/* SPDX-License-Identifier: GPL-2.0-only */
/*
* sortextable.h
*
* Copyright 2011 - 2012 Cavium, Inc.
*
* Some of this code was taken out of recordmcount.h written by:
*
* Copyright 2009 John F. Reiser <jreiser@BitWagon.com>. All rights reserved.
* Copyright 2010 Steven Rostedt <srostedt@redhat.com>, Red Hat Inc.
*/
#undef extable_ent_size
#undef compare_extable
#undef do_func
#undef Elf_Addr
#undef Elf_Ehdr
#undef Elf_Shdr
#undef Elf_Rel
#undef Elf_Rela
#undef Elf_Sym
#undef ELF_R_SYM
#undef Elf_r_sym
#undef ELF_R_INFO
#undef Elf_r_info
#undef ELF_ST_BIND
#undef ELF_ST_TYPE
#undef fn_ELF_R_SYM
#undef fn_ELF_R_INFO
#undef uint_t
#undef _r
#undef _w
#ifdef SORTEXTABLE_64
# define extable_ent_size 16
# define compare_extable compare_extable_64
# define do_func do64
# define Elf_Addr Elf64_Addr
# define Elf_Ehdr Elf64_Ehdr
# define Elf_Shdr Elf64_Shdr
# define Elf_Rel Elf64_Rel
# define Elf_Rela Elf64_Rela
# define Elf_Sym Elf64_Sym
# define ELF_R_SYM ELF64_R_SYM
# define Elf_r_sym Elf64_r_sym
# define ELF_R_INFO ELF64_R_INFO
# define Elf_r_info Elf64_r_info
# define ELF_ST_BIND ELF64_ST_BIND
# define ELF_ST_TYPE ELF64_ST_TYPE
# define fn_ELF_R_SYM fn_ELF64_R_SYM
# define fn_ELF_R_INFO fn_ELF64_R_INFO
# define uint_t uint64_t
# define _r r8
# define _w w8
#else
# define extable_ent_size 8
# define compare_extable compare_extable_32
# define do_func do32
# define Elf_Addr Elf32_Addr
# define Elf_Ehdr Elf32_Ehdr
# define Elf_Shdr Elf32_Shdr
# define Elf_Rel Elf32_Rel
# define Elf_Rela Elf32_Rela
# define Elf_Sym Elf32_Sym
# define ELF_R_SYM ELF32_R_SYM
# define Elf_r_sym Elf32_r_sym
# define ELF_R_INFO ELF32_R_INFO
# define Elf_r_info Elf32_r_info
# define ELF_ST_BIND ELF32_ST_BIND
# define ELF_ST_TYPE ELF32_ST_TYPE
# define fn_ELF_R_SYM fn_ELF32_R_SYM
# define fn_ELF_R_INFO fn_ELF32_R_INFO
# define uint_t uint32_t
# define _r r
# define _w w
#endif
static int compare_extable(const void *a, const void *b)
{
Elf_Addr av = _r(a);
Elf_Addr bv = _r(b);
if (av < bv)
return -1;
if (av > bv)
return 1;
return 0;
}
static int do_func(Elf_Ehdr *ehdr,
char const *const fname,
table_sort_t custom_sort)
{
Elf_Shdr *shdr;
Elf_Shdr *shstrtab_sec;
Elf_Shdr *strtab_sec = NULL;
Elf_Shdr *symtab_sec = NULL;
Elf_Shdr *extab_sec = NULL;
Elf_Sym *sym;
const Elf_Sym *symtab;
Elf32_Word *symtab_shndx_start = NULL;
Elf_Sym *sort_needed_sym;
Elf_Shdr *sort_needed_sec;
Elf_Rel *relocs = NULL;
int relocs_size = 0;
uint32_t *sort_done_location;
const char *secstrtab;
const char *strtab;
char *extab_image;
int extab_index = 0;
int i;
int idx;
unsigned int num_sections;
unsigned int secindex_strings;
shdr = (Elf_Shdr *)((char *)ehdr + _r(&ehdr->e_shoff));
num_sections = r2(&ehdr->e_shnum);
if (num_sections == SHN_UNDEF)
num_sections = _r(&shdr[0].sh_size);
secindex_strings = r2(&ehdr->e_shstrndx);
if (secindex_strings == SHN_XINDEX)
secindex_strings = r(&shdr[0].sh_link);
shstrtab_sec = shdr + secindex_strings;
secstrtab = (const char *)ehdr + _r(&shstrtab_sec->sh_offset);
for (i = 0; i < num_sections; i++) {
idx = r(&shdr[i].sh_name);
if (!strcmp(secstrtab + idx, "__ex_table")) {
extab_sec = shdr + i;
extab_index = i;
}
if ((r(&shdr[i].sh_type) == SHT_REL ||
r(&shdr[i].sh_type) == SHT_RELA) &&
r(&shdr[i].sh_info) == extab_index) {
relocs = (void *)ehdr + _r(&shdr[i].sh_offset);
relocs_size = _r(&shdr[i].sh_size);
}
if (!strcmp(secstrtab + idx, ".symtab"))
symtab_sec = shdr + i;
if (!strcmp(secstrtab + idx, ".strtab"))
strtab_sec = shdr + i;
if (r(&shdr[i].sh_type) == SHT_SYMTAB_SHNDX)
symtab_shndx_start = (Elf32_Word *)(
(const char *)ehdr + _r(&shdr[i].sh_offset));
}
if (!strtab_sec) {
fprintf(stderr, "no .strtab in file: %s\n", fname);
return -1;
}
if (!symtab_sec) {
fprintf(stderr, "no .symtab in file: %s\n", fname);
return -1;
}
symtab = (const Elf_Sym *)((const char *)ehdr +
_r(&symtab_sec->sh_offset));
if (!extab_sec) {
fprintf(stderr, "no __ex_table in file: %s\n", fname);
return -1;
}
strtab = (const char *)ehdr + _r(&strtab_sec->sh_offset);
extab_image = (void *)ehdr + _r(&extab_sec->sh_offset);
if (custom_sort) {
custom_sort(extab_image, _r(&extab_sec->sh_size));
} else {
int num_entries = _r(&extab_sec->sh_size) / extable_ent_size;
qsort(extab_image, num_entries,
extable_ent_size, compare_extable);
}
/* If there were relocations, we no longer need them. */
if (relocs)
memset(relocs, 0, relocs_size);
/* find main_extable_sort_needed */
sort_needed_sym = NULL;
for (i = 0; i < _r(&symtab_sec->sh_size) / sizeof(Elf_Sym); i++) {
sym = (void *)ehdr + _r(&symtab_sec->sh_offset);
sym += i;
if (ELF_ST_TYPE(sym->st_info) != STT_OBJECT)
continue;
idx = r(&sym->st_name);
if (!strcmp(strtab + idx, "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);
return -1;
}
sort_needed_sec = &shdr[get_secindex(r2(&sym->st_shndx),
sort_needed_sym - symtab,
symtab_shndx_start)];
sort_done_location = (void *)ehdr +
_r(&sort_needed_sec->sh_offset) +
_r(&sort_needed_sym->st_value) -
_r(&sort_needed_sec->sh_addr);
/* We sorted it, clear the flag. */
w(0, sort_done_location);
return 0;
}
