4.9-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit 646097940ad35aa2c1f2012af932d55976a9f255 ]
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.
Co-developed-by: Arnd Bergmann arnd@arndb.de Signed-off-by: Arnd Bergmann arnd@arndb.de Signed-off-by: Anders Roxell anders.roxell@linaro.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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 41b0dd67fcce..2d8089fc2139 100644 --- a/drivers/tty/serial/amba-pl011.c +++ b/drivers/tty/serial/amba-pl011.c @@ -2712,6 +2712,7 @@ 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), }, };
@@ -2740,6 +2741,7 @@ 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 7f8e99bbcb73..fb77d55a8d95 100644 --- a/drivers/tty/serial/pic32_uart.c +++ b/drivers/tty/serial/pic32_uart.c @@ -920,6 +920,7 @@ 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 fcf2e51f2cfe..7333d64f68f2 100644 --- a/drivers/tty/serial/xilinx_uartps.c +++ b/drivers/tty/serial/xilinx_uartps.c @@ -1602,6 +1602,7 @@ 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), }, };