Re: [PATCH] trace, kasan: silence Kasan warning in check_stack

[Shi, Yang]

On 2/12/2016 11:35 AM, Steven Rostedt wrote:

On Mon,  8 Feb 2016 10:39:42 -0800
Yang Shi <yang....@linaro.org> wrote:

Signed-off-by: Yang Shi <yang....@linaro.org>
---
  kernel/trace/trace_stack.c | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
index 202df6c..61e5e1e 100644
--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -156,7 +156,7 @@ check_stack(unsigned long ip, unsigned long *stack)
                for (; p < top && i < stack_trace_max.nr_entries; p++) {
                        if (stack_dump_trace[i] == ULONG_MAX)
                                break;
-                       if (*p == stack_dump_trace[i]) {

Can you add a comment explaining this. Something like:

        /*
         * The READ_ONCE_NOCHECK() is used to let KASAN know that
         * this is not an stack-out-of-bounds error.
         */

Sure, will add in v2.

Thanks,
Yang

Thanks,

-- Steve

+                       if ((READ_ONCE_NOCHECK(*p)) == stack_dump_trace[i]) {
                                stack_dump_trace[x] = stack_dump_trace[i++];
                                this_size = stack_trace_index[x++] =
                                        (top - p) * sizeof(unsigned long);