From ea2f9985aa4adeef89e9523be295633bb3d0874a Mon Sep 17 00:00:00 2001 From: Honglei Huang Date: Wed, 1 Jul 2026 14:27:59 +0800 Subject: 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 Signed-off-by: Honglei Huang Signed-off-by: Matthew Brost Link: https://patch.msgid.link/20260701062800.409248-3-honghuan@amd.com --- drivers/gpu/drm/drm_gpusvm.c | 18 ++++++++++++------ 1 file 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; -- cgit v1.2.3