linux-kernel - [PATCH] perf jevents: Fix event syntax error caused by ExtSel

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: <20220525140410.1706851-1-zhengjun.xing@linux.intel.com>
Date:   Wed, 25 May 2022 22:04:10 +0800
From:   zhengjun.xing@...ux.intel.com
To:     acme@...nel.org, peterz@...radead.org, mingo@...hat.com,
        alexander.shishkin@...el.com, jolsa@...hat.com
Cc:     linux-kernel@...r.kernel.org, linux-perf-users@...r.kernel.org,
        irogers@...gle.com, adrian.hunter@...el.com, ak@...ux.intel.com,
        kan.liang@...ux.intel.com, zhengjun.xing@...ux.intel.com
Subject: [PATCH] perf jevents: Fix event syntax error caused by ExtSel

From: Zhengjun Xing <zhengjun.xing@...ux.intel.com>

In the origin code, when "ExtSel" is 1, the eventcode will change to
"eventcode |= 1 << 21”. For event “UNC_Q_RxL_CREDITS_CONSUMED_VN0.DRS",
its "ExtSel" is "1", its eventcode will change from 0x1E to 0x20001E,
but in fact the eventcode should <=0x1FF, so this will cause the parse
fail:

  # perf stat -e "UNC_Q_RxL_CREDITS_CONSUMED_VN0.DRS" -a sleep 0.1
event syntax error: '.._RxL_CREDITS_CONSUMED_VN0.DRS'
                                  \___ value too big for format, maximum is 511

On the perf kernel side, the kernel assumes the valid bits are continuous.
It will adjust the 0x100 (bit 8 for perf tool) to bit 21 in HW.

DEFINE_UNCORE_FORMAT_ATTR(event_ext, event, "config:0-7,21");

So the perf tool follows the kernel side and just set bit8 other than bit21.

Fixes: fedb2b518239 ("perf jevents: Add support for parsing uncore json files")
Signed-off-by: Zhengjun Xing <zhengjun.xing@...ux.intel.com>
Reviewed-by: Kan Liang <kan.liang@...ux.intel.com>
---
 tools/perf/pmu-events/jevents.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/pmu-events/jevents.c b/tools/perf/pmu-events/jevents.c
index cee61c4ed59e..e597e4bac90f 100644
--- a/tools/perf/pmu-events/jevents.c
+++ b/tools/perf/pmu-events/jevents.c
@@ -605,7 +605,7 @@ static int json_events(const char *fn,
 			} else if (json_streq(map, field, "ExtSel")) {
 				char *code = NULL;
 				addfield(map, &code, "", "", val);
-				eventcode |= strtoul(code, NULL, 0) << 21;
+				eventcode |= strtoul(code, NULL, 0) << 8;
 				free(code);
 			} else if (json_streq(map, field, "EventName")) {
 				addfield(map, &je.name, "", "", val);
-- 
2.25.1