commit aff9cf5955185d1f183227e46c5f8673fa483813 upstream.
We were experiencing a crash similar to the one reported as part of
commit:a5ba1d95e46e ("uart: fix race between uart_put_char() and
uart_shutdown()") in our testbed as well. We continue to observe the same
crash after integrating the commit a5ba1d95e46e ("uart: fix race between
uart_put_char() and uart_shutdown()")
On reviewing the change, the port lock should be taken prior to checking for
if (!circ->buf) in fn. __uart_put_char and other fns. that update the buffer
uart_state->xmit.
Traceback:
[11/27/2018 06:24:32.4870] Unable to handle kernel NULL pointer dereference
at virtual address 0000003b
[11/27/2018 06:24:32.4950] PC is at memcpy+0x48/0x180
[11/27/2018 06:24:32.4950] LR is at uart_write+0x74/0x120
[11/27/2018 06:24:32.4950] pc : [<ffffffc0002e6808>]
lr : [<ffffffc0003747cc>] pstate: 000001c5
[11/27/2018 06:24:32.4950] sp : ffffffc076433d30
[11/27/2018 06:24:32.4950] x29: ffffffc076433d30 x28: 0000000000000140
[11/27/2018 06:24:32.4950] x27: ffffffc0009b9d5e x26: ffffffc07ce36580
[11/27/2018 06:24:32.4950] x25: 0000000000000000 x24: 0000000000000140
[11/27/2018 06:24:32.4950] x23: ffffffc000891200 x22: ffffffc01fc34000
[11/27/2018 06:24:32.4950] x21: 0000000000000fff x20: 0000000000000076
[11/27/2018 06:24:32.4950] x19: 0000000000000076 x18: 0000000000000000
[11/27/2018 06:24:32.4950] x17: 000000000047cf08 x16: ffffffc000099e68
[11/27/2018 06:24:32.4950] x15: 0000000000000018 x14: 776d726966205948
[11/27/2018 06:24:32.4950] x13: 50203a6c6974755f x12: 74647075205d3333
[11/27/2018 06:24:32.4950] x11: 3a35323a36203831 x10: 30322f37322f3131
[11/27/2018 06:24:32.4950] x9 : 5b205d303638342e x8 : 746164206f742070
[11/27/2018 06:24:32.4950] x7 : 7520736920657261 x6 : 000000000000003b
[11/27/2018 06:24:32.4950] x5 : 000000000000817a x4 : 0000000000000008
[11/27/2018 06:24:32.4950] x3 : 2f37322f31312a5b x2 : 000000000000006e
[11/27/2018 06:24:32.4950] x1 : ffffffc0009b9cf0 x0 : 000000000000003b
[11/27/2018 06:24:32.4950] CPU2: stopping
[11/27/2018 06:24:32.4950] CPU: 2 PID: 0 Comm: swapper/2 Tainted: P D O 4.1.51 #3
[11/27/2018 06:24:32.4950] Hardware name: Broadcom-v8A (DT)
[11/27/2018 06:24:32.4950] Call trace:
[11/27/2018 06:24:32.4950] [<ffffffc0000883b8>] dump_backtrace+0x0/0x150
[11/27/2018 06:24:32.4950] [<ffffffc00008851c>] show_stack+0x14/0x20
[11/27/2018 06:24:32.4950] [<ffffffc0005ee810>] dump_stack+0x90/0xb0
[11/27/2018 06:24:32.4950] [<ffffffc00008e844>] handle_IPI+0x18c/0x1a0
[11/27/2018 06:24:32.4950] [<ffffffc000080c68>] gic_handle_irq+0x88/0x90
Fixes: a5ba1d95e46e ("uart: fix race between uart_put_char() and uart_shutdown()")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Samir Virmani <samir@embedur.com>
Acked-by: Tycho Andersen <tycho@tycho.ws>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit d72402145ace0697a6a9e8e75a3de5bf3375f78d ]
LKP has hit yet another circular locking dependency between uart
console drivers and debugobjects [1]:
CPU0 CPU1
rhltable_init()
__init_work()
debug_object_init
uart_shutdown() /* db->lock */
/* uart_port->lock */ debug_print_object()
free_page() printk()
call_console_drivers()
debug_check_no_obj_freed() /* uart_port->lock */
/* db->lock */
debug_print_object()
So there are two dependency chains:
uart_port->lock -> db->lock
And
db->lock -> uart_port->lock
This particular circular locking dependency can be addressed in several
ways:
a) One way would be to move debug_print_object() out of db->lock scope
and, thus, break the db->lock -> uart_port->lock chain.
b) Another one would be to free() transmit buffer page out of db->lock
in UART code; which is what this patch does.
It makes sense to apply a) and b) independently: there are too many things
going on behind free(), none of which depend on uart_port->lock.
The patch fixes transmit buffer page free() in uart_shutdown() and,
additionally, in uart_port_startup() (as was suggested by Dmitry Safonov).
[1] https://lore.kernel.org/lkml/20181211091154.GL23332@shao2-debian/T/#u
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Waiman Long <longman@redhat.com>
Cc: Dmitry Safonov <dima@arista.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ 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>
commit 260683137ab5276113fc322fdbbc578024185fee upstream.
This patch Correct the RX interrupt mask value to handle the
RX interrupts properly.
Fixes: c8dbdc842d30 ("serial: xuartps: Rewrite the interrupt handling logic")
Signed-off-by: Nava kishore Manne <nava.manne@xilinx.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull sparc fixes from David Miller: "Just some small fixes here and there, and a refcount leak in a serial driver, nothing serious" * git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc: serial/sunsu: fix refcount leak sparc: Set "ARCH: sunxx" information on the same line sparc: vdso: Drop implicit common-page-size linker flag
The function of_find_node_by_path() acquires a reference to the node returned by it and that reference needs to be dropped by its caller. su_get_type() doesn't do that. The match node are used as an identifier to compare against the current node, so we can directly drop the refcount after getting the node from the path as it is not used as pointer. Fix this by use a single variable and drop the refcount right after of_find_node_by_path(). Signed-off-by: Yangtao Li <tiny.windzz@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Commit f6aa5beb45be ("serial: 8250: Fix clearing FIFOs in RS485 mode
again") makes a change to FIFO clearing code which its commit message
suggests was intended to be specific to use with RS485 mode, however:
1) The change made does not just affect __do_stop_tx_rs485(), it also
affects other uses of serial8250_clear_fifos() including paths for
starting up, shutting down or auto-configuring a port regardless of
whether it's an RS485 port or not.
2) It makes the assumption that resetting the FIFOs is a no-op when
FIFOs are disabled, and as such it checks for this case & explicitly
avoids setting the FIFO reset bits when the FIFO enable bit is
clear. A reading of the PC16550D manual would suggest that this is
OK since the FIFO should automatically be reset if it is later
enabled, but we support many 16550-compatible devices and have never
required this auto-reset behaviour for at least the whole git era.
Starting to rely on it now seems risky, offers no benefit, and
indeed breaks at least the Ingenic JZ4780's UARTs which reads
garbage when the RX FIFO is enabled if we don't explicitly reset it.
3) By only resetting the FIFOs if they're enabled, the behaviour of
serial8250_do_startup() during boot now depends on what the value of
FCR is before the 8250 driver is probed. This in itself seems
questionable and leaves us with FCR=0 & no FIFO reset if the UART
was used by 8250_early, otherwise it depends upon what the
bootloader left behind.
4) Although the naming of serial8250_clear_fifos() may be unclear, it
is clear that callers of it expect that it will disable FIFOs. Both
serial8250_do_startup() & serial8250_do_shutdown() contain comments
to that effect, and other callers explicitly re-enable the FIFOs
after calling serial8250_clear_fifos(). The premise of that patch
that disabling the FIFOs is incorrect therefore seems wrong.
For these reasons, this reverts commit f6aa5beb45be ("serial: 8250: Fix
clearing FIFOs in RS485 mode again").
Signed-off-by: Paul Burton <paul.burton@mips.com>
Fixes: f6aa5beb45be ("serial: 8250: Fix clearing FIFOs in RS485 mode again").
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Daniel Jedrychowski <avistel@gmail.com>
Cc: Marek Vasut <marex@denx.de>
Cc: linux-mips@vger.kernel.org
Cc: linux-serial@vger.kernel.org
Cc: stable <stable@vger.kernel.org> # 4.10+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull tty driver fixes from Greg KH: "Here are three small tty driver fixes for 4.20-rc6 Nothing major, just some bug fixes for reported issues. Full details are in the shortlog. All of these have been in linux-next for a while with no reported issues" * tag 'tty-4.20-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: kgdboc: fix KASAN global-out-of-bounds bug in param_set_kgdboc_var() tty: serial: 8250_mtk: always resume the device in probe. tty: do not set TTY_IO_ERROR flag if console port
This patch is trying to fix KE issue due to "BUG: KASAN: global-out-of-bounds in param_set_kgdboc_var+0x194/0x198" reported by Syzkaller scan." [26364:syz-executor0][name:report8t]BUG: KASAN: global-out-of-bounds in param_set_kgdboc_var+0x194/0x198 [26364:syz-executor0][name:report&]Read of size 1 at addr ffffff900e44f95f by task syz-executor0/26364 [26364:syz-executor0][name:report&] [26364:syz-executor0]CPU: 7 PID: 26364 Comm: syz-executor0 Tainted: G W 0 [26364:syz-executor0]Call trace: [26364:syz-executor0][<ffffff9008095cf8>] dump_bacIctrace+Ox0/0x470 [26364:syz-executor0][<ffffff9008096de0>] show_stack+0x20/0x30 [26364:syz-executor0][<ffffff90089cc9c8>] dump_stack+Oxd8/0x128 [26364:syz-executor0][<ffffff90084edb38>] print_address_description +0x80/0x4a8 [26364:syz-executor0][<ffffff90084ee270>] kasan_report+Ox178/0x390 [26364:syz-executor0][<ffffff90084ee4a0>] _asan_report_loadi_noabort+Ox18/0x20 [26364:syz-executor0][<ffffff9008b092ac>] param_set_kgdboc_var+Ox194/0x198 [26364:syz-executor0][<ffffff900813af64>] param_attr_store+Ox14c/0x270 [26364:syz-executor0][<ffffff90081394c8>] module_attr_store+0x60/0x90 [26364:syz-executor0][<ffffff90086690c0>] sysfs_kl_write+Ox100/0x158 [26364:syz-executor0][<ffffff9008666d84>] kernfs_fop_write+0x27c/0x3a8 [26364:syz-executor0][<ffffff9008508264>] do_loop_readv_writev+0x114/0x1b0 [26364:syz-executor0][<ffffff9008509ac8>] do_readv_writev+0x4f8/0x5e0 [26364:syz-executor0][<ffffff9008509ce4>] vfs_writev+0x7c/Oxb8 [26364:syz-executor0][<ffffff900850ba64>] SyS_writev+Oxcc/0x208 [26364:syz-executor0][<ffffff90080883f0>] elO_svc_naked +0x24/0x28 [26364:syz-executor0][name:report&] [26364:syz-executor0][name:report&]The buggy address belongs to the variable: [26364:syz-executor0][name:report&] kgdb_tty_line+Ox3f/0x40 [26364:syz-executor0][name:report&] [26364:syz-executor0][name:report&]Memory state around the buggy address: [26364:syz-executor0] ffffff900e44f800: 00 00 00 00 00 04 fa fa fa fa fa fa 00 fa fa fa [26364:syz-executor0] ffffff900e44f880: fa fa fa fa 00 fa fa fa fa fa fa fa 00 fa fa fa [26364:syz-executor0]> ffffff900e44f900: fa fa fa fa 04 fa fa fa fa fa fa fa 00 00 00 00 [26364:syz-executor0][name:report&] ^ [26364:syz-executor0] ffffff900e44f980: 00 fa fa fa fa fa fa fa 04 fa fa fa fa fa fa fa [26364:syz-executor0] ffffff900e44fa00: 04 fa fa fa fa fa fa fa 00 fa fa fa fa fa fa fa [26364:syz-executor0][name:report&] [26364:syz-executor0][name:panic&]Disabling lock debugging due to kernel taint [26364:syz-executor0]------------[cut here]------------ After checking the source code, we've found there might be an out-of-bounds access to "config[len - 1]" array when the variable "len" is zero. Signed-off-by: Macpaul Lin <macpaul@gmail.com> Acked-by: Daniel Thompson <daniel.thompson@linaro.org> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
serial8250_register_8250_port calls uart_config_port, which calls
config_port on the port before it tries to power on the port. So we need
the port to be on before calling serial8250_register_8250_port. Change
the code to always do a runtime resume in probe before registering port,
and always do a runtime suspend in remove.
This basically reverts the change in commit 68e5fc4a255a ("tty: serial:
8250_mtk: use pm_runtime callbacks for enabling"), but still use
pm_runtime callbacks.
Fixes: 68e5fc4a255a ("tty: serial: 8250_mtk: use pm_runtime callbacks for enabling")
Signed-off-by: Peter Shih <pihsun@chromium.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>