trace: fix output of stack trace

Impact: fix to output of stack trace

If a function is not found in the stack of the stack tracer, the
number printed is quite strange. This fixes the algorithm to handle
missing functions better.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 4 insertions, 1 deletions

diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
index 06a16115be0f..0b863f2cbc8e 100644
--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -78,6 +78,7 @@ static inline void check_stack(void)
          * on a new max, so it is far from a fast path.
          */
         while (i < max_stack_trace.nr_entries) {
+                int found = 0;
 
                 stack_dump_index[i] = this_size;
                 p = start;
@@ -86,12 +87,14 @@ static inline void check_stack(void)
                         if (*p == stack_dump_trace[i]) {
                                 this_size = stack_dump_index[i++] =
                                         (top - p) * sizeof(unsigned long);
+                                found = 1;
                                 /* Start the search from here */
                                 start = p + 1;
                         }
                 }
 
-                i++;
+                if (!found)
+                        i++;
         }
 
  out: