From: Jiri Olsa <jolsa@redhat.com>
To: John Garry <john.garry@huawei.com>
Cc: Andi Kleen <ak@linux.intel.com>, Ingo Molnar <mingo@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Linuxarm <linuxarm@huawei.com>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Namhyung Kim <namhyung@kernel.org>,
Will Deacon <will.deacon@arm.com>,
Mark Rutland <mark.rutland@arm.com>
Subject: Re: perf segmentation fault from NULL dereference
Date: Tue, 2 Oct 2018 13:16:21 +0200 [thread overview]
Message-ID: <20181002111621.GA6357@krava> (raw)
In-Reply-To: <4ac88076-60fa-4509-7fa0-2f99d73174d2@huawei.com>
On Tue, Oct 02, 2018 at 11:41:36AM +0100, John Garry wrote:
SNIP
> >
> >
> > ---
> > diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
> > index 1ec1d9bc2d63..fb2a0dab3978 100644
> > --- a/tools/perf/util/header.c
> > +++ b/tools/perf/util/header.c
> > @@ -29,6 +29,7 @@
> > #include "symbol.h"
> > #include "debug.h"
> > #include "cpumap.h"
> > +#include "thread_map.h"
> > #include "pmu.h"
> > #include "vdso.h"
> > #include "strbuf.h"
> > @@ -3579,6 +3580,11 @@ perf_event__synthesize_event_update_cpus(struct perf_tool *tool,
> > if (!evsel->own_cpus)
> > return 0;
> >
> > + if (!evsel->id ||
>
> for my test, evsel->id is NULL
>
> > + perf_evsel__alloc_id(evsel, cpu_map__nr(evsel->cpus),
> > + thread_map__nr(evsel->threads)))
>
> and then this function is not called as we return immediately. So did you
> really want this:
>
> if (!evsel->id && perf_evsel__alloc_id(...))
> return -ENOMEM;
ugh.. yes ;-) thanks for the fix.. I'll double
check the logic and post the patch this week
jirka
>
> This looks to work:
>
> root@localhost:~# ./perf_debug_ record -e armv8_pmuv3_0/br_mis_pred/ sleep 1
> [ perf record: Woken up 1 times to write data ]
> [ perf record: Captured and wrote 0.001 MB perf.data (7 samples) ]
> root@localhost:~# ./perf_debug_ report
> # To display the perf.data header info, please use --header/--header-only
> option
> #
> #
> # Total Lost Samples: 0
> #
> # Samples: 7 of event 'armv8_pmuv3_0/br_mis_pred/'
> # Event count (approx.): 8260
> #
> # Overhead Command Shared Object Symbol
> # ........ ....... ................. ......................
> #
> 78.28% sleep libc-2.23.so [.] 0x00000000000faef0
> 20.53% sleep [kernel.kallsyms] [k] vmacache_find
> 1.09% sleep [kernel.kallsyms] [k] find_vma
> 0.10% perf_de [kernel.kallsyms] [k] perf_event_exec
>
>
> #
> # (Cannot load tips.txt file, please install perf!)
> #
> root@localhost:~#
>
>
> > + return -ENOMEM;
> > +
> > ev = cpu_map_data__alloc(evsel->own_cpus, &size, &type, &max);
> > if (!ev)
> > return -ENOMEM;
> >
> > .
> >
>
>
> Thanks,
> John
>
next prev parent reply other threads:[~2018-10-02 11:16 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-25 15:53 perf segmentation fault from NULL dereference John Garry
2018-09-27 3:00 ` Andi Kleen
2018-10-02 10:20 ` John Garry
2018-09-27 16:02 ` Jiri Olsa
2018-10-02 10:41 ` John Garry
2018-10-02 11:16 ` Jiri Olsa [this message]
2018-10-03 11:36 ` [PATCH] perf tools: Allocate id array in perf_event__synthesize_event_update_cpus Jiri Olsa
2018-10-03 14:08 ` John Garry
2018-10-03 14:16 ` Jiri Olsa
2018-10-03 21:20 ` [PATCH] perf tools: Store ids for events with their own cpus perf_event__synthesize_event_update_cpus Jiri Olsa
2018-10-04 9:20 ` John Garry
2018-10-09 10:00 ` Jiri Olsa
2018-10-12 13:25 ` John Garry
2018-10-15 19:15 ` Arnaldo Carvalho de Melo
2018-10-16 9:10 ` John Garry
2018-10-16 10:47 ` Jiri Olsa
2018-10-18 6:18 ` [tip:perf/urgent] perf evsel: " tip-bot for Jiri Olsa
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