summaryrefslogtreecommitdiffstats
path: root/arch/x86/vdso
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/vdso')
-rw-r--r--arch/x86/vdso/Makefile34
-rw-r--r--arch/x86/vdso/vclock_gettime.c3
-rw-r--r--arch/x86/vdso/vdso-fakesections.c32
-rw-r--r--arch/x86/vdso/vdso-layout.lds.S102
-rw-r--r--arch/x86/vdso/vdso.lds.S2
-rw-r--r--arch/x86/vdso/vdso2c.c195
-rw-r--r--arch/x86/vdso/vdso2c.h105
-rw-r--r--arch/x86/vdso/vdso32-setup.c19
-rw-r--r--arch/x86/vdso/vdso32/vdso-fakesections.c1
-rw-r--r--arch/x86/vdso/vdsox32.lds.S2
-rw-r--r--arch/x86/vdso/vma.c26
11 files changed, 290 insertions, 231 deletions
diff --git a/arch/x86/vdso/Makefile b/arch/x86/vdso/Makefile
index 3c0809a0631f..5a4affe025e8 100644
--- a/arch/x86/vdso/Makefile
+++ b/arch/x86/vdso/Makefile
@@ -10,8 +10,7 @@ VDSO32-$(CONFIG_X86_32) := y
VDSO32-$(CONFIG_COMPAT) := y
# files to link into the vdso
-vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o vdso-fakesections.o
-vobjs-nox32 := vdso-fakesections.o
+vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o
# files to link into kernel
obj-y += vma.o
@@ -38,7 +37,8 @@ vdso_img_sodbg := $(vdso_img-y:%=vdso%.so.dbg)
obj-y += $(vdso_img_objs)
targets += $(vdso_img_cfiles)
targets += $(vdso_img_sodbg)
-.SECONDARY: $(vdso_img-y:%=$(obj)/vdso-image-%.c)
+.SECONDARY: $(vdso_img-y:%=$(obj)/vdso-image-%.c) \
+ $(vdso_img-y:%=$(obj)/vdso%.so)
export CPPFLAGS_vdso.lds += -P -C
@@ -55,10 +55,10 @@ hostprogs-y += vdso2c
quiet_cmd_vdso2c = VDSO2C $@
define cmd_vdso2c
- $(obj)/vdso2c $< $@
+ $(obj)/vdso2c $< $(<:%.dbg=%) $@
endef
-$(obj)/vdso-image-%.c: $(obj)/vdso%.so.dbg $(obj)/vdso2c FORCE
+$(obj)/vdso-image-%.c: $(obj)/vdso%.so.dbg $(obj)/vdso%.so $(obj)/vdso2c FORCE
$(call if_changed,vdso2c)
#
@@ -67,7 +67,8 @@ $(obj)/vdso-image-%.c: $(obj)/vdso%.so.dbg $(obj)/vdso2c FORCE
#
CFL := $(PROFILING) -mcmodel=small -fPIC -O2 -fasynchronous-unwind-tables -m64 \
$(filter -g%,$(KBUILD_CFLAGS)) $(call cc-option, -fno-stack-protector) \
- -fno-omit-frame-pointer -foptimize-sibling-calls
+ -fno-omit-frame-pointer -foptimize-sibling-calls \
+ -DDISABLE_BRANCH_PROFILING
$(vobjs): KBUILD_CFLAGS += $(CFL)
@@ -113,6 +114,10 @@ $(obj)/%-x32.o: $(obj)/%.o FORCE
targets += vdsox32.lds $(vobjx32s-y)
+$(obj)/%.so: OBJCOPYFLAGS := -S
+$(obj)/%.so: $(obj)/%.so.dbg
+ $(call if_changed,objcopy)
+
$(obj)/vdsox32.so.dbg: $(src)/vdsox32.lds $(vobjx32s) FORCE
$(call if_changed,vdso)
@@ -150,6 +155,7 @@ KBUILD_CFLAGS_32 += -m32 -msoft-float -mregparm=0 -fpic
KBUILD_CFLAGS_32 += $(call cc-option, -fno-stack-protector)
KBUILD_CFLAGS_32 += $(call cc-option, -foptimize-sibling-calls)
KBUILD_CFLAGS_32 += -fno-omit-frame-pointer
+KBUILD_CFLAGS_32 += -DDISABLE_BRANCH_PROFILING
$(vdso32-images:%=$(obj)/%.dbg): KBUILD_CFLAGS = $(KBUILD_CFLAGS_32)
$(vdso32-images:%=$(obj)/%.dbg): $(obj)/vdso32-%.so.dbg: FORCE \
@@ -169,14 +175,24 @@ quiet_cmd_vdso = VDSO $@
sh $(srctree)/$(src)/checkundef.sh '$(NM)' '$@'
VDSO_LDFLAGS = -fPIC -shared $(call cc-ldoption, -Wl$(comma)--hash-style=sysv) \
- -Wl,-Bsymbolic $(LTO_CFLAGS)
+ $(call cc-ldoption, -Wl$(comma)--build-id) -Wl,-Bsymbolic $(LTO_CFLAGS)
GCOV_PROFILE := n
#
-# Install the unstripped copies of vdso*.so.
+# Install the unstripped copies of vdso*.so. If our toolchain supports
+# build-id, install .build-id links as well.
#
quiet_cmd_vdso_install = INSTALL $(@:install_%=%)
- cmd_vdso_install = cp $< $(MODLIB)/vdso/$(@:install_%=%)
+define cmd_vdso_install
+ cp $< "$(MODLIB)/vdso/$(@:install_%=%)"; \
+ if readelf -n $< |grep -q 'Build ID'; then \
+ buildid=`readelf -n $< |grep 'Build ID' |sed -e 's/^.*Build ID: \(.*\)$$/\1/'`; \
+ first=`echo $$buildid | cut -b-2`; \
+ last=`echo $$buildid | cut -b3-`; \
+ mkdir -p "$(MODLIB)/vdso/.build-id/$$first"; \
+ ln -sf "../../$(@:install_%=%)" "$(MODLIB)/vdso/.build-id/$$first/$$last.debug"; \
+ fi
+endef
vdso_img_insttargets := $(vdso_img_sodbg:%.dbg=install_%)
diff --git a/arch/x86/vdso/vclock_gettime.c b/arch/x86/vdso/vclock_gettime.c
index b2e4f493e5b0..9793322751e0 100644
--- a/arch/x86/vdso/vclock_gettime.c
+++ b/arch/x86/vdso/vclock_gettime.c
@@ -11,9 +11,6 @@
* Check with readelf after changing.
*/
-/* Disable profiling for userspace code: */
-#define DISABLE_BRANCH_PROFILING
-
#include <uapi/linux/time.h>
#include <asm/vgtod.h>
#include <asm/hpet.h>
diff --git a/arch/x86/vdso/vdso-fakesections.c b/arch/x86/vdso/vdso-fakesections.c
deleted file mode 100644
index cb8a8d72c24b..000000000000
--- a/arch/x86/vdso/vdso-fakesections.c
+++ /dev/null
@@ -1,32 +0,0 @@
-/*
- * Copyright 2014 Andy Lutomirski
- * Subject to the GNU Public License, v.2
- *
- * Hack to keep broken Go programs working.
- *
- * The Go runtime had a couple of bugs: it would read the section table to try
- * to figure out how many dynamic symbols there were (it shouldn't have looked
- * at the section table at all) and, if there were no SHT_SYNDYM section table
- * entry, it would use an uninitialized value for the number of symbols. As a
- * workaround, we supply a minimal section table. vdso2c will adjust the
- * in-memory image so that "vdso_fake_sections" becomes the section table.
- *
- * The bug was introduced by:
- * https://code.google.com/p/go/source/detail?r=56ea40aac72b (2012-08-31)
- * and is being addressed in the Go runtime in this issue:
- * https://code.google.com/p/go/issues/detail?id=8197
- */
-
-#ifndef __x86_64__
-#error This hack is specific to the 64-bit vDSO
-#endif
-
-#include <linux/elf.h>
-
-extern const __visible struct elf64_shdr vdso_fake_sections[];
-const __visible struct elf64_shdr vdso_fake_sections[] = {
- {
- .sh_type = SHT_DYNSYM,
- .sh_entsize = sizeof(Elf64_Sym),
- }
-};
diff --git a/arch/x86/vdso/vdso-layout.lds.S b/arch/x86/vdso/vdso-layout.lds.S
index 2ec72f651ebf..de2c921025f5 100644
--- a/arch/x86/vdso/vdso-layout.lds.S
+++ b/arch/x86/vdso/vdso-layout.lds.S
@@ -6,8 +6,37 @@
* This script controls its layout.
*/
+#if defined(BUILD_VDSO64)
+# define SHDR_SIZE 64
+#elif defined(BUILD_VDSO32) || defined(BUILD_VDSOX32)
+# define SHDR_SIZE 40
+#else
+# error unknown VDSO target
+#endif
+
+#define NUM_FAKE_SHDRS 13
+
SECTIONS
{
+ /*
+ * User/kernel shared data is before the vDSO. This may be a little
+ * uglier than putting it after the vDSO, but it avoids issues with
+ * non-allocatable things that dangle past the end of the PT_LOAD
+ * segment.
+ */
+
+ vvar_start = . - 2 * PAGE_SIZE;
+ vvar_page = vvar_start;
+
+ /* Place all vvars at the offsets in asm/vvar.h. */
+#define EMIT_VVAR(name, offset) vvar_ ## name = vvar_page + offset;
+#define __VVAR_KERNEL_LDS
+#include <asm/vvar.h>
+#undef __VVAR_KERNEL_LDS
+#undef EMIT_VVAR
+
+ hpet_page = vvar_start + PAGE_SIZE;
+
. = SIZEOF_HEADERS;
.hash : { *(.hash) } :text
@@ -18,63 +47,56 @@ SECTIONS
.gnu.version_d : { *(.gnu.version_d) }
.gnu.version_r : { *(.gnu.version_r) }
+ .dynamic : { *(.dynamic) } :text :dynamic
+
+ .rodata : {
+ *(.rodata*)
+ *(.data*)
+ *(.sdata*)
+ *(.got.plt) *(.got)
+ *(.gnu.linkonce.d.*)
+ *(.bss*)
+ *(.dynbss*)
+ *(.gnu.linkonce.b.*)
+
+ /*
+ * Ideally this would live in a C file, but that won't
+ * work cleanly for x32 until we start building the x32
+ * C code using an x32 toolchain.
+ */
+ VDSO_FAKE_SECTION_TABLE_START = .;
+ . = . + NUM_FAKE_SHDRS * SHDR_SIZE;
+ VDSO_FAKE_SECTION_TABLE_END = .;
+ } :text
+
+ .fake_shstrtab : { *(.fake_shstrtab) } :text
+
+
.note : { *(.note.*) } :text :note
.eh_frame_hdr : { *(.eh_frame_hdr) } :text :eh_frame_hdr
.eh_frame : { KEEP (*(.eh_frame)) } :text
- .dynamic : { *(.dynamic) } :text :dynamic
-
- .rodata : { *(.rodata*) } :text
- .data : {
- *(.data*)
- *(.sdata*)
- *(.got.plt) *(.got)
- *(.gnu.linkonce.d.*)
- *(.bss*)
- *(.dynbss*)
- *(.gnu.linkonce.b.*)
- }
-
- .altinstructions : { *(.altinstructions) }
- .altinstr_replacement : { *(.altinstr_replacement) }
/*
- * Align the actual code well away from the non-instruction data.
- * This is the best thing for the I-cache.
+ * Text is well-separated from actual data: there's plenty of
+ * stuff that isn't used at runtime in between.
*/
- . = ALIGN(0x100);
.text : { *(.text*) } :text =0x90909090,
/*
- * The remainder of the vDSO consists of special pages that are
- * shared between the kernel and userspace. It needs to be at the
- * end so that it doesn't overlap the mapping of the actual
- * vDSO image.
+ * At the end so that eu-elflint stays happy when vdso2c strips
+ * these. A better implementation would avoid allocating space
+ * for these.
*/
-
- . = ALIGN(PAGE_SIZE);
- vvar_page = .;
-
- /* Place all vvars at the offsets in asm/vvar.h. */
-#define EMIT_VVAR(name, offset) vvar_ ## name = vvar_page + offset;
-#define __VVAR_KERNEL_LDS
-#include <asm/vvar.h>
-#undef __VVAR_KERNEL_LDS
-#undef EMIT_VVAR
-
- . = vvar_page + PAGE_SIZE;
-
- hpet_page = .;
- . = . + PAGE_SIZE;
-
- . = ALIGN(PAGE_SIZE);
- end_mapping = .;
+ .altinstructions : { *(.altinstructions) } :text
+ .altinstr_replacement : { *(.altinstr_replacement) } :text
/DISCARD/ : {
*(.discard)
*(.discard.*)
+ *(__bug_table)
}
}
diff --git a/arch/x86/vdso/vdso.lds.S b/arch/x86/vdso/vdso.lds.S
index 75e3404c83b1..6807932643c2 100644
--- a/arch/x86/vdso/vdso.lds.S
+++ b/arch/x86/vdso/vdso.lds.S
@@ -6,6 +6,8 @@
* the DSO.
*/
+#define BUILD_VDSO64
+
#include "vdso-layout.lds.S"
/*
diff --git a/arch/x86/vdso/vdso2c.c b/arch/x86/vdso/vdso2c.c
index 7a6bf50f9165..8627db24a7f6 100644
--- a/arch/x86/vdso/vdso2c.c
+++ b/arch/x86/vdso/vdso2c.c
@@ -1,3 +1,53 @@
+/*
+ * vdso2c - A vdso image preparation tool
+ * Copyright (c) 2014 Andy Lutomirski and others
+ * Licensed under the GPL v2
+ *
+ * vdso2c requires stripped and unstripped input. It would be trivial
+ * to fully strip the input in here, but, for reasons described below,
+ * we need to write a section table. Doing this is more or less
+ * equivalent to dropping all non-allocatable sections, but it's
+ * easier to let objcopy handle that instead of doing it ourselves.
+ * If we ever need to do something fancier than what objcopy provides,
+ * it would be straightforward to add here.
+ *
+ * We're keep a section table for a few reasons:
+ *
+ * The Go runtime had a couple of bugs: it would read the section
+ * table to try to figure out how many dynamic symbols there were (it
+ * shouldn't have looked at the section table at all) and, if there
+ * were no SHT_SYNDYM section table entry, it would use an
+ * uninitialized value for the number of symbols. An empty DYNSYM
+ * table would work, but I see no reason not to write a valid one (and
+ * keep full performance for old Go programs). This hack is only
+ * needed on x86_64.
+ *
+ * The bug was introduced on 2012-08-31 by:
+ * https://code.google.com/p/go/source/detail?r=56ea40aac72b
+ * and was fixed on 2014-06-13 by:
+ * https://code.google.com/p/go/source/detail?r=fc1cd5e12595
+ *
+ * Binutils has issues debugging the vDSO: it reads the section table to
+ * find SHT_NOTE; it won't look at PT_NOTE for the in-memory vDSO, which
+ * would break build-id if we removed the section table. Binutils
+ * also requires that shstrndx != 0. See:
+ * https://sourceware.org/bugzilla/show_bug.cgi?id=17064
+ *
+ * elfutils might not look for PT_NOTE if there is a section table at
+ * all. I don't know whether this matters for any practical purpose.
+ *
+ * For simplicity, rather than hacking up a partial section table, we
+ * just write a mostly complete one. We omit non-dynamic symbols,
+ * though, since they're rather large.
+ *
+ * Once binutils gets fixed, we might be able to drop this for all but
+ * the 64-bit vdso, since build-id only works in kernel RPMs, and
+ * systems that update to new enough kernel RPMs will likely update
+ * binutils in sync. build-id has never worked for home-built kernel
+ * RPMs without manual symlinking, and I suspect that no one ever does
+ * that.
+ */
+
#include <inttypes.h>
#include <stdint.h>
#include <unistd.h>
@@ -20,9 +70,11 @@ const char *outfilename;
/* Symbols that we need in vdso2c. */
enum {
+ sym_vvar_start,
sym_vvar_page,
sym_hpet_page,
- sym_end_mapping,
+ sym_VDSO_FAKE_SECTION_TABLE_START,
+ sym_VDSO_FAKE_SECTION_TABLE_END,
};
const int special_pages[] = {
@@ -30,15 +82,26 @@ const int special_pages[] = {
sym_hpet_page,
};
-char const * const required_syms[] = {
- [sym_vvar_page] = "vvar_page",
- [sym_hpet_page] = "hpet_page",
- [sym_end_mapping] = "end_mapping",
- "VDSO32_NOTE_MASK",
- "VDSO32_SYSENTER_RETURN",
- "__kernel_vsyscall",
- "__kernel_sigreturn",
- "__kernel_rt_sigreturn",
+struct vdso_sym {
+ const char *name;
+ bool export;
+};
+
+struct vdso_sym required_syms[] = {
+ [sym_vvar_start] = {"vvar_start", true},
+ [sym_vvar_page] = {"vvar_page", true},
+ [sym_hpet_page] = {"hpet_page", true},
+ [sym_VDSO_FAKE_SECTION_TABLE_START] = {
+ "VDSO_FAKE_SECTION_TABLE_START", false
+ },
+ [sym_VDSO_FAKE_SECTION_TABLE_END] = {
+ "VDSO_FAKE_SECTION_TABLE_END", false
+ },
+ {"VDSO32_NOTE_MASK", true},
+ {"VDSO32_SYSENTER_RETURN", true},
+ {"__kernel_vsyscall", true},
+ {"__kernel_sigreturn", true},
+ {"__kernel_rt_sigreturn", true},
};
__attribute__((format(printf, 1, 2))) __attribute__((noreturn))
@@ -48,7 +111,8 @@ static void fail(const char *format, ...)
va_start(ap, format);
fprintf(stderr, "Error: ");
vfprintf(stderr, format, ap);
- unlink(outfilename);
+ if (outfilename)
+ unlink(outfilename);
exit(1);
va_end(ap);
}
@@ -83,62 +147,71 @@ extern void bad_put_le(void);
#define NSYMS (sizeof(required_syms) / sizeof(required_syms[0]))
-#define BITS 64
-#define GOFUNC go64
-#define Elf_Ehdr Elf64_Ehdr
-#define Elf_Shdr Elf64_Shdr
-#define Elf_Phdr Elf64_Phdr
-#define Elf_Sym Elf64_Sym
-#define Elf_Dyn Elf64_Dyn
+#define BITSFUNC3(name, bits, suffix) name##bits##suffix
+#define BITSFUNC2(name, bits, suffix) BITSFUNC3(name, bits, suffix)
+#define BITSFUNC(name) BITSFUNC2(name, ELF_BITS, )
+
+#define INT_BITS BITSFUNC2(int, ELF_BITS, _t)
+
+#define ELF_BITS_XFORM2(bits, x) Elf##bits##_##x
+#define ELF_BITS_XFORM(bits, x) ELF_BITS_XFORM2(bits, x)
+#define ELF(x) ELF_BITS_XFORM(ELF_BITS, x)
+
+#define ELF_BITS 64
#include "vdso2c.h"
-#undef BITS
-#undef GOFUNC
-#undef Elf_Ehdr
-#undef Elf_Shdr
-#undef Elf_Phdr
-#undef Elf_Sym
-#undef Elf_Dyn
-
-#define BITS 32
-#define GOFUNC go32
-#define Elf_Ehdr Elf32_Ehdr
-#define Elf_Shdr Elf32_Shdr
-#define Elf_Phdr Elf32_Phdr
-#define Elf_Sym Elf32_Sym
-#define Elf_Dyn Elf32_Dyn
+#undef ELF_BITS
+
+#define ELF_BITS 32
#include "vdso2c.h"
-#undef BITS
-#undef GOFUNC
-#undef Elf_Ehdr
-#undef Elf_Shdr
-#undef Elf_Phdr
-#undef Elf_Sym
-#undef Elf_Dyn
-
-static void go(void *addr, size_t len, FILE *outfile, const char *name)
+#undef ELF_BITS
+
+static void go(void *raw_addr, size_t raw_len,
+ void *stripped_addr, size_t stripped_len,
+ FILE *outfile, const char *name)
{
- Elf64_Ehdr *hdr = (Elf64_Ehdr *)addr;
+ Elf64_Ehdr *hdr = (Elf64_Ehdr *)raw_addr;
if (hdr->e_ident[EI_CLASS] == ELFCLASS64) {
- go64(addr, len, outfile, name);
+ go64(raw_addr, raw_len, stripped_addr, stripped_len,
+ outfile, name);
} else if (hdr->e_ident[EI_CLASS] == ELFCLASS32) {
- go32(addr, len, outfile, name);
+ go32(raw_addr, raw_len, stripped_addr, stripped_len,
+ outfile, name);
} else {
fail("unknown ELF class\n");
}
}
+static void map_input(const char *name, void **addr, size_t *len, int prot)
+{
+ off_t tmp_len;
+
+ int fd = open(name, O_RDONLY);
+ if (fd == -1)
+ err(1, "%s", name);
+
+ tmp_len = lseek(fd, 0, SEEK_END);
+ if (tmp_len == (off_t)-1)
+ err(1, "lseek");
+ *len = (size_t)tmp_len;
+
+ *addr = mmap(NULL, tmp_len, prot, MAP_PRIVATE, fd, 0);
+ if (*addr == MAP_FAILED)
+ err(1, "mmap");
+
+ close(fd);
+}
+
int main(int argc, char **argv)
{
- int fd;
- off_t len;
- void *addr;
+ size_t raw_len, stripped_len;
+ void *raw_addr, *stripped_addr;
FILE *outfile;
char *name, *tmp;
int namelen;
- if (argc != 3) {
- printf("Usage: vdso2c INPUT OUTPUT\n");
+ if (argc != 4) {
+ printf("Usage: vdso2c RAW_INPUT STRIPPED_INPUT OUTPUT\n");
return 1;
}
@@ -146,7 +219,7 @@ int main(int argc, char **argv)
* Figure out the struct name. If we're writing to a .so file,
* generate raw output insted.
*/
- name = strdup(argv[2]);
+ name = strdup(argv[3]);
namelen = strlen(name);
if (namelen >= 3 && !strcmp(name + namelen - 3, ".so")) {
name = NULL;
@@ -162,26 +235,18 @@ int main(int argc, char **argv)
*tmp = '_';
}
- fd = open(argv[1], O_RDONLY);
- if (fd == -1)
- err(1, "%s", argv[1]);
-
- len = lseek(fd, 0, SEEK_END);
- if (len == (off_t)-1)
- err(1, "lseek");
-
- addr = mmap(NULL, len, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
- if (addr == MAP_FAILED)
- err(1, "mmap");
+ map_input(argv[1], &raw_addr, &raw_len, PROT_READ);
+ map_input(argv[2], &stripped_addr, &stripped_len, PROT_READ);
- outfilename = argv[2];
+ outfilename = argv[3];
outfile = fopen(outfilename, "w");
if (!outfile)
err(1, "%s", argv[2]);
- go(addr, (size_t)len, outfile, name);
+ go(raw_addr, raw_len, stripped_addr, stripped_len, outfile, name);
- munmap(addr, len);
+ munmap(raw_addr, raw_len);
+ munmap(stripped_addr, stripped_len);
fclose(outfile);
return 0;
diff --git a/arch/x86/vdso/vdso2c.h b/arch/x86/vdso/vdso2c.h
index c6eefaf389b9..fd57829b30d8 100644
--- a/arch/x86/vdso/vdso2c.h
+++ b/arch/x86/vdso/vdso2c.h
@@ -4,23 +4,23 @@
* are built for 32-bit userspace.
*/
-static void GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
+static void BITSFUNC(go)(void *raw_addr, size_t raw_len,
+ void *stripped_addr, size_t stripped_len,
+ FILE *outfile, const char *name)
{
int found_load = 0;
unsigned long load_size = -1; /* Work around bogus warning */
- unsigned long data_size;
- Elf_Ehdr *hdr = (Elf_Ehdr *)addr;
+ unsigned long mapping_size;
+ ELF(Ehdr) *hdr = (ELF(Ehdr) *)raw_addr;
int i;
unsigned long j;
- Elf_Shdr *symtab_hdr = NULL, *strtab_hdr, *secstrings_hdr,
+ ELF(Shdr) *symtab_hdr = NULL, *strtab_hdr, *secstrings_hdr,
*alt_sec = NULL;
- Elf_Dyn *dyn = 0, *dyn_end = 0;
+ ELF(Dyn) *dyn = 0, *dyn_end = 0;
const char *secstrings;
- uint64_t syms[NSYMS] = {};
+ INT_BITS syms[NSYMS] = {};
- uint64_t fake_sections_value = 0, fake_sections_size = 0;
-
- Elf_Phdr *pt = (Elf_Phdr *)(addr + GET_LE(&hdr->e_phoff));
+ ELF(Phdr) *pt = (ELF(Phdr) *)(raw_addr + GET_LE(&hdr->e_phoff));
/* Walk the segment table. */
for (i = 0; i < GET_LE(&hdr->e_phnum); i++) {
@@ -38,30 +38,32 @@ static void GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
load_size = GET_LE(&pt[i].p_memsz);
found_load = 1;
} else if (GET_LE(&pt[i].p_type) == PT_DYNAMIC) {
- dyn = addr + GET_LE(&pt[i].p_offset);
- dyn_end = addr + GET_LE(&pt[i].p_offset) +
+ dyn = raw_addr + GET_LE(&pt[i].p_offset);
+ dyn_end = raw_addr + GET_LE(&pt[i].p_offset) +
GET_LE(&pt[i].p_memsz);
}
}
if (!found_load)
fail("no PT_LOAD seg\n");
- data_size = (load_size + 4095) / 4096 * 4096;
+
+ if (stripped_len < load_size)
+ fail("stripped input is too short\n");
/* Walk the dynamic table */
for (i = 0; dyn + i < dyn_end &&
GET_LE(&dyn[i].d_tag) != DT_NULL; i++) {
typeof(dyn[i].d_tag) tag = GET_LE(&dyn[i].d_tag);
- if (tag == DT_REL || tag == DT_RELSZ ||
+ if (tag == DT_REL || tag == DT_RELSZ || tag == DT_RELA ||
tag == DT_RELENT || tag == DT_TEXTREL)
fail("vdso image contains dynamic relocations\n");
}
/* Walk the section table */
- secstrings_hdr = addr + GET_LE(&hdr->e_shoff) +
+ secstrings_hdr = raw_addr + GET_LE(&hdr->e_shoff) +
GET_LE(&hdr->e_shentsize)*GET_LE(&hdr->e_shstrndx);
- secstrings = addr + GET_LE(&secstrings_hdr->sh_offset);
+ secstrings = raw_addr + GET_LE(&secstrings_hdr->sh_offset);
for (i = 0; i < GET_LE(&hdr->e_shnum); i++) {
- Elf_Shdr *sh = addr + GET_LE(&hdr->e_shoff) +
+ ELF(Shdr) *sh = raw_addr + GET_LE(&hdr->e_shoff) +
GET_LE(&hdr->e_shentsize) * i;
if (GET_LE(&sh->sh_type) == SHT_SYMTAB)
symtab_hdr = sh;
@@ -74,7 +76,7 @@ static void GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
if (!symtab_hdr)
fail("no symbol table\n");
- strtab_hdr = addr + GET_LE(&hdr->e_shoff) +
+ strtab_hdr = raw_addr + GET_LE(&hdr->e_shoff) +
GET_LE(&hdr->e_shentsize) * GET_LE(&symtab_hdr->sh_link);
/* Walk the symbol table */
@@ -82,27 +84,27 @@ static void GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
i < GET_LE(&symtab_hdr->sh_size) / GET_LE(&symtab_hdr->sh_entsize);
i++) {
int k;
- Elf_Sym *sym = addr + GET_LE(&symtab_hdr->sh_offset) +
+ ELF(Sym) *sym = raw_addr + GET_LE(&symtab_hdr->sh_offset) +
GET_LE(&symtab_hdr->sh_entsize) * i;
- const char *name = addr + GET_LE(&strtab_hdr->sh_offset) +
+ const char *name = raw_addr + GET_LE(&strtab_hdr->sh_offset) +
GET_LE(&sym->st_name);
for (k = 0; k < NSYMS; k++) {
- if (!strcmp(name, required_syms[k])) {
+ if (!strcmp(name, required_syms[k].name)) {
if (syms[k]) {
fail("duplicate symbol %s\n",
- required_syms[k]);
+ required_syms[k].name);
}
+
+ /*
+ * Careful: we use negative addresses, but
+ * st_value is unsigned, so we rely
+ * on syms[k] being a signed type of the
+ * correct width.
+ */
syms[k] = GET_LE(&sym->st_value);
}
}
-
- if (!strcmp(name, "vdso_fake_sections")) {
- if (fake_sections_value)
- fail("duplicate vdso_fake_sections\n");
- fake_sections_value = GET_LE(&sym->st_value);
- fake_sections_size = GET_LE(&sym->st_size);
- }
}
/* Validate mapping addresses. */
@@ -112,30 +114,24 @@ static void GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
if (syms[i] % 4096)
fail("%s must be a multiple of 4096\n",
- required_syms[i]);
- if (syms[i] < data_size)
- fail("%s must be after the text mapping\n",
- required_syms[i]);
- if (syms[sym_end_mapping] < syms[i] + 4096)
- fail("%s overruns end_mapping\n", required_syms[i]);
+ required_syms[i].name);
+ if (syms[sym_vvar_start] > syms[i] + 4096)
+ fail("%s underruns begin_vvar\n",
+ required_syms[i].name);
+ if (syms[i] + 4096 > 0)
+ fail("%s is on the wrong side of the vdso text\n",
+ required_syms[i].name);
}
- if (syms[sym_end_mapping] % 4096)
- fail("end_mapping must be a multiple of 4096\n");
-
- /* Remove sections or use fakes */
- if (fake_sections_size % sizeof(Elf_Shdr))
- fail("vdso_fake_sections size is not a multiple of %ld\n",
- (long)sizeof(Elf_Shdr));
- PUT_LE(&hdr->e_shoff, fake_sections_value);
- PUT_LE(&hdr->e_shentsize, fake_sections_value ? sizeof(Elf_Shdr) : 0);
- PUT_LE(&hdr->e_shnum, fake_sections_size / sizeof(Elf_Shdr));
- PUT_LE(&hdr->e_shstrndx, SHN_UNDEF);
+ if (syms[sym_vvar_start] % 4096)
+ fail("vvar_begin must be a multiple of 4096\n");
if (!name) {
- fwrite(addr, load_size, 1, outfile);
+ fwrite(stripped_addr, stripped_len, 1, outfile);
return;
}
+ mapping_size = (stripped_len + 4095) / 4096 * 4096;
+
fprintf(outfile, "/* AUTOMATICALLY GENERATED -- DO NOT EDIT */\n\n");
fprintf(outfile, "#include <linux/linkage.h>\n");
fprintf(outfile, "#include <asm/page_types.h>\n");
@@ -143,20 +139,21 @@ static void GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
fprintf(outfile, "\n");
fprintf(outfile,
"static unsigned char raw_data[%lu] __page_aligned_data = {",
- data_size);
- for (j = 0; j < load_size; j++) {
+ mapping_size);
+ for (j = 0; j < stripped_len; j++) {
if (j % 10 == 0)
fprintf(outfile, "\n\t");
- fprintf(outfile, "0x%02X, ", (int)((unsigned char *)addr)[j]);
+ fprintf(outfile, "0x%02X, ",
+ (int)((unsigned char *)stripped_addr)[j]);
}
fprintf(outfile, "\n};\n\n");
fprintf(outfile, "static struct page *pages[%lu];\n\n",
- data_size / 4096);
+ mapping_size / 4096);
fprintf(outfile, "const struct vdso_image %s = {\n", name);
fprintf(outfile, "\t.data = raw_data,\n");
- fprintf(outfile, "\t.size = %lu,\n", data_size);
+ fprintf(outfile, "\t.size = %lu,\n", mapping_size);
fprintf(outfile, "\t.text_mapping = {\n");
fprintf(outfile, "\t\t.name = \"[vdso]\",\n");
fprintf(outfile, "\t\t.pages = pages,\n");
@@ -168,9 +165,9 @@ static void GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
(unsigned long)GET_LE(&alt_sec->sh_size));
}
for (i = 0; i < NSYMS; i++) {
- if (syms[i])
- fprintf(outfile, "\t.sym_%s = 0x%" PRIx64 ",\n",
- required_syms[i], syms[i]);
+ if (required_syms[i].export && syms[i])
+ fprintf(outfile, "\t.sym_%s = %" PRIi64 ",\n",
+ required_syms[i].name, (int64_t)syms[i]);
}
fprintf(outfile, "};\n");
}
diff --git a/arch/x86/vdso/vdso32-setup.c b/arch/x86/vdso/vdso32-setup.c
index e4f7781ee162..e904c270573b 100644
--- a/arch/x86/vdso/vdso32-setup.c
+++ b/arch/x86/vdso/vdso32-setup.c
@@ -115,23 +115,6 @@ static __init int ia32_binfmt_init(void)
return 0;
}
__initcall(ia32_binfmt_init);
-#endif
-
-#else /* CONFIG_X86_32 */
-
-struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
-{
- return NULL;
-}
-
-int in_gate_area(struct mm_struct *mm, unsigned long addr)
-{
- return 0;
-}
-
-int in_gate_area_no_mm(unsigned long addr)
-{
- return 0;
-}
+#endif /* CONFIG_SYSCTL */
#endif /* CONFIG_X86_64 */
diff --git a/arch/x86/vdso/vdso32/vdso-fakesections.c b/arch/x86/vdso/vdso32/vdso-fakesections.c
new file mode 100644
index 000000000000..541468e25265
--- /dev/null
+++ b/arch/x86/vdso/vdso32/vdso-fakesections.c
@@ -0,0 +1 @@
+#include "../vdso-fakesections.c"
diff --git a/arch/x86/vdso/vdsox32.lds.S b/arch/x86/vdso/vdsox32.lds.S
index 46b991b578a8..697c11ece90c 100644
--- a/arch/x86/vdso/vdsox32.lds.S
+++ b/arch/x86/vdso/vdsox32.lds.S
@@ -6,6 +6,8 @@
* the DSO.
*/
+#define BUILD_VDSOX32
+
#include "vdso-layout.lds.S"
/*
diff --git a/arch/x86/vdso/vma.c b/arch/x86/vdso/vma.c
index e1513c47872a..970463b566cf 100644
--- a/arch/x86/vdso/vma.c
+++ b/arch/x86/vdso/vma.c
@@ -62,6 +62,9 @@ struct linux_binprm;
Only used for the 64-bit and x32 vdsos. */
static unsigned long vdso_addr(unsigned long start, unsigned len)
{
+#ifdef CONFIG_X86_32
+ return 0;
+#else
unsigned long addr, end;
unsigned offset;
end = (start + PMD_SIZE - 1) & PMD_MASK;
@@ -83,13 +86,14 @@ static unsigned long vdso_addr(unsigned long start, unsigned len)
addr = align_vdso_addr(addr);
return addr;
+#endif
}
static int map_vdso(const struct vdso_image *image, bool calculate_addr)
{
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
- unsigned long addr;
+ unsigned long addr, text_start;
int ret = 0;
static struct page *no_pages[] = {NULL};
static struct vm_special_mapping vvar_mapping = {
@@ -99,26 +103,28 @@ static int map_vdso(const struct vdso_image *image, bool calculate_addr)
if (calculate_addr) {
addr = vdso_addr(current->mm->start_stack,
- image->sym_end_mapping);
+ image->size - image->sym_vvar_start);
} else {
addr = 0;
}
down_write(&mm->mmap_sem);
- addr = get_unmapped_area(NULL, addr, image->sym_end_mapping, 0, 0);
+ addr = get_unmapped_area(NULL, addr,
+ image->size - image->sym_vvar_start, 0, 0);
if (IS_ERR_VALUE(addr)) {
ret = addr;
goto up_fail;
}
- current->mm->context.vdso = (void __user *)addr;
+ text_start = addr - image->sym_vvar_start;
+ current->mm->context.vdso = (void __user *)text_start;
/*
* MAYWRITE to allow gdb to COW and set breakpoints
*/
vma = _install_special_mapping(mm,
- addr,
+ text_start,
image->size,
VM_READ|VM_EXEC|
VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
@@ -130,9 +136,9 @@ static int map_vdso(const struct vdso_image *image, bool calculate_addr)
}
vma = _install_special_mapping(mm,
- addr + image->size,
- image->sym_end_mapping - image->size,
- VM_READ,
+ addr,
+ -image->sym_vvar_start,
+ VM_READ|VM_MAYREAD,
&vvar_mapping);
if (IS_ERR(vma)) {
@@ -142,7 +148,7 @@ static int map_vdso(const struct vdso_image *image, bool calculate_addr)
if (image->sym_vvar_page)
ret = remap_pfn_range(vma,
- addr + image->sym_vvar_page,
+ text_start + image->sym_vvar_page,
__pa_symbol(&__vvar_page) >> PAGE_SHIFT,
PAGE_SIZE,
PAGE_READONLY);
@@ -153,7 +159,7 @@ static int map_vdso(const struct vdso_image *image, bool calculate_addr)
#ifdef CONFIG_HPET_TIMER
if (hpet_address && image->sym_hpet_page) {
ret = io_remap_pfn_range(vma,
- addr + image->sym_hpet_page,
+ text_start + image->sym_hpet_page,
hpet_address >> PAGE_SHIFT,
PAGE_SIZE,
pgprot_noncached(PAGE_READONLY));
OpenPOWER on IntegriCloud