Messages in this thread | | | Date | Mon, 6 Jan 2014 17:39:50 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH] perf tools: enable close-on-exec flag on perf file descriptor |
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On Mon, Jan 06, 2014 at 08:27:54AM -0800, Andi Kleen wrote: > On Mon, Jan 06, 2014 at 11:51:25AM +0100, Yann Droneaud wrote: > > In a previous patch [1][2], flag PERF_FLAG_FD_CLOEXEC was > > added to perf_event_open(2) syscall to allows userspace > > to enable close-on-exec behavor atomically when creating > > the file descriptor. > > > > This patch makes perf tools use the new flag. > > What is that good for? I can see why for a threaded program, but > "perf" is not threaded.
AFAICT its got nothing to do with threaded or not, but only with exec() and we do in fact call exec() quite a lot in perf.
It ensures we do not leak open perf FDs into our child processes. Now I'm not entirely sure how we do the exec these days but I think we were good about not not leaking them anyway, but more paranoia never really hurts.
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