Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

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

[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

arch/x86_64/kernel/init_task.c

+5 −0
Original line number Diff line number Diff line
@@ -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")))

arch/x86_64/kernel/setup64.c

+2 −1
Original line number Diff line number Diff line
@@ -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);

arch/x86_64/kernel/traps.c

+1 −1
Original line number Diff line number Diff line
@@ -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;

		}

		/*

include/asm-x86_64/processor.h

+6 −0
Original line number Diff line number Diff line
@@ -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)