From a79f248b9b309ebb5f34ca6a8fd1eb9e18db5720 Mon Sep 17 00:00:00 2001 From: David Daney Date: Thu, 19 Apr 2012 14:59:55 -0700 Subject: scripts: Add sortextable to sort the kernel's exception table. Using this build-time sort saves time booting as we don't have to burn cycles sorting the exception table. Signed-off-by: David Daney Link: http://lkml.kernel.org/r/1334872799-14589-2-git-send-email-ddaney.cavm@gmail.com Signed-off-by: H. Peter Anvin --- scripts/sortextable.h | 168 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 168 insertions(+) create mode 100644 scripts/sortextable.h (limited to 'scripts/sortextable.h') diff --git a/scripts/sortextable.h b/scripts/sortextable.h new file mode 100644 index 00000000000..bb6aaf16600 --- /dev/null +++ b/scripts/sortextable.h @@ -0,0 +1,168 @@ +/* + * sortextable.h + * + * Copyright 2011 Cavium, Inc. + * + * Some of this code was taken out of recordmcount.h written by: + * + * Copyright 2009 John F. Reiser . All rights reserved. + * Copyright 2010 Steven Rostedt , Red Hat Inc. + * + * + * Licensed under the GNU General Public License, version 2 (GPLv2). + */ + +#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 _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 _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 _w w +#endif + +static int compare_extable(const void *a, const void *b) +{ + const uint_t *aa = a; + const uint_t *bb = b; + + if (_w(*aa) < _w(*bb)) + return -1; + if (_w(*aa) > _w(*bb)) + return 1; + return 0; +} + +static void +do_func(Elf_Ehdr *const ehdr, char const *const fname) +{ + 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; + Elf_Sym *sort_needed_sym; + Elf_Shdr *sort_needed_sec; + uint32_t *sort_done_location; + const char *secstrtab; + const char *strtab; + 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) + extab_sec = shdr + i; + if (strcmp(secstrtab + idx, ".symtab") == 0) + symtab_sec = shdr + i; + if (strcmp(secstrtab + idx, ".strtab") == 0) + strtab_sec = shdr + i; + } + if (strtab_sec == NULL) { + fprintf(stderr, "no .strtab in file: %s\n", fname); + fail_file(); + } + if (symtab_sec == NULL) { + fprintf(stderr, "no .symtab in file: %s\n", fname); + fail_file(); + } + if (extab_sec == NULL) { + fprintf(stderr, "no __ex_table in file: %s\n", fname); + fail_file(); + } + strtab = (const char *)ehdr + _w(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); + + /* 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); + sym += i; + if (ELF_ST_TYPE(sym->st_info) != STT_OBJECT) + continue; + idx = w(sym->st_name); + if (strcmp(strtab + idx, "main_extable_sort_needed") == 0) { + sort_needed_sym = sym; + break; + } + } + if (sort_needed_sym == NULL) { + fprintf(stderr, + "no main_extable_sort_needed symbol in file: %s\n", + fname); + fail_file(); + } + sort_needed_sec = &shdr[w2(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); + + 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))); + /* We sorted it, clear the flag. */ + *sort_done_location = 0; +} -- cgit v1.2.3