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scripts/sortextable: Refactor the do_func() function

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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.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Shile Zhang 2019-12-04 08:46:30 +08:00 committed by Ingo Molnar
parent abe4f92ca8
commit 57cafdf2a0
2 changed files with 65 additions and 62 deletions
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4
scripts/sortextable.c
View file

@ -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:

123
scripts/sortextable.h
View file

@ -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);
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);
return -1;
}
strtab = (const char *)ehdr + _r(&strtab_sec->sh_offset);
if (!symtab_sec) {
fprintf(stderr, "no .symtab in file: %s\n", fname);
return -1;
}
if (!strtab_sec) {
fprintf(stderr, "no .strtab in file: %s\n", fname);
return -1;
}
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;
}