| From | Ben Hutchings <> | Date | Wed, 12 Feb 2014 08:10:12 +0000 | Subject | [PATCH 3.2 45/79] drm/ttm: Fix accesses through vmas with only partial coverage |
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3.2.55-rc1 review patch. If anyone has any objections, please let me know.
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From: Thomas Hellstrom <thellstrom@vmware.com>
commit d386735588c3e22129c2bc6eb64fc1d37a8f805c upstream.
VMAs covering a bo but that didn't start at the same address space offset as the bo they were mapping were incorrectly generating SEGFAULT errors in the fault handler.
Reported-by: Joseph Dolinak <kanilo2@yahoo.com> Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com> Reviewed-by: Jakob Bornecrantz <jakob@vmware.com> [bwh: Backported to 3.2: drm_vma_node_start() is open-coded; vma_pages() was open-coded] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> --- drivers/gpu/drm/ttm/ttm_bo_vm.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
--- a/drivers/gpu/drm/ttm/ttm_bo_vm.c +++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c @@ -144,9 +144,9 @@ static int ttm_bo_vm_fault(struct vm_are } page_offset = ((address - vma->vm_start) >> PAGE_SHIFT) + - bo->vm_node->start - vma->vm_pgoff; - page_last = ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) + - bo->vm_node->start - vma->vm_pgoff; + vma->vm_pgoff - bo->vm_node->start; + page_last = vma_pages(vma) + vma->vm_pgoff - + bo->vm_node->start; if (unlikely(page_offset >= bo->num_pages)) { retval = VM_FAULT_SIGBUS;
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