From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lj1-f199.google.com (mail-lj1-f199.google.com [209.85.208.199]) by kanga.kvack.org (Postfix) with ESMTP id 1D4EA6B000A for ; Wed, 17 Oct 2018 10:03:26 -0400 (EDT) Received: by mail-lj1-f199.google.com with SMTP id v62-v6so7721502lje.9 for ; Wed, 17 Oct 2018 07:03:26 -0700 (PDT) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id s81-v6sor3309457lfs.47.2018.10.17.07.03.23 for (Google Transport Security); Wed, 17 Oct 2018 07:03:23 -0700 (PDT) From: Anders Roxell 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> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org List-ID: To: linux@armlinux.org.uk, gregkh@linuxfoundation.org, akpm@linux-foundation.org Cc: linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, tj@kernel.org, Anders Roxell , Arnd Bergmann 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), }, }; -- 2.19.1