linux-kernel - [PATCH v6 05/17] perf: cs-etm: Only save valid trace IDs into files

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

Message-Id: <20240722101202.26915-6-james.clark@linaro.org>
Date: Mon, 22 Jul 2024 11:11:47 +0100
From: James Clark <james.clark@...aro.org>
To: coresight@...ts.linaro.org,
	suzuki.poulose@....com,
	gankulkarni@...amperecomputing.com,
	mike.leach@...aro.org,
	leo.yan@...ux.dev,
	anshuman.khandual@....com
Cc: James Clark <james.clark@....com>,
	James Clark <james.clark@...aro.org>,
	Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
	Maxime Coquelin <mcoquelin.stm32@...il.com>,
	Alexandre Torgue <alexandre.torgue@...s.st.com>,
	John Garry <john.g.garry@...cle.com>,
	Will Deacon <will@...nel.org>,
	Peter Zijlstra <peterz@...radead.org>,
	Ingo Molnar <mingo@...hat.com>,
	Arnaldo Carvalho de Melo <acme@...nel.org>,
	Namhyung Kim <namhyung@...nel.org>,
	Mark Rutland <mark.rutland@....com>,
	Jiri Olsa <jolsa@...nel.org>,
	Ian Rogers <irogers@...gle.com>,
	Adrian Hunter <adrian.hunter@...el.com>,
	"Liang, Kan" <kan.liang@...ux.intel.com>,
	linux-kernel@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org,
	linux-stm32@...md-mailman.stormreply.com,
	linux-perf-users@...r.kernel.org
Subject: [PATCH v6 05/17] perf: cs-etm: Only save valid trace IDs into files

From: James Clark <james.clark@....com>

This isn't a bug because Perf always masks with
CORESIGHT_TRACE_ID_VAL_MASK before using these values, but to avoid it
looking like it could be, make an effort to not save bad values.

Signed-off-by: James Clark <james.clark@....com>
Reviewed-by: Mike Leach <mike.leach@...aro.org>
Signed-off-by: James Clark <james.clark@...aro.org>
---
 tools/perf/arch/arm/util/cs-etm.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/perf/arch/arm/util/cs-etm.c b/tools/perf/arch/arm/util/cs-etm.c
index b0118546cd4d..14b8afabce3a 100644
--- a/tools/perf/arch/arm/util/cs-etm.c
+++ b/tools/perf/arch/arm/util/cs-etm.c
@@ -643,7 +643,8 @@ static bool cs_etm_is_ete(struct perf_pmu *cs_etm_pmu, struct perf_cpu cpu)
 
 static __u64 cs_etm_get_legacy_trace_id(struct perf_cpu cpu)
 {
-	return CORESIGHT_LEGACY_CPU_TRACE_ID(cpu.cpu);
+	/* Wrap at 48 so that invalid trace IDs aren't saved into files. */
+	return CORESIGHT_LEGACY_CPU_TRACE_ID(cpu.cpu % 48);
 }
 
 static void cs_etm_save_etmv4_header(__u64 data[], struct auxtrace_record *itr, struct perf_cpu cpu)
-- 
2.34.1