From d59a16836d917548cf41eda3369936684d527f5f Mon Sep 17 00:00:00 2001 From: David Daney Date: Tue, 24 Apr 2012 11:23:14 -0700 Subject: scripts/sortextable: Handle relative entries, and other cleanups 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 Link: http://lkml.kernel.org/r/1335291795-26693-2-git-send-email-ddaney.cavm@gmail.com Signed-off-by: H. Peter Anvin --- scripts/sortextable.h | 79 +++++++++++++++++++++++++++++++++------------------ 1 file changed, 51 insertions(+), 28 deletions(-) (limited to 'scripts/sortextable.h') diff --git a/scripts/sortextable.h b/scripts/sortextable.h index bb6aaf166002..e4fd45b7e456 100644 --- a/scripts/sortextable.h +++ b/scripts/sortextable.h @@ -1,7 +1,7 @@ /* * sortextable.h * - * Copyright 2011 Cavium, Inc. + * Copyright 2011 - 2012 Cavium, Inc. * * Some of this code was taken out of recordmcount.h written by: * @@ -30,6 +30,7 @@ #undef fn_ELF_R_SYM #undef fn_ELF_R_INFO #undef uint_t +#undef _r #undef _w #ifdef SORTEXTABLE_64 @@ -51,6 +52,7 @@ # 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 @@ -71,23 +73,24 @@ # 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) { - const uint_t *aa = a; - const uint_t *bb = b; + Elf_Addr av = _r(a); + Elf_Addr bv = _r(b); - if (_w(*aa) < _w(*bb)) + if (av < bv) return -1; - if (_w(*aa) > _w(*bb)) + if (av > bv) return 1; return 0; } static void -do_func(Elf_Ehdr *const ehdr, char const *const fname) +do_func(Elf_Ehdr *ehdr, char const *const fname, table_sort_t custom_sort) { Elf_Shdr *shdr; Elf_Shdr *shstrtab_sec; @@ -97,19 +100,31 @@ do_func(Elf_Ehdr *const ehdr, char const *const fname) Elf_Sym *sym; Elf_Sym *sort_needed_sym; Elf_Shdr *sort_needed_sec; + Elf_Rel *relocs = NULL; + int relocs_size; uint32_t *sort_done_location; const char *secstrtab; const char *strtab; + char *extab_image; + int extab_index = 0; int i; int idx; - shdr = (Elf_Shdr *)((void *)ehdr + _w(ehdr->e_shoff)); - shstrtab_sec = shdr + w2(ehdr->e_shstrndx); - secstrtab = (const char *)ehdr + _w(shstrtab_sec->sh_offset); - for (i = 0; i < w2(ehdr->e_shnum); i++) { - idx = w(shdr[i].sh_name); - if (strcmp(secstrtab + idx, "__ex_table") == 0) + shdr = (Elf_Shdr *)((char *)ehdr + _r(&ehdr->e_shoff)); + shstrtab_sec = shdr + r2(&ehdr->e_shstrndx); + secstrtab = (const char *)ehdr + _r(&shstrtab_sec->sh_offset); + for (i = 0; i < r2(&ehdr->e_shnum); i++) { + idx = r(&shdr[i].sh_name); + if (strcmp(secstrtab + idx, "__ex_table") == 0) { 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") == 0) symtab_sec = shdr + i; if (strcmp(secstrtab + idx, ".strtab") == 0) @@ -127,21 +142,29 @@ do_func(Elf_Ehdr *const ehdr, char const *const fname) fprintf(stderr, "no __ex_table in file: %s\n", fname); fail_file(); } - strtab = (const char *)ehdr + _w(strtab_sec->sh_offset); + strtab = (const char *)ehdr + _r(&strtab_sec->sh_offset); - /* Sort the table in place */ - qsort((void *)ehdr + _w(extab_sec->sh_offset), - (_w(extab_sec->sh_size) / extable_ent_size), - extable_ent_size, compare_extable); + 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 < _w(symtab_sec->sh_size) / sizeof(Elf_Sym); i++) { - sym = (void *)ehdr + _w(symtab_sec->sh_offset); + 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 = w(sym->st_name); + idx = r(&sym->st_name); if (strcmp(strtab + idx, "main_extable_sort_needed") == 0) { sort_needed_sym = sym; break; @@ -153,16 +176,16 @@ do_func(Elf_Ehdr *const ehdr, char const *const fname) fname); fail_file(); } - sort_needed_sec = &shdr[w2(sort_needed_sym->st_shndx)]; + sort_needed_sec = &shdr[r2(&sort_needed_sym->st_shndx)]; sort_done_location = (void *)ehdr + - _w(sort_needed_sec->sh_offset) + - _w(sort_needed_sym->st_value) - - _w(sort_needed_sec->sh_addr); + _r(&sort_needed_sec->sh_offset) + + _r(&sort_needed_sym->st_value) - + _r(&sort_needed_sec->sh_addr); +#if 1 printf("sort done marker at %lx\n", - (unsigned long) (_w(sort_needed_sec->sh_offset) + - _w(sort_needed_sym->st_value) - - _w(sort_needed_sec->sh_addr))); + (unsigned long)((char *)sort_done_location - (char *)ehdr)); +#endif /* We sorted it, clear the flag. */ - *sort_done_location = 0; + w(0, sort_done_location); } -- cgit v1.2.3-59-g8ed1b