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 4A7B5237ED4; Wed, 4 Dec 2024 17:13:53 +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=1733332434; cv=none; b=FHIdIWsQwS4SGjjeo/zBqfW5BqSS6R5qSsGU6zCkx7aU4bDTuyYg2zBlyjljA1nlpUeNYKsXy7nB3WX6jZ2+h6sLvM6QTsiTINI3l9/4UwNqVXaq5Qsa6MDVtUPTnebxQVqRJlcnBJlqwoydl6PRHOTMVzbzzj77M9gQnRyoAzU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733332434; c=relaxed/simple; bh=eEil3V8vpg3oJ6G0qHOp/snMvidSP/VdhUMCcKQsQq4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=SrxciRXHWlQsl2INTwZlmqJ6KbdaotnYugysrLbfN+tBFgzRvfTcQMfHj1y1oP32FNmANAWsnj8EKo/lwHbD0E4+7/T+LUalvudScOYd6KG9lz/kw4yEASj+WUZxI8v194PCg5sJbtQnd+xHJRkcWg5QKK6auP1UmWWY7mDQzTc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=bkFwFNdc; 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="bkFwFNdc" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 98548C4CECD; Wed, 4 Dec 2024 17:13:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1733332433; bh=eEil3V8vpg3oJ6G0qHOp/snMvidSP/VdhUMCcKQsQq4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bkFwFNdczkl905yj5flFaM14F7+fdT2zWxsMjwDx6kKTkpxj8rG4gdX28rlGCgrgz w5CkQQnjCDkpcw6PPloK/nukEd+YU5rYpdEAC2+oCwWBlUsHKzBFvdRNR0qK71mTkd hsv/FqeYHTuDABB2ijf9gaC2XCwHB3pfsnRTGrWV1nQpiArweHP/F1GRXqox6E0uUp nKPScAcE7id83rk3FY/6ywiJ7lXij94VuZ410MBMH8QavStopnWqEFI51HyIt2NhAX 9gofSIYTILpYrkVTT/Z26eUsVfooOhOFG9iosfVDlD2Sa94fVD2d1NzfGHTeSeIBxR lnKrw2/6V2zjQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Defa Li , Alexandre Belloni , Sasha Levin , matthias.bgg@gmail.com, angelogioacchino.delregno@collabora.com, linux-i3c@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org Subject: [PATCH AUTOSEL 5.4 4/4] i3c: Use i3cdev->desc->info instead of calling i3c_device_get_info() to avoid deadlock Date: Wed, 4 Dec 2024 11:02:25 -0500 Message-ID: <20241204160227.2217428-4-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20241204160227.2217428-1-sashal@kernel.org> References: <20241204160227.2217428-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 5.4.286 Content-Transfer-Encoding: 8bit From: Defa Li [ Upstream commit 6cf7b65f7029914dc0cd7db86fac9ee5159008c6 ] A deadlock may happen since the i3c_master_register() acquires &i3cbus->lock twice. See the log below. Use i3cdev->desc->info instead of calling i3c_device_info() to avoid acquiring the lock twice. v2: - Modified the title and commit message ============================================ WARNING: possible recursive locking detected 6.11.0-mainline -------------------------------------------- init/1 is trying to acquire lock: f1ffff80a6a40dc0 (&i3cbus->lock){++++}-{3:3}, at: i3c_bus_normaluse_lock but task is already holding lock: f1ffff80a6a40dc0 (&i3cbus->lock){++++}-{3:3}, at: i3c_master_register other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&i3cbus->lock); lock(&i3cbus->lock); *** DEADLOCK *** May be due to missing lock nesting notation 2 locks held by init/1: #0: fcffff809b6798f8 (&dev->mutex){....}-{3:3}, at: __driver_attach #1: f1ffff80a6a40dc0 (&i3cbus->lock){++++}-{3:3}, at: i3c_master_register stack backtrace: CPU: 6 UID: 0 PID: 1 Comm: init Call trace: dump_backtrace+0xfc/0x17c show_stack+0x18/0x28 dump_stack_lvl+0x40/0xc0 dump_stack+0x18/0x24 print_deadlock_bug+0x388/0x390 __lock_acquire+0x18bc/0x32ec lock_acquire+0x134/0x2b0 down_read+0x50/0x19c i3c_bus_normaluse_lock+0x14/0x24 i3c_device_get_info+0x24/0x58 i3c_device_uevent+0x34/0xa4 dev_uevent+0x310/0x384 kobject_uevent_env+0x244/0x414 kobject_uevent+0x14/0x20 device_add+0x278/0x460 device_register+0x20/0x34 i3c_master_register_new_i3c_devs+0x78/0x154 i3c_master_register+0x6a0/0x6d4 mtk_i3c_master_probe+0x3b8/0x4d8 platform_probe+0xa0/0xe0 really_probe+0x114/0x454 __driver_probe_device+0xa0/0x15c driver_probe_device+0x3c/0x1ac __driver_attach+0xc4/0x1f0 bus_for_each_dev+0x104/0x160 driver_attach+0x24/0x34 bus_add_driver+0x14c/0x294 driver_register+0x68/0x104 __platform_driver_register+0x20/0x30 init_module+0x20/0xfe4 do_one_initcall+0x184/0x464 do_init_module+0x58/0x1ec load_module+0xefc/0x10c8 __arm64_sys_finit_module+0x238/0x33c invoke_syscall+0x58/0x10c el0_svc_common+0xa8/0xdc do_el0_svc+0x1c/0x28 el0_svc+0x50/0xac el0t_64_sync_handler+0x70/0xbc el0t_64_sync+0x1a8/0x1ac Signed-off-by: Defa Li Link: https://lore.kernel.org/r/20241107132549.25439-1-defa.li@mediatek.com Signed-off-by: Alexandre Belloni Signed-off-by: Sasha Levin --- drivers/i3c/master.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c index 02dc8e29c8280..0503f8398a86a 100644 --- a/drivers/i3c/master.c +++ b/drivers/i3c/master.c @@ -257,7 +257,8 @@ static int i3c_device_uevent(struct device *dev, struct kobj_uevent_env *env) struct i3c_device_info devinfo; u16 manuf, part, ext; - i3c_device_get_info(i3cdev, &devinfo); + if (i3cdev->desc) + devinfo = i3cdev->desc->info; manuf = I3C_PID_MANUF_ID(devinfo.pid); part = I3C_PID_PART_ID(devinfo.pid); ext = I3C_PID_EXTRA_INFO(devinfo.pid); -- 2.43.0