From: Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com>
To: Numfor Mbiziwo-Tiapo <nums@google.com>
Cc: peterz@infradead.org, mingo@redhat.com,
alexander.shishkin@linux.intel.com, jolsa@redhat.com,
namhyung@kernel.org, songliubraving@fb.com, mbd@fb.com,
linux-kernel@vger.kernel.org, irogers@google.com,
eranian@google.com
Subject: Re: [PATCH 0/3] Perf uninitialized value fixes
Date: Wed, 7 Aug 2019 17:38:12 -0300 [thread overview]
Message-ID: <20190807203812.GA20129@kernel.org> (raw)
In-Reply-To: <20190724234500.253358-1-nums@google.com>
Em Wed, Jul 24, 2019 at 04:44:57PM -0700, Numfor Mbiziwo-Tiapo escreveu:
> These patches are all warnings that the MSAN (Memory Sanitizer) build
> of perf has caught.
>
> To build perf with MSAN enabled run:
> make -C tools/perf CLANG=1 CC=clang EXTRA_CFLAGS="-fsanitize=memory\
> -fsanitize-memory-track-origins"
>
> (The -fsanitizer-memory-track-origins makes the bugs clearer but
> isn't strictly necessary.)
>
> (Additionally, llvm might have to be installed and clang might have to
> be specified as the compiler - export CC=/usr/bin/clang).
>
> The patches "Fix util.c use of uninitialized value warning" and "Fix
> annotate.c use of uninitialized value error" build on top of each other
> (the changes in Fix util.c use of uninitialized value warning must be
> made first).
>
> When running the commands provided in the repro instructions, MSAN will
> generate false positive uninitialized memory errors. This is happening
> because libc is not MSAN-instrumented. Finding a way to build libc with
> MSAN will get rid of these false positives and allow the real warnings
> mentioned in the patches to be shown.
So this is because I'm not running a glibc linked with MSAN? Do you have
any pointer to help building glibc with MSAN? I want to do that inside a
container so that I can use these sanitizers, thanks,
[root@quaco ~]# perf record -o - ls / | perf --no-pager annotate -i - --stdio
==29732==WARNING: MemorySanitizer: use-of-uninitialized-value
==29733==WARNING: MemorySanitizer: use-of-uninitialized-value
#0 0xcc136d in add_path /home/acme/git/perf/tools/lib/subcmd/exec-cmd.c:130:6
#1 0xcc075e in setup_path /home/acme/git/perf/tools/lib/subcmd/exec-cmd.c:146:2
#2 0x71298d in main /home/acme/git/perf/tools/perf/perf.c:512:2
#0 0xcc136d in add_path /home/acme/git/perf/tools/lib/subcmd/exec-cmd.c:130:6
#1 0xcc075e in setup_path /home/acme/git/perf/tools/lib/subcmd/exec-cmd.c:146:2
#2 0x71298d in main /home/acme/git/perf/tools/perf/perf.c:512:2
#3 0x7f45b9e29f32 in __libc_start_main (/lib64/libc.so.6+0x23f32)
#4 0x447dcd in _start (/home/acme/bin/perf+0x447dcd)
Uninitialized value was created by a heap allocation
#3 0x7fd6433cff32 in __libc_start_main (/lib64/libc.so.6+0x23f32)
#4 0x447dcd in _start (/home/acme/bin/perf+0x447dcd)
Uninitialized value was created by a heap allocation
#0 0x4507d2 in malloc /home/acme/git/llvm/projects/compiler-rt/lib/msan/msan_interceptors.cc:916:3
#1 0x7f45b9e7fc47 in __vasprintf_internal (/lib64/libc.so.6+0x79c47)
SUMMARY: MemorySanitizer: use-of-uninitialized-value /home/acme/git/perf/tools/lib/subcmd/exec-cmd.c:130:6 in add_path
Exiting
#0 0x4507d2 in malloc /home/acme/git/llvm/projects/compiler-rt/lib/msan/msan_interceptors.cc:916:3
#1 0x7fd643425c47 in __vasprintf_internal (/lib64/libc.so.6+0x79c47)
SUMMARY: MemorySanitizer: use-of-uninitialized-value /home/acme/git/perf/tools/lib/subcmd/exec-cmd.c:130:6 in add_path
Exiting
[root@quaco ~]#
> Numfor Mbiziwo-Tiapo (3):
> Fix util.c use of uninitialized value warning
> Fix annotate.c use of uninitialized value error
> Fix sched-messaging.c use of uninitialized value errors
>
> tools/perf/bench/sched-messaging.c | 3 ++-
> tools/perf/util/annotate.c | 15 +++++++++++----
> tools/perf/util/header.c | 2 +-
> 3 files changed, 14 insertions(+), 6 deletions(-)
>
> --
> 2.22.0.657.g960e92d24f-goog
--
- Arnaldo
next prev parent reply other threads:[~2019-08-07 20:38 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-24 23:44 [PATCH 0/3] Perf uninitialized value fixes Numfor Mbiziwo-Tiapo
2019-07-24 23:44 ` [PATCH 1/3] Fix util.c use of unitialized value warning Numfor Mbiziwo-Tiapo
2019-07-26 19:19 ` Arnaldo Carvalho de Melo
2019-07-29 21:35 ` [tip:perf/urgent] perf header: Fix " tip-bot for Numfor Mbiziwo-Tiapo
2019-07-24 23:44 ` [PATCH 2/3] Fix annotate.c use of uninitialized value error Numfor Mbiziwo-Tiapo
2019-07-26 19:28 ` Arnaldo Carvalho de Melo
2019-07-31 0:40 ` [PATCH v2] " Numfor Mbiziwo-Tiapo
2019-07-24 23:45 ` [PATCH 3/3] Fix sched-messaging.c use of uninitialized value errors Numfor Mbiziwo-Tiapo
2019-07-26 19:32 ` Arnaldo Carvalho de Melo
2019-07-26 23:52 ` Ian Rogers
2019-08-07 20:38 ` Arnaldo Carvalho de Melo [this message]
2019-08-22 21:29 ` [PATCH 0/3] Perf uninitialized value fixes Ian Rogers
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190807203812.GA20129@kernel.org \
--to=arnaldo.melo@gmail.com \
--cc=alexander.shishkin@linux.intel.com \
--cc=eranian@google.com \
--cc=irogers@google.com \
--cc=jolsa@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mbd@fb.com \
--cc=mingo@redhat.com \
--cc=namhyung@kernel.org \
--cc=nums@google.com \
--cc=peterz@infradead.org \
--cc=songliubraving@fb.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).