twx-linux/drivers
Sagar Arun Kamble 70deeaddc6 drm/i915/guc: Fix lockdep due to log relay channel handling under struct_mutex
This patch fixes lockdep issue due to circular locking dependency of
struct_mutex, i_mutex_key, mmap_sem, relay_channels_mutex.
For GuC log relay channel we create debugfs file that requires i_mutex_key
lock and we are doing that under struct_mutex. So we introduced newer
dependency as:
    &dev->struct_mutex --> &sb->s_type->i_mutex_key#3 --> &mm->mmap_sem
However, there is dependency from mmap_sem to struct_mutex. Hence we
separate the relay create/destroy operation from under struct_mutex.
Also added runtime check of relay buffer status.
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>

======================================================
WARNING: possible circular locking dependency detected
4.15.0-rc6-CI-Patchwork_7614+ #1 Not tainted
------------------------------------------------------
debugfs_test/1388 is trying to acquire lock:
 (&dev->struct_mutex){+.+.}, at: [<00000000d5e1d915>] i915_mutex_lock_interruptible+0x47/0x130 [i915]

but task is already holding lock:
 (&mm->mmap_sem){++++}, at: [<0000000029a9c131>] __do_page_fault+0x106/0x560

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #3 (&mm->mmap_sem){++++}:
       _copy_to_user+0x1e/0x70
       filldir+0x8c/0xf0
       dcache_readdir+0xeb/0x160
       iterate_dir+0xdc/0x140
       SyS_getdents+0xa0/0x130
       entry_SYSCALL_64_fastpath+0x1c/0x89

-> #2 (&sb->s_type->i_mutex_key#3){++++}:
       start_creating+0x59/0x110
       __debugfs_create_file+0x2e/0xe0
       relay_create_buf_file+0x62/0x80
       relay_late_setup_files+0x84/0x250
       guc_log_late_setup+0x4f/0x110 [i915]
       i915_guc_log_register+0x32/0x40 [i915]
       i915_driver_load+0x7b6/0x1720 [i915]
       i915_pci_probe+0x2e/0x90 [i915]
       pci_device_probe+0x9c/0x120
       driver_probe_device+0x2a3/0x480
       __driver_attach+0xd9/0xe0
       bus_for_each_dev+0x57/0x90
       bus_add_driver+0x168/0x260
       driver_register+0x52/0xc0
       do_one_initcall+0x39/0x150
       do_init_module+0x56/0x1ef
       load_module+0x231c/0x2d70
       SyS_finit_module+0xa5/0xe0
       entry_SYSCALL_64_fastpath+0x1c/0x89

-> #1 (relay_channels_mutex){+.+.}:
       relay_open+0x12c/0x2b0
       intel_guc_log_runtime_create+0xab/0x230 [i915]
       intel_guc_init+0x81/0x120 [i915]
       intel_uc_init+0x29/0xa0 [i915]
       i915_gem_init+0x182/0x530 [i915]
       i915_driver_load+0xaa9/0x1720 [i915]
       i915_pci_probe+0x2e/0x90 [i915]
       pci_device_probe+0x9c/0x120
       driver_probe_device+0x2a3/0x480
       __driver_attach+0xd9/0xe0
       bus_for_each_dev+0x57/0x90
       bus_add_driver+0x168/0x260
       driver_register+0x52/0xc0
       do_one_initcall+0x39/0x150
       do_init_module+0x56/0x1ef
       load_module+0x231c/0x2d70
       SyS_finit_module+0xa5/0xe0
       entry_SYSCALL_64_fastpath+0x1c/0x89

-> #0 (&dev->struct_mutex){+.+.}:
       __mutex_lock+0x81/0x9b0
       i915_mutex_lock_interruptible+0x47/0x130 [i915]
       i915_gem_fault+0x201/0x790 [i915]
       __do_fault+0x15/0x70
       __handle_mm_fault+0x677/0xdc0
       handle_mm_fault+0x14f/0x2f0
       __do_page_fault+0x2d1/0x560
       page_fault+0x4c/0x60

other info that might help us debug this:

Chain exists of:
  &dev->struct_mutex --> &sb->s_type->i_mutex_key#3 --> &mm->mmap_sem

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&mm->mmap_sem);
                               lock(&sb->s_type->i_mutex_key#3);
                               lock(&mm->mmap_sem);
  lock(&dev->struct_mutex);

 *** DEADLOCK ***

1 lock held by debugfs_test/1388:
 #0:  (&mm->mmap_sem){++++}, at: [<0000000029a9c131>] __do_page_fault+0x106/0x560

stack backtrace:
CPU: 2 PID: 1388 Comm: debugfs_test Not tainted 4.15.0-rc6-CI-Patchwork_7614+ #1
Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./J4205-ITX, BIOS P1.10 09/29/2016
Call Trace:
 dump_stack+0x5f/0x86
 print_circular_bug.isra.18+0x1d0/0x2c0
 __lock_acquire+0x14ae/0x1b60
 ? lock_acquire+0xaf/0x200
 lock_acquire+0xaf/0x200
 ? i915_mutex_lock_interruptible+0x47/0x130 [i915]
 __mutex_lock+0x81/0x9b0
 ? i915_mutex_lock_interruptible+0x47/0x130 [i915]
 ? i915_mutex_lock_interruptible+0x47/0x130 [i915]
 ? i915_mutex_lock_interruptible+0x47/0x130 [i915]
 i915_mutex_lock_interruptible+0x47/0x130 [i915]
 ? __pm_runtime_resume+0x4f/0x80
 i915_gem_fault+0x201/0x790 [i915]
 __do_fault+0x15/0x70
 ? _raw_spin_unlock+0x29/0x40
 __handle_mm_fault+0x677/0xdc0
 handle_mm_fault+0x14f/0x2f0
 __do_page_fault+0x2d1/0x560
 ? page_fault+0x36/0x60
 page_fault+0x4c/0x60

v2: Added lock protection to guc->log.runtime.relay_chan (Chris)
    Fixed locking inside guc_flush_logs uncovered by new lockdep.

v3: Locking guc_read_update_log_buffer entirely with relay_lock. (Chris)
    Prepared intel_guc_init_early. Moved relay_lock inside relay_create
    relay_destroy, relay_file_create, guc_read_update_log_buffer. (Michal)
    Removed struct_mutex lock around guc_log_flush and removed usage
    of guc_log_has_relay() from runtime_create path as it needs
    struct_mutex lock.

v4: Handle NULL relay sub buffer pointer earlier in read_update_log_buffer
    (Chris). Fixed comment suffix **/. (Michal)

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=104693
Testcase: igt/debugfs_test/read_all_entries # with enable_guc=1 and guc_log_level=1
Signed-off-by: Sagar Arun Kamble <sagar.a.kamble@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Marta Lofstedt <marta.lofstedt@intel.com>
Cc: Michal Winiarski <michal.winiarski@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/1516808821-3638-3-git-send-email-sagar.a.kamble@intel.com
2018-01-24 19:44:04 +00:00
..
accessibility License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
acpi Merge branch 'acpi-ec' into acpi 2017-11-30 13:37:29 +01:00
amba A couple of dma-mapping updates: 2017-11-14 16:54:12 -08:00
android Char/Misc patches for 4.15-rc1 2017-11-16 09:10:59 -08:00
ata Merge branch 'for-4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata 2017-11-15 14:11:41 -08:00
atm Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-29 13:10:25 -08:00
auxdisplay auxdisplay: img-ascii-lcd: Only build on archs that have IOMEM 2017-11-27 12:36:45 -08:00
base Merge tag 'drm-misc-next-2017-11-30' of git://anongit.freedesktop.org/drm/drm-misc into drm-next 2017-12-04 05:42:49 +10:00
bcma Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2017-11-15 11:56:19 -08:00
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bus ARM: SoC driver updates for v4.15 2017-11-16 16:05:01 -08:00
cdrom Merge branch 'for-4.15/block' of git://git.kernel.dk/linux-block 2017-11-14 15:32:19 -08:00
char drm/i915: prefer resource_size_t for everything stolen 2017-12-12 12:30:22 +02:00
clk We have two changes to the core framework this time around. The first being a 2017-11-17 20:04:24 -08:00
clocksource - final batch of "non trivial" timer conversions (multi-tree dependencies, 2017-11-23 16:29:05 +01:00
connector
cpufreq cpufreq: mediatek: add missing MODULE_DESCRIPTION/AUTHOR/LICENSE 2017-11-22 00:00:14 +01:00
cpuidle powerpc updates for 4.15 2017-11-16 12:47:46 -08:00
crypto powerpc updates for 4.15 2017-11-16 12:47:46 -08:00
dax device-dax: implement ->split() to catch invalid munmap attempts 2017-11-29 18:40:42 -08:00
dca
devfreq Merge branches 'pm-devfreq' and 'pm-tools' 2017-11-13 01:41:39 +01:00
dio License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
dma dmaengine updates for 4.15-rc1 2017-11-14 16:49:31 -08:00
dma-buf Merge tag 'drm-misc-next-2017-11-30' of git://anongit.freedesktop.org/drm/drm-misc into drm-next 2017-12-04 05:42:49 +10:00
edac Modules updates for v4.15 2017-11-15 13:46:33 -08:00
eisa License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
extcon USB/PHY patches for 4.15-rc1 2017-11-13 21:14:07 -08:00
firewire Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-11-13 17:56:58 -08:00
firmware drivers/firmware: psci: Convert timers to use timer_setup() 2017-11-21 15:46:44 -08:00
fmc License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
fpga Char/Misc patches for 4.15-rc1 2017-11-16 09:10:59 -08:00
fsi
gpio This is the bulk of pin control changes for the v4.15 2017-11-16 10:57:11 -08:00
gpu drm/i915/guc: Fix lockdep due to log relay channel handling under struct_mutex 2018-01-24 19:44:04 +00:00
hid treewide: setup_timer() -> timer_setup() 2017-11-21 15:57:07 -08:00
hsi HSI changes for the v4.15 series 2017-11-15 13:35:43 -08:00
hv Char/Misc patches for 4.15-rc1 2017-11-16 09:10:59 -08:00
hwmon hwmon: (jc42) optionally try to disable the SMBUS timeout 2017-11-30 13:12:44 -08:00
hwspinlock hwspinlock update for v4.15 2017-11-17 20:16:20 -08:00
hwtracing Char/Misc patches for 4.15-rc1 2017-11-16 09:10:59 -08:00
i2c i2c: i2c-boardinfo: fix memory leaks on devinfo 2017-11-27 19:14:29 +01:00
ide Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/ide 2017-11-19 08:04:41 -10:00
idle Merge branch 'pm-cpuidle' 2017-11-13 01:34:14 +01:00
iio treewide: setup_timer() -> timer_setup() 2017-11-21 15:57:07 -08:00
infiniband IB/core: disable memory registration of filesystem-dax vmas 2017-11-29 18:40:42 -08:00
input treewide: Remove TIMER_FUNC_TYPE and TIMER_DATA_TYPE casts 2017-11-21 16:35:54 -08:00
iommu treewide: setup_timer() -> timer_setup() 2017-11-21 15:57:07 -08:00
ipack
irqchip Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-11-26 14:39:20 -08:00
isdn treewide: setup_timer() -> timer_setup() (2 field) 2017-11-21 15:57:09 -08:00
leds LED updates for 4.15rc1 2017-11-14 18:09:31 -08:00
lightnvm lightnvm: Convert timers to use timer_setup() 2017-11-21 15:46:44 -08:00
macintosh Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-11-13 17:56:58 -08:00
mailbox Change to POLL api and fixes for FlexRM and OMAP driver 2017-11-15 13:39:18 -08:00
mcb License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
md bcache: check return value of register_shrinker 2017-11-24 16:23:01 -07:00
media v4l: vsp1: Start and stop DRM pipeline independently of planes 2017-12-04 13:04:11 +02:00
memory ARM: SoC driver updates for v4.15 2017-11-16 16:05:01 -08:00
memstick treewide: setup_timer() -> timer_setup() 2017-11-21 15:57:07 -08:00
message Modules updates for v4.15 2017-11-15 13:46:33 -08:00
mfd treewide: setup_timer() -> timer_setup() 2017-11-21 15:57:07 -08:00
misc Merge branch 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux 2017-12-03 10:48:24 -05:00
mmc MMC core: 2017-12-01 08:14:22 -05:00
mtd Rename superblock flags (MS_xyz -> SB_xyz) 2017-11-27 13:05:09 -08:00
mux
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-29 13:10:25 -08:00
nfc treewide: setup_timer() -> timer_setup() (2 field) 2017-11-21 15:57:09 -08:00
ntb treewide: setup_timer() -> timer_setup() 2017-11-21 15:57:07 -08:00
nubus m68k updates for 4.15 2017-11-13 12:10:24 -08:00
nvdimm libnvdimm for 4.15 2017-11-17 09:51:57 -08:00
nvme nvme-pci: fix NULL pointer dereference in nvme_free_host_mem() 2017-11-28 08:49:26 -08:00
nvmem Char/Misc patches for 4.15-rc1 2017-11-16 09:10:59 -08:00
of DeviceTree fixes for 4.15: 2017-11-20 21:38:41 -10:00
opp
oprofile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
parisc License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
parport Char/Misc patches for 4.15-rc1 2017-11-16 09:10:59 -08:00
pci Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-11-26 14:11:54 -08:00
pcmcia drivers/pcmcia/sa1111_badge4.c: avoid unused function warning 2017-11-17 16:10:04 -08:00
perf arm64 updates for 4.15 2017-11-15 10:56:56 -08:00
phy USB/PHY patches for 4.15-rc1 2017-11-13 21:14:07 -08:00
pinctrl This is the bulk of pin control changes for the v4.15 2017-11-16 10:57:11 -08:00
platform Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-11-25 08:37:16 -10:00
pnp License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
power power supply and reset changes for the v4.15 series 2017-11-15 13:37:15 -08:00
powercap
pps treewide: setup_timer() -> timer_setup() 2017-11-21 15:57:07 -08:00
ps3
ptp xen: features and fixes for v4.15-rc1 2017-11-16 13:06:27 -08:00
pwm pwm: Changes for v4.15-rc1 2017-11-22 21:09:18 -10:00
rapidio Merge branch 'akpm' (patches from Andrew) 2017-11-17 16:56:17 -08:00
ras Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-11-13 17:56:58 -08:00
regulator - New Drivers 2017-11-16 09:15:57 -08:00
remoteproc remoteproc updates for v4.15 2017-11-17 20:14:10 -08:00
reset ARM: SoC driver updates for v4.15 2017-11-16 16:05:01 -08:00
rpmsg rpmsg updates for v4.15 2017-11-17 20:12:08 -08:00
rtc Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-11-25 08:37:16 -10:00
s390 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2017-11-30 08:13:36 -08:00
sbus Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc 2017-11-17 20:21:44 -08:00
scsi Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-11-25 08:37:16 -10:00
sfi
sh A couple of dma-mapping updates: 2017-11-14 16:54:12 -08:00
sn
soc ARM: SoC driver updates for v4.15 2017-11-16 16:05:01 -08:00
spi Merge remote-tracking branches 'spi/topic/sh-msiof', 'spi/topic/slave', 'spi/topic/spreadtrum' and 'spi/topic/tegra114' into spi-next 2017-11-10 21:33:51 +00:00
spmi
ssb License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
staging staging: vboxvideo: adapt to new TTM interface 2017-12-06 12:48:03 -05:00
target Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-11-25 08:37:16 -10:00
tc
tee License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
thermal Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux 2017-11-17 14:31:27 -08:00
thunderbolt Char/Misc patches for 4.15-rc1 2017-11-16 09:10:59 -08:00
tty treewide: Remove TIMER_FUNC_TYPE and TIMER_DATA_TYPE casts 2017-11-21 16:35:54 -08:00
uio License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
usb treewide: setup_timer() -> timer_setup() 2017-11-21 15:57:07 -08:00
uwb treewide: setup_timer() -> timer_setup() 2017-11-21 15:57:07 -08:00
vfio VFIO Updates for Linux v4.15 2017-11-14 16:47:47 -08:00
vhost Merge branch 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-11-17 12:08:18 -08:00
video fbcon: Remove dmi quirk table 2017-12-04 23:03:22 +01:00
virt
virtio virtio_balloon: fix deadlock on OOM 2017-11-14 23:57:38 +02:00
vlynq
vme Char/Misc patches for 4.15-rc1 2017-11-16 09:10:59 -08:00
w1 Char/Misc patches for 4.15-rc1 2017-11-16 09:10:59 -08:00
watchdog treewide: setup_timer() -> timer_setup() 2017-11-21 15:57:07 -08:00
xen treewide: Switch DEFINE_TIMER callbacks to struct timer_list * 2017-11-21 15:57:05 -08:00
zorro License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
Kconfig Merge branches 'pm-cpufreq-sched' and 'pm-opp' 2017-11-13 01:40:52 +01:00
Makefile Merge branches 'pm-cpufreq-sched' and 'pm-opp' 2017-11-13 01:40:52 +01:00