This is a note to let you know that I've just added the patch titled perf bench: Fix 2 memory sanitizer warnings to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: perf-bench-fix-2-memory-sanitizer-warnings.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From d2c73501a767514b6c85c7feff9457a165d51057 Mon Sep 17 00:00:00 2001 From: Ian Rogers <irogers@xxxxxxxxxx> Date: Fri, 11 Sep 2020 22:37:25 -0700 Subject: perf bench: Fix 2 memory sanitizer warnings From: Ian Rogers <irogers@xxxxxxxxxx> commit d2c73501a767514b6c85c7feff9457a165d51057 upstream. Memory sanitizer warns if a write is performed where the memory being read for the write is uninitialized. Avoid this warning by initializing the memory. Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx> Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx> Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx> Cc: Mark Rutland <mark.rutland@xxxxxxx> Cc: Namhyung Kim <namhyung@xxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Stephane Eranian <eranian@xxxxxxxxxx> Link: http://lore.kernel.org/lkml/20200912053725.1405857-1-irogers@xxxxxxxxxx Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> Cc: Anders Roxell <anders.roxell@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- tools/perf/bench/sched-messaging.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/tools/perf/bench/sched-messaging.c +++ b/tools/perf/bench/sched-messaging.c @@ -66,11 +66,10 @@ static void fdpair(int fds[2]) /* Block until we're ready to go */ static void ready(int ready_out, int wakefd) { - char dummy; struct pollfd pollfd = { .fd = wakefd, .events = POLLIN }; /* Tell them we're ready. */ - if (write(ready_out, &dummy, 1) != 1) + if (write(ready_out, "R", 1) != 1) err(EXIT_FAILURE, "CLIENT: ready write"); /* Wait for "GO" signal */ @@ -85,6 +84,7 @@ static void *sender(struct sender_contex unsigned int i, j; ready(ctx->ready_out, ctx->wakefd); + memset(data, 'S', sizeof(data)); /* Now pump to every receiver. */ for (i = 0; i < nr_loops; i++) { Patches currently in stable-queue which might be from irogers@xxxxxxxxxx are queue-5.4/perf-bench-fix-2-memory-sanitizer-warnings.patch