x86, relocs: Refactor the relocs tool to merge 32- and 64-bit ELF

Refactor the relocs tool so that the same tool can handle 32- and
64-bit ELF.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Kees Cook <keescook@chromium.org>
Link: http://lkml.kernel.org/r/1365797627-20874-5-git-send-email-keescook@chromium.org
This commit is contained in:
H. Peter Anvin 2013-04-16 16:02:58 -07:00
parent 17c961f770
commit c889ba801d
9 changed files with 183 additions and 153 deletions

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@ -44,7 +44,7 @@ $(obj)/vmlinux.bin: vmlinux FORCE
targets += $(patsubst $(obj)/%,%,$(VMLINUX_OBJS)) vmlinux.bin.all vmlinux.relocs
CMD_RELOCS = arch/x86/tools/relocs_$(BITS)
CMD_RELOCS = arch/x86/tools/relocs
quiet_cmd_relocs = RELOCS $@
cmd_relocs = $(CMD_RELOCS) $< > $@;$(CMD_RELOCS) --abs-relocs $<
$(obj)/vmlinux.relocs: vmlinux FORCE

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@ -56,7 +56,7 @@ $(obj)/realmode.bin: $(obj)/realmode.elf $(obj)/realmode.relocs
$(call if_changed,objcopy)
quiet_cmd_relocs = RELOCS $@
cmd_relocs = arch/x86/tools/relocs_32 --realmode $< > $@
cmd_relocs = arch/x86/tools/relocs --realmode $< > $@
targets += realmode.relocs
$(obj)/realmode.relocs: $(obj)/realmode.elf FORCE

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@ -1,2 +1 @@
relocs_32*
relocs_64*
relocs

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@ -37,22 +37,7 @@ $(obj)/test_get_len.o: $(srctree)/arch/x86/lib/insn.c $(srctree)/arch/x86/lib/in
$(obj)/insn_sanity.o: $(srctree)/arch/x86/lib/insn.c $(srctree)/arch/x86/lib/inat.c $(srctree)/arch/x86/include/asm/inat_types.h $(srctree)/arch/x86/include/asm/inat.h $(srctree)/arch/x86/include/asm/insn.h $(objtree)/arch/x86/lib/inat-tables.c
HOSTCFLAGS_relocs_32.o += -DELF_BITS=32
HOSTCFLAGS_relocs_64.o += -DELF_BITS=64
quiet_cmd_cp_reloc = GEN $@
cmd_cp_reloc = cp $< $@
$(obj)/relocs_%.c: $(srctree)/arch/x86/tools/relocs.c
$(call cmd,cp_reloc)
HOST_EXTRACFLAGS += -I$(srctree)/tools/include
hostprogs-y += relocs_$(BITS)
relocs_binaries = relocs_$(BITS)
ifeq ($(CONFIG_64BIT),y)
hostprogs-y += relocs_32
relocs_binaries += relocs_32
endif
relocs: $(relocs_binaries)
relocs_32: $(obj)/relocs_32
relocs_64: $(obj)/relocs_64
hostprogs-y += relocs
relocs-objs := relocs_32.o relocs_64.o relocs_common.o
relocs: $(obj)/relocs

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@ -1,63 +1,15 @@
#include <stdio.h>
#include <stdarg.h>
#include <stdlib.h>
#include <stdint.h>
#include <inttypes.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <elf.h>
#include <byteswap.h>
#define USE_BSD
#include <endian.h>
#include <regex.h>
#include <tools/le_byteshift.h>
/* This is included from relocs_32/64.c */
#define ElfW(type) _ElfW(ELF_BITS, type)
#define _ElfW(bits, type) __ElfW(bits, type)
#define __ElfW(bits, type) Elf##bits##_##type
#ifndef ELF_BITS
#define ELF_BITS 32
#endif
#if (ELF_BITS == 64)
#define ELF_MACHINE EM_X86_64
#define ELF_MACHINE_NAME "x86_64"
#define SHT_REL_TYPE SHT_RELA
#define Elf_Rel Elf64_Rela
#else
#define ELF_MACHINE EM_386
#define ELF_MACHINE_NAME "i386"
#define SHT_REL_TYPE SHT_REL
#define Elf_Rel ElfW(Rel)
#endif
#if (ELF_BITS == 64)
#define ELF_CLASS ELFCLASS64
#define ELF_R_SYM(val) ELF64_R_SYM(val)
#define ELF_R_TYPE(val) ELF64_R_TYPE(val)
#define ELF_ST_TYPE(o) ELF64_ST_TYPE(o)
#define ELF_ST_BIND(o) ELF64_ST_BIND(o)
#define ELF_ST_VISIBILITY(o) ELF64_ST_VISIBILITY(o)
#else
#define ELF_CLASS ELFCLASS32
#define ELF_R_SYM(val) ELF32_R_SYM(val)
#define ELF_R_TYPE(val) ELF32_R_TYPE(val)
#define ELF_ST_TYPE(o) ELF32_ST_TYPE(o)
#define ELF_ST_BIND(o) ELF32_ST_BIND(o)
#define ELF_ST_VISIBILITY(o) ELF32_ST_VISIBILITY(o)
#endif
#define Elf_Addr ElfW(Addr)
#define Elf_Ehdr ElfW(Ehdr)
#define Elf_Phdr ElfW(Phdr)
#define Elf_Shdr ElfW(Shdr)
#define Elf_Sym ElfW(Sym)
static void die(char *fmt, ...);
#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
static Elf_Ehdr ehdr;
struct relocs {
@ -79,14 +31,6 @@ struct section {
};
static struct section *secs;
enum symtype {
S_ABS,
S_REL,
S_SEG,
S_LIN,
S_NSYMTYPES
};
static const char * const sym_regex_kernel[S_NSYMTYPES] = {
/*
* Following symbols have been audited. There values are constant and do
@ -98,7 +42,7 @@ static const char * const sym_regex_kernel[S_NSYMTYPES] = {
"^(xen_irq_disable_direct_reloc$|"
"xen_save_fl_direct_reloc$|"
"VDSO|"
#if (ELF_BITS == 64)
#if ELF_BITS == 64
"__vvar_page|"
#endif
"__crc_)",
@ -124,7 +68,7 @@ static const char * const sym_regex_kernel[S_NSYMTYPES] = {
"__end_rodata|"
"__initramfs_start|"
"(jiffies|jiffies_64)|"
#if (ELF_BITS == 64)
#if ELF_BITS == 64
"__per_cpu_load|"
"init_per_cpu__.*|"
"__end_rodata_hpage_align|"
@ -189,15 +133,6 @@ static void regex_init(int use_real_mode)
}
}
static void die(char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
vfprintf(stderr, fmt, ap);
va_end(ap);
exit(1);
}
static const char *sym_type(unsigned type)
{
static const char *type_name[] = {
@ -255,7 +190,7 @@ static const char *rel_type(unsigned type)
{
static const char *type_name[] = {
#define REL_TYPE(X) [X] = #X
#if (ELF_BITS == 64)
#if ELF_BITS == 64
REL_TYPE(R_X86_64_NONE),
REL_TYPE(R_X86_64_64),
REL_TYPE(R_X86_64_PC32),
@ -380,7 +315,7 @@ static uint32_t elf32_to_cpu(uint32_t val)
#define elf_half_to_cpu(x) elf16_to_cpu(x)
#define elf_word_to_cpu(x) elf32_to_cpu(x)
#if (ELF_BITS == 64)
#if ELF_BITS == 64
static uint64_t elf64_to_cpu(uint64_t val)
{
return le64_to_cpu(val);
@ -582,7 +517,7 @@ static void print_absolute_symbols(void)
int i;
const char *format;
if (ehdr.e_ident[EI_CLASS] == ELFCLASS64)
if (ELF_BITS == 64)
format = "%5d %016"PRIx64" %5"PRId64" %10s %10s %12s %s\n";
else
format = "%5d %08"PRIx32" %5"PRId32" %10s %10s %12s %s\n";
@ -622,7 +557,7 @@ static void print_absolute_relocs(void)
int i, printed = 0;
const char *format;
if (ehdr.e_ident[EI_CLASS] == ELFCLASS64)
if (ELF_BITS == 64)
format = "%016"PRIx64" %016"PRIx64" %10s %016"PRIx64" %s\n";
else
format = "%08"PRIx32" %08"PRIx32" %10s %08"PRIx32" %s\n";
@ -785,6 +720,8 @@ static void percpu_init(void)
}
}
#if ELF_BITS == 64
/*
* Check to see if a symbol lies in the .data..percpu section.
* For some as yet not understood reason the "__init_begin"
@ -798,6 +735,7 @@ static int is_percpu_sym(ElfW(Sym) *sym, const char *symname)
strcmp(symname, "__init_begin");
}
static int do_reloc64(struct section *sec, Elf_Rel *rel, ElfW(Sym) *sym,
const char *symname)
{
@ -869,6 +807,7 @@ static int do_reloc64(struct section *sec, Elf_Rel *rel, ElfW(Sym) *sym,
return 0;
}
#else
static int do_reloc32(struct section *sec, Elf_Rel *rel, Elf_Sym *sym,
const char *symname)
@ -984,6 +923,8 @@ static int do_reloc_real(struct section *sec, Elf_Rel *rel, Elf_Sym *sym,
return 0;
}
#endif
static int cmp_relocs(const void *va, const void *vb)
{
const uint32_t *a, *b;
@ -1016,12 +957,17 @@ static void emit_relocs(int as_text, int use_real_mode)
int (*do_reloc)(struct section *sec, Elf_Rel *rel, Elf_Sym *sym,
const char *symname);
if (ehdr.e_ident[EI_CLASS] == ELFCLASS64)
#if ELF_BITS == 64
if (!use_real_mode)
do_reloc = do_reloc64;
else if (!use_real_mode)
else
die("--realmode not valid for a 64-bit ELF file");
#else
if (!use_real_mode)
do_reloc = do_reloc32;
else
do_reloc = do_reloc_real;
#endif
/* Collect up the relocations */
walk_relocs(do_reloc);
@ -1053,7 +999,7 @@ static void emit_relocs(int as_text, int use_real_mode)
for (i = 0; i < relocs32.count; i++)
write_reloc(relocs32.offset[i], stdout);
} else {
if (ehdr.e_ident[EI_CLASS] == ELFCLASS64) {
if (ELF_BITS == 64) {
/* Print a stop */
write_reloc(0, stdout);
@ -1071,76 +1017,30 @@ static void emit_relocs(int as_text, int use_real_mode)
}
}
static void usage(void)
{
die("relocs [--abs-syms|--abs-relocs|--text|--realmode] vmlinux\n");
}
#if ELF_BITS == 64
# define process process_64
#else
# define process process_32
#endif
int main(int argc, char **argv)
void process(FILE *fp, int use_real_mode, int as_text,
int show_absolute_syms, int show_absolute_relocs)
{
int show_absolute_syms, show_absolute_relocs;
int as_text, use_real_mode;
const char *fname;
FILE *fp;
int i;
show_absolute_syms = 0;
show_absolute_relocs = 0;
as_text = 0;
use_real_mode = 0;
fname = NULL;
for (i = 1; i < argc; i++) {
char *arg = argv[i];
if (*arg == '-') {
if (strcmp(arg, "--abs-syms") == 0) {
show_absolute_syms = 1;
continue;
}
if (strcmp(arg, "--abs-relocs") == 0) {
show_absolute_relocs = 1;
continue;
}
if (strcmp(arg, "--text") == 0) {
as_text = 1;
continue;
}
if (strcmp(arg, "--realmode") == 0) {
use_real_mode = 1;
continue;
}
}
else if (!fname) {
fname = arg;
continue;
}
usage();
}
if (!fname) {
usage();
}
regex_init(use_real_mode);
fp = fopen(fname, "r");
if (!fp) {
die("Cannot open %s: %s\n",
fname, strerror(errno));
}
read_ehdr(fp);
read_shdrs(fp);
read_strtabs(fp);
read_symtabs(fp);
read_relocs(fp);
if (ehdr.e_ident[EI_CLASS] == ELFCLASS64)
if (ELF_BITS == 64)
percpu_init();
if (show_absolute_syms) {
print_absolute_symbols();
goto out;
return;
}
if (show_absolute_relocs) {
print_absolute_relocs();
goto out;
return;
}
emit_relocs(as_text, use_real_mode);
out:
fclose(fp);
return 0;
}

36
arch/x86/tools/relocs.h Normal file
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@ -0,0 +1,36 @@
#ifndef RELOCS_H
#define RELOCS_H
#include <stdio.h>
#include <stdarg.h>
#include <stdlib.h>
#include <stdint.h>
#include <inttypes.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <elf.h>
#include <byteswap.h>
#define USE_BSD
#include <endian.h>
#include <regex.h>
#include <tools/le_byteshift.h>
void die(char *fmt, ...);
#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
enum symtype {
S_ABS,
S_REL,
S_SEG,
S_LIN,
S_NSYMTYPES
};
void process_32(FILE *fp, int use_real_mode, int as_text,
int show_absolute_syms, int show_absolute_relocs);
void process_64(FILE *fp, int use_real_mode, int as_text,
int show_absolute_syms, int show_absolute_relocs);
#endif /* RELOCS_H */

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@ -0,0 +1,17 @@
#include "relocs.h"
#define ELF_BITS 32
#define ELF_MACHINE EM_386
#define ELF_MACHINE_NAME "i386"
#define SHT_REL_TYPE SHT_REL
#define Elf_Rel ElfW(Rel)
#define ELF_CLASS ELFCLASS32
#define ELF_R_SYM(val) ELF32_R_SYM(val)
#define ELF_R_TYPE(val) ELF32_R_TYPE(val)
#define ELF_ST_TYPE(o) ELF32_ST_TYPE(o)
#define ELF_ST_BIND(o) ELF32_ST_BIND(o)
#define ELF_ST_VISIBILITY(o) ELF32_ST_VISIBILITY(o)
#include "relocs.c"

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@ -0,0 +1,17 @@
#include "relocs.h"
#define ELF_BITS 64
#define ELF_MACHINE EM_X86_64
#define ELF_MACHINE_NAME "x86_64"
#define SHT_REL_TYPE SHT_RELA
#define Elf_Rel Elf64_Rela
#define ELF_CLASS ELFCLASS64
#define ELF_R_SYM(val) ELF64_R_SYM(val)
#define ELF_R_TYPE(val) ELF64_R_TYPE(val)
#define ELF_ST_TYPE(o) ELF64_ST_TYPE(o)
#define ELF_ST_BIND(o) ELF64_ST_BIND(o)
#define ELF_ST_VISIBILITY(o) ELF64_ST_VISIBILITY(o)
#include "relocs.c"

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@ -0,0 +1,76 @@
#include "relocs.h"
void die(char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
vfprintf(stderr, fmt, ap);
va_end(ap);
exit(1);
}
static void usage(void)
{
die("relocs [--abs-syms|--abs-relocs|--text|--realmode] vmlinux\n");
}
int main(int argc, char **argv)
{
int show_absolute_syms, show_absolute_relocs;
int as_text, use_real_mode;
const char *fname;
FILE *fp;
int i;
unsigned char e_ident[EI_NIDENT];
show_absolute_syms = 0;
show_absolute_relocs = 0;
as_text = 0;
use_real_mode = 0;
fname = NULL;
for (i = 1; i < argc; i++) {
char *arg = argv[i];
if (*arg == '-') {
if (strcmp(arg, "--abs-syms") == 0) {
show_absolute_syms = 1;
continue;
}
if (strcmp(arg, "--abs-relocs") == 0) {
show_absolute_relocs = 1;
continue;
}
if (strcmp(arg, "--text") == 0) {
as_text = 1;
continue;
}
if (strcmp(arg, "--realmode") == 0) {
use_real_mode = 1;
continue;
}
}
else if (!fname) {
fname = arg;
continue;
}
usage();
}
if (!fname) {
usage();
}
fp = fopen(fname, "r");
if (!fp) {
die("Cannot open %s: %s\n", fname, strerror(errno));
}
if (fread(&e_ident, 1, EI_NIDENT, fp) != EI_NIDENT) {
die("Cannot read %s: %s", fname, strerror(errno));
}
rewind(fp);
if (e_ident[EI_CLASS] == ELFCLASS64)
process_64(fp, use_real_mode, as_text,
show_absolute_syms, show_absolute_relocs);
else
process_32(fp, use_real_mode, as_text,
show_absolute_syms, show_absolute_relocs);
fclose(fp);
return 0;
}