From: liu chuansheng <chuansheng....@intel.com>
Subject: [PATCH] x86_dump_trace: avoiding endless " <IRQ> " is printed
Found the case that endless " <IRQ> " printing in dump_trace,
and no real meaningful stack traces are output, so there should
one rare case that possibly context->previous_esp = context or
other cases.
The endless " <IRQ> " is as below:
...
[ 82.215244,0] <IRQ>
[ 82.215399,0] <IRQ>
[ 82.215554,0] <IRQ>
[ 82.215710,0] <IRQ>
[ 82.215865,0] <IRQ>
[ 82.216022,0] <IRQ>
[ 82.216178,0] <IRQ>
[ 82.216333,0] <IRQ>
[ 82.216488,0] <IRQ>
[ 82.216643,0] <IRQ>
[ 82.216798,0] <IRQ>
[ 82.216953,0] <IRQ>
...
This patch aim is:
1/ Limiting the " <IRQ> " outputing, currently the max IRQ contexts
is 2(softirq+harirq combination);
2/ When the max IRQ contexts 2 is reached, print the context content
to confirm;
Signed-off-by: liu chuansheng <chuansheng....@intel.com>
---
arch/x86/kernel/dumpstack_32.c | 11 +++++++++++
1 files changed, 11 insertions(+), 0 deletions(-)
diff --git a/arch/x86/kernel/dumpstack_32.c b/arch/x86/kernel/dumpstack_32.c
index 1038a41..5387429 100644
--- a/arch/x86/kernel/dumpstack_32.c
+++ b/arch/x86/kernel/dumpstack_32.c
@@ -22,6 +22,7 @@ void dump_trace(struct task_struct *task, struct pt_regs
*regs,
const struct stacktrace_ops *ops, void *data)
{
int graph = 0;
+ int dump_irq = 0;
if (!task)
task = current;
@@ -47,8 +48,18 @@ void dump_trace(struct task_struct *task, struct pt_regs
*regs,
stack = (unsigned long *)context->previous_esp;
if (!stack)
break;
+
+ if (unlikely(dump_irq > 2)) {
+ printk(KERN_WARNING "break multi-IRQ print,"
+ "context=%08lx, stack=%08lx\n",
+ (unsigned long)context,
+ (unsigned long)stack);
+ break;
+ }
+
if (ops->stack(data, "IRQ") < 0)
break;
+ dump_irq++;
touch_nmi_watchdog();
}
}
--
1.7.0.4
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