x86: push old stack address on irqstack for unwinder

Impact: Fixes dumpstack and KDB on 64 bits

This re-adds the old stack pointer to the top of the irqstack to help
with unwinding.  It was removed in commit d99015b1ab
as part of the save_args out-of-line work.

Both dumpstack and KDB require this information.

Signed-off-by: Martin Hicks <mort@sgi.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
This commit is contained in:
Martin Hicks 2009-01-30 10:50:54 -06:00 committed by H. Peter Anvin
parent 10b888d6ce
commit a67798cd7b

View file

@ -346,6 +346,7 @@ ENTRY(save_args)
popq_cfi %rax /* move return address... */
mov %gs:pda_irqstackptr,%rsp
EMPTY_FRAME 0
pushq_cfi %rbp /* backlink for unwinder */
pushq_cfi %rax /* ... to the new stack */
/*
* We entered an interrupt context - irqs are off: