It looks like this patch only checks when processing an interrupt, which
doesn't seem like it would give much coverage.
Am I missing something?
David Daney
On 08/20/2010 11:31 PM, jiang.adam@xxxxxxxxx wrote:
From: Adam Jiang<jiang.adam@xxxxxxxxx>
Add stackoverflow detection to mips arch
Signed-off-by: Adam Jiang<jiang.adam@xxxxxxxxx>
---
arch/mips/Kconfig.debug | 7 +++++++
arch/mips/kernel/irq.c | 19 +++++++++++++++++++
2 files changed, 26 insertions(+), 0 deletions(-)
diff --git a/arch/mips/Kconfig.debug b/arch/mips/Kconfig.debug
index 43dc279..f1a00a2 100644
--- a/arch/mips/Kconfig.debug
+++ b/arch/mips/Kconfig.debug
@@ -67,6 +67,13 @@ config CMDLINE_OVERRIDE
Normally, you will choose 'N' here.
+config DEBUG_STACKOVERFLOW
+ bool "Check for stack overflows"
+ depends on DEBUG_KERNEL
+ help
+ This option will cause messages to be printed if free stack space
+ drops below a certain limit.
+
config DEBUG_STACK_USAGE
bool "Enable stack utilization instrumentation"
depends on DEBUG_KERNEL
diff --git a/arch/mips/kernel/irq.c b/arch/mips/kernel/irq.c
index c6345f5..6334037 100644
--- a/arch/mips/kernel/irq.c
+++ b/arch/mips/kernel/irq.c
@@ -151,6 +151,22 @@ void __init init_IRQ(void)
#endif
}
+static inline void check_stack_overflow(void)
+{
+#ifdef CONFIG_DEBUG_STACKOVERFLOW
+ long sp;
+
+ asm volatile("move %0, $sp" : "=r" (sp));
+ sp = sp& (THREAD_SIZE-1);
+
+ /* check for stack overflow: is there less then 2KB free? */
+ if (unlikely(sp< (sizeof(struct thread_info) + 2048))) {
+ printk("do_IRQ: stack overflow: %ld\n",
+ sp - sizeof(struct thread_info));
+ dump_stack();
+ }
+#endif
+}
/*
* do_IRQ handles all normal device IRQ's (the special
* SMP cross-CPU interrupts have their own specific
@@ -159,6 +175,9 @@ void __init init_IRQ(void)
void __irq_entry do_IRQ(unsigned int irq)
{
irq_enter();
+
+ check_stack_overflow();
+
__DO_IRQ_SMTC_HOOK(irq);
generic_handle_irq(irq);
irq_exit();
