linux-kernel - [PATCH v2 2/4] perf tools: Fix SMT not detected

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: Windows password security audit tool. GUI, reports in PDF.

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

Message-Id: <20211124001231.3277836-2-irogers@google.com>
Date:   Tue, 23 Nov 2021 16:12:29 -0800
From:   Ian Rogers <irogers@...gle.com>
To:     Andi Kleen <ak@...ux.intel.com>, Jiri Olsa <jolsa@...hat.com>,
        Namhyung Kim <namhyung@...nel.org>,
        John Garry <john.garry@...wei.com>,
        Kajol Jain <kjain@...ux.ibm.com>,
        "Paul A . Clarke" <pc@...ibm.com>,
        Arnaldo Carvalho de Melo <acme@...nel.org>,
        Kan Liang <kan.liang@...ux.intel.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Ingo Molnar <mingo@...hat.com>,
        Mark Rutland <mark.rutland@....com>,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        Konstantin Khlebnikov <koct9i@...il.com>,
        linux-perf-users@...r.kernel.org, linux-kernel@...r.kernel.org
Cc:     eranian@...gle.com, Ian Rogers <irogers@...gle.com>
Subject: [PATCH v2 2/4] perf tools: Fix SMT not detected

sysfs__read_int returns 0 on success, and so the fast read path was
always failing.

Fixes: bb629484d924 (perf tools: Simplify checking if SMT is active.)
Signed-off-by: Ian Rogers <irogers@...gle.com>
---
 tools/perf/util/smt.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/util/smt.c b/tools/perf/util/smt.c
index 20bacd5972ad..34f1b1b1176c 100644
--- a/tools/perf/util/smt.c
+++ b/tools/perf/util/smt.c
@@ -15,7 +15,7 @@ int smt_on(void)
 	if (cached)
 		return cached_result;
 
-	if (sysfs__read_int("devices/system/cpu/smt/active", &cached_result) > 0)
+	if (sysfs__read_int("devices/system/cpu/smt/active", &cached_result) >= 0)
 		goto done;
 
 	ncpu = sysconf(_SC_NPROCESSORS_CONF);
-- 
2.34.0.rc2.393.gf8c9666880-goog