again and rewritten using new offsets.
+ */
+static int btf_dedup_strings(struct btf_dedup *d)
+{
+ const struct btf_header *hdr = d->btf->hdr;
+ char *start = (char *)d->btf->nohdr_data + hdr->str_off;
+ char *end = start + d->btf->hdr->str_len;
+ char *p = start, *tmp_strs = NULL;
+ struct btf_str_ptrs strs = {
+ .cnt = 0,
+ .cap = 0,
+ .ptrs = NULL,
+ .data = start,
+ };
+ int i, j, err = 0, grp_idx;
+ bool grp_used;
+
+ /* build index of all strings */
+ while (p < end) {
+ if (strs.cnt + 1 > strs.cap) {
+ struct btf_str_ptr *new_ptrs;
+
+ strs.cap += max(strs.cnt / 2, 16);
+ new_ptrs = realloc(strs.ptrs,
+ sizeof(strs.ptrs[0]) * strs.cap);
+ if (!new_ptrs) {
+ err = -ENOMEM;
+ goto done;
+ }
+ strs.ptrs = new_ptrs;
+ }
+
+ strs.ptrs[strs.cnt].str = p;
+ strs.ptrs[strs.cnt].used = false;
+
+ p += strlen(p) + 1;
+ strs.cnt++;
+ }
+
+ /* temporary storage for deduplicated strings */
+ tmp_strs = malloc(d->btf->hdr->str_len);
+ if (!tmp_strs) {
+ err = -ENOMEM;
+ goto done;
+ }
+
+ /* mark all used strings */
+ strs.ptrs[0].used = true;
+ err = btf_for_each_str_off(d, btf_str_mark_as_used, &strs);
+ if (err)
+ goto done;
+
+ /* sort strings by context, so that we can identify duplicates */
+ qsort(strs.ptrs, strs.cnt, sizeof(strs.ptrs[0]), str_sort_by_content);
+
+ /*
+ * iterate groups of equal strings and if any instance in a group was
+ * referenced, emit single instance and remember new offset
+ */
+ p = tmp_strs;
+ grp_idx = 0;
+ grp_used = strs.ptrs[0].used;
+ /* iterate past end to avoid code duplication after loop */
+ for (i = 1; i <= strs.cnt; i++) {
+ /*
+ * when i == strs.cnt, we want to skip string comparison and go
+ * straight to handling last group of strings (otherwise we'd
+ * need to handle last group after the loop w/ duplicated code)
+ */
+ if (i < strs.cnt &&
+ !strcmp(strs.ptrs[i].str, strs.ptrs[grp_idx].str)) {
+ grp_used = grp_used || strs.ptrs[i].used;
+ continue;
+ }
+
+ /*
+ * this check would have been required after the loop to handle
+ * last group of strings, but due to <= condition in a loop
+ * we avoid that duplication
+ */
+ if (grp_used) {
+ int new_off = p - tmp_strs;
+ __u32 len = strlen(strs.ptrs[grp_idx].str);
+
+ memmove(p, strs.ptrs[grp_idx].str, len + 1);
+ for (j = grp_idx; j < i; j++)
+ strs.ptrs[j].new_off = new_off;
+ p += len + 1;
+ }
+
+ if (i < strs.cnt) {
+ grp_idx = i;
+ grp_used = strs.ptrs[i].used;
+ }
+ }
+
+ /* replace original strings with deduped ones */
+ d->btf->hdr->str_len = p - tmp_strs;
+ memmove(start, tmp_strs, d->btf->hdr->str_len);
+ end = start + d->btf->hdr->str_len;
+
+ /* restore original order for further binary search lookups */
+ qsort(strs.ptrs, strs.cnt, sizeof(strs.ptrs[0]), str_sort_by_offset);
+
+ /* remap string offsets */
+ err = btf_for_each_str_off(d, btf_str_remap_offset, &strs);
+ if (err)
+ goto done;
+
+ d->btf->hdr->str_len = end - start;
+
+done:
+ free(tmp_strs);
+ free(strs.ptrs);
+ return err;
+}
+
+static __u32 btf_hash_common(struct btf_type *t)
+{
+ __u32 h;
+
+ h = hash_combine(0, t->name_off);
+ h = hash_combine(h, t->info);
+ h = hash_combine(h, t->size);
+ return h;
+}
+
+static bool btf_equal_common(struct btf_type *t1, struct btf_type *t2)
+{
+ return t1->name_off == t2->name_off &&
+ t1->info == t2->info &&
+ t1->size == t2->size;
+}
+
+/* Calculate type signature hash of INT. */
+static __u32 btf_hash_int(struct btf_type *t)
+{
+ __u32 info = *(__u32 *)(t + 1);
+ __u32 h;
+
+ h = btf_hash_common(t);
+ h = hash_combine(h, info);
+ return h;
+}
+
+/* Check structural equality of two INTs. */
+static bool btf_equal_int(struct btf_type *t1, struct btf_type *t2)
+{
+ __u32 info1, info2;
+
+ if (!btf_equal_common(t1, t2))
+ return false;
+ info1 = *(__u32 *)(t1 + 1);
+ info2 = *(__u32 *)(t2 + 1);
+ return info1 == info2;
+}
+
+/* Calculate type signature hash of ENUM. */
+static __u32 btf_hash_enum(struct btf_type *t)
+{
+ struct btf_enum *member = (struct btf_enum *)(t + 1);
+ __u32 vlen = BTF_INFO_VLEN(t->info);
+ __u32 h = btf_hash_common(t);
+ int i;
+
+ for (i = 0; i < vlen; i++) {
+ h = hash_combine(h, member->name_off);
+ h = hash_combine(h, member->val);
+ member++;
+ }
+ return h;
+}
+
+/* Check structural equality of two ENUMs. */
+static bool btf_equal_enum(struct btf_type *t1, struct btf_type *t2)
+{
+ struct btf_enum *m1, *m2;
+ __u16 vlen;
+ int i;
+
+ if (!btf_equal_common(t1, t2))
+ return false;
+
+ vlen = BTF_INFO_VLEN(t1->info);
+ m1 = (struct btf_enum *)(t1 + 1);
+ m2 = (struct btf_enum *)(t2 + 1);
+ for (i = 0; i < vlen; i++) {
+ if (m1->name_off != m2->name_off || m1->val != m2->val)
+ return false;
+ m1++;
+ m2++;
+ }
+ return true;
+}
+
+/*
+ * Calculate type signature hash of STRUCT/UNION, ignoring referenced type IDs,
+ * as referenced type IDs equivalence is established separately during type
+ * graph equivalence check algorithm.
+ */
+static __u32 btf_hash_struct(struct btf_type *t)
+{
+ struct btf_member *member = (struct btf_member *)(t + 1);
+ __u32 vlen = BTF_INFO_VLEN(t->info);
+ __u32 h = btf_hash_common(t);
+ int i;
+
+ for (i = 0; i < vlen; i++) {
+ h = hash_combine(h, member->name_off);
+ h = hash_combine(h, member->offset);
+ /* no hashing of referenced type ID, it can be unresolved yet */
+ member++;
+ }
+ return h;
+}
+
+/*
+ * Check structural compatibility of two FUNC_PROTOs, ignoring referenced type
+ * IDs. This check is performed during type graph equivalence check and
+ * referenced types equivalence is checked separately.
+ */
+static bool btf_shallow_equal_struct(struct btf_type *t1, struct btf_type *t2)
+{
+ struct btf_member *m1, *m2;
+ __u16 vlen;
+ int i;
+
+ if (!btf_equal_common(t1, t2))
+ return false;
+
+ vlen = BTF_INFO_VLEN(t1->info);
+ m1 = (struct btf_member *)(t1 + 1);
+ m2 = (struct btf_member *)(t2 + 1);
+ for (i = 0; i < vlen; i++) {
+ if (m1->name_off != m2->name_off || m1->offset != m2->offset)
+ return false;
+ m1++;
+ m2++;
+ }
+ return true;
+}
+
+/*
+ * Calculate type signature hash of ARRAY, including referenced type IDs,
+ * under assumption that they were already resolved to canonical type IDs and
+ * are not going to change.
+ */
+static __u32 btf_hash_array(struct btf_type *t)
+{
+ struct btf_array *info = (struct btf_array *)(t + 1);
+ __u32 h = btf_hash_common(t);
+
+ h = hash_combine(h, info->type);
+ h = hash_combine(h, info->index_type);
+ h = hash_combine(h, info->nelems);
+ return h;
+}
+
+/*
+ * Check exact equality of two ARRAYs, taking into account referenced
+ * type IDs, under assumption that they were already resolved to canonical
+ * type IDs and are not going to change.
+ * This function is called during reference types deduplication to compare
+ * ARRAY to potential canonical representative.
+ */
+static bool btf_equal_array(struct btf_type *t1, struct btf_type *t2)
+{
+ struct btf_array *info1, *info2;
+
+ if (!btf_equal_common(t1, t2))
+ return false;
+
+ info1 = (struct btf_array *)(t1 + 1);
+ info2 = (struct btf_array *)(t2 + 1);
+ return info1->type == info2->type &&
+ info1->index_type == info2->index_type &&
+ info1->nelems == info2->nelems;
+}
+
+/*
+ * Check structural compatibility of two ARRAYs, ignoring referenced type
+ * IDs. This check is performed during type graph equivalence check and
+ * referenced types equivalence is checked separately.
+ */
+static bool btf_compat_array(struct btf_type *t1, struct btf_type *t2)
+{
+ struct btf_array *info1, *info2;
+
+ if (!btf_equal_common(t1, t2))
+ return false;
+
+ info1 = (struct btf_array *)(t1 + 1);
+ info2 = (struct btf_array *)(t2 + 1);
+ return info1->nelems == info2->nelems;
+}
+
+/*
+ * Calculate type signature hash of FUNC_PROTO, including referenced type IDs,
+ * under assumption that they were already resolved to canonical type IDs and
+ * are not going to change.
+ */
+static inline __u32 btf_hash_fnproto(struct btf_type *t)
+{
+ struct btf_param *member = (struct btf_param *)(t + 1);
+ __u16 vlen = BTF_INFO_VLEN(t->info);
+ __u32 h = btf_hash_common(t);
+ int i;
+
+ for (i = 0; i < vlen; i++) {
+ h = hash_combine(h, member->name_off);
+ h = hash_combine(h, member->type);
+ member++;
+ }
+ return h;
+}
+
+/*
+ * Check exact equality of two FUNC_PROTOs, taking into account referenced
+ * type IDs, under assumption that they were already resolved to canonical
+ * type IDs and are not going to change.
+ * This function is called during reference types deduplication to compare
+ * FUNC_PROTO to potential canonical representative.
+ */
+static inline bool btf_equal_fnproto(struct btf_type *t1, struct btf_type *t2)
+{
+ struct btf_param *m1, *m2;
+ __u16 vlen;
+ int i;
+
+ if (!btf_equal_common(t1, t2))
+ return false;
+
+ vlen = BTF_INFO_VLEN(t1->info);
+ m1 = (struct btf_param *)(t1 + 1);
+ m2 = (struct btf_param *)(t2 + 1);
+ for (i = 0; i < vlen; i++) {
+ if (m1->name_off != m2->name_off || m1->type != m2->type)
+ return false;
+ m1++;
+ m2++;
+ }
+ return true;
+}
+
+/*
+ * Check structural compatibility of two FUNC_PROTOs, ignoring referenced type
+ * IDs. This check is performed during type graph equivalence check and
+ * referenced types equivalence is checked separately.
+ */
+static inline bool btf_compat_fnproto(struct btf_type *t1, struct btf_type *t2)
+{
+ struct btf_param *m1, *m2;
+ __u16 vlen;
+ int i;
+
+ /* skip return type ID */
+ if (t1->name_off != t2->name_off || t1->info != t2->info)
+ return false;
+
+ vlen = BTF_INFO_VLEN(t1->info);
+ m1 = (struct btf_param *)(t1 + 1);
+ m2 = (struct btf_param *)(t2 + 1);
+ for (i = 0; i < vlen; i++) {
+ if (m1->name_off != m2->name_off)
+ return false;
+ m1++;
+ m2++;
+ }
+ return true;
+}
+
+/*
+ * Deduplicate primitive types, that can't reference other types, by calculating
+ * their type signature hash and comparing them with any possible canonical
+ * candidate. If no canonical candidate matches, type itself is marked as
+ * canonical and is added into `btf_dedup->dedup_table` as another candidate.
+ */
+static int btf_dedup_prim_type(struct btf_dedup *d, __u32 type_id)
+{
+ struct btf_type *t = d->btf->types[type_id];
+ struct btf_type *cand;
+ struct btf_dedup_node *cand_node;
+ /* if we don't find equivalent type, then we are canonical */
+ __u32 new_id = type_id;
+ __u32 h;
+
+ switch (BTF_INFO_KIND(t->info)) {
+ case BTF_KIND_CONST:
+ case BTF_KIND_VOLATILE:
+ case BTF_KIND_RESTRICT:
+ case BTF_KIND_PTR:
+ case BTF_KIND_TYPEDEF:
+ case BTF_KIND_ARRAY:
+ case BTF_KIND_STRUCT:
+ case BTF_KIND_UNION:
+ case BTF_KIND_FUNC:
+ case BTF_KIND_FUNC_PROTO:
+ return 0;
+
+ case BTF_KIND_INT:
+ h = btf_hash_int(t);
+ for_each_dedup_cand(d, h, cand_node) {
+ cand = d->btf->types[cand_node->type_id];
+ if (btf_equal_int(t, cand)) {
+ new_id = cand_node->type_id;
+ break;
+ }
+ }
+ break;
+
+ case BTF_KIND_ENUM:
+ h = btf_hash_enum(t);
+ for_each_dedup_cand(d, h, cand_node) {
+ cand = d->btf->types[cand_node->type_id];
+ if (btf_equal_enum(t, cand)) {
+ new_id = cand_node->type_id;
+ break;
+ }
+ }
+ break;
+
+ case BTF_KIND_FWD:
+ h = btf_hash_common(t);
+ for_each_dedup_cand(d, h, cand_node) {
+ cand = d->btf->types[cand_node->type_id];
+ if (btf_equal_common(t, cand)) {
+ new_id = cand_node->type_id;
+ break;
+ }
+ }
+ break;
+
+ default:
+ return -EINVAL;
+ }
+
+ d->map[type_id] = new_id;
+ if (type_id == new_id && btf_dedup_table_add(d, h, type_id))
+ return -ENOMEM;
+
+ return 0;
+}
+
+static int btf_dedup_prim_types(struct btf_dedup *d)
+{
+ int i, err;
+
+ for (i = 1; i <= d->btf->nr_types; i++) {
+ err = btf_dedup_prim_type(d, i);
+ if (err)
+ return err;
+ }
+ return 0;
+}
+
+/*
+ * Check whether type is already mapped into canonical one (could be to itself).
+ */
+static inline bool is_type_mapped(struct btf_dedup *d, uint32_t type_id)
+{
+ return d->map[type_id] <= BTF_MAX_NR_TYPES;
+}
+
+/*
+ * Resolve type ID into its canonical type ID, if any; otherwise return original
+ * type ID. If type is FWD and is resolved into STRUCT/UNION already, follow
+ * STRUCT/UNION link and resolve it into canonical type ID as well.
+ */
+static inline __u32 resolve_type_id(struct btf_dedup *d, __u32 type_id)
+{
+ while (is_type_mapped(d, type_id) && d->map[type_id] != type_id)
+ type_id = d->map[type_id];
+ return type_id;
+}
+
+/*
+ * Resolve FWD to underlying STRUCT/UNION, if any; otherwise return original
+ * type ID.
+ */
+static uint32_t resolve_fwd_id(struct btf_dedup *d, uint32_t type_id)
+{
+ __u32 orig_type_id = type_id;
+
+ if (BTF_INFO_KIND(d->btf->types[type_id]->info) != BTF_KIND_FWD)
+ return type_id;
+
+ while (is_type_mapped(d, type_id) && d->map[type_id] != type_id)
+ type_id = d->map[type_id];
+
+ if (BTF_INFO_KIND(d->btf->types[type_id]->info) != BTF_KIND_FWD)
+ return type_id;
+
+ return orig_type_id;
+}
+
+
+static inline __u16 btf_fwd_kind(struct btf_type *t)
+{
+ return BTF_INFO_KFLAG(t->info) ? BTF_KIND_UNION : BTF_KIND_STRUCT;
+}
+
+/*
+ * Check equivalence of BTF type graph formed by candidate struct/union (we'll
+ * call it "candidate graph" in this description for brevity) to a type graph
+ * formed by (potential) canonical struct/union ("canonical graph" for brevity
+ * here, though keep in mind that not all types in canonical graph are
+ * necessarily canonical representatives themselves, some of them might be
+ * duplicates or its uniqueness might not have been established yet).
+ * Returns:
+ * - >0, if type graphs are equivalent;
+ * - 0, if not equivalent;
+ * - <0, on error.
+ *
+ * Algorithm performs side-by-side DFS traversal of both type graphs and checks
+ * equivalence of BTF types at each step. If at any point BTF types in candidate
+ * and canonical graphs are not compatible structurally, whole graphs are
+ * incompatible. If types are structurally equivalent (i.e., all information
+ * except referenced type IDs is exactly the same), a mapping from `canon_id` to
+ * a `cand_id` is recored in hypothetical mapping (`btf_dedup->hypot_map`).
+ * If a type references other types, then those referenced types are checked
+ * for equivalence recursively.
+ *
+ * During DFS traversal, if we find that for current `canon_id` type we
+ * already have some mapping in hypothetical map, we check for two possible
+ * situations:
+ * - `canon_id` is mapped to exactly the same type as `cand_id`. This will
+ * happen when type graphs have cycles. In this case we assume those two
+ * types are equivalent.
+ * - `canon_id` is mapped to different type. This is contradiction in our
+ * hypothetical mapping, because same graph in canonical graph corresponds
+ * to two different types in candidate graph, which for equivalent type
+ * graphs shouldn't happen. This condition terminates equivalence check
+ * with negative result.
+ *
+ * If type graphs traversal exhausts types to check and find no contradiction,
+ * then type graphs are equivalent.
+ *
+ * When checking types for equivalence, there is one special case: FWD types.
+ * If FWD type resolution is allowed and one of the types (either from canonical
+ * or candidate graph) is FWD and other is STRUCT/UNION (depending on FWD's kind
+ * flag) and their names match, hypothetical mapping is updated to point from
+ * FWD to STRUCT/UNION. If graphs will be determined as equivalent successfully,
+ * this mapping will be used to record FWD -> STRUCT/UNION mapping permanently.
+ *
+ * Technically, this could lead to incorrect FWD to STRUCT/UNION resolution,
+ * if there are two exactly named (or anonymous) structs/unions that are
+ * compatible structurally, one of which has FWD field, while other is concrete
+ * STRUCT/UNION, but according to C sources they are different structs/unions
+ * that are referencing different types with the same name. This is extremely
+ * unlikely to happen, but btf_dedup API allows to disable FWD resolution if
+ * this logic is causing problems.
+ *
+ * Doing FWD resolution means that both candidate and/or canonical graphs can
+ * consists of portions of the graph that come from multiple compilation units.
+ * This is due to the fact that types within single compilation unit are always
+ * deduplicated and FWDs are already resolved, if referenced struct/union
+ * definiton is available. So, if we had unresolved FWD and found corresponding
+ * STRUCT/UNION, they will be from different compilation units. This
+ * consequently means that when we "link" FWD to corresponding STRUCT/UNION,
+ * type graph will likely have at least two different BTF types that describe
+ * same type (e.g., most probably there will be two different BTF types for the
+ * same 'int' primitive type) and could even have "overlapping" parts of type
+ * graph that describe same subset of types.
+ *
+ * This in turn means that our assumption that each type in canonical graph
+ * must correspond to exactly one type in candidate graph might not hold
+ * anymore and will make it harder to detect contradictions using hypothetical
+ * map. To handle this problem, we allow to follow FWD -> STRUCT/UNION
+ * resolution only in canonical graph. FWDs in candidate graphs are never
+ * resolved. To see why it's OK, let's check all possible situations w.r.t. FWDs
+ * that can occur:
+ * - Both types in canonical and candidate graphs are FWDs. If they are
+ * structurally equivalent, then they can either be both resolved to the
+ * same STRUCT/UNION or not resolved at all. In both cases they are
+ * equivalent and there is no need to resolve FWD on candidate side.
+ * - Both types in canonical and candidate graphs are concrete STRUCT/UNION,
+ * so nothing to resolve as well, algorithm will check equivalence anyway.
+ * - Type in canonical graph is FWD, while type in candidate is concrete
+ * STRUCT/UNION. In this case candidate graph comes from single compilation
+ * unit, so there is exactly one BTF type for each unique C type. After
+ * resolving FWD into STRUCT/UNION, there might be more than one BTF type
+ * in canonical graph mapping to single BTF type in candidate graph, but
+ * because hypothetical mapping maps from canonical to candidate types, it's
+ * alright, and we still maintain the property of having single `canon_id`
+ * mapping to single `cand_id` (there could be two different `canon_id`
+ * mapped to the same `cand_id`, but it's not contradictory).
+ * - Type in canonical graph is concrete STRUCT/UNION, while type in candidate
+ * graph is FWD. In this case we are just going to check compatibility of
+ * STRUCT/UNION and corresponding FWD, and if they are compatible, we'll
+ * assume that whatever STRUCT/UNION FWD resolves to must be equivalent to
+ * a concrete STRUCT/UNION from canonical graph. If the rest of type graphs
+ * turn out equivalent, we'll re-resolve FWD to concrete STRUCT/UNION from
+ * canonical graph.
+ */
+static int btf_dedup_is_equiv(struct btf_dedup *d, __u32 cand_id,
+ __u32 canon_id)
+{
+ struct btf_type *cand_type;
+ struct btf_type *canon_type;
+ __u32 hypot_type_id;
+ __u16 cand_kind;
+ __u16 canon_kind;
+ int i, eq;
+
+ /* if both resolve to the same canonical, they must be equivalent */
+ if (resolve_type_id(d, cand_id) == resolve_type_id(d, canon_id))
+ return 1;
+
+ canon_id = resolve_fwd_id(d, canon_id);
+
+ hypot_type_id = d->hypot_map[canon_id];
+ if (hypot_type_id <= BTF_MAX_NR_TYPES)
+ return hypot_type_id == cand_id;
+
+ if (btf_dedup_hypot_map_add(d, canon_id, cand_id))
+ return -ENOMEM;
+
+ cand_type = d->btf->types[cand_id];
+ canon_type = d->btf->types[canon_id];
+ cand_kind = BTF_INFO_KIND(cand_type->info);
+ canon_kind = BTF_INFO_KIND(canon_type->info);
+
+ if (cand_type->name_off != canon_type->name_off)
+ return 0;
+
+ /* FWD <--> STRUCT/UNION equivalence check, if enabled */
+ if (!d->opts.dont_resolve_fwds
+ && (cand_kind == BTF_KIND_FWD || canon_kind == BTF_KIND_FWD)
+ && cand_kind != canon_kind) {
+ __u16 real_kind;
+ __u16 fwd_kind;
+
+ if (cand_kind == BTF_KIND_FWD) {
+ real_kind = canon_kind;
+ fwd_kind = btf_fwd_kind(cand_type);
+ } else {
+ real_kind = cand_kind;
+ fwd_kind = btf_fwd_kind(canon_type);
+ }
+ return fwd_kind == real_kind;
+ }
+
+ if (cand_type->info != canon_type->info)
+ return 0;
+
+ switch (cand_kind) {
+ case BTF_KIND_INT:
+ return btf_equal_int(cand_type, canon_type);
+
+ case BTF_KIND_ENUM:
+ return btf_equal_enum(cand_type, canon_type);
+
+ case BTF_KIND_FWD:
+ return btf_equal_common(cand_type, canon_type);
+
+ case BTF_KIND_CONST:
+ case BTF_KIND_VOLATILE:
+ case BTF_KIND_RESTRICT:
+ case BTF_KIND_PTR:
+ case BTF_KIND_TYPEDEF:
+ case BTF_KIND_FUNC:
+ return btf_dedup_is_equiv(d, cand_type->type, canon_type->type);
+
+ case BTF_KIND_ARRAY: {
+ struct btf_array *cand_arr, *canon_arr;
+
+ if (!btf_compat_array(cand_type, canon_type))
+ return 0;
+ cand_arr = (struct btf_array *)(cand_type + 1);
+ canon_arr = (struct btf_array *)(canon_type + 1);
+ eq = btf_dedup_is_equiv(d,
+ cand_arr->index_type, canon_arr->index_type);
+ if (eq <= 0)
+ return eq;
+ return btf_dedup_is_equiv(d, cand_arr->type, canon_arr->type);
+ }
+
+ case BTF_KIND_STRUCT:
+ case BTF_KIND_UNION: {
+ struct btf_member *cand_m, *canon_m;
+ __u16 vlen;
+
+ if (!btf_shallow_equal_struct(cand_type, canon_type))
+ return 0;
+ vlen = BTF_INFO_VLEN(cand_type->info);
+ cand_m = (struct btf_member *)(cand_type + 1);
+ canon_m = (struct btf_member *)(canon_type + 1);
+ for (i = 0; i < vlen; i++) {
+ eq = btf_dedup_is_equiv(d, cand_m->type, canon_m->type);
+ if (eq <= 0)
+ return eq;
+ cand_m++;
+ canon_m++;
+ }
+
+ return 1;
+ }
+
+ case BTF_KIND_FUNC_PROTO: {
+ struct btf_param *cand_p, *canon_p;
+ __u16 vlen;
+
+ if (!btf_compat_fnproto(cand_type, canon_type))
+ return 0;
+ eq = btf_dedup_is_equiv(d, cand_type->type, canon_type->type);
+ if (eq <= 0)
+ return eq;
+ vlen = BTF_INFO_VLEN(cand_type->info);
+ cand_p = (struct btf_param *)(cand_type + 1);
+ canon_p = (struct btf_param *)(canon_type + 1);
+ for (i = 0; i < vlen; i++) {
+ eq = btf_dedup_is_equiv(d, cand_p->type, canon_p->type);
+ if (eq <= 0)
+ return eq;
+ cand_p++;
+ canon_p++;
+ }
+ return 1;
+ }
+
+ default:
+ return -EINVAL;
+ }
+ return 0;
+}
+
+/*
+ * Use hypothetical mapping, produced by successful type graph equivalence
+ * check, to augment existing struct/union canonical mapping, where possible.
+ *
+ * If BTF_KIND_FWD resolution is allowed, this mapping is also used to record
+ * FWD -> STRUCT/UNION correspondence as well. FWD resolution is bidirectional:
+ * it doesn't matter if FWD type was part of canonical graph or candidate one,
+ * we are recording the mapping anyway. As opposed to carefulness required
+ * for struct/union correspondence mapping (described below), for FWD resolution
+ * it's not important, as by the time that FWD type (reference type) will be
+ * deduplicated all structs/unions will be deduped already anyway.
+ *
+ * Recording STRUCT/UNION mapping is purely a performance optimization and is
+ * not required for correctness. It needs to be done carefully to ensure that
+ * struct/union from candidate's type graph is not mapped into corresponding
+ * struct/union from canonical type graph that itself hasn't been resolved into
+ * canonical representative. The only guarantee we have is that canonical
+ * struct/union was determined as canonical and that won't change. But any
+ * types referenced through that struct/union fields could have been not yet
+ * resolved, so in case like that it's too early to establish any kind of
+ * correspondence between structs/unions.
+ *
+ * No canonical correspondence is derived for primitive types (they are already
+ * deduplicated completely already anyway) or reference types (they rely on
+ * stability of struct/union canonical relationship for equivalence checks).
+ */
+static void btf_dedup_merge_hypot_map(struct btf_dedup *d)
+{
+ __u32 cand_type_id, targ_type_id;
+ __u16 t_kind, c_kind;
+ __u32 t_id, c_id;
+ int i;
+
+ for (i = 0; i < d->hypot_cnt; i++) {
+ cand_type_id = d->hypot_list[i];
+ targ_type_id = d->hypot_map[cand_type_id];
+ t_id = resolve_type_id(d, targ_type_id);
+ c_id = resolve_type_id(d, cand_type_id);
+ t_kind = BTF_INFO_KIND(d->btf->types[t_id]->info);
+ c_kind = BTF_INFO_KIND(d->btf->types[c_id]->info);
+ /*
+ * Resolve FWD into STRUCT/UNION.
+ * It's ok to resolve FWD into STRUCT/UNION that's not yet
+ * mapped to canonical representative (as opposed to
+ * STRUCT/UNION <--> STRUCT/UNION mapping logic below), because
+ * eventually that struct is going to be mapped and all resolved
+ * FWDs will automatically resolve to correct canonical
+ * representative. This will happen before ref type deduping,
+ * which critically depends on stability of these mapping. This
+ * stability is not a requirement for STRUCT/UNION equivalence
+ * checks, though.
+ */
+ if (t_kind != BTF_KIND_FWD && c_kind == BTF_KIND_FWD)
+ d->map[c_id] = t_id;
+ else if (t_kind == BTF_KIND_FWD && c_kind != BTF_KIND_FWD)
+ d->map[t_id] = c_id;
+
+ if ((t_kind == BTF_KIND_STRUCT || t_kind == BTF_KIND_UNION) &&
+ c_kind != BTF_KIND_FWD &&
+ is_type_mapped(d, c_id) &&
+ !is_type_mapped(d, t_id)) {
+ /*
+ * as a perf optimization, we can map struct/union
+ * that's part of type graph we just verified for
+ * equivalence. We can do that for struct/union that has
+ * canonical representative only, though.
+ */
+ d->map[t_id] = c_id;
+ }
+ }
+}
+
+/*
+ * Deduplicate struct/union types.
+ *
+ * For each struct/union type its type signature hash is calculated, taking
+ * into account type's name, size, number, order and names of fields, but
+ * ignoring type ID's referenced from fields, because they might not be deduped
+ * completely until after reference types deduplication phase. This type hash
+ * is used to iterate over all potential canonical types, sharing same hash.
+ * For each canonical candidate we check whether type graphs that they form
+ * (through referenced types in fields and so on) are equivalent using algorithm
+ * implemented in `btf_dedup_is_equiv`. If such equivalence is found and
+ * BTF_KIND_FWD resolution is allowed, then hypothetical mapping
+ * (btf_dedup->hypot_map) produced by aforementioned type graph equivalence
+ * algorithm is used to record FWD -> STRUCT/UNION mapping. It's also used to
+ * potentially map other structs/unions to their canonical representatives,
+ * if such relationship hasn't yet been established. This speeds up algorithm
+ * by eliminating some of the duplicate work.
+ *
+ * If no matching canonical representative was found, struct/union is marked
+ * as canonical for itself and is added into btf_dedup->dedup_table hash map
+ * for further look ups.
+ */
+static int btf_dedup_struct_type(struct btf_dedup *d, __u32 type_id)
+{
+ struct btf_dedup_node *cand_node;
+ struct btf_type *cand_type, *t;
+ /* if we don't find equivalent type, then we are canonical */
+ __u32 new_id = type_id;
+ __u16 kind;
+ __u32 h;
+
+ /* already deduped or is in process of deduping (loop detected) */
+ if (d->map[type_id] <= BTF_MAX_NR_TYPES)
+ return 0;
+
+ t = d->btf->types[type_id];
+ kind = BTF_INFO_KIND(t->info);
+
+ if (kind != BTF_KIND_STRUCT && kind != BTF_KIND_UNION)
+ return 0;
+
+ h = btf_hash_struct(t);
+ for_each_dedup_cand(d, h, cand_node) {
+ int eq;
+
+ /*
+ * Even though btf_dedup_is_equiv() checks for
+ * btf_shallow_equal_struct() internally when checking two
+ * structs (unions) for equivalence, we need to guard here
+ * from picking matching FWD type as a dedup candidate.
+ * This can happen due to hash collision. In such case just
+ * relying on btf_dedup_is_equiv() would lead to potentially
+ * creating a loop (FWD -> STRUCT and STRUCT -> FWD), because
+ * FWD and compatible STRUCT/UNION are considered equivalent.
+ */
+ cand_type = d->btf->types[cand_node->type_id];
+ if (!btf_shallow_equal_struct(t, cand_type))
+ continue;
+
+ btf_dedup_clear_hypot_map(d);
+ eq = btf_dedup_is_equiv(d, type_id, cand_node->type_id);
+ if (eq < 0)
+ return eq;
+ if (!eq)
+ continue;
+ new_id = cand_node->type_id;
+ btf_dedup_merge_hypot_map(d);
+ break;
+ }
+
+ d->map[type_id] = new_id;
+ if (type_id == new_id && btf_dedup_table_add(d, h, type_id))
+ return -ENOMEM;
+
+ return 0;
+}
+
+static int btf_dedup_struct_types(struct btf_dedup *d)
+{
+ int i, err;
+
+ for (i = 1; i <= d->btf->nr_types; i++) {
+ err = btf_dedup_struct_type(d, i);
+ if (err)
+ return err;
+ }
+ return 0;
+}
+
+/*
+ * Deduplicate reference type.
+ *
+ * Once all primitive and struct/union types got deduplicated, we can easily
+ * deduplicate all other (reference) BTF types. This is done in two steps:
+ *
+ * 1. Resolve all referenced type IDs into their canonical type IDs. This
+ * resolution can be done either immediately for primitive or struct/union types
+ * (because they were deduped in previous two phases) or recursively for
+ * reference types. Recursion will always terminate at either primitive or
+ * struct/union type, at which point we can "unwind" chain of reference types
+ * one by one. There is no danger of encountering cycles because in C type
+ * system the only way to form type cycle is through struct/union, so any chain
+ * of reference types, even those taking part in a type cycle, will inevitably
+ * reach struct/union at some point.
+ *
+ * 2. Once all referenced type IDs are resolved into canonical ones, BTF type
+ * becomes "stable", in the sense that no further deduplication will cause
+ * any changes to it. With that, it's now possible to calculate type's signature
+ * hash (this time taking into account referenced type IDs) and loop over all
+ * potential canonical representatives. If no match was found, current type
+ * will become canonical representative of itself and will be added into
+ * btf_dedup->dedup_table as another possible canonical representative.
+ */
+static int btf_dedup_ref_type(struct btf_dedup *d, __u32 type_id)
+{
+ struct btf_dedup_node *cand_node;
+ struct btf_type *t, *cand;
+ /* if we don't find equivalent type, then we are representative type */
+ __u32 new_id = type_id;
+ int ref_type_id;
+ __u32 h;
+
+ if (d->map[type_id] == BTF_IN_PROGRESS_ID)
+ return -ELOOP;
+ if (d->map[type_id] <= BTF_MAX_NR_TYPES)
+ return resolve_type_id(d, type_id);
+
+ t = d->btf->types[type_id];
+ d->map[type_id] = BTF_IN_PROGRESS_ID;
+
+ switch (BTF_INFO_KIND(t->info)) {
+ case BTF_KIND_CONST:
+ case BTF_KIND_VOLATILE:
+ case BTF_KIND_RESTRICT:
+ case BTF_KIND_PTR:
+ case BTF_KIND_TYPEDEF:
+ case BTF_KIND_FUNC:
+ ref_type_id = btf_dedup_ref_type(d, t->type);
+ if (ref_type_id < 0)
+ return ref_type_id;
+ t->type = ref_type_id;
+
+ h = btf_hash_common(t);
+ for_each_dedup_cand(d, h, cand_node) {
+ cand = d->btf->types[cand_node->type_id];
+ if (btf_equal_common(t, cand)) {
+ new_id = cand_node->type_id;
+ break;
+ }
+ }
+ break;
+
+ case BTF_KIND_ARRAY: {
+ struct btf_array *info = (struct btf_array *)(t + 1);
+
+ ref_type_id = btf_dedup_ref_type(d, info->type);
+ if (ref_type_id < 0)
+ return ref_type_id;
+ info->type = ref_type_id;
+
+ ref_type_id = btf_dedup_ref_type(d, info->index_type);
+ if (ref_type_id < 0)
+ return ref_type_id;
+ info->index_type = ref_type_id;
+
+ h = btf_hash_array(t);
+ for_each_dedup_cand(d, h, cand_node) {
+ cand = d->btf->types[cand_node->type_id];
+ if (btf_equal_array(t, cand)) {
+ new_id = cand_node->type_id;
+ break;
+ }
+ }
+ break;
+ }
+
+ case BTF_KIND_FUNC_PROTO: {
+ struct btf_param *param;
+ __u16 vlen;
+ int i;
+
+ ref_type_id = btf_dedup_ref_type(d, t->type);
+ if (ref_type_id < 0)
+ return ref_type_id;
+ t->type = ref_type_id;
+
+ vlen = BTF_INFO_VLEN(t->info);
+ param = (struct btf_param *)(t + 1);
+ for (i = 0; i < vlen; i++) {
+ ref_type_id = btf_dedup_ref_type(d, param->type);
+ if (ref_type_id < 0)
+ return ref_type_id;
+ param->type = ref_type_id;
+ param++;
+ }
+
+ h = btf_hash_fnproto(t);
+ for_each_dedup_cand(d, h, cand_node) {
+ cand = d->btf->types[cand_node->type_id];
+ if (btf_equal_fnproto(t, cand)) {
+ new_id = cand_node->type_id;
+ break;
+ }
+ }
+ break;
+ }
+
+ default:
+ return -EINVAL;
+ }
+
+ d->map[type_id] = new_id;
+ if (type_id == new_id && btf_dedup_table_add(d, h, type_id))
+ return -ENOMEM;
+
+ return new_id;
+}
+
+static int btf_dedup_ref_types(struct btf_dedup *d)
+{
+ int i, err;
+
+ for (i = 1; i <= d->btf->nr_types; i++) {
+ err = btf_dedup_ref_type(d, i);
+ if (err < 0)
+ return err;
+ }
+ btf_dedup_table_free(d);
+ return 0;
+}
+
+/*
+ * Compact types.
+ *
+ * After we established for each type its corresponding canonical representative
+ * type, we now can eliminate types that are not canonical and leave only
+ * canonical ones layed out sequentially in memory by copying them over
+ * duplicates. During compaction btf_dedup->hypot_map array is reused to store
+ * a map from original type ID to a new compacted type ID, which will be used
+ * during next phase to "fix up" type IDs, referenced from struct/union and
+ * reference types.
+ */
+static int btf_dedup_compact_types(struct btf_dedup *d)
+{
+ struct btf_type **new_types;
+ __u32 next_type_id = 1;
+ char *types_start, *p;
+ int i, len;
+
+ /* we are going to reuse hypot_map to store compaction remapping */
+ d->hypot_map[0] = 0;
+ for (i = 1; i <= d->btf->nr_types; i++)
+ d->hypot_map[i] = BTF_UNPROCESSED_ID;
+
+ types_start = d->btf->nohdr_data + d->btf->hdr->type_off;
+ p = types_start;
+
+ for (i = 1; i <= d->btf->nr_types; i++) {
+ if (d->map[i] != i)
+ continue;
+
+ len = btf_type_size(d->btf->types[i]);
+ if (len < 0)
+ return len;
+
+ memmove(p, d->btf->types[i], len);
+ d->hypot_map[i] = next_type_id;
+ d->btf->types[next_type_id] = (struct btf_type *)p;
+ p += len;
+ next_type_id++;
+ }
+
+ /* shrink struct btf's internal types index and update btf_header */
+ d->btf->nr_types = next_type_id - 1;
+ d->btf->types_size = d->btf->nr_types;
+ d->btf->hdr->type_len = p - types_start;
+ new_types = realloc(d->btf->types,
+ (1 + d->btf->nr_types) * sizeof(struct btf_type *));
+ if (!new_types)
+ return -ENOMEM;
+ d->btf->types = new_types;
+
+ /* make sure string section follows type information without gaps */
+ d->btf->hdr->str_off = p - (char *)d->btf->nohdr_data;
+ memmove(p, d->btf->strings, d->btf->hdr->str_len);
+ d->btf->strings = p;
+ p += d->btf->hdr->str_len;
+
+ d->btf->data_size = p - (char *)d->btf->data;
+ return 0;
+}
+
+/*
+ * Figure out final (deduplicated and compacted) type ID for provided original
+ * `type_id` by first resolving it into corresponding canonical type ID and
+ * then mapping it to a deduplicated type ID, stored in btf_dedup->hypot_map,
+ * which is populated during compaction phase.
+ */
+static int btf_dedup_remap_type_id(struct btf_dedup *d, __u32 type_id)
+{
+ __u32 resolved_type_id, new_type_id;
+
+ resolved_type_id = resolve_type_id(d, type_id);
+ new_type_id = d->hypot_map[resolved_type_id];
+ if (new_type_id > BTF_MAX_NR_TYPES)
+ return -EINVAL;
+ return new_type_id;
+}
+
+/*
+ * Remap referenced type IDs into deduped type IDs.
+ *
+ * After BTF types are deduplicated and compacted, their final type IDs may
+ * differ from original ones. The map from original to a corresponding
+ * deduped type ID is stored in btf_dedup->hypot_map and is populated during
+ * compaction phase. During remapping phase we are rewriting all type IDs
+ * referenced from any BTF type (e.g., struct fields, func proto args, etc) to
+ * their final deduped type IDs.
+ */
+static int btf_dedup_remap_type(struct btf_dedup *d, __u32 type_id)
+{
+ struct btf_type *t = d->btf->types[type_id];
+ int i, r;
+
+ switch (BTF_INFO_KIND(t->info)) {
+ case BTF_KIND_INT:
+ case BTF_KIND_ENUM:
+ break;
+
+ case BTF_KIND_FWD:
+ case BTF_KIND_CONST:
+ case BTF_KIND_VOLATILE:
+ case BTF_KIND_RESTRICT:
+ case BTF_KIND_PTR:
+ case BTF_KIND_TYPEDEF:
+ case BTF_KIND_FUNC:
+ r = btf_dedup_remap_type_id(d, t->type);
+ if (r < 0)
+ return r;
+ t->type = r;
+ break;
+
+ case BTF_KIND_ARRAY: {
+ struct btf_array *arr_info = (struct btf_array *)(t + 1);
+
+ r = btf_dedup_remap_type_id(d, arr_info->type);
+ if (r < 0)
+ return r;
+ arr_info->type = r;
+ r = btf_dedup_remap_type_id(d, arr_info->index_type);
+ if (r < 0)
+ return r;
+ arr_info->index_type = r;
+ break;
+ }
+
+ case BTF_KIND_STRUCT:
+ case BTF_KIND_UNION: {
+ struct btf_member *member = (struct btf_member *)(t + 1);
+ __u16 vlen = BTF_INFO_VLEN(t->info);
+
+ for (i = 0; i < vlen; i++) {
+ r = btf_dedup_remap_type_id(d, member->type);
+ if (r < 0)
+ return r;
+ member->type = r;
+ member++;
+ }
+ break;
+ }
+
+ case BTF_KIND_FUNC_PROTO: {
+ struct btf_param *param = (struct btf_param *)(t + 1);
+ __u16 vlen = BTF_INFO_VLEN(t->info);
+
+ r = btf_dedup_remap_type_id(d, t->type);
+ if (r < 0)
+ return r;
+ t->type = r;
+
+ for (i = 0; i < vlen; i++) {
+ r = btf_dedup_remap_type_id(d, param->type);
+ if (r < 0)
+ return r;
+ param->type = r;
+ param++;
+ }
+ break;
+ }
+
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int btf_dedup_remap_types(struct btf_dedup *d)
+{
+ int i, r;
+
+ for (i = 1; i <= d->btf->nr_types; i++) {
+ r = btf_dedup_remap_type(d, i);
+ if (r < 0)
+ return r;
+ }
+ return 0;
+}
diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h
index b77e7080f7e7..28a1e1e59861 100644
--- a/tools/lib/bpf/btf.h
+++ b/tools/lib/bpf/btf.h
@@ -6,27 +6,99 @@
#include <linux/types.h>
+#ifdef __cplusplus
+extern "C" {
+#endif
+
#ifndef LIBBPF_API
#define LIBBPF_API __attribute__((visibility("default")))
#endif
#define BTF_ELF_SEC ".BTF"
+#define BTF_EXT_ELF_SEC ".BTF.ext"
struct btf;
+struct btf_ext;
struct btf_type;
-typedef int (*btf_print_fn_t)(const char *, ...)
- __attribute__((format(printf, 1, 2)));
+/*
+ * The .BTF.ext ELF section layout defined as
+ * struct btf_ext_header
+ * func_info subsection
+ *
+ * The func_info subsection layout:
+ * record size for struct bpf_func_info in the func_info subsection
+ * struct btf_sec_func_info for section #1
+ * a list of bpf_func_info records for section #1
+ * where struct bpf_func_info mimics one in include/uapi/linux/bpf.h
+ * but may not be identical
+ * struct btf_sec_func_info for section #2
+ * a list of bpf_func_info records for section #2
+ * ......
+ *
+ * Note that the bpf_func_info record size in .BTF.ext may not
+ * be the same as the one defined in include/uapi/linux/bpf.h.
+ * The loader should ensure that record_size meets minimum
+ * requirement and pass the record as is to the kernel. The
+ * kernel will handle the func_info properly based on its contents.
+ */
+struct btf_ext_header {
+ __u16 magic;
+ __u8 version;
+ __u8 flags;
+ __u32 hdr_len;
+
+ /* All offsets are in bytes relative to the end of this header */
+ __u32 func_info_off;
+ __u32 func_info_len;
+ __u32 line_info_off;
+ __u32 line_info_len;
+};
LIBBPF_API void btf__free(struct btf *btf);
-LIBBPF_API struct btf *btf__new(__u8 *data, __u32 size, btf_print_fn_t err_log);
+LIBBPF_API struct btf *btf__new(__u8 *data, __u32 size);
+LIBBPF_API int btf__load(struct btf *btf);
LIBBPF_API __s32 btf__find_by_name(const struct btf *btf,
const char *type_name);
+LIBBPF_API __u32 btf__get_nr_types(const struct btf *btf);
LIBBPF_API const struct btf_type *btf__type_by_id(const struct btf *btf,
__u32 id);
LIBBPF_API __s64 btf__resolve_size(const struct btf *btf, __u32 type_id);
LIBBPF_API int btf__resolve_type(const struct btf *btf, __u32 type_id);
LIBBPF_API int btf__fd(const struct btf *btf);
+LIBBPF_API const void *btf__get_raw_data(const struct btf *btf, __u32 *size);
LIBBPF_API const char *btf__name_by_offset(const struct btf *btf, __u32 offset);
+LIBBPF_API int btf__get_from_id(__u32 id, struct btf **btf);
+LIBBPF_API int btf__get_map_kv_tids(const struct btf *btf, const char *map_name,
+ __u32 expected_key_size,
+ __u32 expected_value_size,
+ __u32 *key_type_id, __u32 *value_type_id);
+
+LIBBPF_API struct btf_ext *btf_ext__new(__u8 *data, __u32 size);
+LIBBPF_API void btf_ext__free(struct btf_ext *btf_ext);
+LIBBPF_API const void *btf_ext__get_raw_data(const struct btf_ext *btf_ext,
+ __u32 *size);
+LIBBPF_API int btf_ext__reloc_func_info(const struct btf *btf,
+ const struct btf_ext *btf_ext,
+ const char *sec_name, __u32 insns_cnt,
+ void **func_info, __u32 *cnt);
+LIBBPF_API int btf_ext__reloc_line_info(const struct btf *btf,
+ const struct btf_ext *btf_ext,
+ const char *sec_name, __u32 insns_cnt,
+ void **line_info, __u32 *cnt);
+LIBBPF_API __u32 btf_ext__func_info_rec_size(const struct btf_ext *btf_ext);
+LIBBPF_API __u32 btf_ext__line_info_rec_size(const struct btf_ext *btf_ext);
+
+struct btf_dedup_opts {
+ unsigned int dedup_table_size;
+ bool dont_resolve_fwds;
+};
+
+LIBBPF_API int btf__dedup(struct btf *btf, struct btf_ext *btf_ext,
+ const struct btf_dedup_opts *opts);
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
#endif /* __LIBBPF_BTF_H */
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index b607be7236d3..f5eb60379c8d 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -9,7 +9,9 @@
* Copyright (C) 2017 Nicira, Inc.
*/
+#ifndef _GNU_SOURCE
#define _GNU_SOURCE
+#endif
#include <stdlib.h>
#include <stdio.h>
#include <stdarg.h>
@@ -24,6 +26,7 @@
#include <linux/kernel.h>
#include <linux/bpf.h>
#include <linux/btf.h>
+#include <linux/filter.h>
#include <linux/list.h>
#include <linux/limits.h>
#include <linux/perf_event.h>
@@ -39,6 +42,7 @@
#include "bpf.h"
#include "btf.h"
#include "str_error.h"
+#include "libbpf_util.h"
#ifndef EM_BPF
#define EM_BPF 247
@@ -50,39 +54,33 @@
#define __printf(a, b) __attribute__((format(printf, a, b)))
-__printf(1, 2)
-static int __base_pr(const char *format, ...)
+static int __base_pr(enum libbpf_print_level level, const char *format,
+ va_list args)
{
- va_list args;
- int err;
+ if (level == LIBBPF_DEBUG)
+ return 0;
- va_start(args, format);
- err = vfprintf(stderr, format, args);
- va_end(args);
- return err;
+ return vfprintf(stderr, format, args);
}
-static __printf(1, 2) libbpf_print_fn_t __pr_warning = __base_pr;
-static __printf(1, 2) libbpf_print_fn_t __pr_info = __base_pr;
-static __printf(1, 2) libbpf_print_fn_t __pr_debug;
+static libbpf_print_fn_t __libbpf_pr = __base_pr;
-#define __pr(func, fmt, ...) \
-do { \
- if ((func)) \
- (func)("libbpf: " fmt, ##__VA_ARGS__); \
-} while (0)
-
-#define pr_warning(fmt, ...) __pr(__pr_warning, fmt, ##__VA_ARGS__)
-#define pr_info(fmt, ...) __pr(__pr_info, fmt, ##__VA_ARGS__)
-#define pr_debug(fmt, ...) __pr(__pr_debug, fmt, ##__VA_ARGS__)
+void libbpf_set_print(libbpf_print_fn_t fn)
+{
+ __libbpf_pr = fn;
+}
-void libbpf_set_print(libbpf_print_fn_t warn,
- libbpf_print_fn_t info,
- libbpf_print_fn_t debug)
+__printf(2, 3)
+void libbpf_print(enum libbpf_print_level level, const char *format, ...)
{
- __pr_warning = warn;
- __pr_info = info;
- __pr_debug = debug;
+ va_list args;
+
+ if (!__libbpf_pr)
+ return;
+
+ va_start(args, format);
+ __libbpf_pr(level, format, args);
+ va_end(args);
}
#define STRERR_BUFSIZE 128
@@ -114,6 +112,11 @@ void libbpf_set_print(libbpf_print_fn_t warn,
# define LIBBPF_ELF_C_READ_MMAP ELF_C_READ
#endif
+struct bpf_capabilities {
+ /* v4.14: kernel support for program & map names. */
+ __u32 name:1;
+};
+
/*
* bpf_prog should be a better name but it has been used in
* linux/filter.h.
@@ -124,6 +127,10 @@ struct bpf_program {
char *name;
int prog_ifindex;
char *section_name;
+ /* section_name with / replaced by _; makes recursive pinning
+ * in bpf_object__pin_programs easier
+ */
+ char *pin_name;
struct bpf_insn *insns;
size_t insns_cnt, main_prog_cnt;
enum bpf_prog_type type;
@@ -152,6 +159,16 @@ struct bpf_program {
bpf_program_clear_priv_t clear_priv;
enum bpf_attach_type expected_attach_type;
+ int btf_fd;
+ void *func_info;
+ __u32 func_info_rec_size;
+ __u32 func_info_cnt;
+
+ struct bpf_capabilities *caps;
+
+ void *line_info;
+ __u32 line_info_rec_size;
+ __u32 line_info_cnt;
};
struct bpf_map {
@@ -159,6 +176,7 @@ struct bpf_map {
char *name;
size_t offset;
int map_ifindex;
+ int inner_map_fd;
struct bpf_map_def def;
__u32 btf_key_type_id;
__u32 btf_value_type_id;
@@ -208,10 +226,13 @@ struct bpf_object {
struct list_head list;
struct btf *btf;
+ struct btf_ext *btf_ext;
void *priv;
bpf_object_clear_priv_t clear_priv;
+ struct bpf_capabilities caps;
+
char path[];
};
#define obj_elf_valid(o) ((o)->efile.elf)
@@ -237,6 +258,10 @@ void bpf_program__unload(struct bpf_program *prog)
prog->instances.nr = -1;
zfree(&prog->instances.fds);
+
+ zclose(prog->btf_fd);
+ zfree(&prog->func_info);
+ zfree(&prog->line_info);
}
static void bpf_program__exit(struct bpf_program *prog)
@@ -253,6 +278,7 @@ static void bpf_program__exit(struct bpf_program *prog)
bpf_program__unload(prog);
zfree(&prog->name);
zfree(&prog->section_name);
+ zfree(&prog->pin_name);
zfree(&prog->insns);
zfree(&prog->reloc_desc);
@@ -261,6 +287,17 @@ static void bpf_program__exit(struct bpf_program *prog)
prog->idx = -1;
}
+static char *__bpf_program__pin_name(struct bpf_program *prog)
+{
+ char *name, *p;
+
+ name = p = strdup(prog->section_name);
+ while ((p = strchr(p, '/')))
+ *p = '_';
+
+ return name;
+}
+
static int
bpf_program__init(void *data, size_t size, char *section_name, int idx,
struct bpf_program *prog)
@@ -270,7 +307,7 @@ bpf_program__init(void *data, size_t size, char *section_name, int idx,
return -EINVAL;
}
- bzero(prog, sizeof(*prog));
+ memset(prog, 0, sizeof(*prog));
prog->section_name = strdup(section_name);
if (!prog->section_name) {
@@ -279,6 +316,13 @@ bpf_program__init(void *data, size_t size, char *section_name, int idx,
goto errout;
}
+ prog->pin_name = __bpf_program__pin_name(prog);
+ if (!prog->pin_name) {
+ pr_warning("failed to alloc pin name for prog under section(%d) %s\n",
+ idx, section_name);
+ goto errout;
+ }
+
prog->insns = malloc(size);
if (!prog->insns) {
pr_warning("failed to alloc insns for prog under section %s\n",
@@ -291,7 +335,8 @@ bpf_program__init(void *data, size_t size, char *section_name, int idx,
prog->idx = idx;
prog->instances.fds = NULL;
prog->instances.nr = -1;
- prog->type = BPF_PROG_TYPE_KPROBE;
+ prog->type = BPF_PROG_TYPE_UNSPEC;
+ prog->btf_fd = -1;
return 0;
errout:
@@ -310,6 +355,7 @@ bpf_object__add_program(struct bpf_object *obj, void *data, size_t size,
if (err)
return err;
+ prog.caps = &obj->caps;
progs = obj->programs;
nr_progs = obj->nr_programs;
@@ -562,6 +608,14 @@ static int compare_bpf_map(const void *_a, const void *_b)
return a->offset - b->offset;
}
+static bool bpf_map_type__is_map_in_map(enum bpf_map_type type)
+{
+ if (type == BPF_MAP_TYPE_ARRAY_OF_MAPS ||
+ type == BPF_MAP_TYPE_HASH_OF_MAPS)
+ return true;
+ return false;
+}
+
static int
bpf_object__init_maps(struct bpf_object *obj, int flags)
{
@@ -625,13 +679,15 @@ bpf_object__init_maps(struct bpf_object *obj, int flags)
}
obj->nr_maps = nr_maps;
- /*
- * fill all fd with -1 so won't close incorrect
- * fd (fd=0 is stdin) when failure (zclose won't close
- * negative fd)).
- */
- for (i = 0; i < nr_maps; i++)
+ for (i = 0; i < nr_maps; i++) {
+ /*
+ * fill all fd with -1 so won't close incorrect
+ * fd (fd=0 is stdin) when failure (zclose won't close
+ * negative fd)).
+ */
obj->maps[i].fd = -1;
+ obj->maps[i].inner_map_fd = -1;
+ }
/*
* Fill obj->maps using data in "maps" section.
@@ -723,6 +779,7 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags)
{
Elf *elf = obj->efile.elf;
GElf_Ehdr *ep = &obj->efile.ehdr;
+ Elf_Data *btf_ext_data = NULL;
Elf_Scn *scn = NULL;
int idx = 0, err = 0;
@@ -777,13 +834,14 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags)
else if (strcmp(name, "maps") == 0)
obj->efile.maps_shndx = idx;
else if (strcmp(name, BTF_ELF_SEC) == 0) {
- obj->btf = btf__new(data->d_buf, data->d_size,
- __pr_debug);
- if (IS_ERR(obj->btf)) {
+ obj->btf = btf__new(data->d_buf, data->d_size);
+ if (IS_ERR(obj->btf) || btf__load(obj->btf)) {
pr_warning("Error loading ELF section %s: %ld. Ignored and continue.\n",
BTF_ELF_SEC, PTR_ERR(obj->btf));
obj->btf = NULL;
}
+ } else if (strcmp(name, BTF_EXT_ELF_SEC) == 0) {
+ btf_ext_data = data;
} else if (sh.sh_type == SHT_SYMTAB) {
if (obj->efile.symbols) {
pr_warning("bpf: multiple SYMTAB in %s\n",
@@ -845,6 +903,21 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags)
pr_warning("Corrupted ELF file: index of strtab invalid\n");
return LIBBPF_ERRNO__FORMAT;
}
+ if (btf_ext_data) {
+ if (!obj->btf) {
+ pr_debug("Ignore ELF section %s because its depending ELF section %s is not found.\n",
+ BTF_EXT_ELF_SEC, BTF_ELF_SEC);
+ } else {
+ obj->btf_ext = btf_ext__new(btf_ext_data->d_buf,
+ btf_ext_data->d_size);
+ if (IS_ERR(obj->btf_ext)) {
+ pr_warning("Error loading ELF section %s: %ld. Ignored and continue.\n",
+ BTF_EXT_ELF_SEC,
+ PTR_ERR(obj->btf_ext));
+ obj->btf_ext = NULL;
+ }
+ }
+ }
if (obj->efile.maps_shndx >= 0) {
err = bpf_object__init_maps(obj, flags);
if (err)
@@ -977,72 +1050,18 @@ bpf_program__collect_reloc(struct bpf_program *prog, GElf_Shdr *shdr,
static int bpf_map_find_btf_info(struct bpf_map *map, const struct btf *btf)
{
- const struct btf_type *container_type;
- const struct btf_member *key, *value;
struct bpf_map_def *def = &map->def;
- const size_t max_name = 256;
- char container_name[max_name];
- __s64 key_size, value_size;
- __s32 container_id;
-
- if (snprintf(container_name, max_name, "____btf_map_%s", map->name) ==
- max_name) {
- pr_warning("map:%s length of '____btf_map_%s' is too long\n",
- map->name, map->name);
- return -EINVAL;
- }
-
- container_id = btf__find_by_name(btf, container_name);
- if (container_id < 0) {
- pr_debug("map:%s container_name:%s cannot be found in BTF. Missing BPF_ANNOTATE_KV_PAIR?\n",
- map->name, container_name);
- return container_id;
- }
-
- container_type = btf__type_by_id(btf, container_id);
- if (!container_type) {
- pr_warning("map:%s cannot find BTF type for container_id:%u\n",
- map->name, container_id);
- return -EINVAL;
- }
-
- if (BTF_INFO_KIND(container_type->info) != BTF_KIND_STRUCT ||
- BTF_INFO_VLEN(container_type->info) < 2) {
- pr_warning("map:%s container_name:%s is an invalid container struct\n",
- map->name, container_name);
- return -EINVAL;
- }
-
- key = (struct btf_member *)(container_type + 1);
- value = key + 1;
-
- key_size = btf__resolve_size(btf, key->type);
- if (key_size < 0) {
- pr_warning("map:%s invalid BTF key_type_size\n",
- map->name);
- return key_size;
- }
-
- if (def->key_size != key_size) {
- pr_warning("map:%s btf_key_type_size:%u != map_def_key_size:%u\n",
- map->name, (__u32)key_size, def->key_size);
- return -EINVAL;
- }
-
- value_size = btf__resolve_size(btf, value->type);
- if (value_size < 0) {
- pr_warning("map:%s invalid BTF value_type_size\n", map->name);
- return value_size;
- }
+ __u32 key_type_id, value_type_id;
+ int ret;
- if (def->value_size != value_size) {
- pr_warning("map:%s btf_value_type_size:%u != map_def_value_size:%u\n",
- map->name, (__u32)value_size, def->value_size);
- return -EINVAL;
- }
+ ret = btf__get_map_kv_tids(btf, map->name, def->key_size,
+ def->value_size, &key_type_id,
+ &value_type_id);
+ if (ret)
+ return ret;
- map->btf_key_type_id = key->type;
- map->btf_value_type_id = value->type;
+ map->btf_key_type_id = key_type_id;
+ map->btf_value_type_id = value_type_id;
return 0;
}
@@ -1094,6 +1113,66 @@ err_free_new_name:
return -errno;
}
+int bpf_map__resize(struct bpf_map *map, __u32 max_entries)
+{
+ if (!map || !max_entries)
+ return -EINVAL;
+
+ /* If map already created, its attributes can't be changed. */
+ if (map->fd >= 0)
+ return -EBUSY;
+
+ map->def.max_entries = max_entries;
+
+ return 0;
+}
+
+static int
+bpf_object__probe_name(struct bpf_object *obj)
+{
+ struct bpf_load_program_attr attr;
+ char *cp, errmsg[STRERR_BUFSIZE];
+ struct bpf_insn insns[] = {
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ };
+ int ret;
+
+ /* make sure basic loading works */
+
+ memset(&attr, 0, sizeof(attr));
+ attr.prog_type = BPF_PROG_TYPE_SOCKET_FILTER;
+ attr.insns = insns;
+ attr.insns_cnt = ARRAY_SIZE(insns);
+ attr.license = "GPL";
+
+ ret = bpf_load_program_xattr(&attr, NULL, 0);
+ if (ret < 0) {
+ cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
+ pr_warning("Error in %s():%s(%d). Couldn't load basic 'r0 = 0' BPF program.\n",
+ __func__, cp, errno);
+ return -errno;
+ }
+ close(ret);
+
+ /* now try the same program, but with the name */
+
+ attr.name = "test";
+ ret = bpf_load_program_xattr(&attr, NULL, 0);
+ if (ret >= 0) {
+ obj->caps.name = 1;
+ close(ret);
+ }
+
+ return 0;
+}
+
+static int
+bpf_object__probe_caps(struct bpf_object *obj)
+{
+ return bpf_object__probe_name(obj);
+}
+
static int
bpf_object__create_maps(struct bpf_object *obj)
{
@@ -1113,7 +1192,8 @@ bpf_object__create_maps(struct bpf_object *obj)
continue;
}
- create_attr.name = map->name;
+ if (obj->caps.name)
+ create_attr.name = map->name;
create_attr.map_ifindex = map->map_ifindex;
create_attr.map_type = def->type;
create_attr.map_flags = def->map_flags;
@@ -1123,6 +1203,9 @@ bpf_object__create_maps(struct bpf_object *obj)
create_attr.btf_fd = 0;
create_attr.btf_key_type_id = 0;
create_attr.btf_value_type_id = 0;
+ if (bpf_map_type__is_map_in_map(def->type) &&
+ map->inner_map_fd >= 0)
+ create_attr.inner_map_fd = map->inner_map_fd;
if (obj->btf && !bpf_map_find_btf_info(map, obj->btf)) {
create_attr.btf_fd = btf__fd(obj->btf);
@@ -1161,12 +1244,89 @@ bpf_object__create_maps(struct bpf_object *obj)
}
static int
+check_btf_ext_reloc_err(struct bpf_program *prog, int err,
+ void *btf_prog_info, const char *info_name)
+{
+ if (err != -ENOENT) {
+ pr_warning("Error in loading %s for sec %s.\n",
+ info_name, prog->section_name);
+ return err;
+ }
+
+ /* err == -ENOENT (i.e. prog->section_name not found in btf_ext) */
+
+ if (btf_prog_info) {
+ /*
+ * Some info has already been found but has problem
+ * in the last btf_ext reloc. Must have to error
+ * out.
+ */
+ pr_warning("Error in relocating %s for sec %s.\n",
+ info_name, prog->section_name);
+ return err;
+ }
+
+ /*
+ * Have problem loading the very first info. Ignore
+ * the rest.
+ */
+ pr_warning("Cannot find %s for main program sec %s. Ignore all %s.\n",
+ info_name, prog->section_name, info_name);
+ return 0;
+}
+
+static int
+bpf_program_reloc_btf_ext(struct bpf_program *prog, struct bpf_object *obj,
+ const char *section_name, __u32 insn_offset)
+{
+ int err;
+
+ if (!insn_offset || prog->func_info) {
+ /*
+ * !insn_offset => main program
+ *
+ * For sub prog, the main program's func_info has to
+ * be loaded first (i.e. prog->func_info != NULL)
+ */
+ err = btf_ext__reloc_func_info(obj->btf, obj->btf_ext,
+ section_name, insn_offset,
+ &prog->func_info,
+ &prog->func_info_cnt);
+ if (err)
+ return check_btf_ext_reloc_err(prog, err,
+ prog->func_info,
+ "bpf_func_info");
+
+ prog->func_info_rec_size = btf_ext__func_info_rec_size(obj->btf_ext);
+ }
+
+ if (!insn_offset || prog->line_info) {
+ err = btf_ext__reloc_line_info(obj->btf, obj->btf_ext,
+ section_name, insn_offset,
+ &prog->line_info,
+ &prog->line_info_cnt);
+ if (err)
+ return check_btf_ext_reloc_err(prog, err,
+ prog->line_info,
+ "bpf_line_info");
+
+ prog->line_info_rec_size = btf_ext__line_info_rec_size(obj->btf_ext);
+ }
+
+ if (!insn_offset)
+ prog->btf_fd = btf__fd(obj->btf);
+
+ return 0;
+}
+
+static int
bpf_program__reloc_text(struct bpf_program *prog, struct bpf_object *obj,
struct reloc_desc *relo)
{
struct bpf_insn *insn, *new_insn;
struct bpf_program *text;
size_t new_cnt;
+ int err;
if (relo->type != RELO_CALL)
return -LIBBPF_ERRNO__RELOC;
@@ -1189,6 +1349,15 @@ bpf_program__reloc_text(struct bpf_program *prog, struct bpf_object *obj,
pr_warning("oom in prog realloc\n");
return -ENOMEM;
}
+
+ if (obj->btf_ext) {
+ err = bpf_program_reloc_btf_ext(prog, obj,
+ text->section_name,
+ prog->insns_cnt);
+ if (err)
+ return err;
+ }
+
memcpy(new_insn + prog->insns_cnt, text->insns,
text->insns_cnt * sizeof(*insn));
prog->insns = new_insn;
@@ -1208,7 +1377,17 @@ bpf_program__relocate(struct bpf_program *prog, struct bpf_object *obj)
{
int i, err;
- if (!prog || !prog->reloc_desc)
+ if (!prog)
+ return 0;
+
+ if (obj->btf_ext) {
+ err = bpf_program_reloc_btf_ext(prog, obj,
+ prog->section_name, 0);
+ if (err)
+ return err;
+ }
+
+ if (!prog->reloc_desc)
return 0;
for (i = 0; i < prog->nr_reloc; i++) {
@@ -1296,9 +1475,8 @@ static int bpf_object__collect_reloc(struct bpf_object *obj)
}
static int
-load_program(enum bpf_prog_type type, enum bpf_attach_type expected_attach_type,
- const char *name, struct bpf_insn *insns, int insns_cnt,
- char *license, __u32 kern_version, int *pfd, int prog_ifindex)
+load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt,
+ char *license, __u32 kern_version, int *pfd)
{
struct bpf_load_program_attr load_attr;
char *cp, errmsg[STRERR_BUFSIZE];
@@ -1306,15 +1484,22 @@ load_program(enum bpf_prog_type type, enum bpf_attach_type expected_attach_type,
int ret;
memset(&load_attr, 0, sizeof(struct bpf_load_program_attr));
- load_attr.prog_type = type;
- load_attr.expected_attach_type = expected_attach_type;
- load_attr.name = name;
+ load_attr.prog_type = prog->type;
+ load_attr.expected_attach_type = prog->expected_attach_type;
+ if (prog->caps->name)
+ load_attr.name = prog->name;
load_attr.insns = insns;
load_attr.insns_cnt = insns_cnt;
load_attr.license = license;
load_attr.kern_version = kern_version;
- load_attr.prog_ifindex = prog_ifindex;
-
+ load_attr.prog_ifindex = prog->prog_ifindex;
+ load_attr.prog_btf_fd = prog->btf_fd >= 0 ? prog->btf_fd : 0;
+ load_attr.func_info = prog->func_info;
+ load_attr.func_info_rec_size = prog->func_info_rec_size;
+ load_attr.func_info_cnt = prog->func_info_cnt;
+ load_attr.line_info = prog->line_info;
+ load_attr.line_info_rec_size = prog->line_info_rec_size;
+ load_attr.line_info_cnt = prog->line_info_cnt;
if (!load_attr.insns || !load_attr.insns_cnt)
return -EINVAL;
@@ -1394,10 +1579,8 @@ bpf_program__load(struct bpf_program *prog,
pr_warning("Program '%s' is inconsistent: nr(%d) != 1\n",
prog->section_name, prog->instances.nr);
}
- err = load_program(prog->type, prog->expected_attach_type,
- prog->name, prog->insns, prog->insns_cnt,
- license, kern_version, &fd,
- prog->prog_ifindex);
+ err = load_program(prog, prog->insns, prog->insns_cnt,
+ license, kern_version, &fd);
if (!err)
prog->instances.fds[0] = fd;
goto out;
@@ -1407,7 +1590,7 @@ bpf_program__load(struct bpf_program *prog,
struct bpf_prog_prep_result result;
bpf_program_prep_t preprocessor = prog->preprocessor;
- bzero(&result, sizeof(result));
+ memset(&result, 0, sizeof(result));
err = preprocessor(prog, i, prog->insns,
prog->insns_cnt, &result);
if (err) {
@@ -1425,11 +1608,9 @@ bpf_program__load(struct bpf_program *prog,
continue;
}
- err = load_program(prog->type, prog->expected_attach_type,
- prog->name, result.new_insn_ptr,
+ err = load_program(prog, result.new_insn_ptr,
result.new_insn_cnt,
- license, kern_version, &fd,
- prog->prog_ifindex);
+ license, kern_version, &fd);
if (err) {
pr_warning("Loading the %dth instance of program '%s' failed\n",
@@ -1495,12 +1676,12 @@ static bool bpf_prog_type__needs_kver(enum bpf_prog_type type)
case BPF_PROG_TYPE_LIRC_MODE2:
case BPF_PROG_TYPE_SK_REUSEPORT:
case BPF_PROG_TYPE_FLOW_DISSECTOR:
- return false;
case BPF_PROG_TYPE_UNSPEC:
- case BPF_PROG_TYPE_KPROBE:
case BPF_PROG_TYPE_TRACEPOINT:
- case BPF_PROG_TYPE_PERF_EVENT:
case BPF_PROG_TYPE_RAW_TRACEPOINT:
+ case BPF_PROG_TYPE_PERF_EVENT:
+ return false;
+ case BPF_PROG_TYPE_KPROBE:
default:
return true;
}
@@ -1627,6 +1808,7 @@ int bpf_object__load(struct bpf_object *obj)
obj->loaded = true;
+ CHECK_ERR(bpf_object__probe_caps(obj), err, out);
CHECK_ERR(bpf_object__create_maps(obj), err, out);
CHECK_ERR(bpf_object__relocate(obj), err, out);
CHECK_ERR(bpf_object__load_progs(obj), err, out);
@@ -1699,6 +1881,34 @@ int bpf_program__pin_instance(struct bpf_program *prog, const char *path,
return 0;
}
+int bpf_program__unpin_instance(struct bpf_program *prog, const char *path,
+ int instance)
+{
+ int err;
+
+ err = check_path(path);
+ if (err)
+ return err;
+
+ if (prog == NULL) {
+ pr_warning("invalid program pointer\n");
+ return -EINVAL;
+ }
+
+ if (instance < 0 || instance >= prog->instances.nr) {
+ pr_warning("invalid prog instance %d of prog %s (max %d)\n",
+ instance, prog->section_name, prog->instances.nr);
+ return -EINVAL;
+ }
+
+ err = unlink(path);
+ if (err != 0)
+ return -errno;
+ pr_debug("unpinned program '%s'\n", path);
+
+ return 0;
+}
+
static int make_dir(const char *path)
{
char *cp, errmsg[STRERR_BUFSIZE];
@@ -1733,6 +1943,11 @@ int bpf_program__pin(struct bpf_program *prog, const char *path)
return -EINVAL;
}
+ if (prog->instances.nr == 1) {
+ /* don't create subdirs when pinning single instance */
+ return bpf_program__pin_instance(prog, path, 0);
+ }
+
err = make_dir(path);
if (err)
return err;
@@ -1742,16 +1957,83 @@ int bpf_program__pin(struct bpf_program *prog, const char *path)
int len;
len = snprintf(buf, PATH_MAX, "%s/%d", path, i);
+ if (len < 0) {
+ err = -EINVAL;
+ goto err_unpin;
+ } else if (len >= PATH_MAX) {
+ err = -ENAMETOOLONG;
+ goto err_unpin;
+ }
+
+ err = bpf_program__pin_instance(prog, buf, i);
+ if (err)
+ goto err_unpin;
+ }
+
+ return 0;
+
+err_unpin:
+ for (i = i - 1; i >= 0; i--) {
+ char buf[PATH_MAX];
+ int len;
+
+ len = snprintf(buf, PATH_MAX, "%s/%d", path, i);
+ if (len < 0)
+ continue;
+ else if (len >= PATH_MAX)
+ continue;
+
+ bpf_program__unpin_instance(prog, buf, i);
+ }
+
+ rmdir(path);
+
+ return err;
+}
+
+int bpf_program__unpin(struct bpf_program *prog, const char *path)
+{
+ int i, err;
+
+ err = check_path(path);
+ if (err)
+ return err;
+
+ if (prog == NULL) {
+ pr_warning("invalid program pointer\n");
+ return -EINVAL;
+ }
+
+ if (prog->instances.nr <= 0) {
+ pr_warning("no instances of prog %s to pin\n",
+ prog->section_name);
+ return -EINVAL;
+ }
+
+ if (prog->instances.nr == 1) {
+ /* don't create subdirs when pinning single instance */
+ return bpf_program__unpin_instance(prog, path, 0);
+ }
+
+ for (i = 0; i < prog->instances.nr; i++) {
+ char buf[PATH_MAX];
+ int len;
+
+ len = snprintf(buf, PATH_MAX, "%s/%d", path, i);
if (len < 0)
return -EINVAL;
else if (len >= PATH_MAX)
return -ENAMETOOLONG;
- err = bpf_program__pin_instance(prog, buf, i);
+ err = bpf_program__unpin_instance(prog, buf, i);
if (err)
return err;
}
+ err = rmdir(path);
+ if (err)
+ return -errno;
+
return 0;
}
@@ -1776,12 +2058,33 @@ int bpf_map__pin(struct bpf_map *map, const char *path)
}
pr_debug("pinned map '%s'\n", path);
+
return 0;
}
-int bpf_object__pin(struct bpf_object *obj, const char *path)
+int bpf_map__unpin(struct bpf_map *map, const char *path)
+{
+ int err;
+
+ err = check_path(path);
+ if (err)
+ return err;
+
+ if (map == NULL) {
+ pr_warning("invalid map pointer\n");
+ return -EINVAL;
+ }
+
+ err = unlink(path);
+ if (err != 0)
+ return -errno;
+ pr_debug("unpinned map '%s'\n", path);
+
+ return 0;
+}
+
+int bpf_object__pin_maps(struct bpf_object *obj, const char *path)
{
- struct bpf_program *prog;
struct bpf_map *map;
int err;
@@ -1797,7 +2100,54 @@ int bpf_object__pin(struct bpf_object *obj, const char *path)
if (err)
return err;
- bpf_map__for_each(map, obj) {
+ bpf_object__for_each_map(map, obj) {
+ char buf[PATH_MAX];
+ int len;
+
+ len = snprintf(buf, PATH_MAX, "%s/%s", path,
+ bpf_map__name(map));
+ if (len < 0) {
+ err = -EINVAL;
+ goto err_unpin_maps;
+ } else if (len >= PATH_MAX) {
+ err = -ENAMETOOLONG;
+ goto err_unpin_maps;
+ }
+
+ err = bpf_map__pin(map, buf);
+ if (err)
+ goto err_unpin_maps;
+ }
+
+ return 0;
+
+err_unpin_maps:
+ while ((map = bpf_map__prev(map, obj))) {
+ char buf[PATH_MAX];
+ int len;
+
+ len = snprintf(buf, PATH_MAX, "%s/%s", path,
+ bpf_map__name(map));
+ if (len < 0)
+ continue;
+ else if (len >= PATH_MAX)
+ continue;
+
+ bpf_map__unpin(map, buf);
+ }
+
+ return err;
+}
+
+int bpf_object__unpin_maps(struct bpf_object *obj, const char *path)
+{
+ struct bpf_map *map;
+ int err;
+
+ if (!obj)
+ return -ENOENT;
+
+ bpf_object__for_each_map(map, obj) {
char buf[PATH_MAX];
int len;
@@ -1808,23 +2158,90 @@ int bpf_object__pin(struct bpf_object *obj, const char *path)
else if (len >= PATH_MAX)
return -ENAMETOOLONG;
- err = bpf_map__pin(map, buf);
+ err = bpf_map__unpin(map, buf);
if (err)
return err;
}
+ return 0;
+}
+
+int bpf_object__pin_programs(struct bpf_object *obj, const char *path)
+{
+ struct bpf_program *prog;
+ int err;
+
+ if (!obj)
+ return -ENOENT;
+
+ if (!obj->loaded) {
+ pr_warning("object not yet loaded; load it first\n");
+ return -ENOENT;
+ }
+
+ err = make_dir(path);
+ if (err)
+ return err;
+
bpf_object__for_each_program(prog, obj) {
char buf[PATH_MAX];
int len;
len = snprintf(buf, PATH_MAX, "%s/%s", path,
- prog->section_name);
+ prog->pin_name);
+ if (len < 0) {
+ err = -EINVAL;
+ goto err_unpin_programs;
+ } else if (len >= PATH_MAX) {
+ err = -ENAMETOOLONG;
+ goto err_unpin_programs;
+ }
+
+ err = bpf_program__pin(prog, buf);
+ if (err)
+ goto err_unpin_programs;
+ }
+
+ return 0;
+
+err_unpin_programs:
+ while ((prog = bpf_program__prev(prog, obj))) {
+ char buf[PATH_MAX];
+ int len;
+
+ len = snprintf(buf, PATH_MAX, "%s/%s", path,
+ prog->pin_name);
+ if (len < 0)
+ continue;
+ else if (len >= PATH_MAX)
+ continue;
+
+ bpf_program__unpin(prog, buf);
+ }
+
+ return err;
+}
+
+int bpf_object__unpin_programs(struct bpf_object *obj, const char *path)
+{
+ struct bpf_program *prog;
+ int err;
+
+ if (!obj)
+ return -ENOENT;
+
+ bpf_object__for_each_program(prog, obj) {
+ char buf[PATH_MAX];
+ int len;
+
+ len = snprintf(buf, PATH_MAX, "%s/%s", path,
+ prog->pin_name);
if (len < 0)
return -EINVAL;
else if (len >= PATH_MAX)
return -ENAMETOOLONG;
- err = bpf_program__pin(prog, buf);
+ err = bpf_program__unpin(prog, buf);
if (err)
return err;
}
@@ -1832,6 +2249,23 @@ int bpf_object__pin(struct bpf_object *obj, const char *path)
return 0;
}
+int bpf_object__pin(struct bpf_object *obj, const char *path)
+{
+ int err;
+
+ err = bpf_object__pin_maps(obj, path);
+ if (err)
+ return err;
+
+ err = bpf_object__pin_programs(obj, path);
+ if (err) {
+ bpf_object__unpin_maps(obj, path);
+ return err;
+ }
+
+ return 0;
+}
+
void bpf_object__close(struct bpf_object *obj)
{
size_t i;
@@ -1845,6 +2279,7 @@ void bpf_object__close(struct bpf_object *obj)
bpf_object__elf_finish(obj);
bpf_object__unload(obj);
btf__free(obj->btf);
+ btf_ext__free(obj->btf_ext);
for (i = 0; i < obj->nr_maps; i++) {
zfree(&obj->maps[i].name);
@@ -1896,6 +2331,11 @@ unsigned int bpf_object__kversion(struct bpf_object *obj)
return obj ? obj->kern_version : 0;
}
+struct btf *bpf_object__btf(struct bpf_object *obj)
+{
+ return obj ? obj->btf : NULL;
+}
+
int bpf_object__btf_fd(const struct bpf_object *obj)
{
return obj->btf ? btf__fd(obj->btf) : -1;
@@ -1918,23 +2358,26 @@ void *bpf_object__priv(struct bpf_object *obj)
}
static struct bpf_program *
-__bpf_program__next(struct bpf_program *prev, struct bpf_object *obj)
+__bpf_program__iter(struct bpf_program *p, struct bpf_object *obj, bool forward)
{
- size_t idx;
+ size_t nr_programs = obj->nr_programs;
+ ssize_t idx;
- if (!obj->programs)
+ if (!nr_programs)
return NULL;
- /* First handler */
- if (prev == NULL)
- return &obj->programs[0];
- if (prev->obj != obj) {
+ if (!p)
+ /* Iter from the beginning */
+ return forward ? &obj->programs[0] :
+ &obj->programs[nr_programs - 1];
+
+ if (p->obj != obj) {
pr_warning("error: program handler doesn't match object\n");
return NULL;
}
- idx = (prev - obj->programs) + 1;
- if (idx >= obj->nr_programs)
+ idx = (p - obj->programs) + (forward ? 1 : -1);
+ if (idx >= obj->nr_programs || idx < 0)
return NULL;
return &obj->programs[idx];
}
@@ -1945,7 +2388,19 @@ bpf_program__next(struct bpf_program *prev, struct bpf_object *obj)
struct bpf_program *prog = prev;
do {
- prog = __bpf_program__next(prog, obj);
+ prog = __bpf_program__iter(prog, obj, true);
+ } while (prog && bpf_program__is_function_storage(prog, obj));
+
+ return prog;
+}
+
+struct bpf_program *
+bpf_program__prev(struct bpf_program *next, struct bpf_object *obj)
+{
+ struct bpf_program *prog = next;
+
+ do {
+ prog = __bpf_program__iter(prog, obj, false);
} while (prog && bpf_program__is_function_storage(prog, obj));
return prog;
@@ -2084,19 +2539,19 @@ void bpf_program__set_expected_attach_type(struct bpf_program *prog,
prog->expected_attach_type = type;
}
-#define BPF_PROG_SEC_IMPL(string, ptype, eatype, atype) \
- { string, sizeof(string) - 1, ptype, eatype, atype }
+#define BPF_PROG_SEC_IMPL(string, ptype, eatype, is_attachable, atype) \
+ { string, sizeof(string) - 1, ptype, eatype, is_attachable, atype }
/* Programs that can NOT be attached. */
-#define BPF_PROG_SEC(string, ptype) BPF_PROG_SEC_IMPL(string, ptype, 0, -EINVAL)
+#define BPF_PROG_SEC(string, ptype) BPF_PROG_SEC_IMPL(string, ptype, 0, 0, 0)
/* Programs that can be attached. */
#define BPF_APROG_SEC(string, ptype, atype) \
- BPF_PROG_SEC_IMPL(string, ptype, 0, atype)
+ BPF_PROG_SEC_IMPL(string, ptype, 0, 1, atype)
/* Programs that must specify expected attach type at load time. */
#define BPF_EAPROG_SEC(string, ptype, eatype) \
- BPF_PROG_SEC_IMPL(string, ptype, eatype, eatype)
+ BPF_PROG_SEC_IMPL(string, ptype, eatype, 1, eatype)
/* Programs that can be attached but attach type can't be identified by section
* name. Kept for backward compatibility.
@@ -2108,6 +2563,7 @@ static const struct {
size_t len;
enum bpf_prog_type prog_type;
enum bpf_attach_type expected_attach_type;
+ int is_attachable;
enum bpf_attach_type attach_type;
} section_names[] = {
BPF_PROG_SEC("socket", BPF_PROG_TYPE_SOCKET_FILTER),
@@ -2169,9 +2625,38 @@ static const struct {
#undef BPF_EAPROG_SEC
#undef BPF_APROG_COMPAT
+#define MAX_TYPE_NAME_SIZE 32
+
+static char *libbpf_get_type_names(bool attach_type)
+{
+ int i, len = ARRAY_SIZE(section_names) * MAX_TYPE_NAME_SIZE;
+ char *buf;
+
+ buf = malloc(len);
+ if (!buf)
+ return NULL;
+
+ buf[0] = '\0';
+ /* Forge string buf with all available names */
+ for (i = 0; i < ARRAY_SIZE(section_names); i++) {
+ if (attach_type && !section_names[i].is_attachable)
+ continue;
+
+ if (strlen(buf) + strlen(section_names[i].sec) + 2 > len) {
+ free(buf);
+ return NULL;
+ }
+ strcat(buf, " ");
+ strcat(buf, section_names[i].sec);
+ }
+
+ return buf;
+}
+
int libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type,
enum bpf_attach_type *expected_attach_type)
{
+ char *type_names;
int i;
if (!name)
@@ -2184,12 +2669,20 @@ int libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type,
*expected_attach_type = section_names[i].expected_attach_type;
return 0;
}
+ pr_warning("failed to guess program type based on ELF section name '%s'\n", name);
+ type_names = libbpf_get_type_names(false);
+ if (type_names != NULL) {
+ pr_info("supported section(type) names are:%s\n", type_names);
+ free(type_names);
+ }
+
return -EINVAL;
}
int libbpf_attach_type_by_name(const char *name,
enum bpf_attach_type *attach_type)
{
+ char *type_names;
int i;
if (!name)
@@ -2198,11 +2691,18 @@ int libbpf_attach_type_by_name(const char *name,
for (i = 0; i < ARRAY_SIZE(section_names); i++) {
if (strncmp(name, section_names[i].sec, section_names[i].len))
continue;
- if (section_names[i].attach_type == -EINVAL)
+ if (!section_names[i].is_attachable)
return -EINVAL;
*attach_type = section_names[i].attach_type;
return 0;
}
+ pr_warning("failed to guess attach type based on ELF section name '%s'\n", name);
+ type_names = libbpf_get_type_names(true);
+ if (type_names != NULL) {
+ pr_info("attachable section(type) names are:%s\n", type_names);
+ free(type_names);
+ }
+
return -EINVAL;
}
@@ -2271,10 +2771,24 @@ void bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex)
map->map_ifindex = ifindex;
}
-struct bpf_map *
-bpf_map__next(struct bpf_map *prev, struct bpf_object *obj)
+int bpf_map__set_inner_map_fd(struct bpf_map *map, int fd)
{
- size_t idx;
+ if (!bpf_map_type__is_map_in_map(map->def.type)) {
+ pr_warning("error: unsupported map type\n");
+ return -EINVAL;
+ }
+ if (map->inner_map_fd != -1) {
+ pr_warning("error: inner_map_fd already specified\n");
+ return -EINVAL;
+ }
+ map->inner_map_fd = fd;
+ return 0;
+}
+
+static struct bpf_map *
+__bpf_map__iter(struct bpf_map *m, struct bpf_object *obj, int i)
+{
+ ssize_t idx;
struct bpf_map *s, *e;
if (!obj || !obj->maps)
@@ -2283,33 +2797,57 @@ bpf_map__next(struct bpf_map *prev, struct bpf_object *obj)
s = obj->maps;
e = obj->maps + obj->nr_maps;
- if (prev == NULL)
- return s;
-
- if ((prev < s) || (prev >= e)) {
+ if ((m < s) || (m >= e)) {
pr_warning("error in %s: map handler doesn't belong to object\n",
__func__);
return NULL;
}
- idx = (prev - obj->maps) + 1;
- if (idx >= obj->nr_maps)
+ idx = (m - obj->maps) + i;
+ if (idx >= obj->nr_maps || idx < 0)
return NULL;
return &obj->maps[idx];
}
struct bpf_map *
+bpf_map__next(struct bpf_map *prev, struct bpf_object *obj)
+{
+ if (prev == NULL)
+ return obj->maps;
+
+ return __bpf_map__iter(prev, obj, 1);
+}
+
+struct bpf_map *
+bpf_map__prev(struct bpf_map *next, struct bpf_object *obj)
+{
+ if (next == NULL) {
+ if (!obj->nr_maps)
+ return NULL;
+ return obj->maps + obj->nr_maps - 1;
+ }
+
+ return __bpf_map__iter(next, obj, -1);
+}
+
+struct bpf_map *
bpf_object__find_map_by_name(struct bpf_object *obj, const char *name)
{
struct bpf_map *pos;
- bpf_map__for_each(pos, obj) {
+ bpf_object__for_each_map(pos, obj) {
if (pos->name && !strcmp(pos->name, name))
return pos;
}
return NULL;
}
+int
+bpf_object__find_map_fd_by_name(struct bpf_object *obj, const char *name)
+{
+ return bpf_map__fd(bpf_object__find_map_by_name(obj, name));
+}
+
struct bpf_map *
bpf_object__find_map_by_offset(struct bpf_object *obj, size_t offset)
{
@@ -2377,8 +2915,6 @@ int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr,
err = bpf_program__identify_section(prog, &prog_type,
&expected_attach_type);
if (err < 0) {
- pr_warning("failed to guess program type based on section name %s\n",
- prog->section_name);
bpf_object__close(obj);
return -EINVAL;
}
@@ -2392,7 +2928,7 @@ int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr,
first_prog = prog;
}
- bpf_map__for_each(map, obj) {
+ bpf_object__for_each_map(map, obj) {
if (!bpf_map__is_offload_neutral(map))
map->map_ifindex = attr->ifindex;
}
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index 1f3468dad8b2..b4652aa1a58a 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -16,6 +16,10 @@
#include <sys/types.h> // for size_t
#include <linux/bpf.h>
+#ifdef __cplusplus
+extern "C" {
+#endif
+
#ifndef LIBBPF_API
#define LIBBPF_API __attribute__((visibility("default")))
#endif
@@ -43,17 +47,16 @@ enum libbpf_errno {
LIBBPF_API int libbpf_strerror(int err, char *buf, size_t size);
-/*
- * __printf is defined in include/linux/compiler-gcc.h. However,
- * it would be better if libbpf.h didn't depend on Linux header files.
- * So instead of __printf, here we use gcc attribute directly.
- */
-typedef int (*libbpf_print_fn_t)(const char *, ...)
- __attribute__((format(printf, 1, 2)));
+enum libbpf_print_level {
+ LIBBPF_WARN,
+ LIBBPF_INFO,
+ LIBBPF_DEBUG,
+};
+
+typedef int (*libbpf_print_fn_t)(enum libbpf_print_level level,
+ const char *, va_list ap);
-LIBBPF_API void libbpf_set_print(libbpf_print_fn_t warn,
- libbpf_print_fn_t info,
- libbpf_print_fn_t debug);
+LIBBPF_API void libbpf_set_print(libbpf_print_fn_t fn);
/* Hide internal to user */
struct bpf_object;
@@ -71,6 +74,13 @@ struct bpf_object *__bpf_object__open_xattr(struct bpf_object_open_attr *attr,
LIBBPF_API struct bpf_object *bpf_object__open_buffer(void *obj_buf,
size_t obj_buf_sz,
const char *name);
+LIBBPF_API int bpf_object__pin_maps(struct bpf_object *obj, const char *path);
+LIBBPF_API int bpf_object__unpin_maps(struct bpf_object *obj,
+ const char *path);
+LIBBPF_API int bpf_object__pin_programs(struct bpf_object *obj,
+ const char *path);
+LIBBPF_API int bpf_object__unpin_programs(struct bpf_object *obj,
+ const char *path);
LIBBPF_API int bpf_object__pin(struct bpf_object *object, const char *path);
LIBBPF_API void bpf_object__close(struct bpf_object *object);
@@ -79,6 +89,9 @@ LIBBPF_API int bpf_object__load(struct bpf_object *obj);
LIBBPF_API int bpf_object__unload(struct bpf_object *obj);
LIBBPF_API const char *bpf_object__name(struct bpf_object *obj);
LIBBPF_API unsigned int bpf_object__kversion(struct bpf_object *obj);
+
+struct btf;
+LIBBPF_API struct btf *bpf_object__btf(struct bpf_object *obj);
LIBBPF_API int bpf_object__btf_fd(const struct bpf_object *obj);
LIBBPF_API struct bpf_program *
@@ -112,6 +125,9 @@ LIBBPF_API struct bpf_program *bpf_program__next(struct bpf_program *prog,
(pos) != NULL; \
(pos) = bpf_program__next((pos), (obj)))
+LIBBPF_API struct bpf_program *bpf_program__prev(struct bpf_program *prog,
+ struct bpf_object *obj);
+
typedef void (*bpf_program_clear_priv_t)(struct bpf_program *,
void *);
@@ -131,7 +147,11 @@ LIBBPF_API int bpf_program__fd(struct bpf_program *prog);
LIBBPF_API int bpf_program__pin_instance(struct bpf_program *prog,
const char *path,
int instance);
+LIBBPF_API int bpf_program__unpin_instance(struct bpf_program *prog,
+ const char *path,
+ int instance);
LIBBPF_API int bpf_program__pin(struct bpf_program *prog, const char *path);
+LIBBPF_API int bpf_program__unpin(struct bpf_program *prog, const char *path);
LIBBPF_API void bpf_program__unload(struct bpf_program *prog);
struct bpf_insn;
@@ -246,6 +266,9 @@ struct bpf_map;
LIBBPF_API struct bpf_map *
bpf_object__find_map_by_name(struct bpf_object *obj, const char *name);
+LIBBPF_API int
+bpf_object__find_map_fd_by_name(struct bpf_object *obj, const char *name);
+
/*
* Get bpf_map through the offset of corresponding struct bpf_map_def
* in the BPF object file.
@@ -255,10 +278,14 @@ bpf_object__find_map_by_offset(struct bpf_object *obj, size_t offset);
LIBBPF_API struct bpf_map *
bpf_map__next(struct bpf_map *map, struct bpf_object *obj);
-#define bpf_map__for_each(pos, obj) \
+#define bpf_object__for_each_map(pos, obj) \
for ((pos) = bpf_map__next(NULL, (obj)); \
(pos) != NULL; \
(pos) = bpf_map__next((pos), (obj)))
+#define bpf_map__for_each bpf_object__for_each_map
+
+LIBBPF_API struct bpf_map *
+bpf_map__prev(struct bpf_map *map, struct bpf_object *obj);
LIBBPF_API int bpf_map__fd(struct bpf_map *map);
LIBBPF_API const struct bpf_map_def *bpf_map__def(struct bpf_map *map);
@@ -271,9 +298,13 @@ LIBBPF_API int bpf_map__set_priv(struct bpf_map *map, void *priv,
bpf_map_clear_priv_t clear_priv);
LIBBPF_API void *bpf_map__priv(struct bpf_map *map);
LIBBPF_API int bpf_map__reuse_fd(struct bpf_map *map, int fd);
+LIBBPF_API int bpf_map__resize(struct bpf_map *map, __u32 max_entries);
LIBBPF_API bool bpf_map__is_offload_neutral(struct bpf_map *map);
LIBBPF_API void bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex);
LIBBPF_API int bpf_map__pin(struct bpf_map *map, const char *path);
+LIBBPF_API int bpf_map__unpin(struct bpf_map *map, const char *path);
+
+LIBBPF_API int bpf_map__set_inner_map_fd(struct bpf_map *map, int fd);
LIBBPF_API long libbpf_get_error(const void *ptr);
@@ -290,6 +321,7 @@ LIBBPF_API int bpf_prog_load(const char *file, enum bpf_prog_type type,
struct bpf_object **pobj, int *prog_fd);
LIBBPF_API int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags);
+LIBBPF_API int bpf_get_link_xdp_id(int ifindex, __u32 *prog_id, __u32 flags);
enum bpf_perf_event_ret {
LIBBPF_PERF_EVENT_DONE = 0,
@@ -317,4 +349,36 @@ int libbpf_nl_get_qdisc(int sock, unsigned int nl_pid, int ifindex,
libbpf_dump_nlmsg_t dump_qdisc_nlmsg, void *cookie);
int libbpf_nl_get_filter(int sock, unsigned int nl_pid, int ifindex, int handle,
libbpf_dump_nlmsg_t dump_filter_nlmsg, void *cookie);
+
+struct bpf_prog_linfo;
+struct bpf_prog_info;
+
+LIBBPF_API void bpf_prog_linfo__free(struct bpf_prog_linfo *prog_linfo);
+LIBBPF_API struct bpf_prog_linfo *
+bpf_prog_linfo__new(const struct bpf_prog_info *info);
+LIBBPF_API const struct bpf_line_info *
+bpf_prog_linfo__lfind_addr_func(const struct bpf_prog_linfo *prog_linfo,
+ __u64 addr, __u32 func_idx, __u32 nr_skip);
+LIBBPF_API const struct bpf_line_info *
+bpf_prog_linfo__lfind(const struct bpf_prog_linfo *prog_linfo,
+ __u32 insn_off, __u32 nr_skip);
+
+/*
+ * Probe for supported system features
+ *
+ * Note that running many of these probes in a short amount of time can cause
+ * the kernel to reach the maximal size of lockable memory allowed for the
+ * user, causing subsequent probes to fail. In this case, the caller may want
+ * to adjust that limit with setrlimit().
+ */
+LIBBPF_API bool bpf_probe_prog_type(enum bpf_prog_type prog_type,
+ __u32 ifindex);
+LIBBPF_API bool bpf_probe_map_type(enum bpf_map_type map_type, __u32 ifindex);
+LIBBPF_API bool bpf_probe_helper(enum bpf_func_id id,
+ enum bpf_prog_type prog_type, __u32 ifindex);
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
#endif /* __LIBBPF_LIBBPF_H */
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
new file mode 100644
index 000000000000..778a26702a70
--- /dev/null
+++ b/tools/lib/bpf/libbpf.map
@@ -0,0 +1,156 @@
+LIBBPF_0.0.1 {
+ global:
+ bpf_btf_get_fd_by_id;
+ bpf_create_map;
+ bpf_create_map_in_map;
+ bpf_create_map_in_map_node;
+ bpf_create_map_name;
+ bpf_create_map_node;
+ bpf_create_map_xattr;
+ bpf_load_btf;
+ bpf_load_program;
+ bpf_load_program_xattr;
+ bpf_map__btf_key_type_id;
+ bpf_map__btf_value_type_id;
+ bpf_map__def;
+ bpf_map__fd;
+ bpf_map__is_offload_neutral;
+ bpf_map__name;
+ bpf_map__next;
+ bpf_map__pin;
+ bpf_map__prev;
+ bpf_map__priv;
+ bpf_map__reuse_fd;
+ bpf_map__set_ifindex;
+ bpf_map__set_inner_map_fd;
+ bpf_map__set_priv;
+ bpf_map__unpin;
+ bpf_map_delete_elem;
+ bpf_map_get_fd_by_id;
+ bpf_map_get_next_id;
+ bpf_map_get_next_key;
+ bpf_map_lookup_and_delete_elem;
+ bpf_map_lookup_elem;
+ bpf_map_update_elem;
+ bpf_obj_get;
+ bpf_obj_get_info_by_fd;
+ bpf_obj_pin;
+ bpf_object__btf_fd;
+ bpf_object__close;
+ bpf_object__find_map_by_name;
+ bpf_object__find_map_by_offset;
+ bpf_object__find_program_by_title;
+ bpf_object__kversion;
+ bpf_object__load;
+ bpf_object__name;
+ bpf_object__next;
+ bpf_object__open;
+ bpf_object__open_buffer;
+ bpf_object__open_xattr;
+ bpf_object__pin;
+ bpf_object__pin_maps;
+ bpf_object__pin_programs;
+ bpf_object__priv;
+ bpf_object__set_priv;
+ bpf_object__unload;
+ bpf_object__unpin_maps;
+ bpf_object__unpin_programs;
+ bpf_perf_event_read_simple;
+ bpf_prog_attach;
+ bpf_prog_detach;
+ bpf_prog_detach2;
+ bpf_prog_get_fd_by_id;
+ bpf_prog_get_next_id;
+ bpf_prog_load;
+ bpf_prog_load_xattr;
+ bpf_prog_query;
+ bpf_prog_test_run;
+ bpf_prog_test_run_xattr;
+ bpf_program__fd;
+ bpf_program__is_kprobe;
+ bpf_program__is_perf_event;
+ bpf_program__is_raw_tracepoint;
+ bpf_program__is_sched_act;
+ bpf_program__is_sched_cls;
+ bpf_program__is_socket_filter;
+ bpf_program__is_tracepoint;
+ bpf_program__is_xdp;
+ bpf_program__load;
+ bpf_program__next;
+ bpf_program__nth_fd;
+ bpf_program__pin;
+ bpf_program__pin_instance;
+ bpf_program__prev;
+ bpf_program__priv;
+ bpf_program__set_expected_attach_type;
+ bpf_program__set_ifindex;
+ bpf_program__set_kprobe;
+ bpf_program__set_perf_event;
+ bpf_program__set_prep;
+ bpf_program__set_priv;
+ bpf_program__set_raw_tracepoint;
+ bpf_program__set_sched_act;
+ bpf_program__set_sched_cls;
+ bpf_program__set_socket_filter;
+ bpf_program__set_tracepoint;
+ bpf_program__set_type;
+ bpf_program__set_xdp;
+ bpf_program__title;
+ bpf_program__unload;
+ bpf_program__unpin;
+ bpf_program__unpin_instance;
+ bpf_prog_linfo__free;
+ bpf_prog_linfo__new;
+ bpf_prog_linfo__lfind_addr_func;
+ bpf_prog_linfo__lfind;
+ bpf_raw_tracepoint_open;
+ bpf_set_link_xdp_fd;
+ bpf_task_fd_query;
+ bpf_verify_program;
+ btf__fd;
+ btf__find_by_name;
+ btf__free;
+ btf__get_from_id;
+ btf__name_by_offset;
+ btf__new;
+ btf__resolve_size;
+ btf__resolve_type;
+ btf__type_by_id;
+ libbpf_attach_type_by_name;
+ libbpf_get_error;
+ libbpf_prog_type_by_name;
+ libbpf_set_print;
+ libbpf_strerror;
+ local:
+ *;
+};
+
+LIBBPF_0.0.2 {
+ global:
+ bpf_probe_helper;
+ bpf_probe_map_type;
+ bpf_probe_prog_type;
+ bpf_map__resize;
+ bpf_map_lookup_elem_flags;
+ bpf_object__btf;
+ bpf_object__find_map_fd_by_name;
+ bpf_get_link_xdp_id;
+ btf__dedup;
+ btf__get_map_kv_tids;
+ btf__get_nr_types;
+ btf__get_raw_data;
+ btf__load;
+ btf_ext__free;
+ btf_ext__func_info_rec_size;
+ btf_ext__get_raw_data;
+ btf_ext__line_info_rec_size;
+ btf_ext__new;
+ btf_ext__reloc_func_info;
+ btf_ext__reloc_line_info;
+ xsk_umem__create;
+ xsk_socket__create;
+ xsk_umem__delete;
+ xsk_socket__delete;
+ xsk_umem__fd;
+ xsk_socket__fd;
+} LIBBPF_0.0.1;
diff --git a/tools/lib/bpf/libbpf_errno.c b/tools/lib/bpf/libbpf_errno.c
index d83b17f8435c..4343e40588c6 100644
--- a/tools/lib/bpf/libbpf_errno.c
+++ b/tools/lib/bpf/libbpf_errno.c
@@ -7,6 +7,7 @@
* Copyright (C) 2017 Nicira, Inc.
*/
+#undef _GNU_SOURCE
#include <stdio.h>
#include <string.h>
diff --git a/tools/lib/bpf/libbpf_probes.c b/tools/lib/bpf/libbpf_probes.c
new file mode 100644
index 000000000000..8c3a1c04dcb2
--- /dev/null
+++ b/tools/lib/bpf/libbpf_probes.c
@@ -0,0 +1,242 @@
+// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
+/* Copyright (c) 2019 Netronome Systems, Inc. */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <string.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <net/if.h>
+#include <sys/utsname.h>
+
+#include <linux/filter.h>
+#include <linux/kernel.h>
+
+#include "bpf.h"
+#include "libbpf.h"
+
+static bool grep(const char *buffer, const char *pattern)
+{
+ return !!strstr(buffer, pattern);
+}
+
+static int get_vendor_id(int ifindex)
+{
+ char ifname[IF_NAMESIZE], path[64], buf[8];
+ ssize_t len;
+ int fd;
+
+ if (!if_indextoname(ifindex, ifname))
+ return -1;
+
+ snprintf(path, sizeof(path), "/sys/class/net/%s/device/vendor", ifname);
+
+ fd = open(path, O_RDONLY);
+ if (fd < 0)
+ return -1;
+
+ len = read(fd, buf, sizeof(buf));
+ close(fd);
+ if (len < 0)
+ return -1;
+ if (len >= (ssize_t)sizeof(buf))
+ return -1;
+ buf[len] = '\0';
+
+ return strtol(buf, NULL, 0);
+}
+
+static int get_kernel_version(void)
+{
+ int version, subversion, patchlevel;
+ struct utsname utsn;
+
+ /* Return 0 on failure, and attempt to probe with empty kversion */
+ if (uname(&utsn))
+ return 0;
+
+ if (sscanf(utsn.release, "%d.%d.%d",
+ &version, &subversion, &patchlevel) != 3)
+ return 0;
+
+ return (version << 16) + (subversion << 8) + patchlevel;
+}
+
+static void
+probe_load(enum bpf_prog_type prog_type, const struct bpf_insn *insns,
+ size_t insns_cnt, char *buf, size_t buf_len, __u32 ifindex)
+{
+ struct bpf_load_program_attr xattr = {};
+ int fd;
+
+ switch (prog_type) {
+ case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
+ xattr.expected_attach_type = BPF_CGROUP_INET4_CONNECT;
+ break;
+ case BPF_PROG_TYPE_KPROBE:
+ xattr.kern_version = get_kernel_version();
+ break;
+ case BPF_PROG_TYPE_UNSPEC:
+ case BPF_PROG_TYPE_SOCKET_FILTER:
+ case BPF_PROG_TYPE_SCHED_CLS:
+ case BPF_PROG_TYPE_SCHED_ACT:
+ case BPF_PROG_TYPE_TRACEPOINT:
+ case BPF_PROG_TYPE_XDP:
+ case BPF_PROG_TYPE_PERF_EVENT:
+ case BPF_PROG_TYPE_CGROUP_SKB:
+ case BPF_PROG_TYPE_CGROUP_SOCK:
+ case BPF_PROG_TYPE_LWT_IN:
+ case BPF_PROG_TYPE_LWT_OUT:
+ case BPF_PROG_TYPE_LWT_XMIT:
+ case BPF_PROG_TYPE_SOCK_OPS:
+ case BPF_PROG_TYPE_SK_SKB:
+ case BPF_PROG_TYPE_CGROUP_DEVICE:
+ case BPF_PROG_TYPE_SK_MSG:
+ case BPF_PROG_TYPE_RAW_TRACEPOINT:
+ case BPF_PROG_TYPE_LWT_SEG6LOCAL:
+ case BPF_PROG_TYPE_LIRC_MODE2:
+ case BPF_PROG_TYPE_SK_REUSEPORT:
+ case BPF_PROG_TYPE_FLOW_DISSECTOR:
+ default:
+ break;
+ }
+
+ xattr.prog_type = prog_type;
+ xattr.insns = insns;
+ xattr.insns_cnt = insns_cnt;
+ xattr.license = "GPL";
+ xattr.prog_ifindex = ifindex;
+
+ fd = bpf_load_program_xattr(&xattr, buf, buf_len);
+ if (fd >= 0)
+ close(fd);
+}
+
+bool bpf_probe_prog_type(enum bpf_prog_type prog_type, __u32 ifindex)
+{
+ struct bpf_insn insns[2] = {
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN()
+ };
+
+ if (ifindex && prog_type == BPF_PROG_TYPE_SCHED_CLS)
+ /* nfp returns -EINVAL on exit(0) with TC offload */
+ insns[0].imm = 2;
+
+ errno = 0;
+ probe_load(prog_type, insns, ARRAY_SIZE(insns), NULL, 0, ifindex);
+
+ return errno != EINVAL && errno != EOPNOTSUPP;
+}
+
+bool bpf_probe_map_type(enum bpf_map_type map_type, __u32 ifindex)
+{
+ int key_size, value_size, max_entries, map_flags;
+ struct bpf_create_map_attr attr = {};
+ int fd = -1, fd_inner;
+
+ key_size = sizeof(__u32);
+ value_size = sizeof(__u32);
+ max_entries = 1;
+ map_flags = 0;
+
+ switch (map_type) {
+ case BPF_MAP_TYPE_STACK_TRACE:
+ value_size = sizeof(__u64);
+ break;
+ case BPF_MAP_TYPE_LPM_TRIE:
+ key_size = sizeof(__u64);
+ value_size = sizeof(__u64);
+ map_flags = BPF_F_NO_PREALLOC;
+ break;
+ case BPF_MAP_TYPE_CGROUP_STORAGE:
+ case BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE:
+ key_size = sizeof(struct bpf_cgroup_storage_key);
+ value_size = sizeof(__u64);
+ max_entries = 0;
+ break;
+ case BPF_MAP_TYPE_QUEUE:
+ case BPF_MAP_TYPE_STACK:
+ key_size = 0;
+ break;
+ case BPF_MAP_TYPE_UNSPEC:
+ case BPF_MAP_TYPE_HASH:
+ case BPF_MAP_TYPE_ARRAY:
+ case BPF_MAP_TYPE_PROG_ARRAY:
+ case BPF_MAP_TYPE_PERF_EVENT_ARRAY:
+ case BPF_MAP_TYPE_PERCPU_HASH:
+ case BPF_MAP_TYPE_PERCPU_ARRAY:
+ case BPF_MAP_TYPE_CGROUP_ARRAY:
+ case BPF_MAP_TYPE_LRU_HASH:
+ case BPF_MAP_TYPE_LRU_PERCPU_HASH:
+ case BPF_MAP_TYPE_ARRAY_OF_MAPS:
+ case BPF_MAP_TYPE_HASH_OF_MAPS:
+ case BPF_MAP_TYPE_DEVMAP:
+ case BPF_MAP_TYPE_SOCKMAP:
+ case BPF_MAP_TYPE_CPUMAP:
+ case BPF_MAP_TYPE_XSKMAP:
+ case BPF_MAP_TYPE_SOCKHASH:
+ case BPF_MAP_TYPE_REUSEPORT_SOCKARRAY:
+ default:
+ break;
+ }
+
+ if (map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS ||
+ map_type == BPF_MAP_TYPE_HASH_OF_MAPS) {
+ /* TODO: probe for device, once libbpf has a function to create
+ * map-in-map for offload
+ */
+ if (ifindex)
+ return false;
+
+ fd_inner = bpf_create_map(BPF_MAP_TYPE_HASH,
+ sizeof(__u32), sizeof(__u32), 1, 0);
+ if (fd_inner < 0)
+ return false;
+ fd = bpf_create_map_in_map(map_type, NULL, sizeof(__u32),
+ fd_inner, 1, 0);
+ close(fd_inner);
+ } else {
+ /* Note: No other restriction on map type probes for offload */
+ attr.map_type = map_type;
+ attr.key_size = key_size;
+ attr.value_size = value_size;
+ attr.max_entries = max_entries;
+ attr.map_flags = map_flags;
+ attr.map_ifindex = ifindex;
+
+ fd = bpf_create_map_xattr(&attr);
+ }
+ if (fd >= 0)
+ close(fd);
+
+ return fd >= 0;
+}
+
+bool bpf_probe_helper(enum bpf_func_id id, enum bpf_prog_type prog_type,
+ __u32 ifindex)
+{
+ struct bpf_insn insns[2] = {
+ BPF_EMIT_CALL(id),
+ BPF_EXIT_INSN()
+ };
+ char buf[4096] = {};
+ bool res;
+
+ probe_load(prog_type, insns, ARRAY_SIZE(insns), buf, sizeof(buf),
+ ifindex);
+ res = !grep(buf, "invalid func ") && !grep(buf, "unknown func ");
+
+ if (ifindex) {
+ switch (get_vendor_id(ifindex)) {
+ case 0x19ee: /* Netronome specific */
+ res = res && !grep(buf, "not supported by FW") &&
+ !grep(buf, "unsupported function id");
+ break;
+ default:
+ break;
+ }
+ }
+
+ return res;
+}
diff --git a/tools/lib/bpf/libbpf_util.h b/tools/lib/bpf/libbpf_util.h
new file mode 100644
index 000000000000..81ecda0cb9c9
--- /dev/null
+++ b/tools/lib/bpf/libbpf_util.h
@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
+/* Copyright (c) 2019 Facebook */
+
+#ifndef __LIBBPF_LIBBPF_UTIL_H
+#define __LIBBPF_LIBBPF_UTIL_H
+
+#include <stdbool.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+extern void libbpf_print(enum libbpf_print_level level,
+ const char *format, ...)
+ __attribute__((format(printf, 2, 3)));
+
+#define __pr(level, fmt, ...) \
+do { \
+ libbpf_print(level, "libbpf: " fmt, ##__VA_ARGS__); \
+} while (0)
+
+#define pr_warning(fmt, ...) __pr(LIBBPF_WARN, fmt, ##__VA_ARGS__)
+#define pr_info(fmt, ...) __pr(LIBBPF_INFO, fmt, ##__VA_ARGS__)
+#define pr_debug(fmt, ...) __pr(LIBBPF_DEBUG, fmt, ##__VA_ARGS__)
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
+#endif
diff --git a/tools/lib/bpf/netlink.c b/tools/lib/bpf/netlink.c
index 0ce67aea8f3b..ce3ec81b71c0 100644
--- a/tools/lib/bpf/netlink.c
+++ b/tools/lib/bpf/netlink.c
@@ -21,6 +21,12 @@
typedef int (*__dump_nlmsg_t)(struct nlmsghdr *nlmsg, libbpf_dump_nlmsg_t,
void *cookie);
+struct xdp_id_md {
+ int ifindex;
+ __u32 flags;
+ __u32 id;
+};
+
int libbpf_netlink_open(__u32 *nl_pid)
{
struct sockaddr_nl sa;
@@ -196,6 +202,85 @@ static int __dump_link_nlmsg(struct nlmsghdr *nlh,
return dump_link_nlmsg(cookie, ifi, tb);
}
+static unsigned char get_xdp_id_attr(unsigned char mode, __u32 flags)
+{
+ if (mode != XDP_ATTACHED_MULTI)
+ return IFLA_XDP_PROG_ID;
+ if (flags & XDP_FLAGS_DRV_MODE)
+ return IFLA_XDP_DRV_PROG_ID;
+ if (flags & XDP_FLAGS_HW_MODE)
+ return IFLA_XDP_HW_PROG_ID;
+ if (flags & XDP_FLAGS_SKB_MODE)
+ return IFLA_XDP_SKB_PROG_ID;
+
+ return IFLA_XDP_UNSPEC;
+}
+
+static int get_xdp_id(void *cookie, void *msg, struct nlattr **tb)
+{
+ struct nlattr *xdp_tb[IFLA_XDP_MAX + 1];
+ struct xdp_id_md *xdp_id = cookie;
+ struct ifinfomsg *ifinfo = msg;
+ unsigned char mode, xdp_attr;
+ int ret;
+
+ if (xdp_id->ifindex && xdp_id->ifindex != ifinfo->ifi_index)
+ return 0;
+
+ if (!tb[IFLA_XDP])
+ return 0;
+
+ ret = libbpf_nla_parse_nested(xdp_tb, IFLA_XDP_MAX, tb[IFLA_XDP], NULL);
+ if (ret)
+ return ret;
+
+ if (!xdp_tb[IFLA_XDP_ATTACHED])
+ return 0;
+
+ mode = libbpf_nla_getattr_u8(xdp_tb[IFLA_XDP_ATTACHED]);
+ if (mode == XDP_ATTACHED_NONE)
+ return 0;
+
+ xdp_attr = get_xdp_id_attr(mode, xdp_id->flags);
+ if (!xdp_attr || !xdp_tb[xdp_attr])
+ return 0;
+
+ xdp_id->id = libbpf_nla_getattr_u32(xdp_tb[xdp_attr]);
+
+ return 0;
+}
+
+int bpf_get_link_xdp_id(int ifindex, __u32 *prog_id, __u32 flags)
+{
+ struct xdp_id_md xdp_id = {};
+ int sock, ret;
+ __u32 nl_pid;
+ __u32 mask;
+
+ if (flags & ~XDP_FLAGS_MASK)
+ return -EINVAL;
+
+ /* Check whether the single {HW,DRV,SKB} mode is set */
+ flags &= (XDP_FLAGS_SKB_MODE | XDP_FLAGS_DRV_MODE | XDP_FLAGS_HW_MODE);
+ mask = flags - 1;
+ if (flags && flags & mask)
+ return -EINVAL;
+
+ sock = libbpf_netlink_open(&nl_pid);
+ if (sock < 0)
+ return sock;
+
+ xdp_id.ifindex = ifindex;
+ xdp_id.flags = flags;
+
+ ret = libbpf_nl_get_link(sock, nl_pid, get_xdp_id, &xdp_id);
+ if (!ret)
+ *prog_id = xdp_id.id;
+
+ close(sock);
+ return ret;
+}
+
int libbpf_nl_get_link(int sock, unsigned int nl_pid,
libbpf_dump_nlmsg_t dump_link_nlmsg, void *cookie)
{
diff --git a/tools/lib/bpf/test_libbpf.cpp b/tools/lib/bpf/test_libbpf.cpp
new file mode 100644
index 000000000000..fc134873bb6d
--- /dev/null
+++ b/tools/lib/bpf/test_libbpf.cpp
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
+#include "libbpf.h"
+#include "bpf.h"
+#include "btf.h"
+
+/* do nothing, just make sure we can link successfully */
+
+int main(int argc, char *argv[])
+{
+ /* libbpf.h */
+ libbpf_set_print(NULL);
+
+ /* bpf.h */
+ bpf_prog_get_fd_by_id(0);
+
+ /* btf.h */
+ btf__new(NULL, 0);
+}
diff --git a/tools/lib/bpf/xsk.c b/tools/lib/bpf/xsk.c
new file mode 100644
index 000000000000..f98ac82c9aea
--- /dev/null
+++ b/tools/lib/bpf/xsk.c
@@ -0,0 +1,723 @@
+// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
+
+/*
+ * AF_XDP user-space access library.
+ *
+ * Copyright(c) 2018 - 2019 Intel Corporation.
+ *
+ * Author(s): Magnus Karlsson <magnus.karlsson@intel.com>
+ */
+
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <arpa/inet.h>
+#include <asm/barrier.h>
+#include <linux/compiler.h>
+#include <linux/ethtool.h>
+#include <linux/filter.h>
+#include <linux/if_ether.h>
+#include <linux/if_packet.h>
+#include <linux/if_xdp.h>
+#include <linux/sockios.h>
+#include <net/if.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+
+#include "bpf.h"
+#include "libbpf.h"
+#include "libbpf_util.h"
+#include "xsk.h"
+
+#ifndef SOL_XDP
+ #define SOL_XDP 283
+#endif
+
+#ifndef AF_XDP
+ #define AF_XDP 44
+#endif
+
+#ifndef PF_XDP
+ #define PF_XDP AF_XDP
+#endif
+
+struct xsk_umem {
+ struct xsk_ring_prod *fill;
+ struct xsk_ring_cons *comp;
+ char *umem_area;
+ struct xsk_umem_config config;
+ int fd;
+ int refcount;
+};
+
+struct xsk_socket {
+ struct xsk_ring_cons *rx;
+ struct xsk_ring_prod *tx;
+ __u64 outstanding_tx;
+ struct xsk_umem *umem;
+ struct xsk_socket_config config;
+ int fd;
+ int xsks_map;
+ int ifindex;
+ int prog_fd;
+ int qidconf_map_fd;
+ int xsks_map_fd;
+ __u32 queue_id;
+ char ifname[IFNAMSIZ];
+};
+
+struct xsk_nl_info {
+ bool xdp_prog_attached;
+ int ifindex;
+ int fd;
+};
+
+/* For 32-bit systems, we need to use mmap2 as the offsets are 64-bit.
+ * Unfortunately, it is not part of glibc.
+ */
+static inline void *xsk_mmap(void *addr, size_t length, int prot, int flags,
+ int fd, __u64 offset)
+{
+#ifdef __NR_mmap2
+ unsigned int page_shift = __builtin_ffs(getpagesize()) - 1;
+ long ret = syscall(__NR_mmap2, addr, length, prot, flags, fd,
+ (off_t)(offset >> page_shift));
+
+ return (void *)ret;
+#else
+ return mmap(addr, length, prot, flags, fd, offset);
+#endif
+}
+
+int xsk_umem__fd(const struct xsk_umem *umem)
+{
+ return umem ? umem->fd : -EINVAL;
+}
+
+int xsk_socket__fd(const struct xsk_socket *xsk)
+{
+ return xsk ? xsk->fd : -EINVAL;
+}
+
+static bool xsk_page_aligned(void *buffer)
+{
+ unsigned long addr = (unsigned long)buffer;
+
+ return !(addr & (getpagesize() - 1));
+}
+
+static void xsk_set_umem_config(struct xsk_umem_config *cfg,
+ const struct xsk_umem_config *usr_cfg)
+{
+ if (!usr_cfg) {
+ cfg->fill_size = XSK_RING_PROD__DEFAULT_NUM_DESCS;
+ cfg->comp_size = XSK_RING_CONS__DEFAULT_NUM_DESCS;
+ cfg->frame_size = XSK_UMEM__DEFAULT_FRAME_SIZE;
+ cfg->frame_headroom = XSK_UMEM__DEFAULT_FRAME_HEADROOM;
+ return;
+ }
+
+ cfg->fill_size = usr_cfg->fill_size;
+ cfg->comp_size = usr_cfg->comp_size;
+ cfg->frame_size = usr_cfg->frame_size;
+ cfg->frame_headroom = usr_cfg->frame_headroom;
+}
+
+static void xsk_set_xdp_socket_config(struct xsk_socket_config *cfg,
+ const struct xsk_socket_config *usr_cfg)
+{
+ if (!usr_cfg) {
+ cfg->rx_size = XSK_RING_CONS__DEFAULT_NUM_DESCS;
+ cfg->tx_size = XSK_RING_PROD__DEFAULT_NUM_DESCS;
+ cfg->libbpf_flags = 0;
+ cfg->xdp_flags = 0;
+ cfg->bind_flags = 0;
+ return;
+ }
+
+ cfg->rx_size = usr_cfg->rx_size;
+ cfg->tx_size = usr_cfg->tx_size;
+ cfg->libbpf_flags = usr_cfg->libbpf_flags;
+ cfg->xdp_flags = usr_cfg->xdp_flags;
+ cfg->bind_flags = usr_cfg->bind_flags;
+}
+
+int xsk_umem__create(struct xsk_umem **umem_ptr, void *umem_area, __u64 size,
+ struct xsk_ring_prod *fill, struct xsk_ring_cons *comp,
+ const struct xsk_umem_config *usr_config)
+{
+ struct xdp_mmap_offsets off;
+ struct xdp_umem_reg mr;
+ struct xsk_umem *umem;
+ socklen_t optlen;
+ void *map;
+ int err;
+
+ if (!umem_area || !umem_ptr || !fill || !comp)
+ return -EFAULT;
+ if (!size && !xsk_page_aligned(umem_area))
+ return -EINVAL;
+
+ umem = calloc(1, sizeof(*umem));
+ if (!umem)
+ return -ENOMEM;
+
+ umem->fd = socket(AF_XDP, SOCK_RAW, 0);
+ if (umem->fd < 0) {
+ err = -errno;
+ goto out_umem_alloc;
+ }
+
+ umem->umem_area = umem_area;
+ xsk_set_umem_config(&umem->config, usr_config);
+
+ mr.addr = (uintptr_t)umem_area;
+ mr.len = size;
+ mr.chunk_size = umem->config.frame_size;
+ mr.headroom = umem->config.frame_headroom;
+
+ err = setsockopt(umem->fd, SOL_XDP, XDP_UMEM_REG, &mr, sizeof(mr));
+ if (err) {
+ err = -errno;
+ goto out_socket;
+ }
+ err = setsockopt(umem->fd, SOL_XDP, XDP_UMEM_FILL_RING,
+ &umem->config.fill_size,
+ sizeof(umem->config.fill_size));
+ if (err) {
+ err = -errno;
+ goto out_socket;
+ }
+ err = setsockopt(umem->fd, SOL_XDP, XDP_UMEM_COMPLETION_RING,
+ &umem->config.comp_size,
+ sizeof(umem->config.comp_size));
+ if (err) {
+ err = -errno;
+ goto out_socket;
+ }
+
+ optlen = sizeof(off);
+ err = getsockopt(umem->fd, SOL_XDP, XDP_MMAP_OFFSETS, &off, &optlen);
+ if (err) {
+ err = -errno;
+ goto out_socket;
+ }
+
+ map = xsk_mmap(NULL, off.fr.desc +
+ umem->config.fill_size * sizeof(__u64),
+ PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE,
+ umem->fd, XDP_UMEM_PGOFF_FILL_RING);
+ if (map == MAP_FAILED) {
+ err = -errno;
+ goto out_socket;
+ }
+
+ umem->fill = fill;
+ fill->mask = umem->config.fill_size - 1;
+ fill->size = umem->config.fill_size;
+ fill->producer = map + off.fr.producer;
+ fill->consumer = map + off.fr.consumer;
+ fill->ring = map + off.fr.desc;
+ fill->cached_cons = umem->config.fill_size;
+
+ map = xsk_mmap(NULL,
+ off.cr.desc + umem->config.comp_size * sizeof(__u64),
+ PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE,
+ umem->fd, XDP_UMEM_PGOFF_COMPLETION_RING);
+ if (map == MAP_FAILED) {
+ err = -errno;
+ goto out_mmap;
+ }
+
+ umem->comp = comp;
+ comp->mask = umem->config.comp_size - 1;
+ comp->size = umem->config.comp_size;
+ comp->producer = map + off.cr.producer;
+ comp->consumer = map + off.cr.consumer;
+ comp->ring = map + off.cr.desc;
+
+ *umem_ptr = umem;
+ return 0;
+
+out_mmap:
+ munmap(umem->fill,
+ off.fr.desc + umem->config.fill_size * sizeof(__u64));
+out_socket:
+ close(umem->fd);
+out_umem_alloc:
+ free(umem);
+ return err;
+}
+
+static int xsk_load_xdp_prog(struct xsk_socket *xsk)
+{
+ char bpf_log_buf[BPF_LOG_BUF_SIZE];
+ int err, prog_fd;
+
+ /* This is the C-program:
+ * SEC("xdp_sock") int xdp_sock_prog(struct xdp_md *ctx)
+ * {
+ * int *qidconf, index = ctx->rx_queue_index;
+ *
+ * // A set entry here means that the correspnding queue_id
+ * // has an active AF_XDP socket bound to it.
+ * qidconf = bpf_map_lookup_elem(&qidconf_map, &index);
+ * if (!qidconf)
+ * return XDP_ABORTED;
+ *
+ * if (*qidconf)
+ * return bpf_redirect_map(&xsks_map, index, 0);
+ *
+ * return XDP_PASS;
+ * }
+ */
+ struct bpf_insn prog[] = {
+ /* r1 = *(u32 *)(r1 + 16) */
+ BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_1, 16),
+ /* *(u32 *)(r10 - 4) = r1 */
+ BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_1, -4),
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4),
+ BPF_LD_MAP_FD(BPF_REG_1, xsk->qidconf_map_fd),
+ BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
+ BPF_MOV32_IMM(BPF_REG_0, 0),
+ /* if r1 == 0 goto +8 */
+ BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 8),
+ BPF_MOV32_IMM(BPF_REG_0, 2),
+ /* r1 = *(u32 *)(r1 + 0) */
+ BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_1, 0),
+ /* if r1 == 0 goto +5 */
+ BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 5),
+ /* r2 = *(u32 *)(r10 - 4) */
+ BPF_LD_MAP_FD(BPF_REG_1, xsk->xsks_map_fd),
+ BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_10, -4),
+ BPF_MOV32_IMM(BPF_REG_3, 0),
+ BPF_EMIT_CALL(BPF_FUNC_redirect_map),
+ /* The jumps are to this instruction */
+ BPF_EXIT_INSN(),
+ };
+ size_t insns_cnt = sizeof(prog) / sizeof(struct bpf_insn);
+
+ prog_fd = bpf_load_program(BPF_PROG_TYPE_XDP, prog, insns_cnt,
+ "LGPL-2.1 or BSD-2-Clause", 0, bpf_log_buf,
+ BPF_LOG_BUF_SIZE);
+ if (prog_fd < 0) {
+ pr_warning("BPF log buffer:\n%s", bpf_log_buf);
+ return prog_fd;
+ }
+
+ err = bpf_set_link_xdp_fd(xsk->ifindex, prog_fd, xsk->config.xdp_flags);
+ if (err) {
+ close(prog_fd);
+ return err;
+ }
+
+ xsk->prog_fd = prog_fd;
+ return 0;
+}
+
+static int xsk_get_max_queues(struct xsk_socket *xsk)
+{
+ struct ethtool_channels channels;
+ struct ifreq ifr;
+ int fd, err, ret;
+
+ fd = socket(AF_INET, SOCK_DGRAM, 0);
+ if (fd < 0)
+ return -errno;
+
+ channels.cmd = ETHTOOL_GCHANNELS;
+ ifr.ifr_data = (void *)&channels;
+ strncpy(ifr.ifr_name, xsk->ifname, IFNAMSIZ);
+ err = ioctl(fd, SIOCETHTOOL, &ifr);
+ if (err && errno != EOPNOTSUPP) {
+ ret = -errno;
+ goto out;
+ }
+
+ if (channels.max_combined == 0 || errno == EOPNOTSUPP)
+ /* If the device says it has no channels, then all traffic
+ * is sent to a single stream, so max queues = 1.
+ */
+ ret = 1;
+ else
+ ret = channels.max_combined;
+
+out:
+ close(fd);
+ return ret;
+}
+
+static int xsk_create_bpf_maps(struct xsk_socket *xsk)
+{
+ int max_queues;
+ int fd;
+
+ max_queues = xsk_get_max_queues(xsk);
+ if (max_queues < 0)
+ return max_queues;
+
+ fd = bpf_create_map_name(BPF_MAP_TYPE_ARRAY, "qidconf_map",
+ sizeof(int), sizeof(int), max_queues, 0);
+ if (fd < 0)
+ return fd;
+ xsk->qidconf_map_fd = fd;
+
+ fd = bpf_create_map_name(BPF_MAP_TYPE_XSKMAP, "xsks_map",
+ sizeof(int), sizeof(int), max_queues, 0);
+ if (fd < 0) {
+ close(xsk->qidconf_map_fd);
+ return fd;
+ }
+ xsk->xsks_map_fd = fd;
+
+ return 0;
+}
+
+static void xsk_delete_bpf_maps(struct xsk_socket *xsk)
+{
+ close(xsk->qidconf_map_fd);
+ close(xsk->xsks_map_fd);
+}
+
+static int xsk_update_bpf_maps(struct xsk_socket *xsk, int qidconf_value,
+ int xsks_value)
+{
+ bool qidconf_map_updated = false, xsks_map_updated = false;
+ struct bpf_prog_info prog_info = {};
+ __u32 prog_len = sizeof(prog_info);
+ struct bpf_map_info map_info;
+ __u32 map_len = sizeof(map_info);
+ __u32 *map_ids;
+ int reset_value = 0;
+ __u32 num_maps;
+ unsigned int i;
+ int err;
+
+ err = bpf_obj_get_info_by_fd(xsk->prog_fd, &prog_info, &prog_len);
+ if (err)
+ return err;
+
+ num_maps = prog_info.nr_map_ids;
+
+ map_ids = calloc(prog_info.nr_map_ids, sizeof(*map_ids));
+ if (!map_ids)
+ return -ENOMEM;
+
+ memset(&prog_info, 0, prog_len);
+ prog_info.nr_map_ids = num_maps;
+ prog_info.map_ids = (__u64)(unsigned long)map_ids;
+
+ err = bpf_obj_get_info_by_fd(xsk->prog_fd, &prog_info, &prog_len);
+ if (err)
+ goto out_map_ids;
+
+ for (i = 0; i < prog_info.nr_map_ids; i++) {
+ int fd;
+
+ fd = bpf_map_get_fd_by_id(map_ids[i]);
+ if (fd < 0) {
+ err = -errno;
+ goto out_maps;
+ }
+
+ err = bpf_obj_get_info_by_fd(fd, &map_info, &map_len);
+ if (err)
+ goto out_maps;
+
+ if (!strcmp(map_info.name, "qidconf_map")) {
+ err = bpf_map_update_elem(fd, &xsk->queue_id,
+ &qidconf_value, 0);
+ if (err)
+ goto out_maps;
+ qidconf_map_updated = true;
+ xsk->qidconf_map_fd = fd;
+ } else if (!strcmp(map_info.name, "xsks_map")) {
+ err = bpf_map_update_elem(fd, &xsk->queue_id,
+ &xsks_value, 0);
+ if (err)
+ goto out_maps;
+ xsks_map_updated = true;
+ xsk->xsks_map_fd = fd;
+ }
+
+ if (qidconf_map_updated && xsks_map_updated)
+ break;
+ }
+
+ if (!(qidconf_map_updated && xsks_map_updated)) {
+ err = -ENOENT;
+ goto out_maps;
+ }
+
+ err = 0;
+ goto out_success;
+
+out_maps:
+ if (qidconf_map_updated)
+ (void)bpf_map_update_elem(xsk->qidconf_map_fd, &xsk->queue_id,
+ &reset_value, 0);
+ if (xsks_map_updated)
+ (void)bpf_map_update_elem(xsk->xsks_map_fd, &xsk->queue_id,
+ &reset_value, 0);
+out_success:
+ if (qidconf_map_updated)
+ close(xsk->qidconf_map_fd);
+ if (xsks_map_updated)
+ close(xsk->xsks_map_fd);
+out_map_ids:
+ free(map_ids);
+ return err;
+}
+
+static int xsk_setup_xdp_prog(struct xsk_socket *xsk)
+{
+ bool prog_attached = false;
+ __u32 prog_id = 0;
+ int err;
+
+ err = bpf_get_link_xdp_id(xsk->ifindex, &prog_id,
+ xsk->config.xdp_flags);
+ if (err)
+ return err;
+
+ if (!prog_id) {
+ prog_attached = true;
+ err = xsk_create_bpf_maps(xsk);
+ if (err)
+ return err;
+
+ err = xsk_load_xdp_prog(xsk);
+ if (err)
+ goto out_maps;
+ } else {
+ xsk->prog_fd = bpf_prog_get_fd_by_id(prog_id);
+ }
+
+ err = xsk_update_bpf_maps(xsk, true, xsk->fd);
+ if (err)
+ goto out_load;
+
+ return 0;
+
+out_load:
+ if (prog_attached)
+ close(xsk->prog_fd);
+out_maps:
+ if (prog_attached)
+ xsk_delete_bpf_maps(xsk);
+ return err;
+}
+
+int xsk_socket__create(struct xsk_socket **xsk_ptr, const char *ifname,
+ __u32 queue_id, struct xsk_umem *umem,
+ struct xsk_ring_cons *rx, struct xsk_ring_prod *tx,
+ const struct xsk_socket_config *usr_config)
+{
+ struct sockaddr_xdp sxdp = {};
+ struct xdp_mmap_offsets off;
+ struct xsk_socket *xsk;
+ socklen_t optlen;
+ void *map;
+ int err;
+
+ if (!umem || !xsk_ptr || !rx || !tx)
+ return -EFAULT;
+
+ if (umem->refcount) {
+ pr_warning("Error: shared umems not supported by libbpf.\n");
+ return -EBUSY;
+ }
+
+ xsk = calloc(1, sizeof(*xsk));
+ if (!xsk)
+ return -ENOMEM;
+
+ if (umem->refcount++ > 0) {
+ xsk->fd = socket(AF_XDP, SOCK_RAW, 0);
+ if (xsk->fd < 0) {
+ err = -errno;
+ goto out_xsk_alloc;
+ }
+ } else {
+ xsk->fd = umem->fd;
+ }
+
+ xsk->outstanding_tx = 0;
+ xsk->queue_id = queue_id;
+ xsk->umem = umem;
+ xsk->ifindex = if_nametoindex(ifname);
+ if (!xsk->ifindex) {
+ err = -errno;
+ goto out_socket;
+ }
+ strncpy(xsk->ifname, ifname, IFNAMSIZ);
+
+ xsk_set_xdp_socket_config(&xsk->config, usr_config);
+
+ if (rx) {
+ err = setsockopt(xsk->fd, SOL_XDP, XDP_RX_RING,
+ &xsk->config.rx_size,
+ sizeof(xsk->config.rx_size));
+ if (err) {
+ err = -errno;
+ goto out_socket;
+ }
+ }
+ if (tx) {
+ err = setsockopt(xsk->fd, SOL_XDP, XDP_TX_RING,
+ &xsk->config.tx_size,
+ sizeof(xsk->config.tx_size));
+ if (err) {
+ err = -errno;
+ goto out_socket;
+ }
+ }
+
+ optlen = sizeof(off);
+ err = getsockopt(xsk->fd, SOL_XDP, XDP_MMAP_OFFSETS, &off, &optlen);
+ if (err) {
+ err = -errno;
+ goto out_socket;
+ }
+
+ if (rx) {
+ map = xsk_mmap(NULL, off.rx.desc +
+ xsk->config.rx_size * sizeof(struct xdp_desc),
+ PROT_READ | PROT_WRITE,
+ MAP_SHARED | MAP_POPULATE,
+ xsk->fd, XDP_PGOFF_RX_RING);
+ if (map == MAP_FAILED) {
+ err = -errno;
+ goto out_socket;
+ }
+
+ rx->mask = xsk->config.rx_size - 1;
+ rx->size = xsk->config.rx_size;
+ rx->producer = map + off.rx.producer;
+ rx->consumer = map + off.rx.consumer;
+ rx->ring = map + off.rx.desc;
+ }
+ xsk->rx = rx;
+
+ if (tx) {
+ map = xsk_mmap(NULL, off.tx.desc +
+ xsk->config.tx_size * sizeof(struct xdp_desc),
+ PROT_READ | PROT_WRITE,
+ MAP_SHARED | MAP_POPULATE,
+ xsk->fd, XDP_PGOFF_TX_RING);
+ if (map == MAP_FAILED) {
+ err = -errno;
+ goto out_mmap_rx;
+ }
+
+ tx->mask = xsk->config.tx_size - 1;
+ tx->size = xsk->config.tx_size;
+ tx->producer = map + off.tx.producer;
+ tx->consumer = map + off.tx.consumer;
+ tx->ring = map + off.tx.desc;
+ tx->cached_cons = xsk->config.tx_size;
+ }
+ xsk->tx = tx;
+
+ sxdp.sxdp_family = PF_XDP;
+ sxdp.sxdp_ifindex = xsk->ifindex;
+ sxdp.sxdp_queue_id = xsk->queue_id;
+ sxdp.sxdp_flags = xsk->config.bind_flags;
+
+ err = bind(xsk->fd, (struct sockaddr *)&sxdp, sizeof(sxdp));
+ if (err) {
+ err = -errno;
+ goto out_mmap_tx;
+ }
+
+ if (!(xsk->config.libbpf_flags & XSK_LIBBPF_FLAGS__INHIBIT_PROG_LOAD)) {
+ err = xsk_setup_xdp_prog(xsk);
+ if (err)
+ goto out_mmap_tx;
+ }
+
+ *xsk_ptr = xsk;
+ return 0;
+
+out_mmap_tx:
+ if (tx)
+ munmap(xsk->tx,
+ off.tx.desc +
+ xsk->config.tx_size * sizeof(struct xdp_desc));
+out_mmap_rx:
+ if (rx)
+ munmap(xsk->rx,
+ off.rx.desc +
+ xsk->config.rx_size * sizeof(struct xdp_desc));
+out_socket:
+ if (--umem->refcount)
+ close(xsk->fd);
+out_xsk_alloc:
+ free(xsk);
+ return err;
+}
+
+int xsk_umem__delete(struct xsk_umem *umem)
+{
+ struct xdp_mmap_offsets off;
+ socklen_t optlen;
+ int err;
+
+ if (!umem)
+ return 0;
+
+ if (umem->refcount)
+ return -EBUSY;
+
+ optlen = sizeof(off);
+ err = getsockopt(umem->fd, SOL_XDP, XDP_MMAP_OFFSETS, &off, &optlen);
+ if (!err) {
+ munmap(umem->fill->ring,
+ off.fr.desc + umem->config.fill_size * sizeof(__u64));
+ munmap(umem->comp->ring,
+ off.cr.desc + umem->config.comp_size * sizeof(__u64));
+ }
+
+ close(umem->fd);
+ free(umem);
+
+ return 0;
+}
+
+void xsk_socket__delete(struct xsk_socket *xsk)
+{
+ struct xdp_mmap_offsets off;
+ socklen_t optlen;
+ int err;
+
+ if (!xsk)
+ return;
+
+ (void)xsk_update_bpf_maps(xsk, 0, 0);
+
+ optlen = sizeof(off);
+ err = getsockopt(xsk->fd, SOL_XDP, XDP_MMAP_OFFSETS, &off, &optlen);
+ if (!err) {
+ if (xsk->rx)
+ munmap(xsk->rx->ring,
+ off.rx.desc +
+ xsk->config.rx_size * sizeof(struct xdp_desc));
+ if (xsk->tx)
+ munmap(xsk->tx->ring,
+ off.tx.desc +
+ xsk->config.tx_size * sizeof(struct xdp_desc));
+ }
+
+ xsk->umem->refcount--;
+ /* Do not close an fd that also has an associated umem connected
+ * to it.
+ */
+ if (xsk->fd != xsk->umem->fd)
+ close(xsk->fd);
+ free(xsk);
+}
diff --git a/tools/lib/bpf/xsk.h b/tools/lib/bpf/xsk.h
new file mode 100644
index 000000000000..a497f00e2962
--- /dev/null
+++ b/tools/lib/bpf/xsk.h
@@ -0,0 +1,203 @@
+/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
+
+/*
+ * AF_XDP user-space access library.
+ *
+ * Copyright(c) 2018 - 2019 Intel Corporation.
+ *
+ * Author(s): Magnus Karlsson <magnus.karlsson@intel.com>
+ */
+
+#ifndef __LIBBPF_XSK_H
+#define __LIBBPF_XSK_H
+
+#include <stdio.h>
+#include <stdint.h>
+#include <linux/if_xdp.h>
+
+#include "libbpf.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Do not access these members directly. Use the functions below. */
+#define DEFINE_XSK_RING(name) \
+struct name { \
+ __u32 cached_prod; \
+ __u32 cached_cons; \
+ __u32 mask; \
+ __u32 size; \
+ __u32 *producer; \
+ __u32 *consumer; \
+ void *ring; \
+}
+
+DEFINE_XSK_RING(xsk_ring_prod);
+DEFINE_XSK_RING(xsk_ring_cons);
+
+struct xsk_umem;
+struct xsk_socket;
+
+static inline __u64 *xsk_ring_prod__fill_addr(struct xsk_ring_prod *fill,
+ __u32 idx)
+{
+ __u64 *addrs = (__u64 *)fill->ring;
+
+ return &addrs[idx & fill->mask];
+}
+
+static inline const __u64 *
+xsk_ring_cons__comp_addr(const struct xsk_ring_cons *comp, __u32 idx)
+{
+ const __u64 *addrs = (const __u64 *)comp->ring;
+
+ return &addrs[idx & comp->mask];
+}
+
+static inline struct xdp_desc *xsk_ring_prod__tx_desc(struct xsk_ring_prod *tx,
+ __u32 idx)
+{
+ struct xdp_desc *descs = (struct xdp_desc *)tx->ring;
+
+ return &descs[idx & tx->mask];
+}
+
+static inline const struct xdp_desc *
+xsk_ring_cons__rx_desc(const struct xsk_ring_cons *rx, __u32 idx)
+{
+ const struct xdp_desc *descs = (const struct xdp_desc *)rx->ring;
+
+ return &descs[idx & rx->mask];
+}
+
+static inline __u32 xsk_prod_nb_free(struct xsk_ring_prod *r, __u32 nb)
+{
+ __u32 free_entries = r->cached_cons - r->cached_prod;
+
+ if (free_entries >= nb)
+ return free_entries;
+
+ /* Refresh the local tail pointer.
+ * cached_cons is r->size bigger than the real consumer pointer so
+ * that this addition can be avoided in the more frequently
+ * executed code that computs free_entries in the beginning of
+ * this function. Without this optimization it whould have been
+ * free_entries = r->cached_prod - r->cached_cons + r->size.
+ */
+ r->cached_cons = *r->consumer + r->size;
+
+ return r->cached_cons - r->cached_prod;
+}
+
+static inline __u32 xsk_cons_nb_avail(struct xsk_ring_cons *r, __u32 nb)
+{
+ __u32 entries = r->cached_prod - r->cached_cons;
+
+ if (entries == 0) {
+ r->cached_prod = *r->producer;
+ entries = r->cached_prod - r->cached_cons;
+ }
+
+ return (entries > nb) ? nb : entries;
+}
+
+static inline size_t xsk_ring_prod__reserve(struct xsk_ring_prod *prod,
+ size_t nb, __u32 *idx)
+{
+ if (unlikely(xsk_prod_nb_free(prod, nb) < nb))
+ return 0;
+
+ *idx = prod->cached_prod;
+ prod->cached_prod += nb;
+
+ return nb;
+}
+
+static inline void xsk_ring_prod__submit(struct xsk_ring_prod *prod, size_t nb)
+{
+ /* Make sure everything has been written to the ring before signalling
+ * this to the kernel.
+ */
+ smp_wmb();
+
+ *prod->producer += nb;
+}
+
+static inline size_t xsk_ring_cons__peek(struct xsk_ring_cons *cons,
+ size_t nb, __u32 *idx)
+{
+ size_t entries = xsk_cons_nb_avail(cons, nb);
+
+ if (likely(entries > 0)) {
+ /* Make sure we do not speculatively read the data before
+ * we have received the packet buffers from the ring.
+ */
+ smp_rmb();
+
+ *idx = cons->cached_cons;
+ cons->cached_cons += entries;
+ }
+
+ return entries;
+}
+
+static inline void xsk_ring_cons__release(struct xsk_ring_cons *cons, size_t nb)
+{
+ *cons->consumer += nb;
+}
+
+static inline void *xsk_umem__get_data(void *umem_area, __u64 addr)
+{
+ return &((char *)umem_area)[addr];
+}
+
+LIBBPF_API int xsk_umem__fd(const struct xsk_umem *umem);
+LIBBPF_API int xsk_socket__fd(const struct xsk_socket *xsk);
+
+#define XSK_RING_CONS__DEFAULT_NUM_DESCS 2048
+#define XSK_RING_PROD__DEFAULT_NUM_DESCS 2048
+#define XSK_UMEM__DEFAULT_FRAME_SHIFT 11 /* 2048 bytes */
+#define XSK_UMEM__DEFAULT_FRAME_SIZE (1 << XSK_UMEM__DEFAULT_FRAME_SHIFT)
+#define XSK_UMEM__DEFAULT_FRAME_HEADROOM 0
+
+struct xsk_umem_config {
+ __u32 fill_size;
+ __u32 comp_size;
+ __u32 frame_size;
+ __u32 frame_headroom;
+};
+
+/* Flags for the libbpf_flags field. */
+#define XSK_LIBBPF_FLAGS__INHIBIT_PROG_LOAD (1 << 0)
+
+struct xsk_socket_config {
+ __u32 rx_size;
+ __u32 tx_size;
+ __u32 libbpf_flags;
+ __u32 xdp_flags;
+ __u16 bind_flags;
+};
+
+/* Set config to NULL to get the default configuration. */
+LIBBPF_API int xsk_umem__create(struct xsk_umem **umem,
+ void *umem_area, __u64 size,
+ struct xsk_ring_prod *fill,
+ struct xsk_ring_cons *comp,
+ const struct xsk_umem_config *config);
+LIBBPF_API int xsk_socket__create(struct xsk_socket **xsk,
+ const char *ifname, __u32 queue_id,
+ struct xsk_umem *umem,
+ struct xsk_ring_cons *rx,
+ struct xsk_ring_prod *tx,
+ const struct xsk_socket_config *config);
+
+/* Returns 0 for success and -EBUSY if the umem is still in use. */
+LIBBPF_API int xsk_umem__delete(struct xsk_umem *umem);
+LIBBPF_API void xsk_socket__delete(struct xsk_socket *xsk);
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
+#endif /* __LIBBPF_XSK_H */
OpenPOWER on IntegriCloud