From: Peter Zijlstra <peterz@infradead.org>
To: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Ingo Molnar <mingo@redhat.com>,
linux-kernel@vger.kernel.org, vince@deater.net,
eranian@google.com, Arnaldo Carvalho de Melo <acme@infradead.org>,
Jiri Olsa <jolsa@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Wang Nan <wangnan0@huawei.com>
Subject: Re: [PATCH v2] perf: Synchronously cleanup child events
Date: Tue, 26 Jan 2016 18:24:25 +0100 [thread overview]
Message-ID: <20160126172425.GJ6375@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <20160126161637.GF6357@twins.programming.kicks-ass.net>
On Tue, Jan 26, 2016 at 05:16:37PM +0100, Peter Zijlstra wrote:
> > +struct file *perf_event_get(unsigned int fd)
> > {
> > + struct file *file;
> >
> > + file = fget_raw(fd);
>
> fget_raw() to guarantee the return value isn't NULL? afaict the O_PATH
> stuff does not apply to perf events, so you'd put any fd for which the
> distinction matters anyway.
>
> > + if (file->f_op != &perf_fops) {
> > + fput(file);
> > + return ERR_PTR(-EBADF);
> > + }
> >
> > + return file;
> > }
It is not possible for one thread to concurrently call close() while
this thread tries to fget() ? In which case, we must check the return
value anyway?
next prev parent reply other threads:[~2016-01-26 17:24 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-15 11:22 [PATCH] perf: Cleanup user's " Alexander Shishkin
2016-01-15 12:54 ` Peter Zijlstra
2016-01-15 13:05 ` Alexander Shishkin
2016-01-15 13:09 ` Peter Zijlstra
2016-01-15 14:07 ` [PATCH] perf: Synchronously cleanup " Alexander Shishkin
2016-01-15 17:57 ` Peter Zijlstra
2016-01-18 12:07 ` Alexander Shishkin
2016-01-18 12:37 ` Alexander Shishkin
2016-01-18 14:44 ` Peter Zijlstra
2016-01-19 15:12 ` [PATCH v2] " Alexander Shishkin
2016-01-19 20:05 ` Peter Zijlstra
2016-01-19 21:58 ` Alexei Starovoitov
2016-01-20 8:32 ` Peter Zijlstra
2016-01-21 4:55 ` Alexei Starovoitov
2016-01-20 7:04 ` Alexander Shishkin
2016-01-20 8:03 ` Peter Zijlstra
2016-01-22 11:35 ` Alexander Shishkin
2016-01-22 12:12 ` Peter Zijlstra
2016-01-22 12:38 ` Peter Zijlstra
2016-01-22 19:44 ` Alexei Starovoitov
2016-01-25 11:48 ` Peter Zijlstra
2016-01-25 14:54 ` Peter Zijlstra
2016-01-25 21:04 ` Peter Zijlstra
2016-01-26 4:59 ` Alexei Starovoitov
2016-01-26 16:16 ` Peter Zijlstra
2016-01-26 17:24 ` Peter Zijlstra [this message]
2016-01-26 23:31 ` Alexei Starovoitov
2016-01-27 9:58 ` Peter Zijlstra
2016-01-27 17:52 ` Alexei Starovoitov
2016-01-29 11:28 ` [tip:perf/urgent] perf/bpf: Convert perf_event_array to use struct file tip-bot for Alexei Starovoitov
2016-01-29 20:01 ` Alexei Starovoitov
2016-01-19 20:07 ` [PATCH v2] perf: Synchronously cleanup child events Peter Zijlstra
2016-01-19 7:45 ` [PATCH] " Ingo Molnar
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