From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org,
Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
Guenter Roeck <linux@roeck-us.net>,
Raul Rangel <rrangel@google.com>,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Subject: [PATCH 4.4 46/62] serial: 8250: change lock order in serial8250_do_startup()
Date: Tue, 1 Sep 2020 17:10:29 +0200 [thread overview]
Message-ID: <20200901150923.043994558@linuxfoundation.org> (raw)
In-Reply-To: <20200901150920.697676718@linuxfoundation.org>
From: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
commit 205d300aea75623e1ae4aa43e0d265ab9cf195fd upstream.
We have a number of "uart.port->desc.lock vs desc.lock->uart.port"
lockdep reports coming from 8250 driver; this causes a bit of trouble
to people, so let's fix it.
The problem is reverse lock order in two different call paths:
chain #1:
serial8250_do_startup()
spin_lock_irqsave(&port->lock);
disable_irq_nosync(port->irq);
raw_spin_lock_irqsave(&desc->lock)
chain #2:
__report_bad_irq()
raw_spin_lock_irqsave(&desc->lock)
for_each_action_of_desc()
printk()
spin_lock_irqsave(&port->lock);
Fix this by changing the order of locks in serial8250_do_startup():
do disable_irq_nosync() first, which grabs desc->lock, and grab
uart->port after that, so that chain #1 and chain #2 have same lock
order.
Full lockdep splat:
======================================================
WARNING: possible circular locking dependency detected
5.4.39 #55 Not tainted
======================================================
swapper/0/0 is trying to acquire lock:
ffffffffab65b6c0 (console_owner){-...}, at: console_lock_spinning_enable+0x31/0x57
but task is already holding lock:
ffff88810a8e34c0 (&irq_desc_lock_class){-.-.}, at: __report_bad_irq+0x5b/0xba
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (&irq_desc_lock_class){-.-.}:
_raw_spin_lock_irqsave+0x61/0x8d
__irq_get_desc_lock+0x65/0x89
__disable_irq_nosync+0x3b/0x93
serial8250_do_startup+0x451/0x75c
uart_startup+0x1b4/0x2ff
uart_port_activate+0x73/0xa0
tty_port_open+0xae/0x10a
uart_open+0x1b/0x26
tty_open+0x24d/0x3a0
chrdev_open+0xd5/0x1cc
do_dentry_open+0x299/0x3c8
path_openat+0x434/0x1100
do_filp_open+0x9b/0x10a
do_sys_open+0x15f/0x3d7
kernel_init_freeable+0x157/0x1dd
kernel_init+0xe/0x105
ret_from_fork+0x27/0x50
-> #1 (&port_lock_key){-.-.}:
_raw_spin_lock_irqsave+0x61/0x8d
serial8250_console_write+0xa7/0x2a0
console_unlock+0x3b7/0x528
vprintk_emit+0x111/0x17f
printk+0x59/0x73
register_console+0x336/0x3a4
uart_add_one_port+0x51b/0x5be
serial8250_register_8250_port+0x454/0x55e
dw8250_probe+0x4dc/0x5b9
platform_drv_probe+0x67/0x8b
really_probe+0x14a/0x422
driver_probe_device+0x66/0x130
device_driver_attach+0x42/0x5b
__driver_attach+0xca/0x139
bus_for_each_dev+0x97/0xc9
bus_add_driver+0x12b/0x228
driver_register+0x64/0xed
do_one_initcall+0x20c/0x4a6
do_initcall_level+0xb5/0xc5
do_basic_setup+0x4c/0x58
kernel_init_freeable+0x13f/0x1dd
kernel_init+0xe/0x105
ret_from_fork+0x27/0x50
-> #0 (console_owner){-...}:
__lock_acquire+0x118d/0x2714
lock_acquire+0x203/0x258
console_lock_spinning_enable+0x51/0x57
console_unlock+0x25d/0x528
vprintk_emit+0x111/0x17f
printk+0x59/0x73
__report_bad_irq+0xa3/0xba
note_interrupt+0x19a/0x1d6
handle_irq_event_percpu+0x57/0x79
handle_irq_event+0x36/0x55
handle_fasteoi_irq+0xc2/0x18a
do_IRQ+0xb3/0x157
ret_from_intr+0x0/0x1d
cpuidle_enter_state+0x12f/0x1fd
cpuidle_enter+0x2e/0x3d
do_idle+0x1ce/0x2ce
cpu_startup_entry+0x1d/0x1f
start_kernel+0x406/0x46a
secondary_startup_64+0xa4/0xb0
other info that might help us debug this:
Chain exists of:
console_owner --> &port_lock_key --> &irq_desc_lock_class
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&irq_desc_lock_class);
lock(&port_lock_key);
lock(&irq_desc_lock_class);
lock(console_owner);
*** DEADLOCK ***
2 locks held by swapper/0/0:
#0: ffff88810a8e34c0 (&irq_desc_lock_class){-.-.}, at: __report_bad_irq+0x5b/0xba
#1: ffffffffab65b5c0 (console_lock){+.+.}, at: console_trylock_spinning+0x20/0x181
stack backtrace:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.4.39 #55
Hardware name: XXXXXX
Call Trace:
<IRQ>
dump_stack+0xbf/0x133
? print_circular_bug+0xd6/0xe9
check_noncircular+0x1b9/0x1c3
__lock_acquire+0x118d/0x2714
lock_acquire+0x203/0x258
? console_lock_spinning_enable+0x31/0x57
console_lock_spinning_enable+0x51/0x57
? console_lock_spinning_enable+0x31/0x57
console_unlock+0x25d/0x528
? console_trylock+0x18/0x4e
vprintk_emit+0x111/0x17f
? lock_acquire+0x203/0x258
printk+0x59/0x73
__report_bad_irq+0xa3/0xba
note_interrupt+0x19a/0x1d6
handle_irq_event_percpu+0x57/0x79
handle_irq_event+0x36/0x55
handle_fasteoi_irq+0xc2/0x18a
do_IRQ+0xb3/0x157
common_interrupt+0xf/0xf
</IRQ>
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Fixes: 768aec0b5bcc ("serial: 8250: fix shared interrupts issues with SMP and RT kernels")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Reported-by: Raul Rangel <rrangel@google.com>
BugLink: https://bugs.chromium.org/p/chromium/issues/detail?id=1114800
Link: https://lore.kernel.org/lkml/CAHQZ30BnfX+gxjPm1DUd5psOTqbyDh4EJE=2=VAMW_VDafctkA@mail.gmail.com/T/#u
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200817022646.1484638-1-sergey.senozhatsky@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/tty/serial/8250/8250_port.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -1902,6 +1902,10 @@ int serial8250_do_startup(struct uart_po
if (port->irq) {
unsigned char iir1;
+
+ if (port->irqflags & IRQF_SHARED)
+ disable_irq_nosync(port->irq);
+
/*
* Test for UARTs that do not reassert THRE when the
* transmitter is idle and the interrupt has already
@@ -1911,8 +1915,6 @@ int serial8250_do_startup(struct uart_po
* allow register changes to become visible.
*/
spin_lock_irqsave(&port->lock, flags);
- if (up->port.irqflags & IRQF_SHARED)
- disable_irq_nosync(port->irq);
wait_for_xmitr(up, UART_LSR_THRE);
serial_port_out_sync(port, UART_IER, UART_IER_THRI);
@@ -1924,9 +1926,10 @@ int serial8250_do_startup(struct uart_po
iir = serial_port_in(port, UART_IIR);
serial_port_out(port, UART_IER, 0);
+ spin_unlock_irqrestore(&port->lock, flags);
+
if (port->irqflags & IRQF_SHARED)
enable_irq(port->irq);
- spin_unlock_irqrestore(&port->lock, flags);
/*
* If the interrupt is not reasserted, or we otherwise
next prev parent reply other threads:[~2020-09-01 17:19 UTC|newest]
Thread overview: 70+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-01 15:09 [PATCH 4.4 00/62] 4.4.235-rc1 review Greg Kroah-Hartman
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2020-09-01 15:09 ` [PATCH 4.4 02/62] tipc: fix uninit skb->data in tipc_nl_compat_dumpit() Greg Kroah-Hartman
2020-09-01 15:09 ` [PATCH 4.4 03/62] ipvlan: fix device features Greg Kroah-Hartman
2020-09-01 15:09 ` [PATCH 4.4 04/62] bonding: show saner speed for broadcast mode Greg Kroah-Hartman
2020-09-01 15:09 ` [PATCH 4.4 05/62] bonding: fix a potential double-unregister Greg Kroah-Hartman
2020-09-01 15:09 ` [PATCH 4.4 06/62] powerpc/pseries: Do not initiate shutdown when system is running on UPS Greg Kroah-Hartman
2020-09-01 15:09 ` [PATCH 4.4 07/62] ALSA: pci: delete repeated words in comments Greg Kroah-Hartman
2020-09-01 15:09 ` [PATCH 4.4 08/62] ASoC: tegra: Fix reference count leaks Greg Kroah-Hartman
2020-09-01 15:09 ` [PATCH 4.4 09/62] media: pci: ttpci: av7110: fix possible buffer overflow caused by bad DMA value in debiirq() Greg Kroah-Hartman
2020-09-01 15:09 ` [PATCH 4.4 10/62] scsi: target: tcmu: Fix crash on ARM during cmd completion Greg Kroah-Hartman
2020-09-01 15:09 ` [PATCH 4.4 11/62] drm/amdkfd: Fix reference count leaks Greg Kroah-Hartman
2020-09-01 15:09 ` [PATCH 4.4 12/62] drm/radeon: fix multiple reference count leak Greg Kroah-Hartman
2020-09-01 15:09 ` [PATCH 4.4 13/62] drm/amdgpu: fix ref count leak in amdgpu_driver_open_kms Greg Kroah-Hartman
2020-09-01 15:09 ` [PATCH 4.4 14/62] drm/amd/display: fix ref count leak in amdgpu_drm_ioctl Greg Kroah-Hartman
2020-09-01 15:09 ` [PATCH 4.4 15/62] drm/amdgpu: fix ref count leak in amdgpu_display_crtc_set_config Greg Kroah-Hartman
2020-09-01 15:09 ` [PATCH 4.4 16/62] drm/amdgpu/display: fix ref count leak when pm_runtime_get_sync fails Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.4 17/62] scsi: lpfc: Fix shost refcount mismatch when deleting vport Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.4 18/62] selftests/powerpc: Purge extra count_pmc() calls of ebb selftests Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.4 19/62] PCI: Fix pci_create_slot() reference count leak Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.4 20/62] rtlwifi: rtl8192cu: Prevent leaking urb Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.4 21/62] mips/vdso: Fix resource leaks in genvdso.c Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.4 22/62] drm/nouveau/drm/noveau: fix reference count leak in nouveau_fbcon_open Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.4 23/62] drm/nouveau: Fix reference count leak in nouveau_connector_detect Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.4 24/62] locking/lockdep: Fix overflow in presentation of average lock-time Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.4 25/62] scsi: iscsi: Do not put host in iscsi_set_flashnode_param() Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.4 26/62] ceph: fix potential mdsc use-after-free crash Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.4 27/62] scsi: fcoe: Memory leak fix in fcoe_sysfs_fcf_del() Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.4 28/62] EDAC/ie31200: Fallback if host bridge device is already initialized Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.4 29/62] media: davinci: vpif_capture: fix potential double free Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.4 30/62] powerpc/spufs: add CONFIG_COREDUMP dependency Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.4 31/62] USB: sisusbvga: Fix a potential UB casued by left shifting a negative value Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.4 32/62] Revert "ath10k: fix DMA related firmware crashes on multiple devices" Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.4 33/62] i2c: rcar: in slave mode, clear NACK earlier Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.4 34/62] jbd2: make sure jh have b_transaction set in refile/unfile_buffer Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.4 35/62] jbd2: abort journal if free a async write error metadata buffer Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.4 36/62] s390/cio: add cond_resched() in the slow_eval_known_fn() loop Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.4 37/62] scsi: ufs: Fix possible infinite loop in ufshcd_hold Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.4 38/62] net: gianfar: Add of_node_put() before goto statement Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.4 39/62] powerpc/perf: Fix soft lockups due to missed interrupt accounting Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.4 40/62] fbcon: prevent user font height or width change from causing potential out-of-bounds access Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.4 41/62] USB: lvtest: return proper error code in probe Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.4 42/62] vt: defer kfree() of vc_screenbuf in vc_do_resize() Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.4 43/62] vt_ioctl: change VT_RESIZEX ioctl to check for error return from vc_resize() Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.4 44/62] serial: samsung: Removes the IRQ not found warning Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.4 45/62] serial: pl011: Dont leak amba_ports entry on driver register error Greg Kroah-Hartman
2020-09-01 15:10 ` Greg Kroah-Hartman [this message]
2020-09-01 15:10 ` [PATCH 4.4 47/62] writeback: Protect inode->i_io_list with inode->i_lock Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.4 48/62] writeback: Avoid skipping inode writeback Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.4 49/62] writeback: Fix sync livelock due to b_dirty_time processing Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.4 50/62] XEN uses irqdesc::irq_data_common::handler_data to store a per interrupt XEN data pointer which contains XEN specific information Greg Kroah-Hartman
2020-09-29 13:13 ` Stefan Bader
2020-09-29 14:05 ` Jürgen Groß
2020-09-29 14:21 ` Stefan Bader
2020-09-30 8:52 ` Stefan Bader
2020-09-30 9:01 ` Jürgen Groß
2020-09-01 15:10 ` [PATCH 4.4 51/62] xhci: Do warm-reset when both CAS and XDEV_RESUME are set Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.4 52/62] PM: sleep: core: Fix the handling of pending runtime resume requests Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.4 53/62] device property: Fix the secondary firmware node handling in set_primary_fwnode() Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.4 54/62] USB: yurex: Fix bad gfp argument Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.4 55/62] usb: uas: Add quirk for PNY Pro Elite Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.4 56/62] USB: quirks: Add no-lpm quirk for another Raydium touchscreen Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.4 57/62] USB: Ignore UAS for JMicron JMS567 ATA/ATAPI Bridge Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.4 58/62] usb: host: ohci-exynos: Fix error handling in exynos_ohci_probe() Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.4 59/62] usb: storage: Add unusual_uas entry for Sony PSZ drives Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.4 60/62] btrfs: check the right error variable in btrfs_del_dir_entries_in_log Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.4 61/62] HID: hiddev: Fix slab-out-of-bounds write in hiddev_ioctl_usage() Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.4 62/62] ALSA: usb-audio: Update documentation comment for MS2109 quirk Greg Kroah-Hartman
2020-09-01 18:58 ` [PATCH 4.4 00/62] 4.4.235-rc1 review Guenter Roeck
2020-09-02 7:37 ` Greg Kroah-Hartman
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