aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorOleg Nesterov <oleg@redhat.com>2013-09-11 17:47:26 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-09-26 17:18:27 -0700
commit73e2c2b7c105e46344eb409575a4508f24a82eee (patch)
tree136e4d4bd360fad308c97cd9a42299072e1ee3d4
parent42cc8e56740efe9acc271f4780b81ac5ecef188c (diff)
uprobes: Fix utask->depth accounting in handle_trampoline()
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>
-rw-r--r--kernel/events/uprobes.c4
1 files changed, 1 insertions, 3 deletions
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index f3569747d62..ad8e1bdca70 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -1682,12 +1682,10 @@ static bool handle_trampoline(struct pt_regs *regs)
tmp = ri;
ri = ri->next;
kfree(tmp);
+ utask->depth--;
if (!chained)
break;
-
- utask->depth--;
-
BUG_ON(!ri);
}