From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 BE2DF15FD1E; Mon, 27 May 2024 14:12:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716819146; cv=none; b=M3Pf3xrSn4lMfXLZWapyFJ5/xmwxw0Svz3Wnu/pqaiLap7MNTlr4s6kubtMBu4NBqigyOGepG+16vnlUoNCUjXujQg0/QNIz0pbFR/vOWye5ZBS/bcBdHQNDhCZil+Y/rr4FJyFgoh5Khw2F3SZhG57PMfR+s2xta6G4a/wlyWc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716819146; c=relaxed/simple; bh=qzdnVBNDG9392ll1ROAf5CYfJzq9O8zBKlbs18HMd7M=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=EL68znZEIvo+lvLp26uWPHt+lXpSWLdEz8a8CWUwzCHOg645O9XJLjlEyGPE/tT2x6LzbAsepc4fPjMQuE6LMsCI9qWclz9g1wWYxjtecq2ePpcNnuGYmLbE04mqMHGovrNOivggD9tIgR4nsGvpL3c02R9I2v3nQ5hC/Kdx1mA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=nmCvbtZ3; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="nmCvbtZ3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B2879C4AF07; Mon, 27 May 2024 14:12:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1716819146; bh=qzdnVBNDG9392ll1ROAf5CYfJzq9O8zBKlbs18HMd7M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nmCvbtZ3/Be7dTuUjA07jfbMz0u7PjDF2vYjFbEM0BlSjNgaLlemS3QkgP0OcmY4c 3J5HuW16pW1XFrJVnkXfDzLmR/xZGTUg51sDze4xQdySX6ebTkmOwj67ZZwQeZsxXl I7/Yj0l0N51WqMxNrvbnB3yf7cIqTfHlIMdGP8E83qrDNogZes+oK9KD2fQtd/M/6A cqBnrkMXBtDAjQ1skR6r7gYcuWtJk+IVyI8f9SWYx+C6tLihVTzj+59T0Xy6tIMTIT f8SV+a8bL2HbcTIpEA7xZvvRVgKOmi1ihvofZgcsAhE19ZugTm2GAVlkoVUIoRFlxp Q8+/OCjdwpeiA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Eric Dumazet , Sven Eckelmann , Simon Wunderlich , Sasha Levin , mareklindner@neomailbox.ch, a@unstable.cc, davem@davemloft.net, kuba@kernel.org, pabeni@redhat.com, b.a.t.m.a.n@lists.open-mesh.org, netdev@vger.kernel.org Subject: [PATCH AUTOSEL 6.9 06/35] batman-adv: bypass empty buckets in batadv_purge_orig_ref() Date: Mon, 27 May 2024 10:11:11 -0400 Message-ID: <20240527141214.3844331-6-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240527141214.3844331-1-sashal@kernel.org> References: <20240527141214.3844331-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.9.2 Content-Transfer-Encoding: 8bit From: Eric Dumazet [ Upstream commit 40dc8ab605894acae1473e434944924a22cfaaa0 ] Many syzbot reports are pointing to soft lockups in batadv_purge_orig_ref() [1] Root cause is unknown, but we can avoid spending too much time there and perhaps get more interesting reports. [1] watchdog: BUG: soft lockup - CPU#0 stuck for 27s! [kworker/u4:6:621] Modules linked in: irq event stamp: 6182794 hardirqs last enabled at (6182793): [] __local_bh_enable_ip+0x224/0x44c kernel/softirq.c:386 hardirqs last disabled at (6182794): [] __el1_irq arch/arm64/kernel/entry-common.c:533 [inline] hardirqs last disabled at (6182794): [] el1_interrupt+0x24/0x68 arch/arm64/kernel/entry-common.c:551 softirqs last enabled at (6182792): [] spin_unlock_bh include/linux/spinlock.h:396 [inline] softirqs last enabled at (6182792): [] batadv_purge_orig_ref+0x114c/0x1228 net/batman-adv/originator.c:1287 softirqs last disabled at (6182790): [] spin_lock_bh include/linux/spinlock.h:356 [inline] softirqs last disabled at (6182790): [] batadv_purge_orig_ref+0x164/0x1228 net/batman-adv/originator.c:1271 CPU: 0 PID: 621 Comm: kworker/u4:6 Not tainted 6.8.0-rc7-syzkaller-g707081b61156 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024 Workqueue: bat_events batadv_purge_orig pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : should_resched arch/arm64/include/asm/preempt.h:79 [inline] pc : __local_bh_enable_ip+0x228/0x44c kernel/softirq.c:388 lr : __local_bh_enable_ip+0x224/0x44c kernel/softirq.c:386 sp : ffff800099007970 x29: ffff800099007980 x28: 1fffe00018fce1bd x27: dfff800000000000 x26: ffff0000d2620008 x25: ffff0000c7e70de8 x24: 0000000000000001 x23: 1fffe00018e57781 x22: dfff800000000000 x21: ffff80008aab71c4 x20: ffff0001b40136c0 x19: ffff0000c72bbc08 x18: 1fffe0001a817bb0 x17: ffff800125414000 x16: ffff80008032116c x15: 0000000000000001 x14: 1fffe0001ee9d610 x13: 0000000000000000 x12: 0000000000000003 x11: 0000000000000000 x10: 0000000000ff0100 x9 : 0000000000000000 x8 : 00000000005e5789 x7 : ffff80008aab61dc x6 : 0000000000000000 x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000000 x2 : 0000000000000006 x1 : 0000000000000080 x0 : ffff800125414000 Call trace: __daif_local_irq_enable arch/arm64/include/asm/irqflags.h:27 [inline] arch_local_irq_enable arch/arm64/include/asm/irqflags.h:49 [inline] __local_bh_enable_ip+0x228/0x44c kernel/softirq.c:386 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:167 [inline] _raw_spin_unlock_bh+0x3c/0x4c kernel/locking/spinlock.c:210 spin_unlock_bh include/linux/spinlock.h:396 [inline] batadv_purge_orig_ref+0x114c/0x1228 net/batman-adv/originator.c:1287 batadv_purge_orig+0x20/0x70 net/batman-adv/originator.c:1300 process_one_work+0x694/0x1204 kernel/workqueue.c:2633 process_scheduled_works kernel/workqueue.c:2706 [inline] worker_thread+0x938/0xef4 kernel/workqueue.c:2787 kthread+0x288/0x310 kernel/kthread.c:388 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 6.8.0-rc7-syzkaller-g707081b61156 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024 pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : arch_local_irq_enable+0x8/0xc arch/arm64/include/asm/irqflags.h:51 lr : default_idle_call+0xf8/0x128 kernel/sched/idle.c:103 sp : ffff800093a17d30 x29: ffff800093a17d30 x28: dfff800000000000 x27: 1ffff00012742fb4 x26: ffff80008ec9d000 x25: 0000000000000000 x24: 0000000000000002 x23: 1ffff00011d93a74 x22: ffff80008ec9d3a0 x21: 0000000000000000 x20: ffff0000c19dbc00 x19: ffff8000802d0fd8 x18: 1fffe00036804396 x17: ffff80008ec9d000 x16: ffff8000802d089c x15: 0000000000000001 x14: 1fffe00036805f10 x13: 0000000000000000 x12: 0000000000000003 x11: 0000000000000001 x10: 0000000000000003 x9 : 0000000000000000 x8 : 00000000000ce8d1 x7 : ffff8000804609e4 x6 : 0000000000000000 x5 : 0000000000000001 x4 : 0000000000000001 x3 : ffff80008ad6aac0 x2 : 0000000000000000 x1 : ffff80008aedea60 x0 : ffff800125436000 Call trace: __daif_local_irq_enable arch/arm64/include/asm/irqflags.h:27 [inline] arch_local_irq_enable+0x8/0xc arch/arm64/include/asm/irqflags.h:49 cpuidle_idle_call kernel/sched/idle.c:170 [inline] do_idle+0x1f0/0x4e8 kernel/sched/idle.c:312 cpu_startup_entry+0x5c/0x74 kernel/sched/idle.c:410 secondary_start_kernel+0x198/0x1c0 arch/arm64/kernel/smp.c:272 __secondary_switched+0xb8/0xbc arch/arm64/kernel/head.S:404 Signed-off-by: Eric Dumazet Signed-off-by: Sven Eckelmann Signed-off-by: Simon Wunderlich Signed-off-by: Sasha Levin --- net/batman-adv/originator.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/batman-adv/originator.c b/net/batman-adv/originator.c index 71c143d4b6d05..ac74f6ead62d5 100644 --- a/net/batman-adv/originator.c +++ b/net/batman-adv/originator.c @@ -1266,6 +1266,8 @@ void batadv_purge_orig_ref(struct batadv_priv *bat_priv) /* for all origins... */ for (i = 0; i < hash->size; i++) { head = &hash->table[i]; + if (hlist_empty(head)) + continue; list_lock = &hash->list_locks[i]; spin_lock_bh(list_lock); -- 2.43.0