linux/scripts/sorttable.c
Steven Rostedt dc208c69c0 scripts/sorttable: Allow matches to functions before function entry
ARM 64 uses -fpatchable-function-entry=4,2 which adds padding before the
function and the addresses in the mcount_loc point there instead of the
function entry that is returned by nm. In order to find a function from nm
to make sure it's not an unused weak function, the entries in the
mcount_loc section needs to match the entries from nm. Since it can be an
instruction before the entry, add a before_func variable that ARM 64 can
set to 8, and if the mcount_loc entry is within 8 bytes of the nm function
entry, then it will be considered a match.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: "Arnd Bergmann" <arnd@arndb.de>
Cc: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/20250225182054.815536219@goodmis.org
Fixes: ef378c3b82338 ("scripts/sorttable: Zero out weak functions in mcount_loc table")
Tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-02-25 13:25:13 -05:00

1415 lines
32 KiB
C

// 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 <shile.zhang@linux.alibaba.com>
*
* Copyright 2011 - 2012 Cavium, Inc.
*
* Based on code taken from recortmcount.c which is:
*
* Copyright 2009 John F. Reiser <jreiser@BitWagon.com>. All rights reserved.
*
* Restructured to fit Linux format, as well as other updates:
* Copyright 2010 Steven Rostedt <srostedt@redhat.com>, 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 <stdbool.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <pthread.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
#ifndef EM_LOONGARCH
#define EM_LOONGARCH 258
#endif
typedef union {
Elf32_Ehdr e32;
Elf64_Ehdr e64;
} Elf_Ehdr;
typedef union {
Elf32_Shdr e32;
Elf64_Shdr e64;
} Elf_Shdr;
typedef union {
Elf32_Sym e32;
Elf64_Sym e64;
} Elf_Sym;
typedef union {
Elf32_Rela e32;
Elf64_Rela e64;
} Elf_Rela;
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 (*w8)(uint64_t, uint64_t *);
typedef void (*table_sort_t)(char *, int);
static struct elf_funcs {
int (*compare_extable)(const void *a, const void *b);
uint64_t (*ehdr_shoff)(Elf_Ehdr *ehdr);
uint16_t (*ehdr_shstrndx)(Elf_Ehdr *ehdr);
uint16_t (*ehdr_shentsize)(Elf_Ehdr *ehdr);
uint16_t (*ehdr_shnum)(Elf_Ehdr *ehdr);
uint64_t (*shdr_addr)(Elf_Shdr *shdr);
uint64_t (*shdr_offset)(Elf_Shdr *shdr);
uint64_t (*shdr_size)(Elf_Shdr *shdr);
uint64_t (*shdr_entsize)(Elf_Shdr *shdr);
uint32_t (*shdr_link)(Elf_Shdr *shdr);
uint32_t (*shdr_name)(Elf_Shdr *shdr);
uint32_t (*shdr_type)(Elf_Shdr *shdr);
uint8_t (*sym_type)(Elf_Sym *sym);
uint32_t (*sym_name)(Elf_Sym *sym);
uint64_t (*sym_value)(Elf_Sym *sym);
uint16_t (*sym_shndx)(Elf_Sym *sym);
uint64_t (*rela_offset)(Elf_Rela *rela);
uint64_t (*rela_info)(Elf_Rela *rela);
uint64_t (*rela_addend)(Elf_Rela *rela);
void (*rela_write_addend)(Elf_Rela *rela, uint64_t val);
} e;
static uint64_t ehdr64_shoff(Elf_Ehdr *ehdr)
{
return r8(&ehdr->e64.e_shoff);
}
static uint64_t ehdr32_shoff(Elf_Ehdr *ehdr)
{
return r(&ehdr->e32.e_shoff);
}
static uint64_t ehdr_shoff(Elf_Ehdr *ehdr)
{
return e.ehdr_shoff(ehdr);
}
#define EHDR_HALF(fn_name) \
static uint16_t ehdr64_##fn_name(Elf_Ehdr *ehdr) \
{ \
return r2(&ehdr->e64.e_##fn_name); \
} \
\
static uint16_t ehdr32_##fn_name(Elf_Ehdr *ehdr) \
{ \
return r2(&ehdr->e32.e_##fn_name); \
} \
\
static uint16_t ehdr_##fn_name(Elf_Ehdr *ehdr) \
{ \
return e.ehdr_##fn_name(ehdr); \
}
EHDR_HALF(shentsize)
EHDR_HALF(shstrndx)
EHDR_HALF(shnum)
#define SHDR_WORD(fn_name) \
static uint32_t shdr64_##fn_name(Elf_Shdr *shdr) \
{ \
return r(&shdr->e64.sh_##fn_name); \
} \
\
static uint32_t shdr32_##fn_name(Elf_Shdr *shdr) \
{ \
return r(&shdr->e32.sh_##fn_name); \
} \
\
static uint32_t shdr_##fn_name(Elf_Shdr *shdr) \
{ \
return e.shdr_##fn_name(shdr); \
}
#define SHDR_ADDR(fn_name) \
static uint64_t shdr64_##fn_name(Elf_Shdr *shdr) \
{ \
return r8(&shdr->e64.sh_##fn_name); \
} \
\
static uint64_t shdr32_##fn_name(Elf_Shdr *shdr) \
{ \
return r(&shdr->e32.sh_##fn_name); \
} \
\
static uint64_t shdr_##fn_name(Elf_Shdr *shdr) \
{ \
return e.shdr_##fn_name(shdr); \
}
#define SHDR_WORD(fn_name) \
static uint32_t shdr64_##fn_name(Elf_Shdr *shdr) \
{ \
return r(&shdr->e64.sh_##fn_name); \
} \
\
static uint32_t shdr32_##fn_name(Elf_Shdr *shdr) \
{ \
return r(&shdr->e32.sh_##fn_name); \
} \
static uint32_t shdr_##fn_name(Elf_Shdr *shdr) \
{ \
return e.shdr_##fn_name(shdr); \
}
SHDR_ADDR(addr)
SHDR_ADDR(offset)
SHDR_ADDR(size)
SHDR_ADDR(entsize)
SHDR_WORD(link)
SHDR_WORD(name)
SHDR_WORD(type)
#define SYM_ADDR(fn_name) \
static uint64_t sym64_##fn_name(Elf_Sym *sym) \
{ \
return r8(&sym->e64.st_##fn_name); \
} \
\
static uint64_t sym32_##fn_name(Elf_Sym *sym) \
{ \
return r(&sym->e32.st_##fn_name); \
} \
\
static uint64_t sym_##fn_name(Elf_Sym *sym) \
{ \
return e.sym_##fn_name(sym); \
}
#define SYM_WORD(fn_name) \
static uint32_t sym64_##fn_name(Elf_Sym *sym) \
{ \
return r(&sym->e64.st_##fn_name); \
} \
\
static uint32_t sym32_##fn_name(Elf_Sym *sym) \
{ \
return r(&sym->e32.st_##fn_name); \
} \
\
static uint32_t sym_##fn_name(Elf_Sym *sym) \
{ \
return e.sym_##fn_name(sym); \
}
#define SYM_HALF(fn_name) \
static uint16_t sym64_##fn_name(Elf_Sym *sym) \
{ \
return r2(&sym->e64.st_##fn_name); \
} \
\
static uint16_t sym32_##fn_name(Elf_Sym *sym) \
{ \
return r2(&sym->e32.st_##fn_name); \
} \
\
static uint16_t sym_##fn_name(Elf_Sym *sym) \
{ \
return e.sym_##fn_name(sym); \
}
static uint8_t sym64_type(Elf_Sym *sym)
{
return ELF64_ST_TYPE(sym->e64.st_info);
}
static uint8_t sym32_type(Elf_Sym *sym)
{
return ELF32_ST_TYPE(sym->e32.st_info);
}
static uint8_t sym_type(Elf_Sym *sym)
{
return e.sym_type(sym);
}
SYM_ADDR(value)
SYM_WORD(name)
SYM_HALF(shndx)
#define __maybe_unused __attribute__((__unused__))
#define RELA_ADDR(fn_name) \
static uint64_t rela64_##fn_name(Elf_Rela *rela) \
{ \
return r8((uint64_t *)&rela->e64.r_##fn_name); \
} \
\
static uint64_t rela32_##fn_name(Elf_Rela *rela) \
{ \
return r((uint32_t *)&rela->e32.r_##fn_name); \
} \
\
static uint64_t __maybe_unused rela_##fn_name(Elf_Rela *rela) \
{ \
return e.rela_##fn_name(rela); \
}
RELA_ADDR(offset)
RELA_ADDR(info)
RELA_ADDR(addend)
static void rela64_write_addend(Elf_Rela *rela, uint64_t val)
{
w8(val, (uint64_t *)&rela->e64.r_addend);
}
static void rela32_write_addend(Elf_Rela *rela, uint64_t val)
{
w(val, (uint32_t *)&rela->e32.r_addend);
}
/*
* 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 wle(uint32_t val, uint32_t *x)
{
put_unaligned_le32(val, x);
}
static void w8be(uint64_t val, uint64_t *x)
{
put_unaligned_be64(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]);
}
static int compare_extable_32(const void *a, const void *b)
{
Elf32_Addr av = r(a);
Elf32_Addr bv = r(b);
if (av < bv)
return -1;
return av > bv;
}
static int compare_extable_64(const void *a, const void *b)
{
Elf64_Addr av = r8(a);
Elf64_Addr bv = r8(b);
if (av < bv)
return -1;
return av > bv;
}
static int compare_extable(const void *a, const void *b)
{
return e.compare_extable(a, b);
}
static inline void *get_index(void *start, int entsize, int index)
{
return start + (entsize * index);
}
static int extable_ent_size;
static int long_size;
#define ERRSTR_MAXSZ 256
#ifdef UNWINDER_ORC_ENABLED
/* ORC unwinder only support X86_64 */
#include <asm/orc_types.h>
static char g_err[ERRSTR_MAXSZ];
static int *g_orc_ip_table;
static struct orc_entry *g_orc_table;
static pthread_t orc_sort_thread;
static inline unsigned long orc_ip(const int *ip)
{
return (unsigned long)ip + *ip;
}
static int orc_sort_cmp(const void *_a, const void *_b)
{
struct orc_entry *orc_a, *orc_b;
const int *a = g_orc_ip_table + *(int *)_a;
const int *b = g_orc_ip_table + *(int *)_b;
unsigned long a_val = orc_ip(a);
unsigned long b_val = orc_ip(b);
if (a_val > b_val)
return 1;
if (a_val < b_val)
return -1;
/*
* The "weak" section terminator entries need to always be on the left
* to ensure the lookup code skips them in favor of real entries.
* These terminator entries exist to handle any gaps created by
* whitelisted .o files which didn't get objtool generation.
*/
orc_a = g_orc_table + (a - g_orc_ip_table);
orc_b = g_orc_table + (b - g_orc_ip_table);
if (orc_a->type == ORC_TYPE_UNDEFINED && orc_b->type == ORC_TYPE_UNDEFINED)
return 0;
return orc_a->type == ORC_TYPE_UNDEFINED ? -1 : 1;
}
static void *sort_orctable(void *arg)
{
int i;
int *idxs = NULL;
int *tmp_orc_ip_table = NULL;
struct orc_entry *tmp_orc_table = NULL;
unsigned int *orc_ip_size = (unsigned int *)arg;
unsigned int num_entries = *orc_ip_size / sizeof(int);
unsigned int orc_size = num_entries * sizeof(struct orc_entry);
idxs = (int *)malloc(*orc_ip_size);
if (!idxs) {
snprintf(g_err, ERRSTR_MAXSZ, "malloc idxs: %s",
strerror(errno));
pthread_exit(g_err);
}
tmp_orc_ip_table = (int *)malloc(*orc_ip_size);
if (!tmp_orc_ip_table) {
snprintf(g_err, ERRSTR_MAXSZ, "malloc tmp_orc_ip_table: %s",
strerror(errno));
pthread_exit(g_err);
}
tmp_orc_table = (struct orc_entry *)malloc(orc_size);
if (!tmp_orc_table) {
snprintf(g_err, ERRSTR_MAXSZ, "malloc tmp_orc_table: %s",
strerror(errno));
pthread_exit(g_err);
}
/* initialize indices array, convert ip_table to absolute address */
for (i = 0; i < num_entries; i++) {
idxs[i] = i;
tmp_orc_ip_table[i] = g_orc_ip_table[i] + i * sizeof(int);
}
memcpy(tmp_orc_table, g_orc_table, orc_size);
qsort(idxs, num_entries, sizeof(int), orc_sort_cmp);
for (i = 0; i < num_entries; i++) {
if (idxs[i] == i)
continue;
/* convert back to relative address */
g_orc_ip_table[i] = tmp_orc_ip_table[idxs[i]] - i * sizeof(int);
g_orc_table[i] = tmp_orc_table[idxs[i]];
}
free(idxs);
free(tmp_orc_ip_table);
free(tmp_orc_table);
pthread_exit(NULL);
}
#endif
#ifdef MCOUNT_SORT_ENABLED
static int compare_values_64(const void *a, const void *b)
{
uint64_t av = *(uint64_t *)a;
uint64_t bv = *(uint64_t *)b;
if (av < bv)
return -1;
return av > bv;
}
static int compare_values_32(const void *a, const void *b)
{
uint32_t av = *(uint32_t *)a;
uint32_t bv = *(uint32_t *)b;
if (av < bv)
return -1;
return av > bv;
}
static int (*compare_values)(const void *a, const void *b);
/* Only used for sorting mcount table */
static void rela_write_addend(Elf_Rela *rela, uint64_t val)
{
e.rela_write_addend(rela, val);
}
struct func_info {
uint64_t addr;
uint64_t size;
};
/* List of functions created by: nm -S vmlinux */
static struct func_info *function_list;
static int function_list_size;
/* Allocate functions in 1k blocks */
#define FUNC_BLK_SIZE 1024
#define FUNC_BLK_MASK (FUNC_BLK_SIZE - 1)
static int add_field(uint64_t addr, uint64_t size)
{
struct func_info *fi;
int fsize = function_list_size;
if (!(fsize & FUNC_BLK_MASK)) {
fsize += FUNC_BLK_SIZE;
fi = realloc(function_list, fsize * sizeof(struct func_info));
if (!fi)
return -1;
function_list = fi;
}
fi = &function_list[function_list_size++];
fi->addr = addr;
fi->size = size;
return 0;
}
/* Used for when mcount/fentry is before the function entry */
static int before_func;
/* Only return match if the address lies inside the function size */
static int cmp_func_addr(const void *K, const void *A)
{
uint64_t key = *(const uint64_t *)K;
const struct func_info *a = A;
if (key + before_func < a->addr)
return -1;
return key >= a->addr + a->size;
}
/* Find the function in function list that is bounded by the function size */
static int find_func(uint64_t key)
{
return bsearch(&key, function_list, function_list_size,
sizeof(struct func_info), cmp_func_addr) != NULL;
}
static int cmp_funcs(const void *A, const void *B)
{
const struct func_info *a = A;
const struct func_info *b = B;
if (a->addr < b->addr)
return -1;
return a->addr > b->addr;
}
static int parse_symbols(const char *fname)
{
FILE *fp;
char addr_str[20]; /* Only need 17, but round up to next int size */
char size_str[20];
char type;
fp = fopen(fname, "r");
if (!fp) {
perror(fname);
return -1;
}
while (fscanf(fp, "%16s %16s %c %*s\n", addr_str, size_str, &type) == 3) {
uint64_t addr;
uint64_t size;
/* Only care about functions */
if (type != 't' && type != 'T' && type != 'W')
continue;
addr = strtoull(addr_str, NULL, 16);
size = strtoull(size_str, NULL, 16);
if (add_field(addr, size) < 0)
return -1;
}
fclose(fp);
qsort(function_list, function_list_size, sizeof(struct func_info), cmp_funcs);
return 0;
}
static pthread_t mcount_sort_thread;
static bool sort_reloc;
static long rela_type;
static char m_err[ERRSTR_MAXSZ];
struct elf_mcount_loc {
Elf_Ehdr *ehdr;
Elf_Shdr *init_data_sec;
uint64_t start_mcount_loc;
uint64_t stop_mcount_loc;
};
/* Fill the array with the content of the relocs */
static int fill_relocs(void *ptr, uint64_t size, Elf_Ehdr *ehdr, uint64_t start_loc)
{
Elf_Shdr *shdr_start;
Elf_Rela *rel;
unsigned int shnum;
unsigned int count = 0;
int shentsize;
void *array_end = ptr + size;
shdr_start = (Elf_Shdr *)((char *)ehdr + ehdr_shoff(ehdr));
shentsize = ehdr_shentsize(ehdr);
shnum = ehdr_shnum(ehdr);
if (shnum == SHN_UNDEF)
shnum = shdr_size(shdr_start);
for (int i = 0; i < shnum; i++) {
Elf_Shdr *shdr = get_index(shdr_start, shentsize, i);
void *end;
if (shdr_type(shdr) != SHT_RELA)
continue;
rel = (void *)ehdr + shdr_offset(shdr);
end = (void *)rel + shdr_size(shdr);
for (; (void *)rel < end; rel = (void *)rel + shdr_entsize(shdr)) {
uint64_t offset = rela_offset(rel);
if (offset >= start_loc && offset < start_loc + size) {
if (ptr + long_size > array_end) {
snprintf(m_err, ERRSTR_MAXSZ,
"Too many relocations");
return -1;
}
/* Make sure this has the correct type */
if (rela_info(rel) != rela_type) {
snprintf(m_err, ERRSTR_MAXSZ,
"rela has type %lx but expected %lx\n",
(long)rela_info(rel), rela_type);
return -1;
}
if (long_size == 4)
*(uint32_t *)ptr = rela_addend(rel);
else
*(uint64_t *)ptr = rela_addend(rel);
ptr += long_size;
count++;
}
}
}
return count;
}
/* Put the sorted vals back into the relocation elements */
static void replace_relocs(void *ptr, uint64_t size, Elf_Ehdr *ehdr, uint64_t start_loc)
{
Elf_Shdr *shdr_start;
Elf_Rela *rel;
unsigned int shnum;
int shentsize;
shdr_start = (Elf_Shdr *)((char *)ehdr + ehdr_shoff(ehdr));
shentsize = ehdr_shentsize(ehdr);
shnum = ehdr_shnum(ehdr);
if (shnum == SHN_UNDEF)
shnum = shdr_size(shdr_start);
for (int i = 0; i < shnum; i++) {
Elf_Shdr *shdr = get_index(shdr_start, shentsize, i);
void *end;
if (shdr_type(shdr) != SHT_RELA)
continue;
rel = (void *)ehdr + shdr_offset(shdr);
end = (void *)rel + shdr_size(shdr);
for (; (void *)rel < end; rel = (void *)rel + shdr_entsize(shdr)) {
uint64_t offset = rela_offset(rel);
if (offset >= start_loc && offset < start_loc + size) {
if (long_size == 4)
rela_write_addend(rel, *(uint32_t *)ptr);
else
rela_write_addend(rel, *(uint64_t *)ptr);
ptr += long_size;
}
}
}
}
static int fill_addrs(void *ptr, uint64_t size, void *addrs)
{
void *end = ptr + size;
int count = 0;
for (; ptr < end; ptr += long_size, addrs += long_size, count++) {
if (long_size == 4)
*(uint32_t *)ptr = r(addrs);
else
*(uint64_t *)ptr = r8(addrs);
}
return count;
}
static void replace_addrs(void *ptr, uint64_t size, void *addrs)
{
void *end = ptr + size;
for (; ptr < end; ptr += long_size, addrs += long_size) {
if (long_size == 4)
w(*(uint32_t *)ptr, addrs);
else
w8(*(uint64_t *)ptr, addrs);
}
}
/* Sort the addresses stored between __start_mcount_loc to __stop_mcount_loc in vmlinux */
static void *sort_mcount_loc(void *arg)
{
struct elf_mcount_loc *emloc = (struct elf_mcount_loc *)arg;
uint64_t offset = emloc->start_mcount_loc - shdr_addr(emloc->init_data_sec)
+ shdr_offset(emloc->init_data_sec);
uint64_t size = emloc->stop_mcount_loc - emloc->start_mcount_loc;
unsigned char *start_loc = (void *)emloc->ehdr + offset;
Elf_Ehdr *ehdr = emloc->ehdr;
void *e_msg = NULL;
void *vals;
int count;
vals = malloc(long_size * size);
if (!vals) {
snprintf(m_err, ERRSTR_MAXSZ, "Failed to allocate sort array");
pthread_exit(m_err);
}
if (sort_reloc) {
count = fill_relocs(vals, size, ehdr, emloc->start_mcount_loc);
/* gcc may use relocs to save the addresses, but clang does not. */
if (!count) {
count = fill_addrs(vals, size, start_loc);
sort_reloc = 0;
}
} else
count = fill_addrs(vals, size, start_loc);
if (count < 0) {
e_msg = m_err;
goto out;
}
if (count != size / long_size) {
snprintf(m_err, ERRSTR_MAXSZ, "Expected %u mcount elements but found %u\n",
(int)(size / long_size), count);
e_msg = m_err;
goto out;
}
/* zero out any locations not found by function list */
if (function_list_size) {
for (void *ptr = vals; ptr < vals + size; ptr += long_size) {
uint64_t key;
key = long_size == 4 ? r((uint32_t *)ptr) : r8((uint64_t *)ptr);
if (!find_func(key)) {
if (long_size == 4)
*(uint32_t *)ptr = 0;
else
*(uint64_t *)ptr = 0;
}
}
}
compare_values = long_size == 4 ? compare_values_32 : compare_values_64;
qsort(vals, count, long_size, compare_values);
if (sort_reloc)
replace_relocs(vals, size, ehdr, emloc->start_mcount_loc);
else
replace_addrs(vals, size, start_loc);
out:
free(vals);
pthread_exit(e_msg);
}
/* Get the address of __start_mcount_loc and __stop_mcount_loc in System.map */
static void get_mcount_loc(struct elf_mcount_loc *emloc, Elf_Shdr *symtab_sec,
const char *strtab)
{
Elf_Sym *sym, *end_sym;
int symentsize = shdr_entsize(symtab_sec);
int found = 0;
sym = (void *)emloc->ehdr + shdr_offset(symtab_sec);
end_sym = (void *)sym + shdr_size(symtab_sec);
while (sym < end_sym) {
if (!strcmp(strtab + sym_name(sym), "__start_mcount_loc")) {
emloc->start_mcount_loc = sym_value(sym);
if (++found == 2)
break;
} else if (!strcmp(strtab + sym_name(sym), "__stop_mcount_loc")) {
emloc->stop_mcount_loc = sym_value(sym);
if (++found == 2)
break;
}
sym = (void *)sym + symentsize;
}
if (!emloc->start_mcount_loc) {
fprintf(stderr, "get start_mcount_loc error!");
return;
}
if (!emloc->stop_mcount_loc) {
fprintf(stderr, "get stop_mcount_loc error!");
return;
}
}
#else /* MCOUNT_SORT_ENABLED */
static inline int parse_symbols(const char *fname) { return 0; }
#endif
static int do_sort(Elf_Ehdr *ehdr,
char const *const fname,
table_sort_t custom_sort)
{
int rc = -1;
Elf_Shdr *shdr_start;
Elf_Shdr *strtab_sec = NULL;
Elf_Shdr *symtab_sec = NULL;
Elf_Shdr *extab_sec = NULL;
Elf_Shdr *string_sec;
Elf_Sym *sym;
const Elf_Sym *symtab;
Elf32_Word *symtab_shndx = NULL;
Elf_Sym *sort_needed_sym = NULL;
Elf_Shdr *sort_needed_sec;
uint32_t *sort_needed_loc;
void *sym_start;
void *sym_end;
const char *secstrings;
const char *strtab;
char *extab_image;
int sort_need_index;
int symentsize;
int shentsize;
int idx;
int i;
unsigned int shnum;
unsigned int shstrndx;
#ifdef MCOUNT_SORT_ENABLED
struct elf_mcount_loc mstruct = {0};
#endif
#ifdef UNWINDER_ORC_ENABLED
unsigned int orc_ip_size = 0;
unsigned int orc_size = 0;
unsigned int orc_num_entries = 0;
#endif
shdr_start = (Elf_Shdr *)((char *)ehdr + ehdr_shoff(ehdr));
shentsize = ehdr_shentsize(ehdr);
shstrndx = ehdr_shstrndx(ehdr);
if (shstrndx == SHN_XINDEX)
shstrndx = shdr_link(shdr_start);
string_sec = get_index(shdr_start, shentsize, shstrndx);
secstrings = (const char *)ehdr + shdr_offset(string_sec);
shnum = ehdr_shnum(ehdr);
if (shnum == SHN_UNDEF)
shnum = shdr_size(shdr_start);
for (i = 0; i < shnum; i++) {
Elf_Shdr *shdr = get_index(shdr_start, shentsize, i);
idx = shdr_name(shdr);
if (!strcmp(secstrings + idx, "__ex_table"))
extab_sec = shdr;
if (!strcmp(secstrings + idx, ".symtab"))
symtab_sec = shdr;
if (!strcmp(secstrings + idx, ".strtab"))
strtab_sec = shdr;
if (shdr_type(shdr) == SHT_SYMTAB_SHNDX)
symtab_shndx = (Elf32_Word *)((const char *)ehdr +
shdr_offset(shdr));
#ifdef MCOUNT_SORT_ENABLED
/* locate the .init.data section in vmlinux */
if (!strcmp(secstrings + idx, ".init.data"))
mstruct.init_data_sec = shdr;
#endif
#ifdef UNWINDER_ORC_ENABLED
/* locate the ORC unwind tables */
if (!strcmp(secstrings + idx, ".orc_unwind_ip")) {
orc_ip_size = shdr_size(shdr);
g_orc_ip_table = (int *)((void *)ehdr +
shdr_offset(shdr));
}
if (!strcmp(secstrings + idx, ".orc_unwind")) {
orc_size = shdr_size(shdr);
g_orc_table = (struct orc_entry *)((void *)ehdr +
shdr_offset(shdr));
}
#endif
} /* for loop */
#ifdef UNWINDER_ORC_ENABLED
if (!g_orc_ip_table || !g_orc_table) {
fprintf(stderr,
"incomplete ORC unwind tables in file: %s\n", fname);
goto out;
}
orc_num_entries = orc_ip_size / sizeof(int);
if (orc_ip_size % sizeof(int) != 0 ||
orc_size % sizeof(struct orc_entry) != 0 ||
orc_num_entries != orc_size / sizeof(struct orc_entry)) {
fprintf(stderr,
"inconsistent ORC unwind table entries in file: %s\n",
fname);
goto out;
}
/* create thread to sort ORC unwind tables concurrently */
if (pthread_create(&orc_sort_thread, NULL,
sort_orctable, &orc_ip_size)) {
fprintf(stderr,
"pthread_create orc_sort_thread failed '%s': %s\n",
strerror(errno), fname);
goto out;
}
#endif
if (!extab_sec) {
fprintf(stderr, "no __ex_table in file: %s\n", fname);
goto out;
}
if (!symtab_sec) {
fprintf(stderr, "no .symtab in file: %s\n", fname);
goto out;
}
if (!strtab_sec) {
fprintf(stderr, "no .strtab in file: %s\n", fname);
goto out;
}
extab_image = (void *)ehdr + shdr_offset(extab_sec);
strtab = (const char *)ehdr + shdr_offset(strtab_sec);
symtab = (const Elf_Sym *)((const char *)ehdr + shdr_offset(symtab_sec));
#ifdef MCOUNT_SORT_ENABLED
mstruct.ehdr = ehdr;
get_mcount_loc(&mstruct, symtab_sec, strtab);
if (!mstruct.init_data_sec || !mstruct.start_mcount_loc || !mstruct.stop_mcount_loc) {
fprintf(stderr,
"incomplete mcount's sort in file: %s\n",
fname);
goto out;
}
/* create thread to sort mcount_loc concurrently */
if (pthread_create(&mcount_sort_thread, NULL, &sort_mcount_loc, &mstruct)) {
fprintf(stderr,
"pthread_create mcount_sort_thread failed '%s': %s\n",
strerror(errno), fname);
goto out;
}
#endif
if (custom_sort) {
custom_sort(extab_image, shdr_size(extab_sec));
} else {
int num_entries = shdr_size(extab_sec) / extable_ent_size;
qsort(extab_image, num_entries,
extable_ent_size, compare_extable);
}
/* find the flag main_extable_sort_needed */
sym_start = (void *)ehdr + shdr_offset(symtab_sec);
sym_end = sym_start + shdr_size(symtab_sec);
symentsize = shdr_entsize(symtab_sec);
for (sym = sym_start; (void *)sym + symentsize < sym_end;
sym = (void *)sym + symentsize) {
if (sym_type(sym) != STT_OBJECT)
continue;
if (!strcmp(strtab + sym_name(sym),
"main_extable_sort_needed")) {
sort_needed_sym = sym;
break;
}
}
if (!sort_needed_sym) {
fprintf(stderr,
"no main_extable_sort_needed symbol in file: %s\n",
fname);
goto out;
}
sort_need_index = get_secindex(sym_shndx(sym),
((void *)sort_needed_sym - (void *)symtab) / symentsize,
symtab_shndx);
sort_needed_sec = get_index(shdr_start, shentsize, sort_need_index);
sort_needed_loc = (void *)ehdr +
shdr_offset(sort_needed_sec) +
sym_value(sort_needed_sym) - shdr_addr(sort_needed_sec);
/* extable has been sorted, clear the flag */
w(0, sort_needed_loc);
rc = 0;
out:
#ifdef UNWINDER_ORC_ENABLED
if (orc_sort_thread) {
void *retval = NULL;
/* wait for ORC tables sort done */
rc = pthread_join(orc_sort_thread, &retval);
if (rc) {
fprintf(stderr,
"pthread_join failed '%s': %s\n",
strerror(errno), fname);
} else if (retval) {
rc = -1;
fprintf(stderr,
"failed to sort ORC tables '%s': %s\n",
(char *)retval, fname);
}
}
#endif
#ifdef MCOUNT_SORT_ENABLED
if (mcount_sort_thread) {
void *retval = NULL;
/* wait for mcount sort done */
rc = pthread_join(mcount_sort_thread, &retval);
if (rc) {
fprintf(stderr,
"pthread_join failed '%s': %s\n",
strerror(errno), fname);
} else if (retval) {
rc = -1;
fprintf(stderr,
"failed to sort mcount '%s': %s\n",
(char *)retval, fname);
}
}
#endif
return rc;
}
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 sort_relative_table_with_data(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 or data */
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 or data */
i += sizeof(uint32_t) * 3;
}
}
static int do_file(char const *const fname, void *addr)
{
Elf_Ehdr *ehdr = addr;
table_sort_t custom_sort = NULL;
switch (ehdr->e32.e_ident[EI_DATA]) {
case ELFDATA2LSB:
r = rle;
r2 = r2le;
r8 = r8le;
w = wle;
w8 = w8le;
break;
case ELFDATA2MSB:
r = rbe;
r2 = r2be;
r8 = r8be;
w = wbe;
w8 = w8be;
break;
default:
fprintf(stderr, "unrecognized ELF data encoding %d: %s\n",
ehdr->e32.e_ident[EI_DATA], fname);
return -1;
}
if (memcmp(ELFMAG, ehdr->e32.e_ident, SELFMAG) != 0 ||
(r2(&ehdr->e32.e_type) != ET_EXEC && r2(&ehdr->e32.e_type) != ET_DYN) ||
ehdr->e32.e_ident[EI_VERSION] != EV_CURRENT) {
fprintf(stderr, "unrecognized ET_EXEC/ET_DYN file %s\n", fname);
return -1;
}
switch (r2(&ehdr->e32.e_machine)) {
case EM_AARCH64:
#ifdef MCOUNT_SORT_ENABLED
sort_reloc = true;
rela_type = 0x403;
/* arm64 uses patchable function entry placing before function */
before_func = 8;
#endif
/* fallthrough */
case EM_386:
case EM_LOONGARCH:
case EM_RISCV:
case EM_S390:
case EM_X86_64:
custom_sort = sort_relative_table_with_data;
break;
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_XTENSA:
break;
default:
fprintf(stderr, "unrecognized e_machine %d %s\n",
r2(&ehdr->e32.e_machine), fname);
return -1;
}
switch (ehdr->e32.e_ident[EI_CLASS]) {
case ELFCLASS32: {
struct elf_funcs efuncs = {
.compare_extable = compare_extable_32,
.ehdr_shoff = ehdr32_shoff,
.ehdr_shentsize = ehdr32_shentsize,
.ehdr_shstrndx = ehdr32_shstrndx,
.ehdr_shnum = ehdr32_shnum,
.shdr_addr = shdr32_addr,
.shdr_offset = shdr32_offset,
.shdr_link = shdr32_link,
.shdr_size = shdr32_size,
.shdr_name = shdr32_name,
.shdr_type = shdr32_type,
.shdr_entsize = shdr32_entsize,
.sym_type = sym32_type,
.sym_name = sym32_name,
.sym_value = sym32_value,
.sym_shndx = sym32_shndx,
.rela_offset = rela32_offset,
.rela_info = rela32_info,
.rela_addend = rela32_addend,
.rela_write_addend = rela32_write_addend,
};
e = efuncs;
long_size = 4;
extable_ent_size = 8;
if (r2(&ehdr->e32.e_ehsize) != sizeof(Elf32_Ehdr) ||
r2(&ehdr->e32.e_shentsize) != sizeof(Elf32_Shdr)) {
fprintf(stderr,
"unrecognized ET_EXEC/ET_DYN file: %s\n", fname);
return -1;
}
}
break;
case ELFCLASS64: {
struct elf_funcs efuncs = {
.compare_extable = compare_extable_64,
.ehdr_shoff = ehdr64_shoff,
.ehdr_shentsize = ehdr64_shentsize,
.ehdr_shstrndx = ehdr64_shstrndx,
.ehdr_shnum = ehdr64_shnum,
.shdr_addr = shdr64_addr,
.shdr_offset = shdr64_offset,
.shdr_link = shdr64_link,
.shdr_size = shdr64_size,
.shdr_name = shdr64_name,
.shdr_type = shdr64_type,
.shdr_entsize = shdr64_entsize,
.sym_type = sym64_type,
.sym_name = sym64_name,
.sym_value = sym64_value,
.sym_shndx = sym64_shndx,
.rela_offset = rela64_offset,
.rela_info = rela64_info,
.rela_addend = rela64_addend,
.rela_write_addend = rela64_write_addend,
};
e = efuncs;
long_size = 8;
extable_ent_size = 16;
if (r2(&ehdr->e64.e_ehsize) != sizeof(Elf64_Ehdr) ||
r2(&ehdr->e64.e_shentsize) != sizeof(Elf64_Shdr)) {
fprintf(stderr,
"unrecognized ET_EXEC/ET_DYN file: %s\n",
fname);
return -1;
}
}
break;
default:
fprintf(stderr, "unrecognized ELF class %d %s\n",
ehdr->e32.e_ident[EI_CLASS], fname);
return -1;
}
return do_sort(ehdr, fname, custom_sort);
}
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;
int c;
while ((c = getopt(argc, argv, "s:")) >= 0) {
switch (c) {
case 's':
if (parse_symbols(optarg) < 0) {
fprintf(stderr, "Could not parse %s\n", optarg);
return -1;
}
break;
default:
fprintf(stderr, "usage: sorttable [-s nm-file] vmlinux...\n");
return 0;
}
}
if ((argc - optind) < 1) {
fprintf(stderr, "usage: sorttable vmlinux...\n");
return 0;
}
/* Process each file in turn, allowing deep failure. */
for (i = optind; 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;
}