Merge ../linux-2.6-watchdog-mm

[linux-drm-fsl-dcu.git] / arch / x86_64 / kernel / traps.c

diff --git a/arch/x86_64/kernel/traps.c b/arch/x86_64/kernel/traps.c
index 7819022a8db5986e29bf36247be94cab99cb7f06..0d65b22f229ccfbf895ff2aa12e3dd2d9977cdd8 100644 (file)
--- a/arch/x86_64/kernel/traps.c
+++ b/arch/x86_64/kernel/traps.c
@@ -242,12 +242,19 @@ static int dump_trace_unwind(struct unwind_frame_info *info, void *context)
  * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
  */
 
+static inline int valid_stack_ptr(struct thread_info *tinfo, void *p)
+{
+       void *t = (void *)tinfo;
+        return p > t && p < t + THREAD_SIZE - 3;
+}
+
 void dump_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long * stack,
                struct stacktrace_ops *ops, void *data)
 {
        const unsigned cpu = smp_processor_id();
        unsigned long *irqstack_end = (unsigned long *)cpu_pda(cpu)->irqstackptr;
        unsigned used = 0;
+       struct thread_info *tinfo;
 
        if (!tsk)
                tsk = current;
@@ -290,6 +297,12 @@ void dump_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long * s
                if (tsk && tsk != current)
                        stack = (unsigned long *)tsk->thread.rsp;
        }
+       /*
+        * Align the stack pointer on word boundary, later loops
+        * rely on that (and corruption / debug info bugs can cause
+        * unaligned values here):
+        */
+       stack = (unsigned long *)((unsigned long)stack & ~(sizeof(long)-1));
 
        /*
         * Print function call entries within a stack. 'cond' is the
@@ -364,7 +377,8 @@ void dump_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long * s
        /*
         * This handles the process stack:
         */
-       HANDLE_STACK (((long) stack & (THREAD_SIZE-1)) != 0);
+       tinfo = current_thread_info();
+       HANDLE_STACK (valid_stack_ptr(tinfo, stack));
 #undef HANDLE_STACK
 }
 EXPORT_SYMBOL(dump_trace);