Re: [PATCH] perf record: Fix BTF type checks in the off-cpu profiling

From: Namhyung Kim <namhyung@kernel.org>
To: Song Liu <song@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>,
	Jiri Olsa <jolsa@kernel.org>, Ian Rogers <irogers@google.com>,
	Adrian Hunter <adrian.hunter@intel.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@kernel.org>,
	LKML <linux-kernel@vger.kernel.org>,
	linux-perf-users@vger.kernel.org, Hao Luo <haoluo@google.com>,
	bpf@vger.kernel.org
Subject: Re: [PATCH] perf record: Fix BTF type checks in the off-cpu profiling
Date: Wed, 27 Sep 2023 20:55:52 -0700	[thread overview]
Message-ID: <CAM9d7cjUiet5kNxk=opNrhGgZ2QeqB6J5Tzok5GaEwtgiM-FEA@mail.gmail.com> (raw)
In-Reply-To: <CAPhsuW6mEWJcZdYbPbqt5ArBMznzQYwHBqTpKCcsB4B0o=PSGA@mail.gmail.com>

On Wed, Sep 27, 2023 at 9:09 AM Song Liu <song@kernel.org> wrote:
>
> On Fri, Sep 22, 2023 at 4:44 PM Namhyung Kim <namhyung@kernel.org> wrote:
> >
> > The BTF func proto for a tracepoint has one more argument than the
> > actual tracepoint function since it has a context argument at the
> > begining.  So it should compare to 5 when the tracepoint has 4
> > arguments.
> >
> >   typedef void (*btf_trace_sched_switch)(void *, bool, struct task_struct *, struct task_struct *, unsigned int);
> >
> > Also, recent change in the perf tool would use a hand-written minimal
> > vmlinux.h to generate BTF in the skeleton.  So it won't have the info
> > of the tracepoint.  Anyway it should use the kernel's vmlinux BTF to
> > check the type in the kernel.
> >
> > Fixes: b36888f71c85 ("perf record: Handle argument change in sched_switch")
> > Cc: Song Liu <song@kernel.org>
> > Cc: Hao Luo <haoluo@google.com>
> > CC: bpf@vger.kernel.org
> > Signed-off-by: Namhyung Kim <namhyung@kernel.org>
>
> Acked-by: Song Liu <song@kernel.org>

Applied to perf-tools-next, thanks!