Skip to content

K
Kernel

openeuler / Kernel
1 年多 前同步成功

通知 8
Star 0
Fork 0
K
Kernel
切换分支/标签
  1. 03 11月, 2022 1 次提交
  3. 27 10月, 2022 1 次提交
  5. 26 10月, 2022 1 次提交
  7. 20 10月, 2022 1 次提交
  9. 15 10月, 2022 1 次提交
    • N
      drm/amd/display: Fix build breakage with CONFIG_DEBUG_FS=n · 2130b87b
      由 Nathan Chancellor 提交于 
      After commit 8799c0be ("drm/amd/display: Fix vblank refcount in vrr
transition"), a build with CONFIG_DEBUG_FS=n is broken due to a
misplaced brace, along the lines of:

  In file included from drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm_trace.h:39,
                   from drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm.c:41:
  drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm.c: At top level:
  ./include/drm/drm_atomic.h:864:9: error: expected identifier or ‘(’ before ‘for’
    864 |         for ((__i) = 0;                                                 \
        |         ^~~
  drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm.c:8317:9: note: in expansion of macro ‘for_each_new_crtc_in_state’
   8317 |         for_each_new_crtc_in_state(state, crtc, new_crtc_state, j)
        |         ^~~~~~~~~~~~~~~~~~~~~~~~~~

Move the brace within the #ifdef so that the file can be built with or
without CONFIG_DEBUG_FS.

Fixes: 8799c0be ("drm/amd/display: Fix vblank refcount in vrr transition")
Signed-off-by: NNathan Chancellor <nathan@kernel.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      2130b87b
  11. 13 10月, 2022 2 次提交
    • A
      mm: free device private pages have zero refcount · ef233450
      由 Alistair Popple 提交于 
      Since 27674ef6 ("mm: remove the extra ZONE_DEVICE struct page
refcount") device private pages have no longer had an extra reference
count when the page is in use.  However before handing them back to the
owning device driver we add an extra reference count such that free pages
have a reference count of one.

This makes it difficult to tell if a page is free or not because both free
and in use pages will have a non-zero refcount.  Instead we should return
pages to the drivers page allocator with a zero reference count.  Kernel
code can then safely use kernel functions such as get_page_unless_zero().

Link: https://lkml.kernel.org/r/cf70cf6f8c0bdb8aaebdbfb0d790aea4c683c3c6.1664366292.git-series.apopple@nvidia.comSigned-off-by: NAlistair Popple <apopple@nvidia.com>
Acked-by: NFelix Kuehling <Felix.Kuehling@amd.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Lyude Paul <lyude@redhat.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Alex Sierra <alex.sierra@amd.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      ef233450
    • A
      mm/memory.c: fix race when faulting a device private page · 16ce101d
      由 Alistair Popple 提交于 
      Patch series "Fix several device private page reference counting issues",
v2

This series aims to fix a number of page reference counting issues in
drivers dealing with device private ZONE_DEVICE pages.  These result in
use-after-free type bugs, either from accessing a struct page which no
longer exists because it has been removed or accessing fields within the
struct page which are no longer valid because the page has been freed.

During normal usage it is unlikely these will cause any problems.  However
without these fixes it is possible to crash the kernel from userspace. 
These crashes can be triggered either by unloading the kernel module or
unbinding the device from the driver prior to a userspace task exiting. 
In modules such as Nouveau it is also possible to trigger some of these
issues by explicitly closing the device file-descriptor prior to the task
exiting and then accessing device private memory.

This involves some minor changes to both PowerPC and AMD GPU code. 
Unfortunately I lack hardware to test either of those so any help there
would be appreciated.  The changes mimic what is done in for both Nouveau
and hmm-tests though so I doubt they will cause problems.


This patch (of 8):

When the CPU tries to access a device private page the migrate_to_ram()
callback associated with the pgmap for the page is called.  However no
reference is taken on the faulting page.  Therefore a concurrent migration
of the device private page can free the page and possibly the underlying
pgmap.  This results in a race which can crash the kernel due to the
migrate_to_ram() function pointer becoming invalid.  It also means drivers
can't reliably read the zone_device_data field because the page may have
been freed with memunmap_pages().

Close the race by getting a reference on the page while holding the ptl to
ensure it has not been freed.  Unfortunately the elevated reference count
will cause the migration required to handle the fault to fail.  To avoid
this failure pass the faulting page into the migrate_vma functions so that
if an elevated reference count is found it can be checked to see if it's
expected or not.

[mpe@ellerman.id.au: fix build]
  Link: https://lkml.kernel.org/r/87fsgbf3gh.fsf@mpe.ellerman.id.au
Link: https://lkml.kernel.org/r/cover.60659b549d8509ddecafad4f498ee7f03bb23c69.1664366292.git-series.apopple@nvidia.com
Link: https://lkml.kernel.org/r/d3e813178a59e565e8d78d9b9a4e2562f6494f90.1664366292.git-series.apopple@nvidia.comSigned-off-by: NAlistair Popple <apopple@nvidia.com>
Acked-by: NFelix Kuehling <Felix.Kuehling@amd.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Lyude Paul <lyude@redhat.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Alex Sierra <alex.sierra@amd.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      16ce101d
  13. 12 10月, 2022 1 次提交
  15. 11 10月, 2022 32 次提交