linux-kernel - Re: [PATCH v2 0/7] Perf stat --null/offline CPU segv related fixes/tests

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: <1dd3d66f-f770-4f38-80da-51a16f084401@linux.ibm.com>
Date: Thu, 4 Dec 2025 08:51:34 +0100
From: Thomas Richter <tmricht@...ux.ibm.com>
To: Ian Rogers <irogers@...gle.com>, Peter Zijlstra <peterz@...radead.org>,
        Ingo Molnar <mingo@...hat.com>,
        Arnaldo Carvalho de Melo <acme@...nel.org>,
        Namhyung Kim <namhyung@...nel.org>,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        Jiri Olsa <jolsa@...nel.org>, Adrian Hunter <adrian.hunter@...el.com>,
        James Clark <james.clark@...aro.org>, linux-perf-users@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 0/7] Perf stat --null/offline CPU segv related
 fixes/tests

On 12/3/25 22:46, Ian Rogers wrote:
> Ingo reported [1] that `perf stat --null` was segfaulting. Fix the
> underlying issue and add a test to the "perf stat tests". Do some
> related fixing/cleanup in the perf util cpumap code.
> 
> Thomas reported an issue fixed by the same patches [2] but caused by
> giving perf stat an offline CPU. Add test coverage for that and
> improve the "error" message that reports "success".
> 
> Ingo further pointed at broken signal handling in repeat mode [3]. I
> observed we weren't giving the best exit code, 0 rather than the
> expected 128+<signal number>. Add a patch fixing this.
> 
> [1] https://lore.kernel.org/linux-perf-users/aSwt7yzFjVJCEmVp@gmail.com/
> [2] https://lore.kernel.org/linux-perf-users/94313b82-888b-4f42-9fb0-4585f9e90080@linux.ibm.com/
> [3] https://lore.kernel.org/lkml/aS5wjmbAM9ka3M2g@gmail.com/
> 
> Ian Rogers (7):
>   perf stat: Allow no events to open if this is a "--null" run
>   libperf cpumap: Fix perf_cpu_map__max for an empty/NULL map
>   perf cpumap: Add "any" CPU handling to cpu_map__snprint_mask
>   perf tests stat: Add "--null" coverage
>   perf stat: When no events, don't report an error if there is none
>   perf tests stat: Add test for error for an offline CPU
>   perf stat: Improve handling of termination by signal
> 
>  tools/lib/perf/cpumap.c        | 10 +++++----
>  tools/perf/builtin-stat.c      | 29 ++++++++++++++++++-------
>  tools/perf/tests/shell/stat.sh | 39 ++++++++++++++++++++++++++++++++++
>  tools/perf/util/cpumap.c       |  9 ++++++--
>  4 files changed, 73 insertions(+), 14 deletions(-)
> 

For the whole series:

Tested-by: Thomas Richter <tmricht@...ux.ibm.com>

Thanks for fixing this, Ian

-- 
Thomas Richter, Dept 3303, IBM s390 Linux Development, Boeblingen, Germany
--
IBM Deutschland Research & Development GmbH

Vorsitzender des Aufsichtsrats: Wolfgang Wendt

Geschäftsführung: David Faller

Sitz der Gesellschaft: Böblingen / Registergericht: Amtsgericht Stuttgart, HRB 243294