From: Huan Yang Date: Mon, 28 Apr 2025 07:38:29 +0000 (+0800) Subject: Revert "udmabuf: fix vmap_udmabuf error page set" X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=ceb7b62eaaaacfcf87473bd2e99ac73a758620cb;p=thirdparty%2Fkernel%2Flinux.git Revert "udmabuf: fix vmap_udmabuf error page set" This reverts commit 18d7de823b7150344d242c3677e65d68c5271b04. We cannot use vmap_pfn() in vmap_udmabuf() as it would fail the pfn_valid() check in vmap_pfn_apply(). This is because vmap_pfn() is intended to be used for mapping non-struct-page memory such as PCIe BARs. Since, udmabuf mostly works with pages/folios backed by shmem/hugetlbfs/THP, vmap_pfn() is not the right tool or API to invoke for implementing vmap. Signed-off-by: Huan Yang Suggested-by: Vivek Kasireddy Reported-by: Bingbu Cao Closes: https://lore.kernel.org/dri-devel/eb7e0137-3508-4287-98c4-816c5fd98e10@vivo.com/T/#mbda4f64a3532b32e061f4e8763bc8e307bea3ca8 Acked-by: Vivek Kasireddy Signed-off-by: Vivek Kasireddy Link: https://lore.kernel.org/r/20250428073831.19942-2-link@vivo.com --- diff --git a/drivers/dma-buf/Kconfig b/drivers/dma-buf/Kconfig index fee04fdb08220..b46eb8a552d7b 100644 --- a/drivers/dma-buf/Kconfig +++ b/drivers/dma-buf/Kconfig @@ -36,7 +36,6 @@ config UDMABUF depends on DMA_SHARED_BUFFER depends on MEMFD_CREATE || COMPILE_TEST depends on MMU - select VMAP_PFN help A driver to let userspace turn memfd regions into dma-bufs. Qemu can use this to create host dmabufs for guest framebuffers. diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c index 7eee3eb47a8ee..79845565089da 100644 --- a/drivers/dma-buf/udmabuf.c +++ b/drivers/dma-buf/udmabuf.c @@ -109,29 +109,21 @@ static int mmap_udmabuf(struct dma_buf *buf, struct vm_area_struct *vma) static int vmap_udmabuf(struct dma_buf *buf, struct iosys_map *map) { struct udmabuf *ubuf = buf->priv; - unsigned long *pfns; + struct page **pages; void *vaddr; pgoff_t pg; dma_resv_assert_held(buf->resv); - /** - * HVO may free tail pages, so just use pfn to map each folio - * into vmalloc area. - */ - pfns = kvmalloc_array(ubuf->pagecount, sizeof(*pfns), GFP_KERNEL); - if (!pfns) + pages = kvmalloc_array(ubuf->pagecount, sizeof(*pages), GFP_KERNEL); + if (!pages) return -ENOMEM; - for (pg = 0; pg < ubuf->pagecount; pg++) { - unsigned long pfn = folio_pfn(ubuf->folios[pg]); - - pfn += ubuf->offsets[pg] >> PAGE_SHIFT; - pfns[pg] = pfn; - } + for (pg = 0; pg < ubuf->pagecount; pg++) + pages[pg] = &ubuf->folios[pg]->page; - vaddr = vmap_pfn(pfns, ubuf->pagecount, PAGE_KERNEL); - kvfree(pfns); + vaddr = vm_map_ram(pages, ubuf->pagecount, -1); + kvfree(pages); if (!vaddr) return -EINVAL;