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Date:   Mon, 27 Nov 2023 10:18:03 -0300
From:   Arnaldo Carvalho de Melo <acme@kernel.org>
To:     Ingo Molnar <mingo@kernel.org>
Cc:     Peter Zijlstra <peterz@infradead.org>,
        zhaimingbing <zhaimingbing@cmss.chinamobile.com>,
        Namhyung Kim <namhyung@kernel.org>,
        Ingo Molnar <mingo@redhat.com>,
        Mark Rutland <mark.rutland@arm.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Jiri Olsa <jolsa@kernel.org>, Ian Rogers <irogers@google.com>,
        Adrian Hunter <adrian.hunter@intel.com>,
        Sean Christopherson <seanjc@google.com>,
        Li Dong <lidong@vivo.com>, linux-perf-users@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] perf lock: Fix a memory leak on an error path
Message-ID: <ZWSXCwrx5BUpYGi/@kernel.org>
References: <20231124092657.10392-1-zhaimingbing@cmss.chinamobile.com>
 <20231124095319.GN3818@noisy.programming.kicks-ass.net>
 <ZWCdg5gcizJitxVw@gmail.com>
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Em Fri, Nov 24, 2023 at 01:56:35PM +0100, Ingo Molnar escreveu:
> 
> * Peter Zijlstra <peterz@infradead.org> wrote:
> 
> > On Fri, Nov 24, 2023 at 05:26:57PM +0800, zhaimingbing wrote:
> > > if a strdup-ed string is NULL,the allocated memory needs freeing.
> > > 
> > > Signed-off-by: zhaimingbing <zhaimingbing@cmss.chinamobile.com>
> > > ---
> > >  tools/perf/builtin-lock.c | 4 +++-
> > >  1 file changed, 3 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/tools/perf/builtin-lock.c b/tools/perf/builtin-lock.c
> > > index b141f2134..086041bcb 100644
> > > --- a/tools/perf/builtin-lock.c
> > > +++ b/tools/perf/builtin-lock.c
> > > @@ -2228,8 +2228,10 @@ static int __cmd_record(int argc, const char **argv)
> > >  		else
> > >  			ev_name = strdup(contention_tracepoints[j].name);
> > >  
> > > -		if (!ev_name)
> > > +		if (!ev_name) {
> > > +			free(rec_argv);
> > >  			return -ENOMEM;
> > > +		}
> > 
> > Isn't this an error path straight into exit?
> 
> It increases the quality of implementation if resources are free()d 
> consistently regardless of whether the task is going to exit() immediately, 
> for example it makes it easier to validate perf for the lack of memory 
> leaks with Valgrind.

I'm taking this positive comment about the patch as an Acked-by, ok?

- Arnaldo