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// SPDX-License-Identifier: GPL-2.0-only
/*
* sorttable.c: Sort the kernel's table
*
* Added ORC unwind tables sort support and other updates:
* Copyright (C) 1999-2019 Alibaba Group Holding Limited. by:
* Shile Zhang <[email protected]>
*
* Copyright 2011 - 2012 Cavium, Inc.
*
* Based on code taken from recortmcount.c which is:
*
* Copyright 2009 John F. Reiser <[email protected]>. All rights reserved.
*
* Restructured to fit Linux format, as well as other updates:
* Copyright 2010 Steven Rostedt <[email protected]>, Red Hat Inc.
*/
/*
* Strategy: alter the vmlinux file in-place.
*/
#include <sys/types.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <getopt.h>
#include <elf.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <tools/be_byteshift.h>
#include <tools/le_byteshift.h>
#ifndef EM_ARCOMPACT
#define EM_ARCOMPACT 93
#endif
#ifndef EM_XTENSA
#define EM_XTENSA 94
#endif
#ifndef EM_AARCH64
#define EM_AARCH64 183
#endif
#ifndef EM_MICROBLAZE
#define EM_MICROBLAZE 189
#endif
#ifndef EM_ARCV2
#define EM_ARCV2 195
#endif
#ifndef EM_RISCV
#define EM_RISCV 243
#endif
static uint32_t (*r)(const uint32_t *);
static uint16_t (*r2)(const uint16_t *);
static uint64_t (*r8)(const uint64_t *);
static void (*w)(uint32_t, uint32_t *);
static void (*w2)(uint16_t, uint16_t *);
static void (*w8)(uint64_t, uint64_t *);
typedef void (*table_sort_t)(char *, int);
/*
* Get the whole file as a programming convenience in order to avoid
* malloc+lseek+read+free of many pieces. If successful, then mmap
* avoids copying unused pieces; else just read the whole file.
* Open for both read and write.
*/
static void *mmap_file(char const *fname, size_t *size)
{
int fd;
struct stat sb;
void *addr = NULL;
fd = open(fname, O_RDWR);
if (fd < 0) {
perror(fname);
return NULL;
}
if (fstat(fd, &sb) < 0) {
perror(fname);
goto out;
}
if (!S_ISREG(sb.st_mode)) {
fprintf(stderr, "not a regular file: %s\n", fname);
goto out;
}
addr = mmap(0, sb.st_size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
if (addr == MAP_FAILED) {
fprintf(stderr, "Could not mmap file: %s\n", fname);
goto out;
}
*size = sb.st_size;
out:
close(fd);
return addr;
}
static uint32_t rbe(const uint32_t *x)
{
return get_unaligned_be32(x);
}
static uint16_t r2be(const uint16_t *x)
{
return get_unaligned_be16(x);
}
static uint64_t r8be(const uint64_t *x)
{
return get_unaligned_be64(x);
}
static uint32_t rle(const uint32_t *x)
{
return get_unaligned_le32(x);
}
static uint16_t r2le(const uint16_t *x)
{
return get_unaligned_le16(x);
}
static uint64_t r8le(const uint64_t *x)
{
return get_unaligned_le64(x);
}
static void wbe(uint32_t val, uint32_t *x)
{
put_unaligned_be32(val, x);
}
static void w2be(uint16_t val, uint16_t *x)
{
put_unaligned_be16(val, x);
}
static void w8be(uint64_t val, uint64_t *x)
{
put_unaligned_be64(val, x);
}
static void wle(uint32_t val, uint32_t *x)
{
put_unaligned_le32(val, x);
}
static void w2le(uint16_t val, uint16_t *x)
{
put_unaligned_le16(val, x);
}
static void w8le(uint64_t val, uint64_t *x)
{
put_unaligned_le64(val, x);
}
/*
* Move reserved section indices SHN_LORESERVE..SHN_HIRESERVE out of
* the way to -256..-1, to avoid conflicting with real section
* indices.
*/
#define SPECIAL(i) ((i) - (SHN_HIRESERVE + 1))
static inline int is_shndx_special(unsigned int i)
{
return i != SHN_XINDEX && i >= SHN_LORESERVE && i <= SHN_HIRESERVE;
}
/* Accessor for sym->st_shndx, hides ugliness of "64k sections" */
static inline unsigned int get_secindex(unsigned int shndx,
unsigned int sym_offs,
const Elf32_Word *symtab_shndx_start)
{
if (is_shndx_special(shndx))
return SPECIAL(shndx);
if (shndx != SHN_XINDEX)
return shndx;
return r(&symtab_shndx_start[sym_offs]);
}
/* 32 bit and 64 bit are very similar */
#include "sorttable.h"
#define SORTTABLE_64
#include "sorttable.h"
static int compare_relative_table(const void *a, const void *b)
{
int32_t av = (int32_t)r(a);
int32_t bv = (int32_t)r(b);
if (av < bv)
return -1;
if (av > bv)
return 1;
return 0;
}
static void sort_relative_table(char *extab_image, int image_size)
{
int i = 0;
/*
* Do the same thing the runtime sort does, first normalize to
* being relative to the start of the section.
*/
while (i < image_size) {
uint32_t *loc = (uint32_t *)(extab_image + i);
w(r(loc) + i, loc);
i += 4;
}
qsort(extab_image, image_size / 8, 8, compare_relative_table);
/* Now denormalize. */
i = 0;
while (i < image_size) {
uint32_t *loc = (uint32_t *)(extab_image + i);
w(r(loc) - i, loc);
i += 4;
}
}
static void x86_sort_relative_table(char *extab_image, int image_size)
{
int i = 0;
while (i < image_size) {
uint32_t *loc = (uint32_t *)(extab_image + i);
w(r(loc) + i, loc);
w(r(loc + 1) + i + 4, loc + 1);
/* Don't touch the fixup type */
i += sizeof(uint32_t) * 3;
}
qsort(extab_image, image_size / 12, 12, compare_relative_table);
i = 0;
while (i < image_size) {
uint32_t *loc = (uint32_t *)(extab_image + i);
w(r(loc) - i, loc);
w(r(loc + 1) - (i + 4), loc + 1);
/* Don't touch the fixup type */
i += sizeof(uint32_t) * 3;
}
}
static void s390_sort_relative_table(char *extab_image, int image_size)
{
int i;
for (i = 0; i < image_size; i += 16) {
char *loc = extab_image + i;
uint64_t handler;
w(r((uint32_t *)loc) + i, (uint32_t *)loc);
w(r((uint32_t *)(loc + 4)) + (i + 4), (uint32_t *)(loc + 4));
/*
* 0 is a special self-relative handler value, which means that
* handler should be ignored. It is safe, because it means that
* handler field points to itself, which should never happen.
* When creating extable-relative values, keep it as 0, since
* this should never occur either: it would mean that handler
* field points to the first extable entry.
*/
handler = r8((uint64_t *)(loc + 8));
if (handler)
handler += i + 8;
w8(handler, (uint64_t *)(loc + 8));
}
qsort(extab_image, image_size / 16, 16, compare_relative_table);
for (i = 0; i < image_size; i += 16) {
char *loc = extab_image + i;
uint64_t handler;
w(r((uint32_t *)loc) - i, (uint32_t *)loc);
w(r((uint32_t *)(loc + 4)) - (i + 4), (uint32_t *)(loc + 4));
handler = r8((uint64_t *)(loc + 8));
if (handler)
handler -= i + 8;
w8(handler, (uint64_t *)(loc + 8));
}
}
static int do_file(char const *const fname, void *addr)
{
int rc = -1;
Elf32_Ehdr *ehdr = addr;
table_sort_t custom_sort = NULL;
switch (ehdr->e_ident[EI_DATA]) {
case ELFDATA2LSB:
r = rle;
r2 = r2le;
r8 = r8le;
w = wle;
w2 = w2le;
w8 = w8le;
break;
case ELFDATA2MSB:
r = rbe;
r2 = r2be;
r8 = r8be;
w = wbe;
w2 = w2be;
w8 = w8be;
break;
default:
fprintf(stderr, "unrecognized ELF data encoding %d: %s\n",
ehdr->e_ident[EI_DATA], fname);
return -1;
}
if (memcmp(ELFMAG, ehdr->e_ident, SELFMAG) != 0 ||
(r2(&ehdr->e_type) != ET_EXEC && r2(&ehdr->e_type) != ET_DYN) ||
ehdr->e_ident[EI_VERSION] != EV_CURRENT) {
fprintf(stderr, "unrecognized ET_EXEC/ET_DYN file %s\n", fname);
return -1;
}
switch (r2(&ehdr->e_machine)) {
case EM_386:
case EM_X86_64:
custom_sort = x86_sort_relative_table;
break;
case EM_S390:
custom_sort = s390_sort_relative_table;
break;
case EM_AARCH64:
case EM_PARISC:
case EM_PPC:
case EM_PPC64:
custom_sort = sort_relative_table;
break;
case EM_ARCOMPACT:
case EM_ARCV2:
case EM_ARM:
case EM_MICROBLAZE:
case EM_MIPS:
case EM_RISCV:
case EM_XTENSA:
break;
default:
fprintf(stderr, "unrecognized e_machine %d %s\n",
r2(&ehdr->e_machine), fname);
return -1;
}
switch (ehdr->e_ident[EI_CLASS]) {
case ELFCLASS32:
if (r2(&ehdr->e_ehsize) != sizeof(Elf32_Ehdr) ||
r2(&ehdr->e_shentsize) != sizeof(Elf32_Shdr)) {
fprintf(stderr,
"unrecognized ET_EXEC/ET_DYN file: %s\n", fname);
break;
}
rc = do_sort_32(ehdr, fname, custom_sort);
break;
case ELFCLASS64:
{
Elf64_Ehdr *const ghdr = (Elf64_Ehdr *)ehdr;
if (r2(&ghdr->e_ehsize) != sizeof(Elf64_Ehdr) ||
r2(&ghdr->e_shentsize) != sizeof(Elf64_Shdr)) {
fprintf(stderr,
"unrecognized ET_EXEC/ET_DYN file: %s\n",
fname);
break;
}
rc = do_sort_64(ghdr, fname, custom_sort);
}
break;
default:
fprintf(stderr, "unrecognized ELF class %d %s\n",
ehdr->e_ident[EI_CLASS], fname);
break;
}
return rc;
}
int main(int argc, char *argv[])
{
int i, n_error = 0; /* gcc-4.3.0 false positive complaint */
size_t size = 0;
void *addr = NULL;
if (argc < 2) {
fprintf(stderr, "usage: sorttable vmlinux...\n");
return 0;
}
/* Process each file in turn, allowing deep failure. */
for (i = 1; i < argc; i++) {
addr = mmap_file(argv[i], &size);
if (!addr) {
++n_error;
continue;
}
if (do_file(argv[i], addr))
++n_error;
munmap(addr, size);
}
return !!n_error;
}
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