summaryrefslogtreecommitdiffstats
path: root/arch/x86/kernel/irq_32.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/kernel/irq_32.c')
-rw-r--r--arch/x86/kernel/irq_32.c16
1 files changed, 8 insertions, 8 deletions
diff --git a/arch/x86/kernel/irq_32.c b/arch/x86/kernel/irq_32.c
index 72090705a656..58b7f27cb3e9 100644
--- a/arch/x86/kernel/irq_32.c
+++ b/arch/x86/kernel/irq_32.c
@@ -28,6 +28,9 @@ DEFINE_PER_CPU(struct pt_regs *, irq_regs);
EXPORT_PER_CPU_SYMBOL(irq_regs);
#ifdef CONFIG_DEBUG_STACKOVERFLOW
+
+int sysctl_panic_on_stackoverflow __read_mostly;
+
/* Debugging check for stack overflow: is there less than 1KB free? */
static int check_stack_overflow(void)
{
@@ -43,6 +46,8 @@ static void print_stack_overflow(void)
{
printk(KERN_WARNING "low stack detected by irq handler\n");
dump_stack();
+ if (sysctl_panic_on_stackoverflow)
+ panic("low stack detected by irq handler - check messages\n");
}
#else
@@ -95,13 +100,8 @@ execute_on_irq_stack(int overflow, struct irq_desc *desc, int irq)
irqctx->tinfo.task = curctx->tinfo.task;
irqctx->tinfo.previous_esp = current_stack_pointer;
- /*
- * Copy the softirq bits in preempt_count so that the
- * softirq checks work in the hardirq context.
- */
- irqctx->tinfo.preempt_count =
- (irqctx->tinfo.preempt_count & ~SOFTIRQ_MASK) |
- (curctx->tinfo.preempt_count & SOFTIRQ_MASK);
+ /* Copy the preempt_count so that the [soft]irq checks work. */
+ irqctx->tinfo.preempt_count = curctx->tinfo.preempt_count;
if (unlikely(overflow))
call_on_stack(print_stack_overflow, isp);
@@ -191,7 +191,7 @@ bool handle_irq(unsigned irq, struct pt_regs *regs)
if (unlikely(!desc))
return false;
- if (!execute_on_irq_stack(overflow, desc, irq)) {
+ if (user_mode_vm(regs) || !execute_on_irq_stack(overflow, desc, irq)) {
if (unlikely(overflow))
print_stack_overflow();
desc->handle_irq(irq, desc);