From 01ebb77b31149d847726a8847ad0d37631d7f049 Mon Sep 17 00:00:00 2001 From: Keith Owens Date: Wed, 30 Aug 2006 19:37:19 +0200 Subject: [PATCH] [PATCH] x86_64: Save original IST values for checking stack addresses The values in init_tss.ist[] can change when an IST event occurs. Save the original IST values for checking stack addresses when debugging or doing stack traces. Signed-off-by: Keith Owens Signed-off-by: Andi Kleen Signed-off-by: Linus Torvalds --- arch/x86_64/kernel/init_task.c | 5 +++++ arch/x86_64/kernel/setup64.c | 3 ++- arch/x86_64/kernel/traps.c | 2 +- include/asm-x86_64/processor.h | 6 ++++++ 4 files changed, 14 insertions(+), 2 deletions(-) diff --git a/arch/x86_64/kernel/init_task.c b/arch/x86_64/kernel/init_task.c index ce31d904d601..3dc5854ba21e 100644 --- a/arch/x86_64/kernel/init_task.c +++ b/arch/x86_64/kernel/init_task.c @@ -46,4 +46,9 @@ EXPORT_SYMBOL(init_task); */ DEFINE_PER_CPU(struct tss_struct, init_tss) ____cacheline_internodealigned_in_smp = INIT_TSS; +/* Copies of the original ist values from the tss are only accessed during + * debugging, no special alignment required. + */ +DEFINE_PER_CPU(struct orig_ist, orig_ist); + #define ALIGN_TO_4K __attribute__((section(".data.init_task"))) diff --git a/arch/x86_64/kernel/setup64.c b/arch/x86_64/kernel/setup64.c index 6fe58a634b5f..417de564456e 100644 --- a/arch/x86_64/kernel/setup64.c +++ b/arch/x86_64/kernel/setup64.c @@ -189,6 +189,7 @@ void __cpuinit cpu_init (void) { int cpu = stack_smp_processor_id(); struct tss_struct *t = &per_cpu(init_tss, cpu); + struct orig_ist *orig_ist = &per_cpu(orig_ist, cpu); unsigned long v; char *estacks = NULL; struct task_struct *me; @@ -256,7 +257,7 @@ void __cpuinit cpu_init (void) estacks += EXCEPTION_STKSZ; break; } - t->ist[v] = (unsigned long)estacks; + orig_ist->ist[v] = t->ist[v] = (unsigned long)estacks; } t->io_bitmap_base = offsetof(struct tss_struct, io_bitmap); diff --git a/arch/x86_64/kernel/traps.c b/arch/x86_64/kernel/traps.c index 5e00af54af65..b1249774d1e8 100644 --- a/arch/x86_64/kernel/traps.c +++ b/arch/x86_64/kernel/traps.c @@ -178,7 +178,7 @@ static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack, break; #endif default: - end = per_cpu(init_tss, cpu).ist[k]; + end = per_cpu(orig_ist, cpu).ist[k]; break; } /* diff --git a/include/asm-x86_64/processor.h b/include/asm-x86_64/processor.h index 3b3c1217fe61..de9c3147ee4c 100644 --- a/include/asm-x86_64/processor.h +++ b/include/asm-x86_64/processor.h @@ -232,8 +232,14 @@ struct tss_struct { unsigned long io_bitmap[IO_BITMAP_LONGS + 1]; } __attribute__((packed)) ____cacheline_aligned; + extern struct cpuinfo_x86 boot_cpu_data; DECLARE_PER_CPU(struct tss_struct,init_tss); +/* Save the original ist values for checking stack pointers during debugging */ +struct orig_ist { + unsigned long ist[7]; +}; +DECLARE_PER_CPU(struct orig_ist, orig_ist); #ifdef CONFIG_X86_VSMP #define ARCH_MIN_TASKALIGN (1 << INTERNODE_CACHE_SHIFT)