Commit 01ebb77b authored by Keith Owens's avatar Keith Owens Committed by Linus Torvalds

[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: default avatarKeith Owens <kaos@ocs.com.au>
Signed-off-by: default avatarAndi Kleen <ak@suse.de>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 386dcafa
......@@ -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")))
......@@ -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);
......
......@@ -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;
}
/*
......
......@@ -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)
......
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