Re: [PATCH] perf script report: fix segfault when using DWARF mode

From: Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com>
To: Andreas Gerstmayr <agerstmayr@redhat.com>
Cc: linux-perf-users@vger.kernel.org,
	Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>,
	Mark Rutland <mark.rutland@arm.com>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Jiri Olsa <jolsa@redhat.com>, Namhyung Kim <namhyung@kernel.org>,
	Adrian Hunter <adrian.hunter@intel.com>,
	"Steven Rostedt (VMware)" <rostedt@goodmis.org>,
	Kan Liang <kan.liang@linux.intel.com>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] perf script report: fix segfault when using DWARF mode
Date: Thu, 2 Apr 2020 12:16:43 -0300	[thread overview]
Message-ID: <20200402151643.GB8736@kernel.org> (raw)
In-Reply-To: <20200402125417.422232-1-agerstmayr@redhat.com>

Em Thu, Apr 02, 2020 at 02:54:16PM +0200, Andreas Gerstmayr escreveu:
> When running perf script report with a Python script and a callgraph in
> DWARF mode, intr_regs->regs can be 0 and therefore crashing the regs_map
> function.
> 
> Added a check for this condition (same check as in builtin-script.c:595).

Thanks, applied to perf/urgent.

- Arnaldo

> Signed-off-by: Andreas Gerstmayr <agerstmayr@redhat.com>
> ---
>  tools/perf/util/scripting-engines/trace-event-python.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/tools/perf/util/scripting-engines/trace-event-python.c b/tools/perf/util/scripting-engines/trace-event-python.c
> index 8c1b27cd8b99..2c372cf5495e 100644
> --- a/tools/perf/util/scripting-engines/trace-event-python.c
> +++ b/tools/perf/util/scripting-engines/trace-event-python.c
> @@ -694,6 +694,9 @@ static int regs_map(struct regs_dump *regs, uint64_t mask, char *bf, int size)
>  
>  	bf[0] = 0;
>  
> +	if (!regs || !regs->regs)
> +		return 0;
> +
>  	for_each_set_bit(r, (unsigned long *) &mask, sizeof(mask) * 8) {
>  		u64 val = regs->regs[i++];
>  
> -- 
> 2.25.1
> 

-- 

- Arnaldo