Merge tag 'v3.10.107' into update

[GitHub/mt8127/android_kernel_alcatel_ttab.git] / arch / x86 / kernel / irq_64.c

diff --git a/arch/x86/kernel/irq_64.c b/arch/x86/kernel/irq_64.c
index 69bca468c47a8ffc22ea5811cb3bdf63caf0f44b..d04d3ecded6299ab2abb7183089908439c2a0e6a 100644 (file)
--- 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
 }