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d59a16836d
x86 is now using relative rather than absolute addresses in its
exception table, so we add a sorter for these. If there are
relocations on the __ex_table section, they are redundant and probably
incorrect after the sort, so they are zeroed out leaving them valid
and consistent.
Also use the unaligned safe accessors from tools/{be,le}_byteshift.h
Signed-off-by: David Daney <david.daney@cavium.com>
Link: http://lkml.kernel.org/r/1335291795-26693-2-git-send-email-ddaney.cavm@gmail.com
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
192 lines
4.9 KiB
C
192 lines
4.9 KiB
C
/*
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* sortextable.h
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*
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* Copyright 2011 - 2012 Cavium, Inc.
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*
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* Some of this code was taken out of recordmcount.h written by:
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*
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* Copyright 2009 John F. Reiser <jreiser@BitWagon.com>. All rights reserved.
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* Copyright 2010 Steven Rostedt <srostedt@redhat.com>, Red Hat Inc.
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*
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*
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* Licensed under the GNU General Public License, version 2 (GPLv2).
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*/
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#undef extable_ent_size
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#undef compare_extable
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#undef do_func
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#undef Elf_Addr
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#undef Elf_Ehdr
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#undef Elf_Shdr
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#undef Elf_Rel
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#undef Elf_Rela
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#undef Elf_Sym
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#undef ELF_R_SYM
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#undef Elf_r_sym
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#undef ELF_R_INFO
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#undef Elf_r_info
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#undef ELF_ST_BIND
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#undef ELF_ST_TYPE
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#undef fn_ELF_R_SYM
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#undef fn_ELF_R_INFO
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#undef uint_t
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#undef _r
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#undef _w
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#ifdef SORTEXTABLE_64
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# define extable_ent_size 16
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# define compare_extable compare_extable_64
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# define do_func do64
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# define Elf_Addr Elf64_Addr
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# define Elf_Ehdr Elf64_Ehdr
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# define Elf_Shdr Elf64_Shdr
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# define Elf_Rel Elf64_Rel
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# define Elf_Rela Elf64_Rela
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# define Elf_Sym Elf64_Sym
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# define ELF_R_SYM ELF64_R_SYM
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# define Elf_r_sym Elf64_r_sym
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# define ELF_R_INFO ELF64_R_INFO
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# define Elf_r_info Elf64_r_info
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# define ELF_ST_BIND ELF64_ST_BIND
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# define ELF_ST_TYPE ELF64_ST_TYPE
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# define fn_ELF_R_SYM fn_ELF64_R_SYM
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# define fn_ELF_R_INFO fn_ELF64_R_INFO
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# define uint_t uint64_t
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# define _r r8
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# define _w w8
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#else
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# define extable_ent_size 8
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# define compare_extable compare_extable_32
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# define do_func do32
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# define Elf_Addr Elf32_Addr
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# define Elf_Ehdr Elf32_Ehdr
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# define Elf_Shdr Elf32_Shdr
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# define Elf_Rel Elf32_Rel
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# define Elf_Rela Elf32_Rela
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# define Elf_Sym Elf32_Sym
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# define ELF_R_SYM ELF32_R_SYM
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# define Elf_r_sym Elf32_r_sym
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# define ELF_R_INFO ELF32_R_INFO
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# define Elf_r_info Elf32_r_info
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# define ELF_ST_BIND ELF32_ST_BIND
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# define ELF_ST_TYPE ELF32_ST_TYPE
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# define fn_ELF_R_SYM fn_ELF32_R_SYM
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# define fn_ELF_R_INFO fn_ELF32_R_INFO
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# define uint_t uint32_t
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# define _r r
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# define _w w
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#endif
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static int compare_extable(const void *a, const void *b)
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{
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Elf_Addr av = _r(a);
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Elf_Addr bv = _r(b);
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if (av < bv)
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return -1;
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if (av > bv)
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return 1;
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return 0;
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}
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static void
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do_func(Elf_Ehdr *ehdr, char const *const fname, table_sort_t custom_sort)
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{
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Elf_Shdr *shdr;
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Elf_Shdr *shstrtab_sec;
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Elf_Shdr *strtab_sec = NULL;
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Elf_Shdr *symtab_sec = NULL;
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Elf_Shdr *extab_sec = NULL;
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Elf_Sym *sym;
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Elf_Sym *sort_needed_sym;
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Elf_Shdr *sort_needed_sec;
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Elf_Rel *relocs = NULL;
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int relocs_size;
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uint32_t *sort_done_location;
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const char *secstrtab;
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const char *strtab;
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char *extab_image;
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int extab_index = 0;
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int i;
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int idx;
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shdr = (Elf_Shdr *)((char *)ehdr + _r(&ehdr->e_shoff));
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shstrtab_sec = shdr + r2(&ehdr->e_shstrndx);
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secstrtab = (const char *)ehdr + _r(&shstrtab_sec->sh_offset);
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for (i = 0; i < r2(&ehdr->e_shnum); i++) {
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idx = r(&shdr[i].sh_name);
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if (strcmp(secstrtab + idx, "__ex_table") == 0) {
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extab_sec = shdr + i;
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extab_index = i;
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}
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if ((r(&shdr[i].sh_type) == SHT_REL ||
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r(&shdr[i].sh_type) == SHT_RELA) &&
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r(&shdr[i].sh_info) == extab_index) {
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relocs = (void *)ehdr + _r(&shdr[i].sh_offset);
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relocs_size = _r(&shdr[i].sh_size);
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}
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if (strcmp(secstrtab + idx, ".symtab") == 0)
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symtab_sec = shdr + i;
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if (strcmp(secstrtab + idx, ".strtab") == 0)
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strtab_sec = shdr + i;
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}
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if (strtab_sec == NULL) {
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fprintf(stderr, "no .strtab in file: %s\n", fname);
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fail_file();
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}
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if (symtab_sec == NULL) {
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fprintf(stderr, "no .symtab in file: %s\n", fname);
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fail_file();
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}
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if (extab_sec == NULL) {
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fprintf(stderr, "no __ex_table in file: %s\n", fname);
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fail_file();
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}
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strtab = (const char *)ehdr + _r(&strtab_sec->sh_offset);
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extab_image = (void *)ehdr + _r(&extab_sec->sh_offset);
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if (custom_sort) {
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custom_sort(extab_image, _r(&extab_sec->sh_size));
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} else {
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int num_entries = _r(&extab_sec->sh_size) / extable_ent_size;
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qsort(extab_image, num_entries,
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extable_ent_size, compare_extable);
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}
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/* If there were relocations, we no longer need them. */
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if (relocs)
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memset(relocs, 0, relocs_size);
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/* find main_extable_sort_needed */
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sort_needed_sym = NULL;
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for (i = 0; i < _r(&symtab_sec->sh_size) / sizeof(Elf_Sym); i++) {
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sym = (void *)ehdr + _r(&symtab_sec->sh_offset);
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sym += i;
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if (ELF_ST_TYPE(sym->st_info) != STT_OBJECT)
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continue;
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idx = r(&sym->st_name);
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if (strcmp(strtab + idx, "main_extable_sort_needed") == 0) {
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sort_needed_sym = sym;
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break;
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}
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}
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if (sort_needed_sym == NULL) {
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fprintf(stderr,
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"no main_extable_sort_needed symbol in file: %s\n",
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fname);
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fail_file();
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}
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sort_needed_sec = &shdr[r2(&sort_needed_sym->st_shndx)];
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sort_done_location = (void *)ehdr +
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_r(&sort_needed_sec->sh_offset) +
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_r(&sort_needed_sym->st_value) -
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_r(&sort_needed_sec->sh_addr);
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#if 1
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printf("sort done marker at %lx\n",
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(unsigned long)((char *)sort_done_location - (char *)ehdr));
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#endif
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/* We sorted it, clear the flag. */
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w(0, sort_done_location);
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}
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