aboutsummaryrefslogtreecommitdiff
path: root/kernel/module.c
diff options
context:
space:
mode:
authorSatoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>2012-12-05 12:29:04 +1030
committerRusty Russell <rusty@rustcorp.com.au>2012-12-14 13:06:43 +1030
commit54523ec71f8ce99accae97c74152f14f261f7e18 (patch)
tree0bd21d6d928da01bff4dac47ae6fe057a7541d7d /kernel/module.c
parent99cca91e370ab9224755365dda98b78eb5a5417f (diff)
downloadlinaro-lsk-54523ec71f8ce99accae97c74152f14f261f7e18.tar.gz
module: Remove a extra null character at the top of module->strtab.
There is a extra null character('\0') at the top of module->strtab for each module. Commit 59ef28b introduced this bug and this patch fixes it. Live dump log of the current linus git kernel(HEAD is 2844a4870): ============================================================================ crash> mod | grep loop ffffffffa01db0a0 loop 16689 (not loaded) [CONFIG_KALLSYMS] crash> module.core_symtab ffffffffa01db0a0 core_symtab = 0xffffffffa01db320crash> rd 0xffffffffa01db320 12 ffffffffa01db320: 0000005500000001 0000000000000000 ....U........... ffffffffa01db330: 0000000000000000 0002007400000002 ............t... ffffffffa01db340: ffffffffa01d8000 0000000000000038 ........8....... ffffffffa01db350: 001a00640000000e ffffffffa01daeb0 ....d........... ffffffffa01db360: 00000000000000a0 0002007400000019 ............t... ffffffffa01db370: ffffffffa01d8068 000000000000001b h............... crash> module.core_strtab ffffffffa01db0a0 core_strtab = 0xffffffffa01dbb30 "" crash> rd 0xffffffffa01dbb30 4 ffffffffa01dbb30: 615f70616d6b0000 66780063696d6f74 ..kmap_atomic.xf ffffffffa01dbb40: 73636e75665f7265 72665f646e696600 er_funcs.find_fr ============================================================================ We expect Just first one byte of '\0', but actually first two bytes are '\0'. Here is The relationship between symtab and strtab. symtab_idx strtab_idx symbol ----------------------------------------------- 0 0x1 "\0" # startab_idx should be 0 1 0x2 "kmap_atomic" 2 0xe "xfer_funcs" 3 0x19 "find_fr..." By applying this patch, it becomes as follows. symtab_idx strtab_idx symbol ----------------------------------------------- 0 0x0 "\0" # extra byte is removed 1 0x1 "kmap_atomic" 2 0xd "xfer_funcs" 3 0x18 "find_fr..." Signed-off-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com> Cc: Masaki Kimura <masaki.kimura.kz@hitachi.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Diffstat (limited to 'kernel/module.c')
-rw-r--r--kernel/module.c6
1 files changed, 1 insertions, 5 deletions
diff --git a/kernel/module.c b/kernel/module.c
index a1d2ed8bab9..79a526dd1b1 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -2285,7 +2285,7 @@ static void layout_symtab(struct module *mod, struct load_info *info)
Elf_Shdr *symsect = info->sechdrs + info->index.sym;
Elf_Shdr *strsect = info->sechdrs + info->index.str;
const Elf_Sym *src;
- unsigned int i, nsrc, ndst, strtab_size;
+ unsigned int i, nsrc, ndst, strtab_size = 0;
/* Put symbol section at end of init part of module. */
symsect->sh_flags |= SHF_ALLOC;
@@ -2296,9 +2296,6 @@ static void layout_symtab(struct module *mod, struct load_info *info)
src = (void *)info->hdr + symsect->sh_offset;
nsrc = symsect->sh_size / sizeof(*src);
- /* strtab always starts with a nul, so offset 0 is the empty string. */
- strtab_size = 1;
-
/* Compute total space required for the core symbols' strtab. */
for (ndst = i = 0; i < nsrc; i++) {
if (i == 0 ||
@@ -2340,7 +2337,6 @@ static void add_kallsyms(struct module *mod, const struct load_info *info)
mod->core_symtab = dst = mod->module_core + info->symoffs;
mod->core_strtab = s = mod->module_core + info->stroffs;
src = mod->symtab;
- *s++ = 0;
for (ndst = i = 0; i < mod->num_symtab; i++) {
if (i == 0 ||
is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum)) {