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Date: Mon, 9 Dec 2013 14:03:42 -0500
From: Steven Rostedt <rostedt@goodmis.org>
To: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Namhyung Kim <namhyung@kernel.org>,
        Frederic Weisbecker <fweisbec@gmail.com>,
        Ingo Molnar <mingo@kernel.org>, Jiri Olsa <jolsa@redhat.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Namhyung Kim <namhyung.kim@lge.com>
Subject: Re: [PATCH 01/14] tools lib traceevent: Get rid of malloc_or_die()
 in show_error()
Message-ID: <20131209140342.5f72298f@gandalf.local.home>
In-Reply-To: <20131209183009.GC8098@ghostprotocols.net>
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On Mon, 9 Dec 2013 15:30:09 -0300
Arnaldo Carvalho de Melo <acme@ghostprotocols.net> wrote:


> > +		error = malloc(MAX_ERR_STR_SIZE);
> > +		if (error == NULL) {
> > +			/* no memory */
> > +			*error_str = "failed to allocate memory";
> > +			return;
> 
> Can *error_str point to either malloc'ed or constant strings? Who
> releases the allocated memory?
> 

Good question. Perhaps we should have a flag that states if the string
is allocated or not. Or better yet, since the only reason it would be
pointing to a static string is if the string for error_str itself
failed to allocate. Then we could use a string within pevent for it:

static char *pevent_failed_error_alloc = "failed to allocate memory";

Then in the freeing of error str:

void pevent_free_error_str(error_str)
{
	if (error_str != pevent_failed_error_alloc)
		free(error_str);
}

-- Steve