diff options
| author | Brian Gerst <brgerst@gmail.com> | 2009-01-19 12:21:28 +0900 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2009-01-20 12:29:20 +0900 |
| commit | 947e76cdc34c782fc947313d4331380686eebbad (patch) | |
| tree | de5d424c4760269fd7800bc745e48b060c725300 /arch/x86/kernel/setup_percpu.c | |
| parent | 8c7e58e690ae60ab4215b025f433ed4af261e103 (diff) | |
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 <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'arch/x86/kernel/setup_percpu.c')
| -rw-r--r-- | arch/x86/kernel/setup_percpu.c | 34 |
1 files changed, 4 insertions, 30 deletions
diff --git a/arch/x86/kernel/setup_percpu.c b/arch/x86/kernel/setup_percpu.c index efbafbbff584..90b8e154bb53 100644 --- a/arch/x86/kernel/setup_percpu.c +++ b/arch/x86/kernel/setup_percpu.c @@ -77,30 +77,6 @@ static void __init setup_node_to_cpumask_map(void); static inline void setup_node_to_cpumask_map(void) { } #endif -/* - * Define load_pda_offset() and per-cpu __pda for x86_64. - * load_pda_offset() is responsible for loading the offset of pda into - * %gs. - * - * On SMP, pda offset also duals as percpu base address and thus it - * should be at the start of per-cpu area. To achieve this, it's - * preallocated in vmlinux_64.lds.S directly instead of using - * DEFINE_PER_CPU(). - */ -#ifdef CONFIG_X86_64 -void __cpuinit load_pda_offset(int cpu) -{ - /* Memory clobbers used to order pda/percpu accesses */ - mb(); - wrmsrl(MSR_GS_BASE, cpu_pda(cpu)); - mb(); -} -#ifndef CONFIG_SMP -DEFINE_PER_CPU(struct x8664_pda, __pda); -#endif -EXPORT_PER_CPU_SYMBOL(__pda); -#endif /* CONFIG_SMP && CONFIG_X86_64 */ - #ifdef CONFIG_X86_64 /* correctly size the local cpu masks */ @@ -207,15 +183,13 @@ void __init setup_per_cpu_areas(void) per_cpu(cpu_number, cpu) = cpu; #ifdef CONFIG_X86_64 per_cpu(irq_stack_ptr, cpu) = - (char *)per_cpu(irq_stack, cpu) + IRQ_STACK_SIZE - 64; + per_cpu(irq_stack_union.irq_stack, cpu) + IRQ_STACK_SIZE - 64; /* - * CPU0 modified pda in the init data area, reload pda - * offset for CPU0 and clear the area for others. + * Up to this point, CPU0 has been using .data.init + * area. Reload %gs offset for CPU0. */ if (cpu == 0) - load_pda_offset(0); - else - memset(cpu_pda(cpu), 0, sizeof(*cpu_pda(cpu))); + load_gs_base(cpu); #endif DBG("PERCPU: cpu %4d %p\n", cpu, ptr); |