tree 3a3844a79cff56d84ecafd65ba5d8da25e158d2b
parent 0b2bfb4e7ff61f286676867c3508569bea6fbf7a
author Haren Myneni <[EMAIL PROTECTED]> Wed, 03 Aug 2005 15:08:18 +1000
committer Linus Torvalds <[EMAIL PROTECTED]> Wed, 03 Aug 2005 12:16:45 -0700
[PATCH] Xmon bug fix for soft-reset
For soft reset during system hang, got an error "CPU did not take
control" for some CPUs even though they responded to soft-reset (called
SystemReset, die and called debugger - xmon). First these CPUs entered
into xmon by IPI callback and then got a soft-reset exception and
re-entered into xmon again. The first CPU which re-entered into xmon got
the output lock and made into xmon successfully without unlocking.
Hence, the next CPU(s) which re-entered into xmon try to acquire a lock
(get_output_lock). Therefore, we can not view state of those CPU(s).
[This is a simple, very low risk, obvious fix for an obvious bug, and
should go into 2.6.13. -- paulus]
Signed-off-by: Haren Myneni <[EMAIL PROTECTED]>
Signed-off-by: Paul Mackerras <[EMAIL PROTECTED]>
Signed-off-by: Linus Torvalds <[EMAIL PROTECTED]>
arch/ppc64/xmon/xmon.c | 3 +++
1 files changed, 3 insertions(+)
diff --git a/arch/ppc64/xmon/xmon.c b/arch/ppc64/xmon/xmon.c
--- a/arch/ppc64/xmon/xmon.c
+++ b/arch/ppc64/xmon/xmon.c
@@ -329,13 +329,16 @@ int xmon_core(struct pt_regs *regs, int
printf("cpu 0x%x: Exception %lx %s in xmon, "
"returning to main loop\n",
cpu, regs->trap, getvecname(TRAP(regs)));
+ release_output_lock();
longjmp(xmon_fault_jmp[cpu], 1);
}
if (setjmp(recurse_jmp) != 0) {
if (!in_xmon || !xmon_gate) {
+ get_output_lock();
printf("xmon: WARNING: bad recursive fault "
"on cpu 0x%x\n", cpu);
+ release_output_lock();
goto waiting;
}
secondary = !(xmon_taken && cpu == xmon_owner);
-
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