| From 878b5a6efd38030c7a90895dc8346e8fb1e09b4c Mon Sep 17 00:00:00 2001 |
| From: Oleg Nesterov <oleg@redhat.com> |
| Date: Wed, 11 Sep 2013 17:47:26 +0200 |
| Subject: uprobes: Fix utask->depth accounting in handle_trampoline() |
| |
| From: Oleg Nesterov <oleg@redhat.com> |
| |
| commit 878b5a6efd38030c7a90895dc8346e8fb1e09b4c upstream. |
| |
| Currently utask->depth is simply the number of allocated/pending |
| return_instance's in uprobe_task->return_instances list. |
| |
| handle_trampoline() should decrement this counter every time we |
| handle/free an instance, but due to typo it does this only if |
| ->chained == T. This means that in the likely case this counter |
| is never decremented and the probed task can't report more than |
| MAX_URETPROBE_DEPTH events. |
| |
| Reported-by: Mikhail Kulemin <Mikhail.Kulemin@ru.ibm.com> |
| Reported-by: Hemant Kumar Shaw <hkshaw@linux.vnet.ibm.com> |
| Signed-off-by: Oleg Nesterov <oleg@redhat.com> |
| Acked-by: Anton Arapov <anton@redhat.com> |
| Cc: masami.hiramatsu.pt@hitachi.com |
| Cc: srikar@linux.vnet.ibm.com |
| Cc: systemtap@sourceware.org |
| Link: http://lkml.kernel.org/r/20130911154726.GA8093@redhat.com |
| Signed-off-by: Ingo Molnar <mingo@kernel.org> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| kernel/events/uprobes.c | 4 +--- |
| 1 file changed, 1 insertion(+), 3 deletions(-) |
| |
| --- a/kernel/events/uprobes.c |
| +++ b/kernel/events/uprobes.c |
| @@ -1682,12 +1682,10 @@ static bool handle_trampoline(struct pt_ |
| tmp = ri; |
| ri = ri->next; |
| kfree(tmp); |
| + utask->depth--; |
| |
| if (!chained) |
| break; |
| - |
| - utask->depth--; |
| - |
| BUG_ON(!ri); |
| } |
| |
