diff options
| author | Tejun Heo <tj@kernel.org> | 2009-01-20 06:29:19 +0300 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2009-01-20 06:29:19 +0300 |
| commit | c6e50f93db5bd0895ec7c7d1b6f3886c6e1f11b6 (patch) | |
| tree | 3d6b2d04118bb61fb50cf7624aaf7f7e4f5916ce | |
| parent | 7890ba8c87604ca4c2c73f7de846bf5305d743e4 (diff) | |
| download | linux-c6e50f93db5bd0895ec7c7d1b6f3886c6e1f11b6.tar.xz | |
x86: cleanup stack protector
Impact: cleanup
Make the following cleanups.
* remove duplicate comment from boot_init_stack_canary() which fits
better in the other place - cpu_idle().
* move stack_canary offset check from __switch_to() to
boot_init_stack_canary().
Signed-off-by: Tejun Heo <tj@kernel.org>
| -rw-r--r-- | arch/x86/include/asm/pda.h | 2 | ||||
| -rw-r--r-- | arch/x86/include/asm/stackprotector.h | 13 | ||||
| -rw-r--r-- | arch/x86/kernel/process_64.c | 7 |
3 files changed, 6 insertions, 16 deletions
diff --git a/arch/x86/include/asm/pda.h b/arch/x86/include/asm/pda.h index 5976cd803e9a..4a8c9d382c93 100644 --- a/arch/x86/include/asm/pda.h +++ b/arch/x86/include/asm/pda.h @@ -40,6 +40,4 @@ extern void pda_init(int); #endif -#define refresh_stack_canary() write_pda(stack_canary, current->stack_canary) - #endif /* _ASM_X86_PDA_H */ diff --git a/arch/x86/include/asm/stackprotector.h b/arch/x86/include/asm/stackprotector.h index c7f0d10bae7b..2383e5bb475c 100644 --- a/arch/x86/include/asm/stackprotector.h +++ b/arch/x86/include/asm/stackprotector.h @@ -16,13 +16,12 @@ static __always_inline void boot_init_stack_canary(void) u64 tsc; /* - * If we're the non-boot CPU, nothing set the PDA stack - * canary up for us - and if we are the boot CPU we have - * a 0 stack canary. This is a good place for updating - * it, as we wont ever return from this function (so the - * invalid canaries already on the stack wont ever - * trigger). - * + * Build time only check to make sure the stack_canary is at + * offset 40 in the pda; this is a gcc ABI requirement + */ + BUILD_BUG_ON(offsetof(struct x8664_pda, stack_canary) != 40); + + /* * We both use the random pool and the current TSC as a source * of randomness. The TSC only matters for very early init, * there it already has some randomness on most systems. Later diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index aa89eabf09e0..088bc9a0f82c 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -638,13 +638,6 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) percpu_write(kernel_stack, (unsigned long)task_stack_page(next_p) + THREAD_SIZE - KERNEL_STACK_OFFSET); -#ifdef CONFIG_CC_STACKPROTECTOR - /* - * Build time only check to make sure the stack_canary is at - * offset 40 in the pda; this is a gcc ABI requirement - */ - BUILD_BUG_ON(offsetof(struct x8664_pda, stack_canary) != 40); -#endif /* * Now maybe reload the debug registers and handle I/O bitmaps |