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* | libbpf: typo and formatting fixesAndrii Nakryiko2019-05-301-8/+7
| | | | | | | | | | | | | | | | A bunch of typo and formatting fixes. Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | libbpf: simplify two pieces of logicAndrii Nakryiko2019-05-301-3/+1
| | | | | | | | | | | | | | | | | | | | | | Extra check for type is unnecessary in first case. Extra zeroing is unnecessary, as snprintf guarantees that it will zero-terminate string. Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | libbpf: use negative fd to specify missing BTFAndrii Nakryiko2019-05-301-6/+7
| | | | | | | | | | | | | | | | | | | | | | 0 is a valid FD, so it's better to initialize it to -1, as is done in other places. Also, technically, BTF type ID 0 is valid (it's a VOID type), so it's more reliable to check btf_fd, instead of btf_key_type_id, to determine if there is any BTF associated with a map. Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | libbpf: fix error code returned on corrupted ELFAndrii Nakryiko2019-05-301-1/+1
| | | | | | | | | | | | | | | | All of libbpf errors are negative, except this one. Fix it. Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | libbpf: check map name retrieved from ELFAndrii Nakryiko2019-05-301-0/+5
| | | | | | | | | | | | | | | | | | Validate there was no error retrieving symbol name corresponding to a BPF map. Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | libbpf: simplify endianness checkAndrii Nakryiko2019-05-301-25/+12
| | | | | | | | | | | | | | | | | | | | Rewrite endianness check to use "more canonical" way, using compiler-defined macros, similar to few other places in libbpf. It also is more obvious and shorter. Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | libbpf: preserve errno before calling into user callbackAndrii Nakryiko2019-05-301-4/+4
| | | | | | | | | | | | | | | | | | pr_warning ultimately may call into user-provided callback function, which can clobber errno value, so we need to save it before that. Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | libbpf: fix detection of corrupted BPF instructions sectionAndrii Nakryiko2019-05-301-5/+7
| | | | | | | | | | | | | | | | | | Ensure that size of a section w/ BPF instruction is exactly a multiple of BPF instruction size. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | libbpf: prevent overwriting of log_level in bpf_object__load_progs()Quentin Monnet2019-05-291-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are two functions in libbpf that support passing a log_level parameter for the verifier for loading programs: bpf_object__load_xattr() and bpf_prog_load_xattr(). Both accept an attribute object containing the log_level, and apply it to the programs to load. It turns out that to effectively load the programs, the latter function eventually relies on the former. This was not taken into account when adding support for log_level in bpf_object__load_xattr(), and the log_level passed to bpf_prog_load_xattr() later gets overwritten with a zero value, thus disabling verifier logs for the program in all cases: bpf_prog_load_xattr() // prog->log_level = attr1->log_level; -> bpf_object__load() // attr2->log_level = 0; -> bpf_object__load_xattr() // <pass prog and attr2> -> bpf_object__load_progs() // prog->log_level = attr2->log_level; Fix this by OR-ing the log_level in bpf_object__load_progs(), instead of overwriting it. v2: Fix commit log description (confusion on function names in v1). Fixes: 60276f984998 ("libbpf: add bpf_object__load_xattr() API function to pass log_level") Reported-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | libbpf: add bpf_object__load_xattr() API function to pass log_levelQuentin Monnet2019-05-284-4/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | libbpf was recently made aware of the log_level attribute for programs, used to specify the level of information expected to be dumped by the verifier. Function bpf_prog_load_xattr() got support for this log_level parameter. But some applications using libbpf rely on another function to load programs, bpf_object__load(), which does accept any parameter for log level. Create an API function based on bpf_object__load(), but accepting an "attr" object as a parameter. Then add a log_level field to that object, so that applications calling the new bpf_object__load_xattr() can pick the desired log level. v3: - Rewrite commit log. v2: - We are in a new cycle, bump libbpf extraversion number. Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com> Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | libbpf: fix warning that PTR_ERR_OR_ZERO can be usedHariprasad Kelam2019-05-281-3/+1
| | | | | | | | | | | | | | | | | | | | Fix below warning reported by coccicheck: /tools/lib/bpf/libbpf.c:3461:1-3: WARNING: PTR_ERR_OR_ZERO can be used Signed-off-by: Hariprasad Kelam <hariprasad.kelam@gmail.com> Acked-by: Yonghong Song <yhs@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | libbpf: add "prog_flags" to bpf_program/bpf_prog_load_attr/bpf_load_program_attrJiong Wang2019-05-244-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | libbpf doesn't allow passing "prog_flags" during bpf program load in a couple of load related APIs, "bpf_load_program_xattr", "load_program" and "bpf_prog_load_xattr". It makes sense to allow passing "prog_flags" which is useful for customizing program loading. Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Jiong Wang <jiong.wang@netronome.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | libbpf: add btf_dump API for BTF-to-C conversionAndrii Nakryiko2019-05-244-1/+1359
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BTF contains enough type information to allow generating valid compilable C header w/ correct layout of structs/unions and all the typedef/enum definitions. This patch adds a new "object" - btf_dump to facilitate dumping BTF as valid C. btf_dump__dump_type() is the main API which takes care of dumping out (through user-provided printf-like callback function) C definitions for given type ID and it's required dependencies. This allows for not just dumping out entirety of BTF types, but also selective filtering based on user-provided criterias w/ minimal set of dependent types. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | libbpf: switch btf_dedup() to hashmap for dedup tableAndrii Nakryiko2019-05-241-116/+85
| | | | | | | | | | | | | | Utilize libbpf's hashmap as a multimap fof dedup_table implementation. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | libbpf: add resizable non-thread safe internal hashmapAndrii Nakryiko2019-05-243-1/+403
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is a need for fast point lookups inside libbpf for multiple use cases (e.g., name resolution for BTF-to-C conversion, by-name lookups in BTF for upcoming BPF CO-RE relocation support, etc). This patch implements simple resizable non-thread safe hashmap using single linked list chains. Four different insert strategies are supported: - HASHMAP_ADD - only add key/value if key doesn't exist yet; - HASHMAP_SET - add key/value pair if key doesn't exist yet; otherwise, update value; - HASHMAP_UPDATE - update value, if key already exists; otherwise, do nothing and return -ENOENT; - HASHMAP_APPEND - always add key/value pair, even if key already exists. This turns hashmap into a multimap by allowing multiple values to be associated with the same key. Most useful read API for such hashmap is hashmap__for_each_key_entry() iteration. If hashmap__find() is still used, it will return last inserted key/value entry (first in a bucket chain). For HASHMAP_SET and HASHMAP_UPDATE, old key/value pair is returned, so that calling code can handle proper memory management, if necessary. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | libbpf: add btf__parse_elf API to load .BTF and .BTF.extAndrii Nakryiko2019-05-243-0/+135
| | | | | | | | | | | | | | | | | | | | | | | | | | Loading BTF and BTF.ext from ELF file is a common need. Instead of requiring every user to re-implement it, let's provide this API from libbpf itself. It's mostly copy/paste from `bpftool btf dump` implementation, which will be switched to libbpf's version in next patch. btf__parse_elf allows to load BTF and optionally BTF.ext. This is also useful for tests that need to load/work with BTF, loaded from test ELF files. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | libbpf: ensure libbpf.h is included along libbpf_internal.hAndrii Nakryiko2019-05-241-0/+2
| | | | | | | | | | | | | | | | libbpf_internal.h expects a bunch of stuff defined in libbpf.h to be defined. This patch makes sure that libbpf.h is always included. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | libbpf: emit diff of mismatched public API, if anyAndrii Nakryiko2019-05-221-0/+10
|/ | | | | | | | | | | It's easy to have a mismatch of "intended to be public" vs really exposed API functions. While Makefile does check for this mismatch, if it actually occurs it's not trivial to determine which functions are accidentally exposed. This patch dumps out a diff showing what's not supposed to be exposed facilitating easier fixing. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* libbpf: move logging helpers into libbpf_internal.hAndrii Nakryiko2019-05-165-16/+15
| | | | | | | | | | | | | libbpf_util.h header was recently exposed as public as a dependency of xsk.h. In addition to memory barriers, it contained logging helpers, which are not supposed to be exposed. This patch moves those into libbpf_internal.h, which is kept as an internal header. Cc: Stanislav Fomichev <sdf@google.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Fixes: 7080da890984 ("libbpf: add libbpf_util.h to header install.") Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* libbpf: don't fail when feature probing failsStanislav Fomichev2019-05-161-1/+1
| | | | | | | | | | | | | Otherwise libbpf is unusable from unprivileged process with kernel.kernel.unprivileged_bpf_disabled=1. All I get is EPERM from the probes, even if I just want to open an ELF object and look at what progs/maps it has. Instead of dying on probes, let's just pr_debug the error and try to continue. Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* libbpf: detect supported kernel BTF features and sanitize BTFAndrii Nakryiko2019-05-133-33/+197
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Depending on used versions of libbpf, Clang, and kernel, it's possible to have valid BPF object files with valid BTF information, that still won't load successfully due to Clang emitting newer BTF features (e.g., BTF_KIND_FUNC, .BTF.ext's line_info/func_info, BTF_KIND_DATASEC, etc), that are not yet supported by older kernel. This patch adds detection of BTF features and sanitizes BPF object's BTF by substituting various supported BTF kinds, which have compatible layout: - BTF_KIND_FUNC -> BTF_KIND_TYPEDEF - BTF_KIND_FUNC_PROTO -> BTF_KIND_ENUM - BTF_KIND_VAR -> BTF_KIND_INT - BTF_KIND_DATASEC -> BTF_KIND_STRUCT Replacement is done in such a way as to preserve as much information as possible (names, sizes, etc) where possible without violating kernel's validation rules. v2->v3: - remove duplicate #defines from libbpf_util.h v1->v2: - add internal libbpf_internal.h w/ common stuff - switch SK storage BTF to use new libbpf__probe_raw_btf() Reported-by: Alexei Starovoitov <ast@fb.com> Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* libbpf: remove unnecessary cast-to-voidBjörn Töpel2019-05-061-14/+10
| | | | | | | | | | | | | | The patches with fixes tags added a cast-to-void in the places when the return value of a function was ignored. This is not common practice in the kernel, and is therefore removed in this patch. Reported-by: Daniel Borkmann <daniel@iogearbox.net> Fixes: 5750902a6e9b ("libbpf: proper XSKMAP cleanup") Fixes: 0e6741f09297 ("libbpf: fix invalid munmap call") Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* libbpf: add libbpf_util.h to header install.William Tu2019-05-051-0/+1
| | | | | | | | | | The libbpf_util.h is used by xsk.h, so add it to the install headers. Reported-by: Ben Pfaff <blp@ovn.org> Signed-off-by: William Tu <u9012063@gmail.com> Acked-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* tools/bpf: fix perf build error with uClibc (seen on ARC)Vineet Gupta2019-05-051-0/+2
| | | | | | | | | | | | | | | | | | | | | | When build perf for ARC recently, there was a build failure due to lack of __NR_bpf. | Auto-detecting system features: | | ... get_cpuid: [ OFF ] | ... bpf: [ on ] | | # error __NR_bpf not defined. libbpf does not support your arch. ^~~~~ | bpf.c: In function 'sys_bpf': | bpf.c:66:17: error: '__NR_bpf' undeclared (first use in this function) | return syscall(__NR_bpf, cmd, attr, size); | ^~~~~~~~ | sys_bpf Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Acked-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* libbpf: proper XSKMAP cleanupBjörn Töpel2019-05-041-55/+60
| | | | | | | | | | | | | | | | The bpf_map_update_elem() function, when used on an XSKMAP, will fail if not a valid AF_XDP socket is passed as value. Therefore, this is function cannot be used to clear the XSKMAP. Instead, the bpf_map_delete_elem() function should be used for that. This patch also simplifies the code by breaking up xsk_update_bpf_maps() into three smaller functions. Reported-by: William Tu <u9012063@gmail.com> Fixes: 1cad07884239 ("libbpf: add support for using AF_XDP sockets") Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Tested-by: William Tu <u9012063@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* libbpf: fix invalid munmap callBjörn Töpel2019-05-041-37/+40
| | | | | | | | | | | | | | | | | When unmapping the AF_XDP memory regions used for the rings, an invalid address was passed to the munmap() calls. Instead of passing the beginning of the memory region, the descriptor region was passed to munmap. When the userspace application tried to tear down an AF_XDP socket, the operation failed and the application would still have a reference to socket it wished to get rid of. Reported-by: William Tu <u9012063@gmail.com> Fixes: 1cad07884239 ("libbpf: add support for using AF_XDP sockets") Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Tested-by: William Tu <u9012063@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2019-05-021-0/+1
|\ | | | | | | | | | | Three trivial overlapping conflicts. Signed-off-by: David S. Miller <davem@davemloft.net>
| * libbpf: add binary to gitignoreMatteo Croce2019-04-251-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | Some binaries are generated when building libbpf from tools/lib/bpf/, namely libbpf.so.0.0.2 and libbpf.so.0. Add them to the local .gitignore. Signed-off-by: Matteo Croce <mcroce@redhat.com> Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | bpf: Support BPF_MAP_TYPE_SK_STORAGE in bpf map probingMartin KaFai Lau2019-04-271-1/+73
| | | | | | | | | | | | | | | | | | This patch supports probing for the new BPF_MAP_TYPE_SK_STORAGE. BPF_MAP_TYPE_SK_STORAGE enforces BTF usage, so the new probe requires to create and load a BTF also. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | tools: sync bpf.hMatt Mullins2019-04-262-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | This adds BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE, and fixes up the error: enumeration value ‘BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE’ not handled in switch [-Werror=switch-enum] build errors it would otherwise cause in libbpf. Signed-off-by: Matt Mullins <mmullins@fb.com> Acked-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | libbpf: fix samples/bpf build failure due to undefined UINT32_MAXDaniel T. Lee2019-04-251-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, building bpf samples will cause the following error. ./tools/lib/bpf/bpf.h:132:27: error: 'UINT32_MAX' undeclared here (not in a function) .. #define BPF_LOG_BUF_SIZE (UINT32_MAX >> 8) /* verifier maximum in kernels <= 5.1 */ ^ ./samples/bpf/bpf_load.h:31:25: note: in expansion of macro 'BPF_LOG_BUF_SIZE' extern char bpf_log_buf[BPF_LOG_BUF_SIZE]; ^~~~~~~~~~~~~~~~ Due to commit 4519efa6f8ea ("libbpf: fix BPF_LOG_BUF_SIZE off-by-one error") hard-coded size of BPF_LOG_BUF_SIZE has been replaced with UINT32_MAX which is defined in <stdint.h> header. Even with this change, bpf selftests are running fine since these are built with clang and it includes header(-idirafter) from clang/6.0.0/include. (it has <stdint.h>) clang -I. -I./include/uapi -I../../../include/uapi -idirafter /usr/local/include -idirafter /usr/include \ -idirafter /usr/lib/llvm-6.0/lib/clang/6.0.0/include -idirafter /usr/include/x86_64-linux-gnu \ -Wno-compare-distinct-pointer-types -O2 -target bpf -emit-llvm -c progs/test_sysctl_prog.c -o - | \ llc -march=bpf -mcpu=generic -filetype=obj -o /linux/tools/testing/selftests/bpf/test_sysctl_prog.o But bpf samples are compiled with GCC, and it only searches and includes headers declared at the target file. As '#include <stdint.h>' hasn't been declared in tools/lib/bpf/bpf.h, it causes build failure of bpf samples. gcc -Wp,-MD,./samples/bpf/.sockex3_user.o.d -Wall -Wmissing-prototypes -Wstrict-prototypes \ -O2 -fomit-frame-pointer -std=gnu89 -I./usr/include -I./tools/lib/ -I./tools/testing/selftests/bpf/ \ -I./tools/ lib/ -I./tools/include -I./tools/perf -c -o ./samples/bpf/sockex3_user.o ./samples/bpf/sockex3_user.c; This commit add declaration of '#include <stdint.h>' to tools/lib/bpf/bpf.h to fix this problem. Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com> Acked-by: Yonghong Song <yhs@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | bpf, libbpf: fix segfault in bpf_object__init_maps' pr_debug statementDaniel Borkmann2019-04-251-3/+3
| | | | | | | | | | | | | | | | | | | | | | Ran into it while testing; in bpf_object__init_maps() data can be NULL in the case where no map section is present. Therefore we simply cannot access data->d_size before NULL test. Move the pr_debug() where it's safe to access. Fixes: d859900c4c56 ("bpf, libbpf: support global data/bss/rodata sections") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | bpf, libbpf: handle old kernels more graceful wrt global data sectionsDaniel Borkmann2019-04-251-13/+86
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Andrii reported a corner case where e.g. global static data is present in the BPF ELF file in form of .data/.bss/.rodata section, but without any relocations to it. Such programs could be loaded before commit d859900c4c56 ("bpf, libbpf: support global data/bss/rodata sections"), whereas afterwards if kernel lacks support then loading would fail. Add a probing mechanism which skips setting up libbpf internal maps in case of missing kernel support. In presence of relocation entries, we abort the load attempt. Fixes: d859900c4c56 ("bpf, libbpf: support global data/bss/rodata sections") Reported-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | libbpf: fix BPF_LOG_BUF_SIZE off-by-one errorMcCabe, Robert J2019-04-191-1/+1
| | | | | | | | | | | | | | | | | | The BPF_PROG_LOAD condition for kernel version <= 5.1 is log->len_total > UINT_MAX >> 8 /* (16 * 1024 * 1024) - 1 */ Signed-off-by: McCabe, Robert J <robert.mccabe@rockwellcollins.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | libbpf: remove compile time warning from libbpf_util.hMagnus Karlsson2019-04-181-1/+1
| | | | | | | | | | | | | | | | | | | | | | Having a helpful compile time warning in libbpf_util.h is not a good idea since all warnings are treated as errors. Change this into a comment in the code instead. Fixes: b7e3a28019c9 ("libbpf: remove dependency on barrier.h in xsk.h") Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Acked-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | libbpf: optimize barrier for XDP socket ringsMagnus Karlsson2019-04-162-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The full memory barrier in the XDP socket rings on the consumer side between the load of the data and the store of the consumer ring is there to protect the store from being executed before the load of the data. If this was allowed to happen, the producer might overwrite the data field with a new entry before the consumer got the chance to read it. On x86, stores are guaranteed not to be reordered with older loads, so it does not need a full memory barrier here. A compile time barrier would be enough. This patch introdcues a new primitive in libbpf_util.h that implements a new barrier type (libbpf_smp_rwmb) hindering stores to be reordered with older loads. It is then used in the XDP socket ring access code in libbpf to improve performance. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | libbpf: remove dependency on barrier.h in xsk.hMagnus Karlsson2019-04-162-3/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The use of smp_rmb() and smp_wmb() creates a Linux header dependency on barrier.h that is unnecessary in most parts. This patch implements the two small defines that are needed from barrier.h. As a bonus, the new implementations are faster than the default ones as they default to sfence and lfence for x86, while we only need a compiler barrier in our case. Just as it is when the same ring access code is compiled in the kernel. Fixes: 1cad07884239 ("libbpf: add support for using AF_XDP sockets") Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | libbpf: remove likely/unlikely in xsk.hMagnus Karlsson2019-04-161-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | This patch removes the use of likely and unlikely in xsk.h since they create a dependency on Linux headers as reported by several users. There have also been reports that the use of these decreases performance as the compiler puts the code on two different cache lines instead of on a single one. All in all, I think we are better off without them. Fixes: 1cad07884239 ("libbpf: add support for using AF_XDP sockets") Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | libbpf: fix XDP socket ring buffer memory orderingMagnus Karlsson2019-04-161-2/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The ring buffer code of XDP sockets is missing a memory barrier on the consumer side between the load of the data and the write that signals that it is ok for the producer to put new data into the buffer. On architectures that does not guarantee that stores are not reordered with older loads, the producer might put data into the ring before the consumer had the chance to read it. As IA does guarantee this ordering, it would only need a compiler barrier here, but there are no primitives in barrier.h for this specific case (hinder writes to be ordered before older reads) so I had to add a smp_mb() here which will translate into a run-time synch operation on IA. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | libbpf: fix printf formatter for ptrdiff_t argumentAndrii Nakryiko2019-04-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Using %ld for printing out value of ptrdiff_t type is not portable between 32-bit and 64-bit archs. This is causing compilation errors for libbpf on 32-bit platform (discovered as part of an effort to integrate libbpf into systemd ([0])). Proper formatter is %td, which is used in this patch. v2->v1: - add Reported-by - provide more context on how this issue was discovered [0] https://github.com/systemd/systemd/pull/12151 Reported-by: Evgeny Vereshchagin <evvers@ya.ru> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Alexei Starovoitov <ast@fb.com> Cc: Yonghong Song <yhs@fb.com> Signed-off-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | btf: add support for VAR and DATASEC in btf_dedup()Andrii Nakryiko2019-04-161-2/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds support for VAR and DATASEC in btf_dedup(). VAR/DATASEC are never deduplicated, but they need to be processed anyway as types they refer to might need to be remapped due to deduplication and compaction. Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Yonghong Song <yhs@fb.com> Cc: Alexei Starovoitov <ast@fb.com> Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | libbpf: Support sysctl hookAndrey Ignatov2019-04-122-0/+4
| | | | | | | | | | | | | | | | Support BPF_PROG_TYPE_CGROUP_SYSCTL program in libbpf: identifying program and attach types by section name, probe. Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller2019-04-1111-115/+651
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Daniel Borkmann says: ==================== pull-request: bpf-next 2019-04-12 The following pull-request contains BPF updates for your *net-next* tree. The main changes are: 1) Improve BPF verifier scalability for large programs through two optimizations: i) remove verifier states that are not useful in pruning, ii) stop walking parentage chain once first LIVE_READ is seen. Combined gives approx 20x speedup. Increase limits for accepting large programs under root, and add various stress tests, from Alexei. 2) Implement global data support in BPF. This enables static global variables for .data, .rodata and .bss sections to be properly handled which allows for more natural program development. This also opens up the possibility to optimize program workflow by compiling ELFs only once and later only rewriting section data before reload, from Daniel and with test cases and libbpf refactoring from Joe. 3) Add config option to generate BTF type info for vmlinux as part of the kernel build process. DWARF debug info is converted via pahole to BTF. Latter relies on libbpf and makes use of BTF deduplication algorithm which results in 100x savings compared to DWARF data. Resulting .BTF section is typically about 2MB in size, from Andrii. 4) Add BPF verifier support for stack access with variable offset from helpers and add various test cases along with it, from Andrey. 5) Extend bpf_skb_adjust_room() growth BPF helper to mark inner MAC header so that L2 encapsulation can be used for tc tunnels, from Alan. 6) Add support for input __sk_buff context in BPF_PROG_TEST_RUN so that users can define a subset of allowed __sk_buff fields that get fed into the test program, from Stanislav. 7) Add bpf fs multi-dimensional array tests for BTF test suite and fix up various UBSAN warnings in bpftool, from Yonghong. 8) Generate a pkg-config file for libbpf, from Luca. 9) Dump program's BTF id in bpftool, from Prashant. 10) libbpf fix to use smaller BPF log buffer size for AF_XDP's XDP program, from Magnus. 11) kallsyms related fixes for the case when symbols are not present in BPF selftests and samples, from Daniel ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
| * libbpf: add support for ctx_{size, }_{in, out} in BPF_PROG_TEST_RUNStanislav Fomichev2019-04-112-0/+10
| | | | | | | | | | | | | | | | | | | | Support recently introduced input/output context for test runs. We extend only bpf_prog_test_run_xattr. bpf_prog_test_run is unextendable and left as is. Signed-off-by: Stanislav Fomichev <sdf@google.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| * libbpf: Fix build with gcc-8Andrey Ignatov2019-04-111-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Reported in [1]. With gcc 8.3.0 the following error is issued: cc -Ibpf@sta -I. -I.. -I.././include -I.././include/uapi -fdiagnostics-color=always -fsanitize=address,undefined -fno-omit-frame-pointer -pipe -D_FILE_OFFSET_BITS=64 -Wall -Winvalid-pch -Werror -g -fPIC -g -O2 -Werror -Wall -Wno-pointer-arith -Wno-sign-compare -MD -MQ 'bpf@sta/src_libbpf.c.o' -MF 'bpf@sta/src_libbpf.c.o.d' -o 'bpf@sta/src_libbpf.c.o' -c ../src/libbpf.c ../src/libbpf.c: In function 'bpf_object__elf_collect': ../src/libbpf.c:947:18: error: 'map_def_sz' may be used uninitialized in this function [-Werror=maybe-uninitialized] if (map_def_sz <= sizeof(struct bpf_map_def)) { ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ../src/libbpf.c:827:18: note: 'map_def_sz' was declared here int i, map_idx, map_def_sz, nr_syms, nr_maps = 0, nr_maps_glob = 0; ^~~~~~~~~~ According to [2] -Wmaybe-uninitialized is enabled by -Wall. Same error is generated by clang's -Wconditional-uninitialized. [1] https://github.com/libbpf/libbpf/pull/29#issuecomment-481902601 [2] https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html Fixes: d859900c4c56 ("bpf, libbpf: support global data/bss/rodata sections") Reported-by: Evgeny Vereshchagin <evvers@ya.ru> Signed-off-by: Andrey Ignatov <rdna@fb.com> Acked-by: Yonghong Song <yhs@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| * libbpf: fix crash in XDP socket part with new larger BPF_LOG_BUF_SIZEMagnus Karlsson2019-04-101-4/+5
| | | | | | | | | | | | | | | | | | | | | | | | In commit da11b417583e ("libbpf: teach libbpf about log_level bit 2"), the BPF_LOG_BUF_SIZE was increased to 16M. The XDP socket part of libbpf allocated the log_buf on the stack, but for the new 16M buffer size this is not going to work. Change the code so it uses a 16K buffer instead. Fixes: da11b417583e ("libbpf: teach libbpf about log_level bit 2") Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| * bpf, bpftool: fix a few ubsan warningsYonghong Song2019-04-101-10/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The issue is reported at https://github.com/libbpf/libbpf/issues/28. Basically, per C standard, for void *memcpy(void *dest, const void *src, size_t n) if "dest" or "src" is NULL, regardless of whether "n" is 0 or not, the result of memcpy is undefined. clang ubsan reported three such instances in bpf.c with the following pattern: memcpy(dest, 0, 0). Although in practice, no known compiler will cause issues when copy size is 0. Let us still fix the issue to silence ubsan warnings. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| * bpf, libbpf: add support for BTF Var and DataSecDaniel Borkmann2019-04-095-20/+235
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds libbpf support for BTF Var and DataSec kinds. Main point here is that libbpf needs to do some preparatory work before the whole BTF object can be loaded into the kernel, that is, fixing up of DataSec size taken from the ELF section size and non-static variable offset which needs to be taken from the ELF's string section. Upstream LLVM doesn't fix these up since at time of BTF emission it is too early in the compilation process thus this information isn't available yet, hence loader needs to take care of it. Note, deduplication handling has not been in the scope of this work and needs to be addressed in a future commit. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://reviews.llvm.org/D59441 Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * bpf, libbpf: support global data/bss/rodata sectionsDaniel Borkmann2019-04-096-48/+314
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This work adds BPF loader support for global data sections to libbpf. This allows to write BPF programs in more natural C-like way by being able to define global variables and const data. Back at LPC 2018 [0] we presented a first prototype which implemented support for global data sections by extending BPF syscall where union bpf_attr would get additional memory/size pair for each section passed during prog load in order to later add this base address into the ldimm64 instruction along with the user provided offset when accessing a variable. Consensus from LPC was that for proper upstream support, it would be more desirable to use maps instead of bpf_attr extension as this would allow for introspection of these sections as well as potential live updates of their content. This work follows this path by taking the following steps from loader side: 1) In bpf_object__elf_collect() step we pick up ".data", ".rodata", and ".bss" section information. 2) If present, in bpf_object__init_internal_map() we add maps to the obj's map array that corresponds to each of the present sections. Given section size and access properties can differ, a single entry array map is created with value size that is corresponding to the ELF section size of .data, .bss or .rodata. These internal maps are integrated into the normal map handling of libbpf such that when user traverses all obj maps, they can be differentiated from user-created ones via bpf_map__is_internal(). In later steps when we actually create these maps in the kernel via bpf_object__create_maps(), then for .data and .rodata sections their content is copied into the map through bpf_map_update_elem(). For .bss this is not necessary since array map is already zero-initialized by default. Additionally, for .rodata the map is frozen as read-only after setup, such that neither from program nor syscall side writes would be possible. 3) In bpf_program__collect_reloc() step, we record the corresponding map, insn index, and relocation type for the global data. 4) And last but not least in the actual relocation step in bpf_program__relocate(), we mark the ldimm64 instruction with src_reg = BPF_PSEUDO_MAP_VALUE where in the first imm field the map's file descriptor is stored as similarly done as in BPF_PSEUDO_MAP_FD, and in the second imm field (as ldimm64 is 2-insn wide) we store the access offset into the section. Given these maps have only single element ldimm64's off remains zero in both parts. 5) On kernel side, this special marked BPF_PSEUDO_MAP_VALUE load will then store the actual target address in order to have a 'map-lookup'-free access. That is, the actual map value base address + offset. The destination register in the verifier will then be marked as PTR_TO_MAP_VALUE, containing the fixed offset as reg->off and backing BPF map as reg->map_ptr. Meaning, it's treated as any other normal map value from verification side, only with efficient, direct value access instead of actual call to map lookup helper as in the typical case. Currently, only support for static global variables has been added, and libbpf rejects non-static global variables from loading. This can be lifted until we have proper semantics for how BPF will treat multi-object BPF loads. From BTF side, libbpf will set the value type id of the types corresponding to the ".bss", ".data" and ".rodata" names which LLVM will emit without the object name prefix. The key type will be left as zero, thus making use of the key-less BTF option in array maps. Simple example dump of program using globals vars in each section: # bpftool prog [...] 6784: sched_cls name load_static_dat tag a7e1291567277844 gpl loaded_at 2019-03-11T15:39:34+0000 uid 0 xlated 1776B jited 993B memlock 4096B map_ids 2238,2237,2235,2236,2239,2240 # bpftool map show id 2237 2237: array name test_glo.bss flags 0x0 key 4B value 64B max_entries 1 memlock 4096B # bpftool map show id 2235 2235: array name test_glo.data flags 0x0 key 4B value 64B max_entries 1 memlock 4096B # bpftool map show id 2236 2236: array name test_glo.rodata flags 0x80 key 4B value 96B max_entries 1 memlock 4096B # bpftool prog dump xlated id 6784 int load_static_data(struct __sk_buff * skb): ; int load_static_data(struct __sk_buff *skb) 0: (b7) r6 = 0 ; test_reloc(number, 0, &num0); 1: (63) *(u32 *)(r10 -4) = r6 2: (bf) r2 = r10 ; int load_static_data(struct __sk_buff *skb) 3: (07) r2 += -4 ; test_reloc(number, 0, &num0); 4: (18) r1 = map[id:2238] 6: (18) r3 = map[id:2237][0]+0 <-- direct addr in .bss area 8: (b7) r4 = 0 9: (85) call array_map_update_elem#100464 10: (b7) r1 = 1 ; test_reloc(number, 1, &num1); [...] ; test_reloc(string, 2, str2); 120: (18) r8 = map[id:2237][0]+16 <-- same here at offset +16 122: (18) r1 = map[id:2239] 124: (18) r3 = map[id:2237][0]+16 126: (b7) r4 = 0 127: (85) call array_map_update_elem#100464 128: (b7) r1 = 120 ; str1[5] = 'x'; 129: (73) *(u8 *)(r9 +5) = r1 ; test_reloc(string, 3, str1); 130: (b7) r1 = 3 131: (63) *(u32 *)(r10 -4) = r1 132: (b7) r9 = 3 133: (bf) r2 = r10 ; int load_static_data(struct __sk_buff *skb) 134: (07) r2 += -4 ; test_reloc(string, 3, str1); 135: (18) r1 = map[id:2239] 137: (18) r3 = map[id:2235][0]+16 <-- direct addr in .data area 139: (b7) r4 = 0 140: (85) call array_map_update_elem#100464 141: (b7) r1 = 111 ; __builtin_memcpy(&str2[2], "hello", sizeof("hello")); 142: (73) *(u8 *)(r8 +6) = r1 <-- further access based on .bss data 143: (b7) r1 = 108 144: (73) *(u8 *)(r8 +5) = r1 [...] For Cilium use-case in particular, this enables migrating configuration constants from Cilium daemon's generated header defines into global data sections such that expensive runtime recompilations with LLVM can be avoided altogether. Instead, the ELF file becomes effectively a "template", meaning, it is compiled only once (!) and the Cilium daemon will then rewrite relevant configuration data from the ELF's .data or .rodata sections directly instead of recompiling the program. The updated ELF is then loaded into the kernel and atomically replaces the existing program in the networking datapath. More info in [0]. Based upon recent fix in LLVM, commit c0db6b6bd444 ("[BPF] Don't fail for static variables"). [0] LPC 2018, BPF track, "ELF relocation for static data in BPF", http://vger.kernel.org/lpc-bpf2018.html#session-3 Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * bpf, libbpf: refactor relocation handlingJoe Stringer2019-04-091-30/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | Adjust the code for relocations slightly with no functional changes, so that upcoming patches that will introduce support for relocations into the .data, .rodata and .bss sections can be added independent of these changes. Signed-off-by: Joe Stringer <joe@wand.net.nz> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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