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| author | Kirill A. Shutemov <[email protected]> | 2017-04-25 09:25:57 +0000 |
|---|---|---|
| committer | Ingo Molnar <[email protected]> | 2017-04-26 06:26:43 +0000 |
| commit | e6ab9c4d437764c7fb728d428dc9e717cdb183d0 (patch) | |
| tree | 4cae14dfd336fb180108154065811653dcfe23f3 /drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c | |
| parent | Revert "x86/mm/gup: Switch GUP to the generic get_user_page_fast() implementa... (diff) | |
| download | kernel-e6ab9c4d437764c7fb728d428dc9e717cdb183d0.tar.gz kernel-e6ab9c4d437764c7fb728d428dc9e717cdb183d0.zip | |
x86/mm/64: Fix crash in remove_pagetable()
remove_pagetable() does page walk using p*d_page_vaddr() plus cast.
It's not canonical approach -- we usually use p*d_offset() for that.
It works fine as long as all page table levels are present. We broke the
invariant by introducing folded p4d page table level.
As result, remove_pagetable() interprets PMD as PUD and it leads to
crash:
BUG: unable to handle kernel paging request at ffff880300000000
IP: memchr_inv+0x60/0x110
PGD 317d067
P4D 317d067
PUD 3180067
PMD 33f102067
PTE 8000000300000060
Let's fix this by using p*d_offset() instead of p*d_page_vaddr() for
page walk.
Reported-by: Dan Williams <[email protected]>
Tested-by: Dan Williams <[email protected]>
Signed-off-by: Kirill A. Shutemov <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Fixes: f2a6a7050109 ("x86: Convert the rest of the code to support p4d_t")
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
Diffstat (limited to 'drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c')
0 files changed, 0 insertions, 0 deletions