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authorRalf Baechle <ralf@linux-mips.org>2012-08-08 16:59:43 +0200
committerRalf Baechle <ralf@linux-mips.org>2012-08-17 10:57:28 +0200
commit861667dc82f561e65336ea67f73021b782b4ff74 (patch)
tree822734b6d8c58b92e118215c27deb9bc61aeb2bc /arch/mips
parentd3cac35cd0a2a987f7559e1829fb0253cea33872 (diff)
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MIPS: Fix race condition in module relocation code.
The relocation code was essentially taken from the 2.4 modutils which perform relocation in userspace. In 2.6 relocation of multiple modules may be performed in parallel by the in-kernel loader so the global variable mips_hi16_list won't fly anymore. Fix race by moving it into mod_arch_specific. [ralf@linux-mips.org: folded in Tony's followup fix. Thanks Tony!] Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Tony Wu <tung7970@gmail.com> Cc: linux-mips@linux-mips.org Patchwork: http://patchwork.linux-mips.org/patch/4189/
Diffstat (limited to 'arch/mips')
-rw-r--r--arch/mips/include/asm/module.h1
-rw-r--r--arch/mips/kernel/module.c13
2 files changed, 7 insertions, 7 deletions
diff --git a/arch/mips/include/asm/module.h b/arch/mips/include/asm/module.h
index 7531ecd654d6..dca8bce8c7ab 100644
--- a/arch/mips/include/asm/module.h
+++ b/arch/mips/include/asm/module.h
@@ -10,6 +10,7 @@ struct mod_arch_specific {
struct list_head dbe_list;
const struct exception_table_entry *dbe_start;
const struct exception_table_entry *dbe_end;
+ struct mips_hi16 *r_mips_hi16_list;
};
typedef uint8_t Elf64_Byte; /* Type for a 8-bit quantity. */
diff --git a/arch/mips/kernel/module.c b/arch/mips/kernel/module.c
index e5f2f56524ea..8e1fb802c3e2 100644
--- a/arch/mips/kernel/module.c
+++ b/arch/mips/kernel/module.c
@@ -39,8 +39,6 @@ struct mips_hi16 {
Elf_Addr value;
};
-static struct mips_hi16 *mips_hi16_list;
-
static LIST_HEAD(dbe_list);
static DEFINE_SPINLOCK(dbe_lock);
@@ -128,8 +126,8 @@ static int apply_r_mips_hi16_rel(struct module *me, u32 *location, Elf_Addr v)
n->addr = (Elf_Addr *)location;
n->value = v;
- n->next = mips_hi16_list;
- mips_hi16_list = n;
+ n->next = me->arch.r_mips_hi16_list;
+ me->arch.r_mips_hi16_list = n;
return 0;
}
@@ -151,9 +149,9 @@ static int apply_r_mips_lo16_rel(struct module *me, u32 *location, Elf_Addr v)
/* Sign extend the addend we extract from the lo insn. */
vallo = ((insnlo & 0xffff) ^ 0x8000) - 0x8000;
- if (mips_hi16_list != NULL) {
+ if (me->arch.r_mips_hi16_list != NULL) {
- l = mips_hi16_list;
+ l = me->arch.r_mips_hi16_list;
while (l != NULL) {
unsigned long insn;
@@ -187,7 +185,7 @@ static int apply_r_mips_lo16_rel(struct module *me, u32 *location, Elf_Addr v)
l = next;
}
- mips_hi16_list = NULL;
+ me->arch.r_mips_hi16_list = NULL;
}
/*
@@ -278,6 +276,7 @@ int apply_relocate(Elf_Shdr *sechdrs, const char *strtab,
pr_debug("Applying relocate section %u to %u\n", relsec,
sechdrs[relsec].sh_info);
+ me->arch.r_mips_hi16_list = NULL;
for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
/* This is where to make the change */
location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr