drm/amdkfd: Avoid topology_lock in kfd_mmap

Browse source

Use process-local GPU lookup in kfd_mmap() instead of kfd_device_by_id(),
so mmap path does not take topology_lock while holding mmap_lock.

Lockdep warning: possible circular locking dependency detected.
Chain:
  &topology_lock -> &root->kernfs_rwsem -> &mm->mmap_lock

Backtrace #0 (&topology_lock):
  down_read+0x8b/0x490
  kfd_device_by_id+0x1d/0xf0 [amdgpu]
  kfd_mmap+0x11e/0x750 [amdgpu]
  __mmap_region+0x101f/0x25e0
  mmap_region+0x228/0x2e0
  do_mmap+0x9f2/0x1070
  vm_mmap_pgoff+0x25d/0x430

Backtrace #1 (&root->kernfs_rwsem):
  down_write+0x80/0x200
  kernfs_add_one+0x30/0x6a0
  kernfs_create_dir_ns+0xd2/0x160
  sysfs_create_dir_ns+0x12c/0x2a0
  kobject_add_internal+0x280/0x8e0
  kfd_topology_update_sysfs+0xb85/0x1970 [amdgpu]

Backtrace #2 (&mm->mmap_lock):
  down_read_killable+0x8e/0x510
  lock_mm_and_find_vma+0x299/0xb00
  do_user_addr_fault+0x3fc/0xf80
  exc_page_fault+0x73/0x110
  filldir64+0x1aa/0x610
  kernfs_fop_readdir+0x3c2/0x810

Signed-off-by: Philip Yang <Philip.Yang@amd.com>
Reviewed-by: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

...

This commit is contained in:

Philip Yang 2026-06-21 11:46:37 -04:00 • committed by Alex Deucher

parent 7e1b4bdb0e

commit 2c381b75fa

1 changed files with 5 additions and 3 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

8

drivers/gpu/drm/amd/amdkfd/kfd_chardev.c

View file