Add stackoverflow detection to mips arch
This is the 3rd version of the smiple patch. 2K is too big for many
system, so I Modified the warning line by following Ralf's suggestion.
Signed-off-by: Adam Jiang <jiang.adam@xxxxxxxxx>
---
arch/mips/Kconfig.debug | 7 +++++++
arch/mips/include/asm/thread_info.h | 2 ++
arch/mips/kernel/irq.c | 25 +++++++++++++++++++++++++
3 files changed, 34 insertions(+), 0 deletions(-)
diff --git a/arch/mips/Kconfig.debug b/arch/mips/Kconfig.debug
index 43dc279..30c58d4 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/include/asm/thread_info.h b/arch/mips/include/asm/thread_info.h
index 70df9c0..b60b28d 100644
--- a/arch/mips/include/asm/thread_info.h
+++ b/arch/mips/include/asm/thread_info.h
@@ -83,6 +83,8 @@ register struct thread_info *__current_thread_info __asm__("$28");
#define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER)
#define THREAD_MASK (THREAD_SIZE - 1UL)
+#define STACK_WARN (THREAD_SIZE/8)
+
#define __HAVE_ARCH_THREAD_INFO_ALLOCATOR
#ifdef CONFIG_DEBUG_STACK_USAGE
diff --git a/arch/mips/kernel/irq.c b/arch/mips/kernel/irq.c
index c6345f5..b43edb7 100644
--- a/arch/mips/kernel/irq.c
+++ b/arch/mips/kernel/irq.c
@@ -151,6 +151,28 @@ void __init init_IRQ(void)
#endif
}
+#ifdef CONFIG_DEBUG_STACKOVERFLOW
+static inline void check_stack_overflow(void)
+{
+ unsigned long sp;
+
+ asm volatile("move %0, $sp" : "=r" (sp));
+ sp = sp & THREAD_MASK;
+
+ /*
+ * check for stack overflow: is there less than STACK_WARN free?
+ * STACK_WARN is defined as 1/8 of THREAD_SIZE by default.
+ */
+ if (unlikely(sp < (sizeof(struct thread_info) + STACK_WARN))) {
+ printk("do_IRQ: stack overflow: %ld\n",
+ sp - sizeof(struct thread_info));
+ dump_stack();
+ }
+}
+#else
+static inline void check_stack_overflow(void) {}
+#endif
+
/*
* do_IRQ handles all normal device IRQ's (the special
* SMP cross-CPU interrupts have their own specific
@@ -159,6 +181,9 @@ 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();
--
1.7.2.2
