| Message ID | 1436779421-22029-1-git-send-email-luis.henriques@canonical.com |
|---|---|
| State | New |
| Headers | show |
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c index cb347e85f75e..61959fa704ed 100644 --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -1413,7 +1413,9 @@ static int check_preds(struct filter_parse_state *ps) continue; } n_normal_preds++; - WARN_ON_ONCE(cnt < 0); + /* all ops should have operands */ + if (cnt < 0) + break; } if (cnt != 1 || !n_normal_preds || n_logical_preds >= n_normal_preds) {
This is a note to let you know that I have just added a patch titled tracing/filter: Do not WARN on operand count going below zero to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue This patch is scheduled to be released in version 3.16.7-ckt15. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.16.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ------ From c70b62299d0366e4fc1fe0ab447b4711f91f6d0e Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" <rostedt@goodmis.org> Date: Thu, 25 Jun 2015 18:02:29 -0400 Subject: tracing/filter: Do not WARN on operand count going below zero commit b4875bbe7e68f139bd3383828ae8e994a0df6d28 upstream. When testing the fix for the trace filter, I could not come up with a scenario where the operand count goes below zero, so I added a WARN_ON_ONCE(cnt < 0) to the logic. But there is legitimate case that it can happen (although the filter would be wrong). # echo '>' > /sys/kernel/debug/events/ext4/ext4_truncate_exit/filter That is, a single operation without any operands will hit the path where the WARN_ON_ONCE() can trigger. Although this is harmless, and the filter is reported as a error. But instead of spitting out a warning to the kernel dmesg, just fail nicely and report it via the proper channels. Link: http://lkml.kernel.org/r/558C6082.90608@oracle.com Reported-by: Vince Weaver <vincent.weaver@maine.edu> Reported-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- kernel/trace/trace_events_filter.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)