Re: [PATCH v5] driver core: enforce device_lock for driver_match_device()

[Wang Jiayue <akaieurus@gmail.com>]

> I'm seeing boot hangs on Arm Juno in next/pending-fixes which bisect to
> this commit.  The boot grinds to a halt near the end of boot:
> 
> [    2.570549] ledtrig-cpu: registered to indicate activity on CPUs
> [    2.618301] Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled
> [    2.623547] msm_serial: driver initialized
> [    2.624058] SuperH (H)SCI(F) driver initialized
> [    2.624312] STM32 USART driver initialized

After partially modifying juno.dts, I managed to roughly emulate kernel
boot on juno board with qemu and successfully reproduced the boot hang.
Below is the gdb backtrace:

#0  0xffff800080114ae0 in mutex_spin_on_owner (lock=0xffff0000036bfc90, owner=0xffff000003510000, ww_ctx=0x0, waiter=0x0) at kernel/locking/mutex.c:377
#1  0xffff80008118cecc in mutex_optimistic_spin (waiter=<optimized out>, ww_ctx=<optimized out>, lock=<optimized out>) at kernel/locking/mutex.c:480
#2  __mutex_lock_common (use_ww_ctx=<optimized out>, ww_ctx=<optimized out>, ip=<optimized out>, nest_lock=<optimized out>, subclass=<optimized out>, state=<optimized out>, lock=<optimized out>) at kernel/locking/mutex.c:618
#3  __mutex_lock (lock=0xffff0000036bfc90, state=0x2, ip=<optimized out>, nest_lock=<optimized out>, subclass=<optimized out>) at kernel/locking/mutex.c:776
#4  0xffff80008118d1dc in __mutex_lock_slowpath (lock=0xffff0000036bfc90) at kernel/locking/mutex.c:1065
#5  0xffff80008118d230 in mutex_lock (lock=0xffff0000036bfc90) at kernel/locking/mutex.c:290
#6  0xffff8000809cdd1c in device_lock (dev=<optimized out>) at ./include/linux/device.h:895
#7  class_device_constructor (_T=<optimized out>) at ./include/linux/device.h:913
#8  driver_match_device_locked (dev=<optimized out>, drv=<optimized out>) at drivers/base/base.h:193
#9  __driver_attach (dev=0xffff0000036bfc10, data=0xffff800082e64440 <qcom_smmu_tbu_driver+40>) at drivers/base/dd.c:1183
#10 0xffff8000809cb17c in bus_for_each_dev (bus=0xffff0000036bfc90, start=0x0, data=0xffff800082e64440 <qcom_smmu_tbu_driver+40>, fn=0xffff8000809cdcec <__driver_attach>) at drivers/base/bus.c:383
#11 0xffff8000809cd03c in driver_attach (drv=0x0) at drivers/base/dd.c:1245
#12 0xffff8000809cc748 in bus_add_driver (drv=0xffff800082e64440 <qcom_smmu_tbu_driver+40>) at drivers/base/bus.c:715
#13 0xffff8000809ced28 in driver_register (drv=0xffff800082e64440 <qcom_smmu_tbu_driver+40>) at drivers/base/driver.c:249
#14 0xffff8000809d0254 in __platform_driver_register (drv=0x0, owner=0xffff000003510000) at drivers/base/platform.c:908
#15 0xffff8000809a6208 in qcom_smmu_impl_init (smmu=0xffff0000037c0080) at drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c:780
#16 0xffff8000809a48a0 in arm_smmu_impl_init (smmu=0xffff0000037c0080) at drivers/iommu/arm/arm-smmu/arm-smmu-impl.c:224
#17 0xffff8000809a2ae0 in arm_smmu_device_probe (pdev=0xffff0000036bfc00) at drivers/iommu/arm/arm-smmu/arm-smmu.c:2155
#18 0xffff8000809d060c in platform_probe (_dev=0xffff0000036bfc10) at drivers/base/platform.c:1446
#19 0xffff8000809cd6a4 in call_driver_probe (drv=<optimized out>, dev=<optimized out>) at drivers/base/dd.c:583
#20 really_probe (dev=0xffff0000036bfc10, drv=0xffff800082e641c0 <arm_smmu_driver+40>) at drivers/base/dd.c:661
#21 0xffff8000809cd8f8 in __driver_probe_device (drv=0xffff800082e641c0 <arm_smmu_driver+40>, dev=0xffff0000036bfc10) at drivers/base/dd.c:803
#22 0xffff8000809cdb34 in driver_probe_device (drv=0xffff0000036bfc90, dev=0xffff0000036bfc10) at drivers/base/dd.c:833
#23 0xffff8000809cddb8 in __driver_attach (data=<optimized out>, dev=<optimized out>) at drivers/base/dd.c:1227
#24 __driver_attach (dev=0xffff0000036bfc10, data=0xffff800082e641c0 <arm_smmu_driver+40>) at drivers/base/dd.c:1167
#25 0xffff8000809cb17c in bus_for_each_dev (bus=0xffff0000036bfc90, start=0x0, data=0xffff800082e641c0 <arm_smmu_driver+40>, fn=0xffff8000809cdcec <__driver_attach>) at drivers/base/bus.c:383
#26 0xffff8000809cd03c in driver_attach (drv=0x0) at drivers/base/dd.c:1245
#27 0xffff8000809cc748 in bus_add_driver (drv=0xffff800082e641c0 <arm_smmu_driver+40>) at drivers/base/bus.c:715
#28 0xffff8000809ced28 in driver_register (drv=0xffff800082e641c0 <arm_smmu_driver+40>) at drivers/base/driver.c:249
#29 0xffff8000809d0254 in __platform_driver_register (drv=0x0, owner=0xffff000003510000) at drivers/base/platform.c:908
#30 0xffff800081f3d12c in arm_smmu_driver_init () at drivers/iommu/arm/arm-smmu/arm-smmu.c:2368
#31 0xffff800080015218 in do_one_initcall (fn=0xffff800081f3d10c <arm_smmu_driver_init>) at init/main.c:1378
#32 0xffff800081ed13e4 in do_initcall_level (command_line=<optimized out>, level=<optimized out>) at init/main.c:1440
#33 do_initcalls () at init/main.c:1456
#34 do_basic_setup () at init/main.c:1475
#35 kernel_init_freeable () at init/main.c:1688
#36 0xffff800081187b50 in kernel_init (unused=0xffff0000036bfc90) at init/main.c:1578
#37 0xffff800080015f58 in ret_from_fork () at arch/arm64/kernel/entry.S:860
Backtrace stopped: previous frame identical to this frame (corrupt stack?)