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| author | Robin Murphy <robin.murphy@arm.com> | 2019-10-28 20:08:25 +0000 |
|---|---|---|
| committer | Rob Herring <robh@kernel.org> | 2019-10-29 13:18:17 -0500 |
| commit | f70744c68779c8a72a0c82294e3233b994af656d (patch) | |
| tree | 96605060d4e9da19aaa30a854b001277da6401b2 /Documentation/xz.txt | |
| parent | 6f39188c9d5f81af7a3bc687636b7abc9629ee27 (diff) | |
drm/panfrost: Don't dereference bogus MMU pointers
It seems that killing an application while faults are occurring
(particularly with a GPU in FPGA at a whopping 40MHz) can lead to
handling a lingering page fault after all the address space contexts
have already been freed. In this situation, the LRU list is empty so
addr_to_drm_mm_node() ends up dereferencing the list head as if it were
a struct panfrost_mmu entry; this leaves "mmu->as" actually pointing at
the pfdev->alloc_mask bitmap, which is also empty, and given that the
fault has a high likelihood of being in AS0, hilarity ensues.
Sadly, the cleanest solution seems to involve another goto. Oh well, at
least it's robust...
Fixes: 65e51e30d862 ("drm/panfrost: Prevent race when handling page fault")
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/9a0b09e6b5851f0d4428b72dd6b8b4c0d0ef4206.1572293305.git.robin.murphy@arm.com
Diffstat (limited to 'Documentation/xz.txt')
0 files changed, 0 insertions, 0 deletions