From: Will Hawkins <hawkinsw@borlaugic.com>
To: linux-kernel@vger.kernel.org, hawkinsw@gmail.com, rostedt@goodmis.org
Cc: Will Hawkins <hawkinsw@borlaugic.com>
Subject: [PATCH v2] trace-cmd record: Fix syntax in make_pid_filter
Date: Fri, 13 Oct 2017 14:40:06 -0400 [thread overview]
Message-ID: <1507920006-10204-1-git-send-email-hawkinsw@borlaugic.com> (raw)
In-Reply-To: <CADx9qWjVny-+Sct2-pmHmZ73ohCu_6ay67-GBYP5w_gjvG0TDQ () mail ! gmail ! com>
In older versions of the kernel, event filtering by
pid does not use the set_event_pid file. Instead,
ftrace uses a common filter (created in make_pid_filter)
to filter events based on PID.
The syntax of the filter generated by this function is
overly permissive. When filtering by pid, || is used
where && should be (in certain cases) which means that
unrelated events are captured.
Signed-off-by: Will Hawkins <hawkinsw@borlaugic.com>
---
trace-record.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)
diff --git a/trace-record.c b/trace-record.c
index a0b6541..741fe53 100644
--- a/trace-record.c
+++ b/trace-record.c
@@ -935,14 +935,16 @@ static char *make_pid_filter(char *curr_filter, const char *field)
str = filter + curr_len;
for (p = filter_pids; p; p = p->next) {
- if (p == filter_pids)
- orit = "";
- else
- orit = "||";
- if (p->exclude)
+ if (p->exclude) {
match = "!=";
- else
+ orit = "&&";
+ } else {
match = "==";
+ orit = "||";
+ }
+ if (p == filter_pids)
+ orit = "";
+
len = sprintf(str, "%s(%s%s%d)", orit, field, match, p->pid);
str += len;
}
--
2.7.4
next parent reply other threads:[~2017-10-13 18:40 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CADx9qWjVny-+Sct2-pmHmZ73ohCu_6ay67-GBYP5w_gjvG0TDQ () mail ! gmail ! com>
2017-10-13 18:40 ` Will Hawkins [this message]
2017-10-23 20:41 ` [PATCH v2] trace-cmd record: Fix syntax in make_pid_filter Will Hawkins
2017-10-31 16:17 ` Steven Rostedt
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