From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 80D6B21771B; Tue, 29 Apr 2025 15:49:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.92.199 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745941800; cv=none; b=Hkvctj+KvOB9zKaxnjv7Ewl1lfztvePACCU1SGdjR2vUtREteDXfNDi7Z0jw6QotL7VMxy+RNNCBM03N+Gaz4i4vYifVIh1EY6OVyK3fgvVAnXpeUX/BO2LEwDJK6C2+4XJtPmEuNWHhAEh5symDRTnuMjDAzI3FJs0Ftkq9E/I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745941800; c=relaxed/simple; bh=SWA30VtLEsbKUxXYuBVojhQkeXIFkAjMhnPUSK81HNk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ThKqCPI6M5WQXUBMupaFZ36Eqs9audP549NWWTyN2OSxrVTCQPoclFvamaaWtXFHgRA+0IV/NO6lSy1SMG/i1A2n5q6DDHyWAscMLVSROa70FSiQS2jgsdQwbsDpxMweiF977kJidAEcLOaXqVnuEDn/q/sbbkme5Cb12qRhz7E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=Voz75BMs; arc=none smtp.client-ip=90.155.92.199 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="Voz75BMs" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=HzDcT6NzZ8VkLqeQVpl0smJGiuB7wxJtJRI/zTXIq3o=; b=Voz75BMsteZL0PPUQ+gTkryk1w BTron6lHlau6SX4sgZF045B6msd1Entzv7YViyHTQi6mIWw+zC8g+xCk2qofpU5AHKKZ84egJ8PCf yjRsR088SEdlP3X/a6G7CsLmv1ZSbDA2j64AAqTpcIAl6c85+T5cksz/NNQY1EdXTUi7eW4SqMSnS tgr03i5IRKr5JGpPNVVOXm1PcN1BtHeDqKDZ+nXbv/U5VoK/JEgzfLZrqGu8cOIjU9RLfJiHCniid JcyOmD53lTuzS8RZNDQrwbP4anvInd14bqybm4Ac7I0OZ4QzwaUM3bsoUAcJu+lhAVvUh1iiQgp9P y0fgdVdg==; Received: from 77-249-17-252.cable.dynamic.v4.ziggo.nl ([77.249.17.252] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.98.1 #2 (Red Hat Linux)) id 1u9nDP-0000000DSQz-2ynT; Tue, 29 Apr 2025 15:49:47 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 26DD730057C; Tue, 29 Apr 2025 17:49:47 +0200 (CEST) Date: Tue, 29 Apr 2025 17:49:46 +0200 From: Peter Zijlstra To: Jianzhou Zhao Cc: stable@vger.kernel.org, alexander.shishkin@linux.intel.com, mingo@redhat.com, acme@kernel.org, namhyung@kernel.org, mark.rutland@arm.com, jolsa@kernel.org, irogers@google.com, adrian.hunter@intel.com, kan.liang@linux.intel.com, linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: possible deadlock in perf_ctx_lock in linux6.12.25(longterm maintenance) Message-ID: <20250429154946.GA4439@noisy.programming.kicks-ass.net> References: <77c2ee24.b63e.19681e979ea.Coremail.luckd0g@163.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: <77c2ee24.b63e.19681e979ea.Coremail.luckd0g@163.com> On Tue, Apr 29, 2025 at 10:18:04PM +0800, Jianzhou Zhao wrote: > Hello, I found a potential bug titled " possible deadlock in perf_ctx_lock " with modified syzkaller in the Linux6.12.25(longterm maintenance, last updated on April 25, 2025) Nah, you hit a WARN and then printk being lousy made it explode worse. > WARNING: CPU: 0 PID: 15835 at kernel/trace/trace_event_perf.c:375 perf_trace_add+0x2da/0x390 kernel/trace/trace_event_perf.c:375 > Modules linked in: > CPU: 0 UID: 0 PID: 15835 Comm: syz.9.499 Not tainted 6.12.25 #3 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 > RIP: 0010:perf_trace_add+0x2da/0x390 kernel/trace/trace_event_perf.c:375 > Code: fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 75 64 48 89 ab f8 01 00 00 48 89 df e8 b1 ab 26 00 e9 f3 fd ff ff e8 37 87 f6 ff 90 <0f> 0b 90 41 bc ea ff ff ff e9 77 ff ff ff e8 23 c5 56 00 e9 8a fd > RSP: 0018:ffffc9000713f7f0 EFLAGS: 00010006 > RAX: 0000000040000002 RBX: ffff88802a069880 RCX: ffffffff8195a68e > RDX: ffff888045ec2500 RSI: ffffffff8195a839 RDI: ffffffff8deabf48 > RBP: 0000000000000000 R08: 0000000000000001 R09: fffff52000e27eef > R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 > R13: ffffffff8deabee0 R14: ffff88802a069928 R15: ffff888051237200 > FS: 00007fe4fec1c640(0000) GS:ffff88802b800000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007f50219e7bac CR3: 00000000743bc000 CR4: 0000000000752ef0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > PKRU: 80000000 > Call Trace: > > event_sched_in+0x434/0xac0 kernel/events/core.c:2629 > group_sched_in kernel/events/core.c:2662 [inline] > merge_sched_in+0x895/0x1570 kernel/events/core.c:3940 > visit_groups_merge.constprop.0.isra.0+0x6d2/0x1250 kernel/events/core.c:3885 > pmu_groups_sched_in kernel/events/core.c:3967 [inline] > __pmu_ctx_sched_in kernel/events/core.c:3979 [inline] > ctx_sched_in+0x5c1/0xa30 kernel/events/core.c:4030 > perf_event_sched_in+0x5d/0x90 kernel/events/core.c:2760 > perf_event_context_sched_in kernel/events/core.c:4077 [inline] > __perf_event_task_sched_in+0x33a/0x6f0 kernel/events/core.c:4106 > perf_event_task_sched_in include/linux/perf_event.h:1524 [inline] > finish_task_switch.isra.0+0x5f9/0xcb0 kernel/sched/core.c:5201 > context_switch kernel/sched/core.c:5335 [inline] > __schedule+0x1156/0x5b20 kernel/sched/core.c:6710 > preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7032 > irqentry_exit+0x36/0x90 kernel/entry/common.c:354 > asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 Not quite sure which of the WARNs that is, as I don't keep the stable trees around and .12 is quite old by now. Anyway, if you can reproduce I'll take a look.