Blackfin arch: Add basic irq stack checking for Blackfin

Signed-off-by: Robin Getz <rgetz@blackfin.uclinux.org>
Signed-off-by: Bryan Wu <cooloney@kernel.org>

1 files changed, 15 insertions, 1 deletions

diff --git a/arch/blackfin/kernel/irqchip.c b/arch/blackfin/kernel/irqchip.c
index 5ad07525ea3f..1624e1129681 100644
--- a/arch/blackfin/kernel/irqchip.c
+++ b/arch/blackfin/kernel/irqchip.c
@@ -120,7 +120,21 @@ asmlinkage void asm_do_IRQ(unsigned int irq, struct pt_regs *regs)
                 desc = &bad_irq_desc;
 
         irq_enter();
-
+#ifdef CONFIG_DEBUG_STACKOVERFLOW
+        /* Debugging check for stack overflow: is there less than STACK_WARN free? */
+        {
+                long sp;
+
+                sp = __get_SP() & (THREAD_SIZE-1);
+
+                if (unlikely(sp < (sizeof(struct thread_info) + STACK_WARN))) {
+                        dump_stack();
+                        printk(KERN_EMERG "%s: possible stack overflow while handling irq %i "
+                                        " only %ld bytes free\n",
+                                __func__, irq, sp - sizeof(struct thread_info));
+                }
+        }
+#endif
         generic_handle_irq(irq);
 
         /* If we're the only interrupt running (ignoring IRQ15 which is for