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| author | Oleg Nesterov <oleg@redhat.com> | 2013-09-11 17:47:26 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-09-26 17:21:56 -0700 |
| commit | 003386069c5be7067c98172549780f428702d5b9 (patch) | |
| tree | fc674ecd3aa101733963ee48a899c4a67484b9d7 /kernel | |
| parent | cc321317742a40f067481dcc4077392305d76054 (diff) | |
| download | lwn-003386069c5be7067c98172549780f428702d5b9.tar.gz lwn-003386069c5be7067c98172549780f428702d5b9.zip | |
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>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/events/uprobes.c | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index f3569747d629..ad8e1bdca70e 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); } |