From 59c36455d061e200f386e1817362f6afd6265b6a Mon Sep 17 00:00:00 2001 From: Jamie Iles Date: Tue, 12 Nov 2013 15:06:51 -0800 Subject: [PATCH] scripts/sortextable: support objects with more than 64K sections. Building with a large config and -ffunction-sections results in a large number of sections and sortextable needs to be able to handle that. Implement support for > 64K sections as modpost does. Signed-off-by: Jamie Iles Cc: Rusty Russell Cc: Michal Marek Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- scripts/sortextable.c | 24 ++++++++++++++++++++++++ scripts/sortextable.h | 26 +++++++++++++++++++++++--- 2 files changed, 47 insertions(+), 3 deletions(-) diff --git a/scripts/sortextable.c b/scripts/sortextable.c index 7c2310c5b996..5f7a8b663cb9 100644 --- a/scripts/sortextable.c +++ b/scripts/sortextable.c @@ -152,6 +152,30 @@ static void (*w2)(uint16_t, uint16_t *); typedef void (*table_sort_t)(char *, int); +/* + * 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]); +} + /* 32 bit and 64 bit are very similar */ #include "sortextable.h" #define SORTEXTABLE_64 diff --git a/scripts/sortextable.h b/scripts/sortextable.h index f5eb43d42926..8fac3fd697a6 100644 --- a/scripts/sortextable.h +++ b/scripts/sortextable.h @@ -98,6 +98,8 @@ do_func(Elf_Ehdr *ehdr, char const *const fname, table_sort_t custom_sort) 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; @@ -109,11 +111,22 @@ do_func(Elf_Ehdr *ehdr, char const *const fname, table_sort_t custom_sort) 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)); - shstrtab_sec = shdr + r2(&ehdr->e_shstrndx); + + 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 < r2(&ehdr->e_shnum); i++) { + for (i = 0; i < num_sections; i++) { idx = r(&shdr[i].sh_name); if (strcmp(secstrtab + idx, "__ex_table") == 0) { extab_sec = shdr + i; @@ -129,6 +142,9 @@ do_func(Elf_Ehdr *ehdr, char const *const fname, table_sort_t custom_sort) symtab_sec = shdr + i; if (strcmp(secstrtab + idx, ".strtab") == 0) 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 == NULL) { fprintf(stderr, "no .strtab in file: %s\n", fname); @@ -138,6 +154,8 @@ do_func(Elf_Ehdr *ehdr, char const *const fname, table_sort_t custom_sort) fprintf(stderr, "no .symtab in file: %s\n", fname); fail_file(); } + symtab = (const Elf_Sym *)((const char *)ehdr + + _r(&symtab_sec->sh_offset)); if (extab_sec == NULL) { fprintf(stderr, "no __ex_table in file: %s\n", fname); fail_file(); @@ -176,7 +194,9 @@ do_func(Elf_Ehdr *ehdr, char const *const fname, table_sort_t custom_sort) fname); fail_file(); } - sort_needed_sec = &shdr[r2(&sort_needed_sym->st_shndx)]; + 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) -