1 files changed, 29 insertions, 6 deletions

diff --git a/arch/x86/kernel/irq_64.c b/arch/x86/kernel/irq_64.c
index 69bca468c47a..d04d3ecded62 100644
--- a/arch/x86/kernel/irq_64.c
+++ b/arch/x86/kernel/irq_64.c
@@ -26,6 +26,8 @@ EXPORT_PER_CPU_SYMBOL(irq_stat);
 DEFINE_PER_CPU(struct pt_regs *, irq_regs);
 EXPORT_PER_CPU_SYMBOL(irq_regs);
 
+int sysctl_panic_on_stackoverflow;
+
 /*
  * Probabilistic stack overflow check:
  *
@@ -36,18 +38,39 @@ EXPORT_PER_CPU_SYMBOL(irq_regs);
 static inline void stack_overflow_check(struct pt_regs *regs)
 {
 #ifdef CONFIG_DEBUG_STACKOVERFLOW
+#define STACK_TOP_MARGIN        128
+        struct orig_ist *oist;
+        u64 irq_stack_top, irq_stack_bottom;
+        u64 estack_top, estack_bottom;
         u64 curbase = (u64)task_stack_page(current);
 
         if (user_mode_vm(regs))
                 return;
 
-        WARN_ONCE(regs->sp >= curbase &&
-                  regs->sp <= curbase + THREAD_SIZE &&
-                  regs->sp <  curbase + sizeof(struct thread_info) +
-                                        sizeof(struct pt_regs) + 128,
+        if (regs->sp >= curbase + sizeof(struct thread_info) +
+                                  sizeof(struct pt_regs) + STACK_TOP_MARGIN &&
+            regs->sp <= curbase + THREAD_SIZE)
+                return;
+
+        irq_stack_top = (u64)__get_cpu_var(irq_stack_union.irq_stack) +
+                        STACK_TOP_MARGIN;
+        irq_stack_bottom = (u64)__get_cpu_var(irq_stack_ptr);
+        if (regs->sp >= irq_stack_top && regs->sp <= irq_stack_bottom)
+                return;
+
+        oist = &__get_cpu_var(orig_ist);
+        estack_top = (u64)oist->ist[0] - EXCEPTION_STKSZ + STACK_TOP_MARGIN;
+        estack_bottom = (u64)oist->ist[N_EXCEPTION_STACKS - 1];
+        if (regs->sp >= estack_top && regs->sp <= estack_bottom)
+                return;
+
+        WARN_ONCE(1, "do_IRQ(): %s has overflown the kernel stack (cur:%Lx,sp:%lx,irq stk top-bottom:%Lx-%Lx,exception stk top-bottom:%Lx-%Lx)\n",
+                current->comm, curbase, regs->sp,
+                irq_stack_top, irq_stack_bottom,
+                estack_top, estack_bottom);
 
-                  "do_IRQ: %s near stack overflow (cur:%Lx,sp:%lx)\n",
-                        current->comm, curbase, regs->sp);
+        if (sysctl_panic_on_stackoverflow)
+                panic("low stack detected by irq handler - check messages\n");
 #endif
 }