* misuse of fget_raw() in perf_event_get()
@ 2019-04-13 21:02 Al Viro
2019-04-15 4:42 ` Alexei Starovoitov
0 siblings, 1 reply; 4+ messages in thread
From: Al Viro @ 2019-04-13 21:02 UTC (permalink / raw)
To: Alexei Starovoitov; +Cc: linux-fsdevel, linux-kernel
What's the point of using fget_raw(), if you do
_not_ accept O_PATH descriptors? That should be fget()...
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: misuse of fget_raw() in perf_event_get()
2019-04-13 21:02 misuse of fget_raw() in perf_event_get() Al Viro
@ 2019-04-15 4:42 ` Alexei Starovoitov
2019-04-15 9:04 ` Peter Zijlstra
0 siblings, 1 reply; 4+ messages in thread
From: Alexei Starovoitov @ 2019-04-15 4:42 UTC (permalink / raw)
To: Al Viro; +Cc: linux-fsdevel, linux-kernel, peterz, tj
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.
Now it looks like that it can be fget just fine.
I think cgroup_get_from_fd() should do the same too?
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: misuse of fget_raw() in perf_event_get()
2019-04-15 4:42 ` Alexei Starovoitov
@ 2019-04-15 9:04 ` Peter Zijlstra
2019-06-27 0:56 ` Al Viro
0 siblings, 1 reply; 4+ messages in thread
From: Peter Zijlstra @ 2019-04-15 9:04 UTC (permalink / raw)
To: Alexei Starovoitov; +Cc: Al Viro, linux-fsdevel, linux-kernel, tj
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@twins.programming.kicks-ass.net
I too wondered about the fget_raw() at the time, whatever Al wants
though, I never quite remember how that file stuff works :/
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: misuse of fget_raw() in perf_event_get()
2019-04-15 9:04 ` Peter Zijlstra
@ 2019-06-27 0:56 ` Al Viro
0 siblings, 0 replies; 4+ messages in thread
From: Al Viro @ 2019-06-27 0:56 UTC (permalink / raw)
To: Peter Zijlstra; +Cc: Alexei Starovoitov, linux-fsdevel, linux-kernel, tj
On Mon, Apr 15, 2019 at 11:04:06AM +0200, Peter Zijlstra wrote:
> 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@twins.programming.kicks-ass.net
>
> I too wondered about the fget_raw() at the time, whatever Al wants
> though, I never quite remember how that file stuff works :/
Anyway, fget() it becomes...
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2019-06-27 0:56 UTC | newest]
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2019-04-13 21:02 misuse of fget_raw() in perf_event_get() Al Viro
2019-04-15 4:42 ` Alexei Starovoitov
2019-04-15 9:04 ` Peter Zijlstra
2019-06-27 0:56 ` Al Viro
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