AngeloGioacchino Del Regno 353d921468 rpmsg: mtk_rpmsg: Fix circular locking dependency ... During execution of the worker that's used to register rpmsg devices we are safely locking the channels mutex but, when creating a new endpoint for such devices, we are registering a IPI on the SCP, which then makes the SCP to trigger an interrupt, lock its own mutex and in turn register more subdevices. This creates a circular locking dependency situation, as the mtk_rpmsg channels_lock will then depend on the SCP IPI lock. [ 15.447736] ====================================================== [ 15.460158] WARNING: possible circular locking dependency detected [ 15.460161] 5.17.0-next-20220324+ #399 Not tainted [ 15.460165] ------------------------------------------------------ [ 15.460166] kworker/0:3/155 is trying to acquire lock: [ 15.460170] ffff5b4d0eaf1308 (&scp->ipi_desc[i].lock){+.+.}-{4:4}, at: scp_ipi_lock+0x34/0x50 [mtk_scp_ipi] [ 15.504958] [] but task is already holding lock: [ 15.504960] ffff5b4d0e8f1918 (&mtk_subdev->channels_lock){+.+.}-{4:4}, at: mtk_register_device_work_function+0x50/0x1cc [mtk_rpmsg] [ 15.504978] [] which lock already depends on the new lock. [ 15.504980] [] the existing dependency chain (in reverse order) is: [ 15.504982] [] -> #1 (&mtk_subdev->channels_lock){+.+.}-{4:4}: [ 15.504990] lock_acquire+0x68/0x84 [ 15.504999] __mutex_lock+0xa4/0x3e0 [ 15.505007] mutex_lock_nested+0x40/0x70 [ 15.505012] mtk_rpmsg_ns_cb+0xe4/0x134 [mtk_rpmsg] [ 15.641684] mtk_rpmsg_ipi_handler+0x38/0x64 [mtk_rpmsg] [ 15.641693] scp_ipi_handler+0xbc/0x180 [mtk_scp] [ 15.663905] mt8192_scp_irq_handler+0x44/0xa4 [mtk_scp] [ 15.663915] scp_irq_handler+0x6c/0xa0 [mtk_scp] [ 15.685779] irq_thread_fn+0x34/0xa0 [ 15.685785] irq_thread+0x18c/0x240 [ 15.685789] kthread+0x104/0x110 [ 15.709579] ret_from_fork+0x10/0x20 [ 15.709586] [] -> #0 (&scp->ipi_desc[i].lock){+.+.}-{4:4}: [ 15.731271] __lock_acquire+0x11e4/0x1910 [ 15.740367] lock_acquire.part.0+0xd8/0x220 [ 15.749813] lock_acquire+0x68/0x84 [ 15.757861] __mutex_lock+0xa4/0x3e0 [ 15.766084] mutex_lock_nested+0x40/0x70 [ 15.775006] scp_ipi_lock+0x34/0x50 [mtk_scp_ipi] [ 15.785503] scp_ipi_register+0x40/0xa4 [mtk_scp_ipi] [ 15.796697] scp_register_ipi+0x1c/0x30 [mtk_scp] [ 15.807194] mtk_rpmsg_create_ept+0xa0/0x108 [mtk_rpmsg] [ 15.818912] rpmsg_create_ept+0x44/0x60 [ 15.827660] cros_ec_rpmsg_probe+0x15c/0x1f0 [ 15.837282] rpmsg_dev_probe+0x128/0x1d0 [ 15.846203] really_probe.part.0+0xa4/0x2a0 [ 15.855649] __driver_probe_device+0xa0/0x150 [ 15.865443] driver_probe_device+0x48/0x150 [ 15.877157] __device_attach_driver+0xc0/0x12c [ 15.889359] bus_for_each_drv+0x80/0xe0 [ 15.900330] __device_attach+0xe4/0x190 [ 15.911303] device_initial_probe+0x1c/0x2c [ 15.922969] bus_probe_device+0xa8/0xb0 [ 15.933927] device_add+0x3a8/0x8a0 [ 15.944193] device_register+0x28/0x40 [ 15.954970] rpmsg_register_device+0x5c/0xa0 [ 15.966782] mtk_register_device_work_function+0x148/0x1cc [mtk_rpmsg] [ 15.983146] process_one_work+0x294/0x664 [ 15.994458] worker_thread+0x7c/0x45c [ 16.005069] kthread+0x104/0x110 [ 16.014789] ret_from_fork+0x10/0x20 [ 16.025201] [] other info that might help us debug this: [ 16.047769] Possible unsafe locking scenario: [ 16.063942] CPU0 CPU1 [ 16.075166] ---- ---- [ 16.086376] lock(&mtk_subdev->channels_lock); [ 16.097592] lock(&scp->ipi_desc[i].lock); [ 16.113188] lock(&mtk_subdev->channels_lock); [ 16.129482] lock(&scp->ipi_desc[i].lock); [ 16.140020] [] *** DEADLOCK *** [ 16.158282] 4 locks held by kworker/0:3/155: [ 16.168978] #0: ffff5b4d00008748 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x1fc/0x664 [ 16.190017] #1: ffff80000953bdc8 ((work_completion)(&mtk_subdev->register_work)){+.+.}-{0:0}, at: process_one_work+0x1fc/0x664 [ 16.215269] #2: ffff5b4d0e8f1918 (&mtk_subdev->channels_lock){+.+.}-{4:4}, at: mtk_register_device_work_function+0x50/0x1cc [mtk_rpmsg] [ 16.242131] #3: ffff5b4d05964190 (&dev->mutex){....}-{4:4}, at: __device_attach+0x44/0x190 To solve this, simply unlock the channels_lock mutex before calling mtk_rpmsg_register_device() and relock it right after, as safety is still ensured by the locking mechanism that happens right after through SCP. Fixes: 7017996951 ("rpmsg: add rpmsg support for mt8183 SCP.") Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> Link: https://lore.kernel.org/r/20220525091201.14210-1-angelogioacchino.delregno@collabora.com Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>		2022-06-14 16:41:10 -06:00
..
accessibility	Revert "speakup: Generate speakupmap.h automatically"	2022-05-20 21:07:05 +02:00
acpi	More power management updates for 5.19-rc1	2022-05-30 11:37:26 -07:00
amba	Driver core changes for 5.19-rc1	2022-06-03 11:48:47 -07:00
android	fix for breakage in #work.fd this window	2022-06-05 17:14:03 -07:00
ata	ata: libata-transport: fix {dma|pio|xfer}_mode sysfs files	2022-06-09 09:25:25 +09:00
atm
auxdisplay
base	firmware_loader: enable XZ by default if compressed support is enabled	2022-06-03 15:46:03 -07:00
bcma
block	xen: branch for v5.19-rc1b	2022-06-04 13:42:53 -07:00
bluetooth	Bluetooth: btmtksdio: fix the reset takes too long	2022-05-13 13:19:01 +02:00
bus	Driver core changes for 5.19-rc1	2022-06-03 11:48:47 -07:00
cdrom	cdrom: remove obsolete TODO list	2022-05-15 18:31:28 -06:00
char	Random number generator fixes for Linux 5.19-rc2.	2022-06-12 10:33:38 -07:00
clk	Driver core changes for 5.19-rc1	2022-06-03 11:48:47 -07:00
clocksource	Clockevent/clocksource updates:	2022-06-05 10:47:06 -07:00
comedi	drivers: comedi: replace ternary operator with min()	2022-05-19 18:54:45 +02:00
connector
counter
cpufreq	ARM: multiplatform changes, part 2	2022-06-02 15:23:54 -07:00
cpuidle	Merge branches 'pm-em' and 'pm-cpuidle'	2022-05-23 19:18:51 +02:00
crypto	virtio-crypto: enable retry for virtio-crypto-dev	2022-05-31 12:45:09 -04:00
cxl	cxl/port: Enable HDM Capability after validating DVSEC Ranges	2022-05-20 12:30:53 -07:00
dax	dax: add .recovery_write dax_operation	2022-05-16 13:37:59 -07:00
dca
devfreq	PM / devfreq: passive: Return non-error when not-supported event is required	2022-05-19 19:32:19 +02:00
dio	drivers: dio: add missing iounmap() in dio_init()	2022-05-19 18:56:51 +02:00
dma	dmaengine updates for v5.19-rc1	2022-05-29 11:38:27 -07:00
dma-buf	drm for 5.19-rc1	2022-05-25 16:18:27 -07:00
edac	- A gargen variety of fixes which don't fit any other tip bucket:	2022-05-23 19:32:59 -07:00
eisa
extcon
firewire	Merge branch 'for-linus' into for-next	2022-05-23 07:48:27 +02:00
firmware	Follow-up tweaks for the EFI changes in v5.19	2022-06-03 13:39:30 -07:00
fpga
fsi
gnss
gpio	gpio: dwapb: Don't print error on -EPROBE_DEFER	2022-06-10 14:26:15 +02:00
gpu	drm fixes for 5.19-rc2	2022-06-10 10:13:24 -07:00
greybus
hid	USB / Thunderbolt changes for 5.19-rc1	2022-06-03 11:17:49 -07:00
hsi
hte	hte: Uninitialized variable in hte_ts_get()	2022-05-20 15:54:41 +02:00
hv	Driver core changes for 5.19-rc1	2022-06-03 11:48:47 -07:00
hwmon	hwmon: (aquacomputer_d5next) Fix an error handling path in aqc_probe()	2022-05-22 12:25:55 -07:00
hwspinlock
hwtracing
i2c	i2c: ismt: prevent memory corruption in ismt_access()	2022-06-02 08:40:56 -07:00
i3c	i3c: master: svc: fix returnvar.cocci warning	2022-05-17 22:34:42 +02:00
idle	cpuidle,intel_idle: Fix CPUIDLE_FLAG_IRQ_ENABLE	2022-06-08 18:05:45 +02:00
iio	Bitmap patches for 5.19-rc1	2022-06-04 14:04:27 -07:00
infiniband	v5.19 pull request	2022-05-26 21:08:40 -07:00
input	Input updates for v5.19-rc1	2022-06-07 15:00:29 -07:00
interconnect	Char / Misc / Other smaller driver subsystem updates for 5.19-rc1	2022-06-03 11:36:34 -07:00
iommu	IOMMU Updates for Linux v5.19	2022-05-31 09:56:54 -07:00
ipack
irqchip	irq: mips: replace cpumask_weight with cpumask_empty where appropriate	2022-06-03 06:52:57 -07:00
isdn
leds	ARM: multiplatform changes, part 2	2022-06-02 15:23:54 -07:00
macintosh	macintosh: via-pmu and via-cuda need RTC_LIB	2022-05-22 15:58:30 +10:00
mailbox	mailbox: qcom-ipcc: Fix -Wunused-function with CONFIG_PM_SLEEP=n	2022-05-24 08:08:24 -05:00
mcb
md	dm: fix zoned locking imbalance due to needless check in clone_endio	2022-06-10 15:23:54 -04:00
media	USB / Thunderbolt changes for 5.19-rc1	2022-06-03 11:17:49 -07:00
memory	More power management updates for 5.19-rc1	2022-05-30 11:37:26 -07:00
memstick
message
mfd	ARM: multiplatform changes, part 2	2022-06-02 15:23:54 -07:00
misc	Char / Misc / Other smaller driver subsystem updates for 5.19-rc1	2022-06-03 11:36:34 -07:00
mmc	MMC core:	2022-06-07 14:24:30 -07:00
most
mtd	This pull request contains fixes for JFFS2, UBI and UBIFS	2022-06-03 14:42:24 -07:00
mux
net	mlx5-fixes-2022-06-08	2022-06-09 22:05:37 -07:00
nfc	nfc: nfcmrvl: Fix memory leak in nfcmrvl_play_deferred	2022-06-08 10:18:10 -07:00
ntb
nubus
nvdimm	cxl for 5.19	2022-05-27 21:24:19 -07:00
nvme	SCSI misc on 20220604	2022-06-05 09:25:12 -07:00
nvmem
of	drm for 5.19-rc1	2022-05-25 16:18:27 -07:00
opp	OPP updates for 5.19-rc1	2022-05-25 15:02:26 +02:00
parisc
parport
pci	Driver core changes for 5.19-rc1	2022-06-03 11:48:47 -07:00
pcmcia	ARM: multiplatform changes, part 2	2022-06-02 15:23:54 -07:00
peci
perf	arm64 updates for 5.19:	2022-05-23 21:06:11 -07:00
phy	phy-for-5.19	2022-05-19 16:56:17 +02:00
pinctrl	Pin control bulk changes for the v5.19 series:	2022-05-28 11:15:54 -07:00
platform	platform-drivers-x86 for v5.19-2	2022-06-12 11:33:42 -07:00
pnp
power	Char / Misc / Other smaller driver subsystem updates for 5.19-rc1	2022-06-03 11:36:34 -07:00
powercap	Merge branches 'pm-em' and 'pm-cpuidle'	2022-05-23 19:18:51 +02:00
pps
ps3
ptp	ptp: ptp_clockmatrix: fix is_single_shot	2022-05-25 21:51:32 -07:00
pwm	pwm: pwm-cros-ec: Add channel type support	2022-05-20 16:40:01 +02:00
rapidio
ras
regulator	Merge back reboot/poweroff notifiers rework for 5.19-rc1.	2022-05-25 14:38:29 +02:00
remoteproc
reset
rpmsg	rpmsg: mtk_rpmsg: Fix circular locking dependency	2022-06-14 16:41:10 -06:00
rtc	ARM: multiplatform changes, part 2	2022-06-02 15:23:54 -07:00
s390	Driver core changes for 5.19-rc1	2022-06-03 11:48:47 -07:00
sbus
scsi	scsi: pmcraid: Fix missing resource cleanup in error case	2022-06-07 22:05:14 -04:00
sh
siox
slimbus	Driver core changes for 5.19-rc1	2022-06-03 11:48:47 -07:00
soc	Char / Misc / Other smaller driver subsystem updates for 5.19-rc1	2022-06-03 11:36:34 -07:00
soundwire
spi	Driver core changes for 5.19-rc1	2022-06-03 11:48:47 -07:00
spmi
ssb
staging	Char / Misc / Other smaller driver subsystem updates for 5.19-rc1	2022-06-03 11:36:34 -07:00
target	blk-mq: remove the done argument to blk_execute_rq_nowait	2022-05-28 06:15:27 -06:00
tc
tee	Fix a compiler warning in OP-TEE driver	2022-05-30 14:44:27 +02:00
thermal	Additional thermal control update for 5.19-rc1	2022-05-30 11:34:13 -07:00
thunderbolt	USB / Thunderbolt changes for 5.19-rc1	2022-06-03 11:17:49 -07:00
tty	xen: branch for v5.19-rc1b	2022-06-04 13:42:53 -07:00
ufs	SCSI misc on 20220604	2022-06-05 09:25:12 -07:00
uio
usb	Char / Misc / Other smaller driver subsystem updates for 5.19-rc1	2022-06-03 11:36:34 -07:00
vdpa	vduse: Fix NULL pointer dereference on sysfs access	2022-06-08 08:56:03 -04:00
vfio	VFIO updates for v5.19-rc1	2022-06-01 13:49:15 -07:00
vhost	vdpa: make get_vq_group and set_group_asid optional	2022-06-09 00:26:35 -04:00
video	parisc architecture fixes & updates for kernel v5.19-rc1	2022-06-04 13:50:23 -07:00
virt	Char / Misc / Other smaller driver subsystem updates for 5.19-rc1	2022-06-03 11:36:34 -07:00
virtio	virtio,vdpa: fixes	2022-06-11 16:32:47 -07:00
vlynq
vme
w1
watchdog	ARM: SoC changes, part 2	2022-06-02 15:27:44 -07:00
xen	xen: unexport __init-annotated xen_xlate_map_ballooned_pages()	2022-06-07 08:11:35 +02:00
zorro
Kconfig	SCSI misc on 20220604	2022-06-05 09:25:12 -07:00
Makefile	SCSI misc on 20220604	2022-06-05 09:25:12 -07:00