On Tue, 27 Oct 2009 18:21:11 -0400, Takao Indoh wrote:
>On Tue, 27 Oct 2009 10:36:53 +1100, Keith Owens wrote:
>
>>On Mon, 26 Oct 2009 18:15:22 -0400,
>>Takao Indoh <indou.takao@xxxxxxxxxxxxxx> wrote:
>>>As Intel manual says, it seems that pmsa_iip has a value of ip register
>>>where INIT interrupted when psr.ic is 0. Ok, I'll make a patch so that
>>>pmsa_iip is used irrespective of a value of psr.ic.
>>>
>>>Please let me know if I need to confirm something else before I make a
>>>patch.
>>
>>That looks good. The only problem I can think of is an MCA/INIT
>>arriving while code like SAVE_MIN or SAVE_REST is executing. Back
>>tracing at that point using pmsa_iip is going to be a problem, you have
>>no idea what state the registers or stack are in.
>
>I inserted another debug code into IA64_NATIVE_DO_SAVE_MIN to send
>INIT during SAVE_MIN.
>
>diff -Nurp a/arch/ia64/kernel/minstate.h b/arch/ia64/kernel/minstate.h
>--- a/arch/ia64/kernel/minstate.h 2009-10-22 12:28:07.000000000 -0400
>+++ b/arch/ia64/kernel/minstate.h 2009-10-27 12:42:02.000000000 -0400
>@@ -55,6 +55,14 @@
> mov r21=ar.fpsr; /* M */ \
> __COVER; /* B;; (or nothing) */ \
> ;; \
>+ movl r24=debug_flag; \
>+ ;; \
>+ ld8 r23=[r24]; \
>+ ;; \
>+ cmp.eq p2,p3=0,r23; \
>+(p2) br.sptk 2f; \
>+1: br.sptk 1b; \
>+2: \
> adds r16=IA64_TASK_THREAD_ON_USTACK_OFFSET,r16; \
> ;; \
> ld1 r17=[r16]; /* load current->thread.on_ustack flag */ \
>
>As a result, backtrace in the case using xip works, and backtrace in the
>case using iip does NOT work, as you said. Hm, it seems that I have to
>reconsider how to fix.
Now I think it's better to keep it as-is, I mean, use
pmsa_{xip,xpsr,xfs} if PSR.ic is 0. Instead of that, I'd like to
save pmsa_{iip,ipsr,ifs} somewhere for debugging. For example,
diff -Nurp a/arch/ia64/include/asm/mca.h b/arch/ia64/include/asm/mca.h
--- a/arch/ia64/include/asm/mca.h 2009-10-22 12:28:07.000000000 -0400
+++ b/arch/ia64/include/asm/mca.h 2009-11-03 17:01:33.000000000 -0500
@@ -106,6 +106,11 @@ struct ia64_sal_os_state {
unsigned long os_status; /* OS status to SAL, enum below */
unsigned long context; /* 0 if return to same context
1 if return to new context */
+
+ /* I-resources */
+ unsigned long iip;
+ unsigned long ipsr;
+ unsigned long ifs;
};
enum {
diff -Nurp a/arch/ia64/kernel/mca.c b/arch/ia64/kernel/mca.c
--- a/arch/ia64/kernel/mca.c 2009-10-22 12:28:07.000000000 -0400
+++ b/arch/ia64/kernel/mca.c 2009-11-05 11:10:45.000000000 -0500
@@ -888,9 +888,10 @@ ia64_mca_modify_comm(const struct task_s
}
static void
-finish_pt_regs(struct pt_regs *regs, const pal_min_state_area_t *ms,
+finish_pt_regs(struct pt_regs *regs, struct ia64_sal_os_state *sos,
unsigned long *nat)
{
+ const pal_min_state_area_t *ms = sos->pal_min_state;
const u64 *bank;
/* If ipsr.ic then use pmsa_{iip,ipsr,ifs}, else use
@@ -904,6 +905,10 @@ finish_pt_regs(struct pt_regs *regs, con
regs->cr_iip = ms->pmsa_xip;
regs->cr_ipsr = ms->pmsa_xpsr;
regs->cr_ifs = ms->pmsa_xfs;
+
+ sos->iip = ms->pmsa_iip;
+ sos->ipsr = ms->pmsa_ipsr;
+ sos->ifs = ms->pmsa_ifs;
}
regs->pr = ms->pmsa_pr;
regs->b0 = ms->pmsa_br0;
(snip)
Any idea or comments?
Thanks,
Takao Indoh
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