From patchwork Wed Oct 17 14:03:10 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anders Roxell X-Patchwork-Id: 10645687 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id E92771057 for ; Wed, 17 Oct 2018 14:03:53 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D47292B155 for ; Wed, 17 Oct 2018 14:03:53 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C7DF62B168; Wed, 17 Oct 2018 14:03:53 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_NONE autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 4DA252B155 for ; Wed, 17 Oct 2018 14:03:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-Id:Date:Subject:To :From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=3o/ZOpKDxPDGK0SIM3BUxaNPl46rCPQvTT9UrmqTlgc=; b=r58shH8fzj0vZ6 ZEkPDNWtrNng20XvILTSatqiRdSPyqa2Ej/3Jr01NFpiEhCMm0mMN5/E60tPI5uzxig5y4i8UZESQ iZIXbEEEQaS4tjwnBF9XRpPlLATuC52bml9w70iwDCLZv7RaIvV+1JSaRj6HHHIFLZBKCmFjp/9RL zk1cYu7RBv+4CIsWVAd4xH3uRx+khHfQBzfGSJLM8Vjzsy+KyW9JGzH/NK7oQHJtYykvucR43Pcy3 M3gD5c4XNDavHtYiG9MsrStzY4crgANGubm+kgk92OJxFgGjtbvQcq3n/U5wdgMqAbhTW+v7TZY6a KJ+BrBPcfCgWnB/hqHvA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gCmQK-0007SW-01; Wed, 17 Oct 2018 14:03:44 +0000 Received: from mail-lf1-x143.google.com ([2a00:1450:4864:20::143]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1gCmQB-0007QY-RC for linux-arm-kernel@lists.infradead.org; Wed, 17 Oct 2018 14:03:42 +0000 Received: by mail-lf1-x143.google.com with SMTP id x24-v6so4141179lfe.5 for ; Wed, 17 Oct 2018 07:03:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=2OVLIv4pvK4XbXbssL49o+sbDOxAj20Y8ait05owHZA=; b=gR94kALd7TJgf5KSzQ0BeBDO/KnKugVpX9MaEe+IiXNjdnMswjUbw438EFPpKm5AlY ZZ/kZg6v3/jiTOVcfi87k7bW9a6ENuj0Z9+4rG5ko1xiZhNhLgfHSb660qUcKzeTSWrk MxtQtUJwYi67/q3bWfr7p5XqoGMYBdzC9ltXQ= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=2OVLIv4pvK4XbXbssL49o+sbDOxAj20Y8ait05owHZA=; b=DPcSh8FkDFQQ9KeQy2HbR1GNS8uVmgnjKJw4UcUWFG4MRBa/U8NJ+UDDQJQSgUcRGs n6pJiD4Rt6IvmcY+upzbaOf+46ysP1hmJnSYzcp7l7NbNLDLMLYCx1WsxSttKuY5Z4+q H7nJmvs8XDHxnNOpiTWYzyYUJtr24j55XwfsSA2803YPKB1fntTzaPy7GtZk7XXg2rDW 6kU4/vhyi40FDKkgANLPgKoQqvMb96jkxzTnSAlVDPCB5iVXOH5tsI3uIn0zwTjXvwOv D9r86SStY6Prj1W0JebePIeyTr+/55XmJVdaJgS1kMk39MgiPvfE/ocHB1JPeV/k4eRq PPOw== X-Gm-Message-State: ABuFfoiLevX3ourzAcPZOKBgNmgUYN+Lxw/liNQw1rPtjJakYWuf2DPN 5FqeATfhVO2ZRPw+A4vRUoLs8g== X-Google-Smtp-Source: ACcGV63+7PHqdPWkwXKKgC0n01Ja+9wkJ/YFluFvwY90yj5/x8DubZbWZNEG4KjqPiKeWd/s8CvWew== X-Received: by 2002:a19:e013:: with SMTP id x19-v6mr15182454lfg.89.1539785003149; Wed, 17 Oct 2018 07:03:23 -0700 (PDT) Received: from localhost (c-732171d5.07-21-73746f28.bbcust.telenor.se. [213.113.33.115]) by smtp.gmail.com with ESMTPSA id y3-v6sm4093739ljy.95.2018.10.17.07.03.22 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 17 Oct 2018 07:03:22 -0700 (PDT) From: Anders Roxell To: linux@armlinux.org.uk, gregkh@linuxfoundation.org, akpm@linux-foundation.org Subject: [PATCH 1/2] serial: set suppress_bind_attrs flag only if builtin Date: Wed, 17 Oct 2018 16:03:10 +0200 Message-Id: <20181017140311.28679-1-anders.roxell@linaro.org> X-Mailer: git-send-email 2.19.1 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20181017_070335_892448_1D8EF699 X-CRM114-Status: GOOD ( 13.52 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Anders Roxell , Arnd Bergmann , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-serial@vger.kernel.org, tj@kernel.org, linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP When the test 'CONFIG_DEBUG_TEST_DRIVER_REMOVE=y' is enabled, arch_initcall(pl011_init) came before subsys_initcall(default_bdi_init). devtmpfs gets killed because we try to remove a file and decrement the wb reference count before the noop_backing_device_info gets initialized. [ 0.332075] Serial: AMBA PL011 UART driver [ 0.485276] 9000000.pl011: ttyAMA0 at MMIO 0x9000000 (irq = 39, base_baud = 0) is a PL011 rev1 [ 0.502382] console [ttyAMA0] enabled [ 0.515710] Unable to handle kernel paging request at virtual address 0000800074c12000 [ 0.516053] Mem abort info: [ 0.516222] ESR = 0x96000004 [ 0.516417] Exception class = DABT (current EL), IL = 32 bits [ 0.516641] SET = 0, FnV = 0 [ 0.516826] EA = 0, S1PTW = 0 [ 0.516984] Data abort info: [ 0.517149] ISV = 0, ISS = 0x00000004 [ 0.517339] CM = 0, WnR = 0 [ 0.517553] [0000800074c12000] user address but active_mm is swapper [ 0.517928] Internal error: Oops: 96000004 [#1] PREEMPT SMP [ 0.518305] Modules linked in: [ 0.518839] CPU: 0 PID: 13 Comm: kdevtmpfs Not tainted 4.19.0-rc5-next-20180928-00002-g2ba39ab0cd01-dirty #82 [ 0.519307] Hardware name: linux,dummy-virt (DT) [ 0.519681] pstate: 80000005 (Nzcv daif -PAN -UAO) [ 0.519959] pc : __destroy_inode+0x94/0x2a8 [ 0.520212] lr : __destroy_inode+0x78/0x2a8 [ 0.520401] sp : ffff0000098c3b20 [ 0.520590] x29: ffff0000098c3b20 x28: 00000000087a3714 [ 0.520904] x27: 0000000000002000 x26: 0000000000002000 [ 0.521179] x25: ffff000009583000 x24: 0000000000000000 [ 0.521467] x23: ffff80007bb52000 x22: ffff80007bbaa7c0 [ 0.521737] x21: ffff0000093f9338 x20: 0000000000000000 [ 0.522033] x19: ffff80007bbb05d8 x18: 0000000000000400 [ 0.522376] x17: 0000000000000000 x16: 0000000000000000 [ 0.522727] x15: 0000000000000400 x14: 0000000000000400 [ 0.523068] x13: 0000000000000001 x12: 0000000000000001 [ 0.523421] x11: 0000000000000000 x10: 0000000000000970 [ 0.523749] x9 : ffff0000098c3a60 x8 : ffff80007bbab190 [ 0.524017] x7 : ffff80007bbaa880 x6 : 0000000000000c88 [ 0.524305] x5 : ffff0000093d96c8 x4 : 61c8864680b583eb [ 0.524567] x3 : ffff0000093d6180 x2 : ffffffffffffffff [ 0.524872] x1 : 0000800074c12000 x0 : 0000800074c12000 [ 0.525207] Process kdevtmpfs (pid: 13, stack limit = 0x(____ptrval____)) [ 0.525529] Call trace: [ 0.525806] __destroy_inode+0x94/0x2a8 [ 0.526108] destroy_inode+0x34/0x88 [ 0.526370] evict+0x144/0x1c8 [ 0.526636] iput+0x184/0x230 [ 0.526871] dentry_unlink_inode+0x118/0x130 [ 0.527152] d_delete+0xd8/0xe0 [ 0.527420] vfs_unlink+0x240/0x270 [ 0.527665] handle_remove+0x1d8/0x330 [ 0.527875] devtmpfsd+0x138/0x1c8 [ 0.528085] kthread+0x14c/0x158 [ 0.528291] ret_from_fork+0x10/0x18 [ 0.528720] Code: 92800002 aa1403e0 d538d081 8b010000 (c85f7c04) [ 0.529367] ---[ end trace 5a3dee47727f877c ]--- Rework to set suppress_bind_attrs flag to avoid removing the device when CONFIG_DEBUG_TEST_DRIVER_REMOVE=y. This applies for pic32_uart and xilinx_uartps as well. Cc: Arnd Bergmann Co-developed-by: Arnd Bergmann Signed-off-by: Anders Roxell --- drivers/tty/serial/amba-pl011.c | 2 ++ drivers/tty/serial/pic32_uart.c | 1 + drivers/tty/serial/xilinx_uartps.c | 1 + 3 files changed, 4 insertions(+) diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c index ebd33c0232e6..89ade213a1a9 100644 --- a/drivers/tty/serial/amba-pl011.c +++ b/drivers/tty/serial/amba-pl011.c @@ -2780,6 +2780,7 @@ static struct platform_driver arm_sbsa_uart_platform_driver = { .name = "sbsa-uart", .of_match_table = of_match_ptr(sbsa_uart_of_match), .acpi_match_table = ACPI_PTR(sbsa_uart_acpi_match), + .suppress_bind_attrs = IS_BUILTIN(CONFIG_SERIAL_AMBA_PL011), }, }; @@ -2808,6 +2809,7 @@ static struct amba_driver pl011_driver = { .drv = { .name = "uart-pl011", .pm = &pl011_dev_pm_ops, + .suppress_bind_attrs = IS_BUILTIN(CONFIG_SERIAL_AMBA_PL011), }, .id_table = pl011_ids, .probe = pl011_probe, diff --git a/drivers/tty/serial/pic32_uart.c b/drivers/tty/serial/pic32_uart.c index fd80d999308d..0bdf1687983f 100644 --- a/drivers/tty/serial/pic32_uart.c +++ b/drivers/tty/serial/pic32_uart.c @@ -919,6 +919,7 @@ static struct platform_driver pic32_uart_platform_driver = { .driver = { .name = PIC32_DEV_NAME, .of_match_table = of_match_ptr(pic32_serial_dt_ids), + .suppress_bind_attrs = IS_BUILTIN(CONFIG_SERIAL_PIC32), }, }; diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c index 0e3dae461f71..806a953ac8d4 100644 --- a/drivers/tty/serial/xilinx_uartps.c +++ b/drivers/tty/serial/xilinx_uartps.c @@ -1717,6 +1717,7 @@ static struct platform_driver cdns_uart_platform_driver = { .name = CDNS_UART_NAME, .of_match_table = cdns_uart_of_match, .pm = &cdns_uart_dev_pm_ops, + .suppress_bind_attrs = IS_BUILTIN(CONFIG_SERIAL_XILINX_PS_UART), }, }; From patchwork Wed Oct 17 14:03:11 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anders Roxell X-Patchwork-Id: 10645691 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 28DD71057 for ; Wed, 17 Oct 2018 14:04:27 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 135EC2B13B for ; 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[213.113.33.115]) by smtp.gmail.com with ESMTPSA id o101-v6sm3931820lfg.53.2018.10.17.07.03.32 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 17 Oct 2018 07:03:32 -0700 (PDT) From: Anders Roxell To: linux@armlinux.org.uk, gregkh@linuxfoundation.org, akpm@linux-foundation.org Subject: [PATCH 2/2] writeback: don't decrement wb->refcnt if !wb->bdi Date: Wed, 17 Oct 2018 16:03:11 +0200 Message-Id: <20181017140311.28679-2-anders.roxell@linaro.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181017140311.28679-1-anders.roxell@linaro.org> References: <20181017140311.28679-1-anders.roxell@linaro.org> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20181017_070345_109892_0785DB53 X-CRM114-Status: GOOD ( 16.27 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Anders Roxell , Arnd Bergmann , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-serial@vger.kernel.org, tj@kernel.org, linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP When enabling CONFIG_DEBUG_TEST_DRIVER_REMOVE devtmpfs gets killed because we try to remove a file and decrement the wb reference count before the noop_backing_device_info gets initialized. Since arch_initcall(pl011_init) came before subsys_initcall(default_bdi_init), devtmpfs' handle_remove() crashes because the reference count is a NULL pointer only because bdi->wb hasn't been initialized yet. [ 0.332075] Serial: AMBA PL011 UART driver [ 0.485276] 9000000.pl011: ttyAMA0 at MMIO 0x9000000 (irq = 39, base_baud = 0) is a PL011 rev1 [ 0.502382] console [ttyAMA0] enabled [ 0.515710] Unable to handle kernel paging request at virtual address 0000800074c12000 [ 0.516053] Mem abort info: [ 0.516222] ESR = 0x96000004 [ 0.516417] Exception class = DABT (current EL), IL = 32 bits [ 0.516641] SET = 0, FnV = 0 [ 0.516826] EA = 0, S1PTW = 0 [ 0.516984] Data abort info: [ 0.517149] ISV = 0, ISS = 0x00000004 [ 0.517339] CM = 0, WnR = 0 [ 0.517553] [0000800074c12000] user address but active_mm is swapper [ 0.517928] Internal error: Oops: 96000004 [#1] PREEMPT SMP [ 0.518305] Modules linked in: [ 0.518839] CPU: 0 PID: 13 Comm: kdevtmpfs Not tainted 4.19.0-rc5-next-20180928-00002-g2ba39ab0cd01-dirty #82 [ 0.519307] Hardware name: linux,dummy-virt (DT) [ 0.519681] pstate: 80000005 (Nzcv daif -PAN -UAO) [ 0.519959] pc : __destroy_inode+0x94/0x2a8 [ 0.520212] lr : __destroy_inode+0x78/0x2a8 [ 0.520401] sp : ffff0000098c3b20 [ 0.520590] x29: ffff0000098c3b20 x28: 00000000087a3714 [ 0.520904] x27: 0000000000002000 x26: 0000000000002000 [ 0.521179] x25: ffff000009583000 x24: 0000000000000000 [ 0.521467] x23: ffff80007bb52000 x22: ffff80007bbaa7c0 [ 0.521737] x21: ffff0000093f9338 x20: 0000000000000000 [ 0.522033] x19: ffff80007bbb05d8 x18: 0000000000000400 [ 0.522376] x17: 0000000000000000 x16: 0000000000000000 [ 0.522727] x15: 0000000000000400 x14: 0000000000000400 [ 0.523068] x13: 0000000000000001 x12: 0000000000000001 [ 0.523421] x11: 0000000000000000 x10: 0000000000000970 [ 0.523749] x9 : ffff0000098c3a60 x8 : ffff80007bbab190 [ 0.524017] x7 : ffff80007bbaa880 x6 : 0000000000000c88 [ 0.524305] x5 : ffff0000093d96c8 x4 : 61c8864680b583eb [ 0.524567] x3 : ffff0000093d6180 x2 : ffffffffffffffff [ 0.524872] x1 : 0000800074c12000 x0 : 0000800074c12000 [ 0.525207] Process kdevtmpfs (pid: 13, stack limit = 0x(____ptrval____)) [ 0.525529] Call trace: [ 0.525806] __destroy_inode+0x94/0x2a8 [ 0.526108] destroy_inode+0x34/0x88 [ 0.526370] evict+0x144/0x1c8 [ 0.526636] iput+0x184/0x230 [ 0.526871] dentry_unlink_inode+0x118/0x130 [ 0.527152] d_delete+0xd8/0xe0 [ 0.527420] vfs_unlink+0x240/0x270 [ 0.527665] handle_remove+0x1d8/0x330 [ 0.527875] devtmpfsd+0x138/0x1c8 [ 0.528085] kthread+0x14c/0x158 [ 0.528291] ret_from_fork+0x10/0x18 [ 0.528720] Code: 92800002 aa1403e0 d538d081 8b010000 (c85f7c04) [ 0.529367] ---[ end trace 5a3dee47727f877c ]--- Rework so that wb_put have an extra check if wb->bdi before decrement wb->refcnt and also add a WARN_ON to get a warning if it happens again in other drivers. Fixes: 52ebea749aae ("writeback: make backing_dev_info host cgroup-specific bdi_writebacks") Cc: Arnd Bergmann Co-developed-by: Arnd Bergmann Signed-off-by: Anders Roxell Signed-off-by: Arnd, please. --- include/linux/backing-dev-defs.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/linux/backing-dev-defs.h b/include/linux/backing-dev-defs.h index 9a6bc0951cfa..20721550d32a 100644 --- a/include/linux/backing-dev-defs.h +++ b/include/linux/backing-dev-defs.h @@ -258,7 +258,7 @@ static inline void wb_get(struct bdi_writeback *wb) */ static inline void wb_put(struct bdi_writeback *wb) { - if (wb != &wb->bdi->wb) + if (!WARN_ON(!wb->bdi) && wb != &wb->bdi->wb) percpu_ref_put(&wb->refcnt); }