Re: [PATCH] bpf: fix sample_flags for bpf_perf_event_output

From: Alexei Starovoitov <alexei.starovoitov@gmail.com>
To: Peter Zijlstra <peterz@infradead.org>,
	Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Olsa <olsajiri@gmail.com>,
	Sumanth Korikkar <sumanthk@linux.ibm.com>,
	bpf <bpf@vger.kernel.org>, Vasily Gorbik <gor@linux.ibm.com>,
	Heiko Carstens <hca@linux.ibm.com>,
	Ilya Leoshkevich <iii@linux.ibm.com>,
	LKML <linux-kernel@vger.kernel.org>,
	Namhyung Kim <namhyung@kernel.org>,
	Sven Schnelle <svens@linux.ibm.com>,
	Thomas Richter <tmricht@linux.ibm.com>, X86 ML <x86@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Andrii Nakryiko <andrii@kernel.org>,
	Jakub Kicinski <kuba@kernel.org>,
	"David S. Miller" <davem@davemloft.net>
Subject: Re: [PATCH] bpf: fix sample_flags for bpf_perf_event_output
Date: Thu, 20 Oct 2022 18:36:16 -0700	[thread overview]
Message-ID: <CAADnVQ+gquOKjo68ryUhpw4nQYoQzpUYJhdA2e6Wfqs=_oHV8g@mail.gmail.com> (raw)
In-Reply-To: <CAADnVQJ0ur6Pox9aTjoSkXs43strqN__e1h4JWya46WOER9V4w@mail.gmail.com>

Peter,

Another 2 days have passed and bpf side is still broken
due to the change that went during the merge window without
corresponding fix from the bpf side.
Looks like the patch is sitting in tip:perf/urgent.
Please send it to Linus asap.

We're not sending bpf fixes to avoid breaking bpf tree too.
We've worked around the issue in bpf CI for bpf-next tree only.
Developers still see failures when they run tests locally.

On Tue, Oct 18, 2022 at 9:57 PM Alexei Starovoitov
<alexei.starovoitov@gmail.com> wrote:
>
> On Fri, Oct 7, 2022 at 8:31 AM Peter Zijlstra <peterz@infradead.org> wrote:
> >
> > On Fri, Oct 07, 2022 at 11:45:36AM +0200, Jiri Olsa wrote:
> > > On Fri, Oct 07, 2022 at 10:13:27AM +0200, Sumanth Korikkar wrote:
> > > > * Raw data is also filled by bpf_perf_event_output.
> > > > * Add sample_flags to indicate raw data.
> > > > * This eliminates the segfaults as shown below:
> > > >   Run ./samples/bpf/trace_output
> > > >   BUG pid 9 cookie 1001000000004 sized 4
> > > >   BUG pid 9 cookie 1001000000004 sized 4
> > > >   BUG pid 9 cookie 1001000000004 sized 4
> > > >   Segmentation fault (core dumped)
> > > >
> > > > Fixes: 838d9bb62d13 ("perf: Use sample_flags for raw_data")
> > > > Acked-by: Namhyung Kim <namhyung@kernel.org>
> > > > Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
> > >
> > > Acked-by: Jiri Olsa <jolsa@kernel.org>
> > >
> > > Peter,
> > > I think this should go through your tree again?
> > > bpf-next/master does not have sample_flags merged yet
> >
> > Yep can do. I'll line it up in perf/urgent (Ingo just send out
> > perf/core).
>
> Peter,
>
> Could you please hurry up. 11 days have passed.
>
> This issue affects everyone the hard way now after merging
> all the trees: tip -> linus -> net-next -> bpf-next.
> The BPF CI is red right now with 5 tests failing because
> this fix is still missing.
> It's causing a headache to maintainers and developers.