From 861667dc82f561e65336ea67f73021b782b4ff74 Mon Sep 17 00:00:00 2001 From: Ralf Baechle Date: Wed, 8 Aug 2012 16:59:43 +0200 Subject: [PATCH] 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 Signed-off-by: Tony Wu Cc: linux-mips@linux-mips.org Patchwork: http://patchwork.linux-mips.org/patch/4189/ --- arch/mips/include/asm/module.h | 1 + arch/mips/kernel/module.c | 13 ++++++------- 2 files changed, 7 insertions(+), 7 deletions(-) diff --git a/arch/mips/include/asm/module.h b/arch/mips/include/asm/module.h index 7531ecd..dca8bce 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 e5f2f56..8e1fb80 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 -- 2.7.4