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From: Ingo Molnar <mingo@kernel.org>
To: David Ahern <dsahern@gmail.com>
Cc: acme@ghostprotocols.net, linux-kernel@vger.kernel.org,
	Frederic Weisbecker <fweisbec@gmail.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Jiri Olsa <jolsa@redhat.com>, Namhyung Kim <namhyung@kernel.org>,
	Mike Galbraith <efault@gmx.de>,
	Stephane Eranian <eranian@google.com>
Subject: Re: [PATCH] perf record: Delete file if a failure occurs writing the perf data file
Date: Mon, 11 Nov 2013 10:37:47 +0100	[thread overview]
Message-ID: <20131111093747.GA14810@gmail.com> (raw)
In-Reply-To: <1383928906-31470-1-git-send-email-dsahern@gmail.com>


* David Ahern <dsahern@gmail.com> wrote:

> If perf fails to write data to the data file (e.g., ENOSPC error) it fails
> with the message:
>   failed to write perf data, error: No space left on device
> 
> and stops — killing the workload too. The file is an unknown state. 
> Trying to read it (e.g., perf report) fails with a SIGBUS error.

Ouch - guys please first investiage that SIGBUS, we should not behave 
unexpectedly on _any_ (read: random) perf.data file contents. The SIGBUS 
likely suggests that the parsing isn't robust enough.

> Fix by deleting the file on a failure.

That only works around the issue - if the same data file is produced by 
some other method (or maliciously) then perf report will still SIGBUS ...

Thanks,

	Ingo

  parent reply	other threads:[~2013-11-11  9:37 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-11-08 16:41 [PATCH] perf record: Delete file if a failure occurs writing the perf data file David Ahern
2013-11-08 17:58 ` Jiri Olsa
2013-11-11  9:37 ` Ingo Molnar [this message]
2013-11-11 14:43   ` David Ahern
2013-11-12 14:51     ` David Ahern
2013-11-12 15:04       ` Peter Zijlstra
2013-11-12 15:25         ` David Ahern
2013-11-12 15:34           ` Peter Zijlstra
2013-11-20  4:39             ` David Ahern

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