6.6-stable review patch. If anyone has any objections, please let me know.
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From: Boris Brezillon boris.brezillon@collabora.com
commit 1fc9af813b25e146d3607669247d0f970f5a87c3 upstream.
Subject: [PATCH 6.6 092/122] drm/panfrost: Fix the error path in panfrost_mmu_map_fault_addr()
If some the pages or sgt allocation failed, we shouldn't release the pages ref we got earlier, otherwise we will end up with unbalanced get/put_pages() calls. We should instead leave everything in place and let the BO release function deal with extra cleanup when the object is destroyed, or let the fault handler try again next time it's called.
Fixes: 187d2929206e ("drm/panfrost: Add support for GPU heap allocations") Cc: stable@vger.kernel.org Reviewed-by: Steven Price steven.price@arm.com Reviewed-by: AngeloGioacchino Del Regno angelogioacchino.delregno@collabora.com Signed-off-by: Boris Brezillon boris.brezillon@collabora.com Co-developed-by: Dmitry Osipenko dmitry.osipenko@collabora.com Signed-off-by: Dmitry Osipenko dmitry.osipenko@collabora.com Link: https://patchwork.freedesktop.org/patch/msgid/20240105184624.508603-18-dmitr... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/gpu/drm/panfrost/panfrost_mmu.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-)
--- a/drivers/gpu/drm/panfrost/panfrost_mmu.c +++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c @@ -500,11 +500,18 @@ static int panfrost_mmu_map_fault_addr(s mapping_set_unevictable(mapping);
for (i = page_offset; i < page_offset + NUM_FAULT_PAGES; i++) { + /* Can happen if the last fault only partially filled this + * section of the pages array before failing. In that case + * we skip already filled pages. + */ + if (pages[i]) + continue; + pages[i] = shmem_read_mapping_page(mapping, i); if (IS_ERR(pages[i])) { ret = PTR_ERR(pages[i]); pages[i] = NULL; - goto err_pages; + goto err_unlock; } }
@@ -512,7 +519,7 @@ static int panfrost_mmu_map_fault_addr(s ret = sg_alloc_table_from_pages(sgt, pages + page_offset, NUM_FAULT_PAGES, 0, SZ_2M, GFP_KERNEL); if (ret) - goto err_pages; + goto err_unlock;
ret = dma_map_sgtable(pfdev->dev, sgt, DMA_BIDIRECTIONAL, 0); if (ret) @@ -534,8 +541,6 @@ out:
err_map: sg_free_table(sgt); -err_pages: - drm_gem_shmem_put_pages(&bo->base); err_unlock: dma_resv_unlock(obj->resv); err_bo: