7d623575a3
Lockdep gives the following splat:
[ 594.158863] ffff888140da53f0 (&vm->userptr.notifier_lock){++++}-{3:3}, at: vma_userptr_invalidate+0xeb/0x330 [xe]
[ 594.158921]
but task is already holding lock:
[ 594.158926] ffffffff82761940
(mmu_notifier_invalidate_range_start){+.+.}-{0:0}, at: unmap_vmas+0x0/0x1c0
[ 594.158941]
which lock already depends on the new lock.
[ 594.158947]
the existing dependency chain (in reverse order) is:
[ 594.158953]
-> #5 (mmu_notifier_invalidate_range_start){+.+.}-{0:0}:
[ 594.158961] fs_reclaim_acquire+0x68/0xd0
[ 594.158969] __kmem_cache_alloc_node+0x2c/0x1b0
[ 594.158975] kmalloc_node_trace+0x1d/0xb0
[ 594.158983] alloc_worker+0x18/0x50
[ 594.158989] init_rescuer.part.0+0x13/0xa0
[ 594.158995] workqueue_init+0xdf/0x210
[ 594.159001] kernel_init_freeable+0x5c/0x2f0
[ 594.159009] kernel_init+0x11/0x1a0
[ 594.159017] ret_from_fork+0x29/0x50
[ 594.159023]
-> #4 (fs_reclaim){+.+.}-{0:0}:
[ 594.159031] fs_reclaim_acquire+0xa0/0xd0
[ 594.159037] __kmem_cache_alloc_node+0x2c/0x1b0
[ 594.159042] kmalloc_trace+0x20/0xb0
[ 594.159048] acpi_device_add+0x25a/0x3f0
[ 594.159056] acpi_add_single_object+0x387/0x750
[ 594.159063] acpi_bus_check_add+0x108/0x280
[ 594.159069] acpi_bus_scan+0x34/0xf0
[ 594.159075] acpi_scan_init+0xed/0x2b0
[ 594.159082] acpi_init+0x21e/0x520
[ 594.159087] do_one_initcall+0x53/0x260
[ 594.159092] kernel_init_freeable+0x18a/0x2f0
[ 594.159099] kernel_init+0x11/0x1a0
[ 594.159105] ret_from_fork+0x29/0x50
[ 594.159110]
-> #3 (acpi_device_lock){+.+.}-{3:3}:
[ 594.159117] __mutex_lock+0x95/0xd10
[ 594.159122] acpi_enable_wakeup_device_power+0x30/0x120
[ 594.159130] __acpi_device_wakeup_enable+0x34/0x110
[ 594.159138] acpi_pm_set_device_wakeup+0x55/0x140
[ 594.159143] __pci_enable_wake+0x56/0xb0
[ 594.159150] pci_finish_runtime_suspend+0x35/0x80
[ 594.159157] pci_pm_runtime_suspend+0xb5/0x1a0
[ 594.159162] __rpm_callback+0x3c/0x110
[ 594.159170] rpm_callback+0x58/0x70
[ 594.159176] rpm_suspend+0x15c/0x6f0
[ 594.159182] pm_runtime_work+0x9b/0xb0
[ 594.159188] process_one_work+0x263/0x520
[ 594.159195] worker_thread+0x4d/0x3b0
[ 594.159200] kthread+0xeb/0x120
[ 594.159206] ret_from_fork+0x29/0x50
[ 594.159211]
-> #2 (acpi_wakeup_lock){+.+.}-{3:3}:
[ 594.159218] __mutex_lock+0x95/0xd10
[ 594.159223] acpi_pm_set_device_wakeup+0x7a/0x140
[ 594.159228] __pci_enable_wake+0x77/0xb0
[ 594.159234] pci_pm_runtime_resume+0x70/0xd0
[ 594.159240] __rpm_callback+0x3c/0x110
[ 594.159246] rpm_callback+0x58/0x70
[ 594.159252] rpm_resume+0x50d/0x7a0
[ 594.159258] rpm_resume+0x267/0x7a0
[ 594.159264] __pm_runtime_resume+0x45/0x90
[ 594.159270] xe_pm_runtime_resume_and_get+0x12/0x50 [xe]
[ 594.159314] xe_device_mem_access_get+0x97/0xc0 [xe]
[ 594.159346] hw_engines+0x65/0xf0 [xe]
[ 594.159380] seq_read_iter+0x10d/0x4b0
[ 594.159385] seq_read+0x9e/0xd0
[ 594.159390] full_proxy_read+0x4e/0x80
[ 594.159396] vfs_read+0xb6/0x310
[ 594.159401] ksys_read+0x60/0xe0
[ 594.159406] do_syscall_64+0x38/0x90
[ 594.159413] entry_SYSCALL_64_after_hwframe+0x72/0xdc
[ 594.159419]
-> #1 (&xe->mem_access.lock){+.+.}-{3:3}:
[ 594.159427] xe_device_mem_access_get+0x43/0xc0 [xe]
[ 594.159457] xe_gt_tlb_invalidation_vma+0x53/0x190 [xe]
[ 594.159490] invalidation_fence_init+0x1d2/0x2c0 [xe]
[ 594.159529] __xe_pt_unbind_vma+0x151/0x4e0 [xe]
[ 594.159564] vm_bind_ioctl+0x48a/0xae0 [xe]
[ 594.159602] async_op_work_func+0x20c/0x530 [xe]
[ 594.159634] process_one_work+0x263/0x520
[ 594.159640] worker_thread+0x4d/0x3b0
[ 594.159646] kthread+0xeb/0x120
[ 594.159650] ret_from_fork+0x29/0x50
[ 594.159655]
-> #0 (&vm->userptr.notifier_lock){++++}-{3:3}:
[ 594.159663] __lock_acquire+0x16fa/0x2850
[ 594.159670] lock_acquire+0xd2/0x2e0
[ 594.159676] down_write+0x36/0xd0
[ 594.159681] vma_userptr_invalidate+0xeb/0x330 [xe]
[ 594.159714] __mmu_notifier_invalidate_range_start+0x239/0x2a0
[ 594.159722] unmap_vmas+0x1ac/0x1c0
[ 594.159727] unmap_region+0xb5/0x120
[ 594.159732] do_vmi_align_munmap+0x2be/0x430
[ 594.159739] do_vmi_munmap+0xea/0x120
[ 594.159744] __vm_munmap+0x9c/0x160
[ 594.159750] __x64_sys_munmap+0x12/0x20
[ 594.159756] do_syscall_64+0x38/0x90
[ 594.159761] entry_SYSCALL_64_after_hwframe+0x72/0xdc
[ 594.159768]
other info that might help us debug this:
[ 594.159773] Chain exists of:
&vm->userptr.notifier_lock --> fs_reclaim -->
mmu_notifier_invalidate_range_start
[ 594.159785] Possible unsafe locking scenario:
[ 594.159790] CPU0 CPU1
[ 594.159794] ---- ----
[ 594.159797] lock(mmu_notifier_invalidate_range_start);
[ 594.159802] lock(fs_reclaim);
[ 594.159808]
lock(mmu_notifier_invalidate_range_start);
[ 594.159814] lock(&vm->userptr.notifier_lock);
[ 594.159819]
The VM should be holding a mem_access.ref so this looks like it should
be a false positive and we can just drop the explicit mem_access in
xe_gt_tlb_invalidation(). The GGTT invalidation path also takes care to
hold mem_access.ref so should be fine there also, and we already assert
that we hold access.ref for the GuC communication underneath.
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.