From 947e76cdc34c782fc947313d4331380686eebbad Mon Sep 17 00:00:00 2001 From: Brian Gerst Date: Mon, 19 Jan 2009 12:21:28 +0900 Subject: x86: move stack_canary into irq_stack Impact: x86_64 percpu area layout change, irq_stack now at the beginning Now that the PDA is empty except for the stack canary, it can be removed. The irqstack is moved to the start of the per-cpu section. If the stack protector is enabled, the canary overlaps the bottom 48 bytes of the irqstack. tj: * updated subject * dropped asm relocation of irq_stack_ptr * updated comments a bit * rebased on top of stack canary changes Signed-off-by: Brian Gerst Signed-off-by: Tejun Heo --- arch/x86/include/asm/stackprotector.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'arch/x86/include/asm/stackprotector.h') diff --git a/arch/x86/include/asm/stackprotector.h b/arch/x86/include/asm/stackprotector.h index 2383e5bb475c..36a700acaf2b 100644 --- a/arch/x86/include/asm/stackprotector.h +++ b/arch/x86/include/asm/stackprotector.h @@ -2,7 +2,7 @@ #define _ASM_STACKPROTECTOR_H 1 #include -#include +#include /* * Initialize the stackprotector canary value. @@ -19,7 +19,7 @@ static __always_inline void boot_init_stack_canary(void) * 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); + BUILD_BUG_ON(offsetof(union irq_stack_union, stack_canary) != 40); /* * We both use the random pool and the current TSC as a source @@ -32,7 +32,7 @@ static __always_inline void boot_init_stack_canary(void) canary += tsc + (tsc << 32UL); current->stack_canary = canary; - write_pda(stack_canary, canary); + percpu_write(irq_stack_union.stack_canary, canary); } #endif -- cgit v1.2.3