linux-kernel - [PATCH] perf tests: evsel-tp-sched: Fix bitwise operator

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20190122233439.GA5868@embeddedor>
Date:   Tue, 22 Jan 2019 17:34:39 -0600
From:   "Gustavo A. R. Silva" <gustavo@...eddedor.com>
To:     Peter Zijlstra <peterz@...radead.org>,
        Ingo Molnar <mingo@...hat.com>,
        Arnaldo Carvalho de Melo <acme@...nel.org>,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        Jiri Olsa <jolsa@...hat.com>,
        Namhyung Kim <namhyung@...nel.org>
Cc:     linux-kernel@...r.kernel.org,
        "Gustavo A. R. Silva" <gustavo@...eddedor.com>
Subject: [PATCH] perf tests: evsel-tp-sched: Fix bitwise operator

Notice that the use of the bitwise OR operator '|' always leads to
true in this particular case, which seems a bit suspicious due to
the context in which this expression is being used.

Fix this by using bitwise AND operator '&' instead.

This bug was detected with the help of Coccinelle.

Fixes: 6a6cd11d4e57 ("perf test: Add test for the sched tracepoint format fields")
Cc: stable@...r.kernel.org
Signed-off-by: Gustavo A. R. Silva <gustavo@...eddedor.com>
---

NOTE: Notice that this code has been there since 2012. So, it would
      be helpful if someone can double-check this. Thanks.

 tools/perf/tests/evsel-tp-sched.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/tests/evsel-tp-sched.c b/tools/perf/tests/evsel-tp-sched.c
index 5f8501c68da4..5cbba70bcdd0 100644
--- a/tools/perf/tests/evsel-tp-sched.c
+++ b/tools/perf/tests/evsel-tp-sched.c
@@ -17,7 +17,7 @@ static int perf_evsel__test_field(struct perf_evsel *evsel, const char *name,
 		return -1;
 	}
 
-	is_signed = !!(field->flags | TEP_FIELD_IS_SIGNED);
+	is_signed = !!(field->flags & TEP_FIELD_IS_SIGNED);
 	if (should_be_signed && !is_signed) {
 		pr_debug("%s: \"%s\" signedness(%d) is wrong, should be %d\n",
 			 evsel->name, name, is_signed, should_be_signed);
-- 
2.20.1