From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id E0A042C69D; Fri, 5 Jan 2024 11:30:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 49962C15; Fri, 5 Jan 2024 03:31:17 -0800 (PST) Received: from FVFF77S0Q05N (unknown [10.57.86.44]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id AFF2E3F7A6; Fri, 5 Jan 2024 03:30:28 -0800 (PST) Date: Fri, 5 Jan 2024 11:30:22 +0000 From: Mark Rutland To: Jiri Olsa Cc: Edward Adam Davis , syzbot+07144c543a5c002c7305@syzkaller.appspotmail.com, acme@kernel.org, adrian.hunter@intel.com, alexander.shishkin@linux.intel.com, irogers@google.com, linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, mingo@redhat.com, namhyung@kernel.org, netdev@vger.kernel.org, peterz@infradead.org, syzkaller-bugs@googlegroups.com, xrivendell7@gmail.com Subject: Re: [PATCH] perf: fix WARNING in perf_event_open Message-ID: References: <0000000000005b23dc060d58ee7a@google.com> Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Wed, Dec 27, 2023 at 08:34:57AM +0100, Jiri Olsa wrote: > On Tue, Dec 26, 2023 at 03:25:15PM +0800, Edward Adam Davis wrote: > > The new version of __perf_event_read_size() only has a read action and does not > > require a mutex, so the mutex assertion in the original loop is removed. > > > > Fixes: 382c27f4ed28 ("perf: Fix perf_event_validate_size()") > > Reported-and-tested-by: syzbot+07144c543a5c002c7305@syzkaller.appspotmail.com > > Signed-off-by: Edward Adam Davis > > hi, > Mark suggested another fix earlier [1], but I haven't seen the formal patch yet > > jirka > > > [1] https://lore.kernel.org/linux-perf-users/ZXwubNIxKH9s7DWt@FVFF77S0Q05N/ For the sake of the archive, that went out as: https://lore.kernel.org/lkml/20231215112450.3972309-1-mark.rutland@arm.com/ ... was picked up in the tip branch: https://lore.kernel.org/lkml/170264057897.398.420625380438569608.tip-bot2@tip-bot2/ ... was sent to Linus: https://lore.kernel.org/lkml/20231217202613.GAZX9ZZWMM%2FytA74VC@fat_crate.local/ ... was merged in v6.7-rc6: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?h=v6.7-rc6&id=177c2ffe69555dde28fad5ddb62a6d806982e53f ... and can be found at: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?h=v6.7-rc6&id=7e2c1e4b34f07d9aa8937fab88359d4a0fce468e Mark. > > > --- > > kernel/events/core.c | 6 +++++- > > 1 file changed, 5 insertions(+), 1 deletion(-) > > > > diff --git a/kernel/events/core.c b/kernel/events/core.c > > index 9efd0d7775e7..e71e61b46416 100644 > > --- a/kernel/events/core.c > > +++ b/kernel/events/core.c > > @@ -1924,6 +1924,10 @@ static void perf_event__id_header_size(struct perf_event *event) > > event->id_header_size = size; > > } > > > > +#define read_for_each_sibling_event(sibling, event) \ > > + if ((event)->group_leader == (event)) \ > > + list_for_each_entry((sibling), &(event)->sibling_list, sibling_list) > > + > > /* > > * Check that adding an event to the group does not result in anybody > > * overflowing the 64k event limit imposed by the output buffer. > > @@ -1957,7 +1961,7 @@ static bool perf_event_validate_size(struct perf_event *event) > > if (event == group_leader) > > return true; > > > > - for_each_sibling_event(sibling, group_leader) { > > + read_for_each_sibling_event(sibling, group_leader) { > > if (__perf_event_read_size(sibling->attr.read_format, > > group_leader->nr_siblings + 1) > 16*1024) > > return false; > > -- > > 2.43.0 > >