On 07/23/2018 05:25 PM, Joel Fernandes wrote:
> From: "Joel Fernandes (Google)" <j...@joelfernandes.org>
>
> Recently we debugged an issue where debugobject tracking was telling
> us of an annotation issue. Turns out the issue was due to the object in
> concern being on a different stack which was due to another issue.
>
> Discussing with tglx, he suggested printing the pointers and the
> location of the stack for the currently running task. This helped find
> the object was on the wrong stack. I turned the resulting patch into
> something upstreamable, so that the error message is more informative
> and can help in debugging for similar issues in the future.
>
> Signed-off-by: Joel Fernandes (Google) <j...@joelfernandes.org>
> ---
> lib/debugobjects.c | 7 +++++--
> 1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/lib/debugobjects.c b/lib/debugobjects.c
> index 994be4805cec..24c1df0d7466 100644
> --- a/lib/debugobjects.c
> +++ b/lib/debugobjects.c
> @@ -360,9 +360,12 @@ static void debug_object_is_on_stack(void *addr, int
> onstack)
>
> limit++;
> if (is_on_stack)
> - pr_warn("object is on stack, but not annotated\n");
> + pr_warn("object %p is on stack %p, but NOT annotated.\n", addr,
> + task_stack_page(current));
> else
> - pr_warn("object is not on stack, but annotated\n");
> + pr_warn("object %p is NOT on stack %p, but annotated.\n", addr,
> + task_stack_page(current));
> +
> WARN_ON(1);
> }
>
Acked-by: Waiman Long <long...@redhat.com>
