From: Shile Zhang shile.zhang@linux.alibaba.com
mainline inclusion from mainline-v5.6-rc1 commit 57cafdf2a04e161b9654c4ae3888a7549594c499 category: feature bugzilla: NA CVE: NA
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Refine the loop, naming and code structure, make the code more readable and extendable. No functional changes intended.
Signed-off-by: Shile Zhang shile.zhang@linux.alibaba.com Acked-by: Peter Zijlstra (Intel) peterz@infradead.org Cc: Josh Poimboeuf jpoimboe@redhat.com Cc: Masahiro Yamada yamada.masahiro@socionext.com Cc: Michal Marek michal.lkml@markovi.net Cc: linux-kbuild@vger.kernel.org Link: https://lkml.kernel.org/r/20191204004633.88660-5-shile.zhang@linux.alibaba.c... Signed-off-by: Ingo Molnar mingo@kernel.org Signed-off-by: Yang Yingliang yangyingliang@huawei.com Reviewed-by: Jian Cheng cj.chengjian@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- scripts/sortextable.c | 4 +- scripts/sortextable.h | 115 ++++++++++++++++++++++-------------------- 2 files changed, 61 insertions(+), 58 deletions(-)
diff --git a/scripts/sortextable.c b/scripts/sortextable.c index e5384e86b58c5..efa2839865cdb 100644 --- a/scripts/sortextable.c +++ b/scripts/sortextable.c @@ -320,7 +320,7 @@ static int do_file(char const *const fname, void *addr) "unrecognized ET_EXEC/ET_DYN file: %s\n", fname); break; } - rc = do32(ehdr, fname, custom_sort); + rc = do_sort_32(ehdr, fname, custom_sort); break; case ELFCLASS64: { @@ -332,7 +332,7 @@ static int do_file(char const *const fname, void *addr) fname); break; } - rc = do64(ghdr, fname, custom_sort); + rc = do_sort_64(ghdr, fname, custom_sort); } break; default: diff --git a/scripts/sortextable.h b/scripts/sortextable.h index a2e3af7bf2119..6485513f7caeb 100644 --- a/scripts/sortextable.h +++ b/scripts/sortextable.h @@ -12,7 +12,7 @@
#undef extable_ent_size #undef compare_extable -#undef do_func +#undef do_sort #undef Elf_Addr #undef Elf_Ehdr #undef Elf_Shdr @@ -34,7 +34,7 @@ #ifdef SORTEXTABLE_64 # define extable_ent_size 16 # define compare_extable compare_extable_64 -# define do_func do64 +# define do_sort do_sort_64 # define Elf_Addr Elf64_Addr # define Elf_Ehdr Elf64_Ehdr # define Elf_Shdr Elf64_Shdr @@ -55,7 +55,7 @@ #else # define extable_ent_size 8 # define compare_extable compare_extable_32 -# define do_func do32 +# define do_sort do_sort_32 # define Elf_Addr Elf32_Addr # define Elf_Ehdr Elf32_Ehdr # define Elf_Shdr Elf32_Shdr @@ -87,81 +87,81 @@ static int compare_extable(const void *a, const void *b) return 0; }
-static int do_func(Elf_Ehdr *ehdr, +static int do_sort(Elf_Ehdr *ehdr, char const *const fname, table_sort_t custom_sort) { - Elf_Shdr *shdr; - Elf_Shdr *shstrtab_sec; + Elf_Shdr *s, *shdr = (Elf_Shdr *)((char *)ehdr + _r(&ehdr->e_shoff)); 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; + Elf32_Word *symtab_shndx = NULL; + Elf_Sym *sort_needed_sym = NULL; Elf_Shdr *sort_needed_sec; Elf_Rel *relocs = NULL; int relocs_size = 0; - uint32_t *sort_done_location; - const char *secstrtab; + uint32_t *sort_needed_loc; + const char *secstrings; const char *strtab; char *extab_image; int extab_index = 0; int i; int idx; - unsigned int num_sections; - unsigned int secindex_strings; + unsigned int shnum; + unsigned int shstrndx;
- shdr = (Elf_Shdr *)((char *)ehdr + _r(&ehdr->e_shoff)); + shstrndx = r2(&ehdr->e_shstrndx); + if (shstrndx == SHN_XINDEX) + shstrndx = r(&shdr[0].sh_link); + secstrings = (const char *)ehdr + _r(&shdr[shstrndx].sh_offset);
- num_sections = r2(&ehdr->e_shnum); - if (num_sections == SHN_UNDEF) - num_sections = _r(&shdr[0].sh_size); + shnum = r2(&ehdr->e_shnum); + if (shnum == SHN_UNDEF) + shnum = _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; + for (i = 0, s = shdr; s < shdr + shnum; i++, s++) { + idx = r(&s->sh_name); + if (!strcmp(secstrings + idx, "__ex_table")) { + extab_sec = s; 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(secstrings + idx, ".symtab")) + symtab_sec = s; + if (!strcmp(secstrings + idx, ".strtab")) + strtab_sec = s; + + if ((r(&s->sh_type) == SHT_REL || + r(&s->sh_type) == SHT_RELA) && + r(&s->sh_info) == extab_index) { + relocs = (void *)ehdr + _r(&s->sh_offset); + relocs_size = _r(&s->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 (r(&s->sh_type) == SHT_SYMTAB_SHNDX) + symtab_shndx = (Elf32_Word *)((const char *)ehdr + + _r(&s->sh_offset)); } - if (!strtab_sec) { - fprintf(stderr, "no .strtab in file: %s\n", fname); + + if (!extab_sec) { + fprintf(stderr, "no __ex_table 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); + + if (!strtab_sec) { + fprintf(stderr, "no .strtab 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); + strtab = (const char *)ehdr + _r(&strtab_sec->sh_offset); + symtab = (const Elf_Sym *)((const char *)ehdr + + _r(&symtab_sec->sh_offset));
if (custom_sort) { custom_sort(extab_image, _r(&extab_sec->sh_size)); @@ -170,38 +170,41 @@ static int do_func(Elf_Ehdr *ehdr, 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; + /* find the flag main_extable_sort_needed */ + for (sym = (void *)ehdr + _r(&symtab_sec->sh_offset); + sym < sym + _r(&symtab_sec->sh_size) / sizeof(Elf_Sym); + sym++) { if (ELF_ST_TYPE(sym->st_info) != STT_OBJECT) continue; - idx = r(&sym->st_name); - if (!strcmp(strtab + idx, "main_extable_sort_needed")) { + if (!strcmp(strtab + r(&sym->st_name), + "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 + + symtab_shndx)]; + sort_needed_loc = (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); + /* extable has been sorted, clear the flag */ + w(0, sort_needed_loc); + return 0; }