Re: misuse of fget_raw() in perf_event_get()

From: Peter Zijlstra
Date: Mon Apr 15 2019 - 05:04:13 EST


On Sun, Apr 14, 2019 at 09:42:00PM -0700, Alexei Starovoitov wrote:
> On Sat, Apr 13, 2019 at 10:02:42PM +0100, Al Viro wrote:
> > What's the point of using fget_raw(), if you do
> > _not_ accept O_PATH descriptors? That should be fget()...
>
> I think you're talking about commit e03e7ee34fdd ("perf/bpf: Convert perf_event_array to use struct file")
> I don't really remember why we went with this instead of fget().
> There was a bunch of back and forth back then with Peter.

That was mostly on what refcount to use, you wanted to use the event
refcount, and I suggested using the file refcount.

If you look at:

lkml.kernel.org/r/20160126161637.GF6357@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

I too wondered about the fget_raw() at the time, whatever Al wants
though, I never quite remember how that file stuff works :/