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| author | Honglei Huang <honghuan@amd.com> | 2026-07-01 14:27:59 +0800 |
|---|---|---|
| committer | Matthew Brost <matthew.brost@intel.com> | 2026-07-14 09:27:31 -0700 |
| commit | ea2f9985aa4adeef89e9523be295633bb3d0874a (patch) | |
| tree | c83dd5d9a578ec7078a43e708698b25dfd6f5f1c | |
| parent | 0bc7c196f3ab855da0879283ba633c4c51ddfd81 (diff) | |
| download | linux-next-ea2f9985aa4adeef89e9523be295633bb3d0874a.tar.gz linux-next-ea2f9985aa4adeef89e9523be295633bb3d0874a.zip | |
drm/gpusvm: do not route system pages to device_unmap() on IOVA unmap
In a mixed range: ctx->allow_mixed dpagemap is not NULL while some entries
are system pages. The unmap loop used:
dma_unmap_page(...);
else if (dpagemap && dpagemap->ops->device_unmap)
dpagemap->ops->device_unmap(...);
When use_iova is true the first condition is false for system pages,
so they fall through to device_unmap() and a system DMA address is
handed to the device specific unmap callback, risking invalid accesses
or state corruption.
Key the branch off addr->proto instead: system pages only need an explicit
dma_unmap_page() in the non IOVA case, IOVA system pages are already torn
down by the single dma_iova_destroy(), and only genuine device pages
reach device_unmap().
This issue was found by Sashiko AI review.
Fixes: 37ad039fb367 ("drm/gpusvm: Use dma-map IOVA alloc, link, and sync API in GPU SVM")
Cc: stable@vger.kernel.org
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Honglei Huang <honghuan@amd.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Link: https://patch.msgid.link/20260701062800.409248-3-honghuan@amd.com
| -rw-r--r-- | drivers/gpu/drm/drm_gpusvm.c | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/drivers/gpu/drm/drm_gpusvm.c b/drivers/gpu/drm/drm_gpusvm.c index 3145d55cd860..44bb19658dd6 100644 --- a/drivers/gpu/drm/drm_gpusvm.c +++ b/drivers/gpu/drm/drm_gpusvm.c @@ -1163,12 +1163,18 @@ static void __drm_gpusvm_unmap_pages(struct drm_gpusvm *gpusvm, for (i = 0, j = 0; i < npages; j++) { struct drm_pagemap_addr *addr = &svm_pages->dma_addr[j]; - if (!use_iova && addr->proto == DRM_INTERCONNECT_SYSTEM) - dma_unmap_page(dev, - addr->addr, - PAGE_SIZE << addr->order, - addr->dir); - else if (dpagemap && dpagemap->ops->device_unmap) + if (addr->proto == DRM_INTERCONNECT_SYSTEM) { + /* + * Linked IOVA pages were already torn down by + * the dma_iova_unlink()/dma_iova_free() above; + * only the non-IOVA mappings need unmap here. + */ + if (!use_iova) + dma_unmap_page(dev, + addr->addr, + PAGE_SIZE << addr->order, + addr->dir); + } else if (dpagemap && dpagemap->ops->device_unmap) dpagemap->ops->device_unmap(dpagemap, dev, addr); i += 1 << addr->order; |