bpf+perf is still broken. Was: [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: bpf+perf is still broken. Was: [PATCH] bpf: fix sample_flags for bpf_perf_event_output
Date: Sat, 22 Oct 2022 18:16:30 -0700	[thread overview]
Message-ID: <CAADnVQKj5B1nfkQTSTrSCPq+TQU_SD22F7uG7Carks8oVi8=aQ@mail.gmail.com> (raw)
In-Reply-To: <CAADnVQ+gquOKjo68ryUhpw4nQYoQzpUYJhdA2e6Wfqs=_oHV8g@mail.gmail.com>

Another 2 days have passed and the fix is still not in the Linus's tree.

Peter,
whatever your excuse is for not sending tip:perf/urgent
this is not acceptable.

Linus,

please apply this fix directly:
https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/commit/?h=perf/urgent&id=21da7472a040420f2dc624ffec70291a72c5d6a6

or suggest the course of action.

It sucked to have such a breakage in rc1 and we don't want rc2
to stay broken.

Thanks

On Thu, Oct 20, 2022 at 6:36 PM Alexei Starovoitov
<alexei.starovoitov@gmail.com> wrote:
>
> 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.