xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

scripts/sortextable: Handle relative entries, and other cleanups

Browse Source 
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 <david.daney@cavium.com>
Link: http://lkml.kernel.org/r/1335291795-26693-2-git-send-email-ddaney.cavm@gmail.com
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
This commit is contained in:
David Daney
2012-04-24 11:23:14 -07:00
committed by H. Peter Anvin
parent 706276543b
commit d59a16836d
3 changed files with 172 additions and 96 deletions
Download Patch File Download Diff File Expand all files Collapse all files

79
scripts/sortextable.h
View File

@@ -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);
}