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Sergey Senozhatsky 2e76a3a166 serial: 8250: change lock order in serial8250_do_startup() 
commit 205d300aea 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: 768aec0b5b ("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>
 		2020-09-03 11:27:04 +02:00
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acpi ACPICA: Do not increment operation_region reference counts for field units 2020-08-19 08:16:05 +02:00
amba
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cpuidle cpuidle: Fix three reference count leaks 2020-06-22 09:31:10 +02:00
crypto crypto: caam - Remove broken arc4 support 2020-08-21 13:05:32 +02:00
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devfreq PM / devfreq: rk3399_dmc: Fix kernel oops when rockchip,pmu is absent 2020-09-03 11:26:50 +02:00
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dma dmaengine: ioat setting ioat timeout as module parameter 2020-07-29 10:18:37 +02:00
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edac EDAC/{i7core,sb,pnd2,skx}: Fix error event severity 2020-09-03 11:26:53 +02:00
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extcon extcon: adc-jack: Fix an error handling path in 'adc_jack_probe()' 2020-06-24 17:50:36 +02:00
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firmware efi: add missed destroy_workqueue when efisubsys_init fails 2020-08-26 10:41:07 +02:00
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hid HID: i2c-hid: Always sleep 60ms after I2C_HID_PWR_ON commands 2020-09-03 11:27:01 +02:00
hsi
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hv Drivers: hv: vmbus: Ignore CHANNELMSG_TL_CONNECT_RESULT(23) 2020-08-11 15:33:38 +02:00
hwmon hwmon: (nct7904) Correct divide by 0 2020-09-03 11:26:54 +02:00
hwspinlock
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hwtracing coresight: tmc: Fix TMC mode read in tmc_read_unprepare_etb() 2020-08-19 08:16:14 +02:00
i2c i2c: rcar: in slave mode, clear NACK earlier 2020-09-03 11:26:55 +02:00
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ide
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iio iio: dac: ad5592r: fix unbalanced mutex unlocks in ad5592r_read_raw() 2020-08-21 13:05:24 +02:00
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input Input: psmouse - add a newline when printing 'proto' by sysfs 2020-08-26 10:40:55 +02:00
interconnect
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iommu iommu/iova: Don't BUG on invalid PFNs 2020-09-03 11:26:43 +02:00
ipack ipack: tpci200: fix error return code in tpci200_register() 2020-05-27 17:46:47 +02:00
irqchip genirq/affinity: Make affinity setting if activated opt-in 2020-08-21 13:05:20 +02:00
isdn
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leds leds: core: Flush scheduled work for system suspend 2020-08-19 08:16:11 +02:00
lightnvm
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macintosh macintosh/via-macii: Access autopoll_devs when inside lock 2020-08-19 08:16:15 +02:00
mailbox mailbox: zynqmp-ipi: Fix NULL vs IS_ERR() check in zynqmp_ipi_mbox_probe() 2020-06-24 17:50:36 +02:00
mcb
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md bcache: avoid nr_stripes overflow in bcache_device_init() 2020-08-26 10:40:48 +02:00
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memory
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memstick
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message scsi: mptscsih: Fix read sense data size 2020-07-16 08:16:36 +02:00
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mmc mmc: renesas_sdhi_internal_dmac: clean up the code for dma complete 2020-08-21 13:05:32 +02:00
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mux
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net net: gianfar: Add of_node_put() before goto statement 2020-09-03 11:27:00 +02:00
nfc nfc: s3fwrn5: add missing release on skb in s3fwrn5_recv_frame 2020-08-05 09:59:50 +02:00
ntb NTB: perf: Fix race condition when run with ntb_test 2020-06-24 17:50:41 +02:00
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nvdimm libnvdimm/security: ensure sysfs poll thread woke up and fetch updated attr 2020-08-21 13:05:35 +02:00
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nvmem nvmem: qfprom: remove incorrect write support 2020-06-10 20:24:57 +02:00
of of: of_mdio: Correct loop scanning logic 2020-07-22 09:32:55 +02:00
opp opp: Enable resources again if they were disabled earlier 2020-08-26 10:40:53 +02:00
oprofile
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parisc parisc: mask out enable and reserved bits from sba imask 2020-08-19 08:16:26 +02:00
parport
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pci PCI: qcom: Add missing reset for ipq806x 2020-09-03 11:26:53 +02:00
pcmcia
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perf drivers/perf: Prevent forced unbinding of PMU drivers 2020-07-29 10:18:40 +02:00
phy phy: armada-38x: fix NETA lockup when repeatedly switching speeds 2020-08-19 08:16:14 +02:00
pinctrl pinctrl: ingenic: Properly detect GPIO direction when configured for IRQ 2020-08-21 13:05:29 +02:00
platform platform/chrome: cros_ec_ishtp: Fix a double-unlock issue 2020-08-21 13:05:30 +02:00
pnp
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power power: supply: check if calc_soc succeeded in pm860x_init_battery 2020-08-19 08:16:16 +02:00
powercap
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pps
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ps3
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ptp
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pwm pwm: bcm-iproc: handle clk_get_rate() return 2020-08-21 13:05:34 +02:00
rapidio rapidio: fix an error in get_user_pages_fast() error handling 2020-05-27 17:46:48 +02:00
ras
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regulator regulator: fix memory leak on error path of regulator_register() 2020-08-19 08:15:57 +02:00
remoteproc remoteproc: qcom_q6v5_mss: Validate modem blob firmware size before load 2020-08-21 13:05:29 +02:00
reset
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rpmsg
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rtc rtc: goldfish: Enable interrupt in set_alarm() when necessary 2020-08-26 10:40:54 +02:00
s390 s390/cio: add cond_resched() in the slow_eval_known_fn() loop 2020-09-03 11:26:59 +02:00
sbus
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scsi Revert "scsi: qla2xxx: Fix crash on qla2x00_mailbox_command" 2020-09-03 11:27:00 +02:00
sfi
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sh
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siox
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slimbus slimbus: core: Fix mismatch in of_node_get/put 2020-07-22 09:33:08 +02:00
soc soc: qcom: rpmh-rsc: Set suppress_bind_attrs flag 2020-08-19 08:15:59 +02:00
soundwire soundwire: intel: fix memory leak with devm_kasprintf 2020-07-22 09:33:00 +02:00
spi spi: stm32: always perform registers configuration prior to transfer 2020-09-03 11:26:58 +02:00
spmi
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ssb
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staging staging: rtl8192u: fix a dubious looking mask before a shift 2020-08-19 08:16:13 +02:00
target scsi: target: Fix xcopy sess release leak 2020-09-03 11:26:44 +02:00
tc
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tee
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thermal thermal: ti-soc-thermal: Fix reversed condition in ti_thermal_expose_sensor() 2020-08-19 08:16:14 +02:00
thunderbolt
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tty serial: 8250: change lock order in serial8250_do_startup() 2020-09-03 11:27:04 +02:00
uio uio_pdrv_genirq: fix use without device tree and no interrupt 2020-07-22 09:33:13 +02:00
usb USB: lvtest: return proper error code in probe 2020-09-03 11:27:02 +02:00
vfio vfio/type1: Add proper error unwind for vfio_iommu_replay() 2020-08-26 10:41:03 +02:00
vhost vhost/scsi: fix up req type endian-ness 2020-08-05 09:59:42 +02:00
video fbcon: prevent user font height or width change from causing potential out-of-bounds access 2020-09-03 11:27:02 +02:00
virt virt: vbox: Fix guest capabilities mask check 2020-07-22 09:33:11 +02:00
virtio virtio_ring: Avoid loop when vq is broken in virtqueue_poll 2020-08-26 10:40:57 +02:00
visorbus
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vlynq
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vme
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w1 w1: omap-hdq: cleanup to add missing newline for some dev_dbg 2020-06-22 09:31:26 +02:00
watchdog watchdog: initialize device before misc_register 2020-08-21 13:05:36 +02:00
xen xen: don't reschedule in preemption off sections 2020-08-26 10:41:07 +02:00
zorro
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Kconfig
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