[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 <kaos@ocs.com.au>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 6 insertions, 0 deletions

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)