4.4-stable review patch. If anyone has any objections, please let me know.
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From: Joel Fernandes (Google) joel@joelfernandes.org
commit fc91a3c4c27acdca0bc13af6fbb68c35cfd519f2 upstream.
While debugging an issue debugobject tracking warned about an annotation issue of an object on stack. It turned out that the issue was due to the object in concern being on a different stack which was due to another issue.
Thomas suggested to print the pointers and the location of the stack for the currently running task. This helped to figure out that the object was on the wrong stack.
As this is general useful information for debugging similar issues, make the error message more informative by printing the pointers.
[ tglx: Massaged changelog ]
Signed-off-by: Joel Fernandes (Google) joel@joelfernandes.org Signed-off-by: Thomas Gleixner tglx@linutronix.de Acked-by: Waiman Long longman@redhat.com Acked-by: Yang Shi yang.shi@linux.alibaba.com Cc: kernel-team@android.com Cc: Arnd Bergmann arnd@arndb.de Cc: astrachan@google.com Link: https://lkml.kernel.org/r/20180723212531.202328-1-joel@joelfernandes.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- lib/debugobjects.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
--- a/lib/debugobjects.c +++ b/lib/debugobjects.c @@ -295,9 +295,12 @@ static void debug_object_is_on_stack(voi
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); }