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authorOleg Nesterov <oleg@redhat.com>2013-09-11 17:47:26 +0200
committerIngo Molnar <mingo@kernel.org>2013-09-12 08:00:55 +0200
commit878b5a6efd38030c7a90895dc8346e8fb1e09b4c (patch)
tree5b58037396e9afa4799106c5c38cf9498d5db2d1
parent6113af14c82726d5a2993a7ba238df24c990a5ee (diff)
downloadop-kernel-dev-878b5a6efd38030c7a90895dc8346e8fb1e09b4c.zip
op-kernel-dev-878b5a6efd38030c7a90895dc8346e8fb1e09b4c.tar.gz
uprobes: Fix utask->depth accounting in handle_trampoline()
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 Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/20130911154726.GA8093@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.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 f356974..ad8e1bd 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);
}
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