Linaro-mm-sig September 2018

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[PATCH v2 05/13] udmabuf: constify udmabuf_create args

by Gerd Hoffmann

5 years, 7 months

[PATCH v2 10/13] udmabuf: use ENOTTY for invalid ioctls

by Gerd Hoffmann

5 years, 7 months

[PATCH v2 09/13] udmabuf: use EBADFD in case we didn't got a memfd

by Gerd Hoffmann

Reported-by: Laurent Pinchart <laurent.pinchart(a)ideasonboard.com> Signed-off-by: Gerd Hoffmann <kraxel(a)redhat.com> Acked-by: Daniel Vetter <daniel.vetter(a)ffwll.ch> --- drivers/dma-buf/udmabuf.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c index e821361566..652707f993 100644 --- a/drivers/dma-buf/udmabuf.c +++ b/drivers/dma-buf/udmabuf.c @@ -154,14 +154,17 @@ static long udmabuf_create(const struct udmabuf_create_list *head, pgbuf = 0; for (i = 0; i < head->count; i++) { + ret = -EBADFD; memfd = fget(list[i].memfd); if (!memfd) goto err; if (!shmem_mapping(file_inode(memfd)->i_mapping)) goto err; seals = memfd_fcntl(memfd, F_GET_SEALS, 0); - if (seals == -EINVAL || - (seals & SEALS_WANTED) != SEALS_WANTED || + if (seals == -EINVAL) + goto err; + ret = -EINVAL; + if ((seals & SEALS_WANTED) != SEALS_WANTED || (seals & SEALS_DENIED) != 0) goto err; pgoff = list[i].offset >> PAGE_SHIFT; -- 2.9.3

5 years, 7 months

[PATCH v2 08/13] udmabuf: improve udmabuf_create error handling

by Gerd Hoffmann

Reported-by: Laurent Pinchart <laurent.pinchart(a)ideasonboard.com> Signed-off-by: Gerd Hoffmann <kraxel(a)redhat.com> Reviewed-by: Laurent Pinchart <laurent.pinchart(a)ideasonboard.com> Acked-by: Daniel Vetter <daniel.vetter(a)ffwll.ch> --- drivers/dma-buf/udmabuf.c | 25 ++++++++++++------------- 1 file changed, 12 insertions(+), 13 deletions(-) diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c index a01fcf6a66..e821361566 100644 --- a/drivers/dma-buf/udmabuf.c +++ b/drivers/dma-buf/udmabuf.c @@ -126,7 +126,7 @@ static long udmabuf_create(const struct udmabuf_create_list *head, struct file *memfd = NULL; struct udmabuf *ubuf; struct dma_buf *buf; - pgoff_t pgoff, pgcnt, pgidx, pgbuf, pglimit; + pgoff_t pgoff, pgcnt, pgidx, pgbuf = 0, pglimit; struct page *page; int seals, ret = -EINVAL; u32 i, flags; @@ -138,32 +138,32 @@ static long udmabuf_create(const struct udmabuf_create_list *head, pglimit = (size_limit_mb * 1024 * 1024) >> PAGE_SHIFT; for (i = 0; i < head->count; i++) { if (!IS_ALIGNED(list[i].offset, PAGE_SIZE)) - goto err_free_ubuf; + goto err; if (!IS_ALIGNED(list[i].size, PAGE_SIZE)) - goto err_free_ubuf; + goto err; ubuf->pagecount += list[i].size >> PAGE_SHIFT; if (ubuf->pagecount > pglimit) - goto err_free_ubuf; + goto err; } ubuf->pages = kmalloc_array(ubuf->pagecount, sizeof(struct page *), GFP_KERNEL); if (!ubuf->pages) { ret = -ENOMEM; - goto err_free_ubuf; + goto err; } pgbuf = 0; for (i = 0; i < head->count; i++) { memfd = fget(list[i].memfd); if (!memfd) - goto err_put_pages; + goto err; if (!shmem_mapping(file_inode(memfd)->i_mapping)) - goto err_put_pages; + goto err; seals = memfd_fcntl(memfd, F_GET_SEALS, 0); if (seals == -EINVAL || (seals & SEALS_WANTED) != SEALS_WANTED || (seals & SEALS_DENIED) != 0) - goto err_put_pages; + goto err; pgoff = list[i].offset >> PAGE_SHIFT; pgcnt = list[i].size >> PAGE_SHIFT; for (pgidx = 0; pgidx < pgcnt; pgidx++) { @@ -171,13 +171,13 @@ static long udmabuf_create(const struct udmabuf_create_list *head, file_inode(memfd)->i_mapping, pgoff + pgidx); if (IS_ERR(page)) { ret = PTR_ERR(page); - goto err_put_pages; + goto err; } ubuf->pages[pgbuf++] = page; } fput(memfd); + memfd = NULL; } - memfd = NULL; exp_info.ops = &udmabuf_ops; exp_info.size = ubuf->pagecount << PAGE_SHIFT; @@ -186,7 +186,7 @@ static long udmabuf_create(const struct udmabuf_create_list *head, buf = dma_buf_export(&exp_info); if (IS_ERR(buf)) { ret = PTR_ERR(buf); - goto err_put_pages; + goto err; } flags = 0; @@ -194,10 +194,9 @@ static long udmabuf_create(const struct udmabuf_create_list *head, flags |= O_CLOEXEC; return dma_buf_fd(buf, flags); -err_put_pages: +err: while (pgbuf > 0) put_page(ubuf->pages[--pgbuf]); -err_free_ubuf: if (memfd) fput(memfd); kfree(ubuf->pages); -- 2.9.3

5 years, 7 months

[PATCH v2 07/13] udmabuf: rework limits

by Gerd Hoffmann

Create variable for the list length limit. Serves as documentation, also allows to make it a module parameter if needed. Also add a total size limit. Signed-off-by: Gerd Hoffmann <kraxel(a)redhat.com> Acked-by: Daniel Vetter <daniel.vetter(a)ffwll.ch> --- drivers/dma-buf/udmabuf.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c index 4167da8141..a01fcf6a66 100644 --- a/drivers/dma-buf/udmabuf.c +++ b/drivers/dma-buf/udmabuf.c @@ -12,6 +12,9 @@ #include <linux/slab.h> #include <linux/udmabuf.h> +static const u32 list_limit = 1024; /* udmabuf_create_list->count limit */ +static const size_t size_limit_mb = 64; /* total dmabuf size, in megabytes */ + struct udmabuf { pgoff_t pagecount; struct page **pages; @@ -123,7 +126,7 @@ static long udmabuf_create(const struct udmabuf_create_list *head, struct file *memfd = NULL; struct udmabuf *ubuf; struct dma_buf *buf; - pgoff_t pgoff, pgcnt, pgidx, pgbuf; + pgoff_t pgoff, pgcnt, pgidx, pgbuf, pglimit; struct page *page; int seals, ret = -EINVAL; u32 i, flags; @@ -132,12 +135,15 @@ static long udmabuf_create(const struct udmabuf_create_list *head, if (!ubuf) return -ENOMEM; + pglimit = (size_limit_mb * 1024 * 1024) >> PAGE_SHIFT; for (i = 0; i < head->count; i++) { if (!IS_ALIGNED(list[i].offset, PAGE_SIZE)) goto err_free_ubuf; if (!IS_ALIGNED(list[i].size, PAGE_SIZE)) goto err_free_ubuf; ubuf->pagecount += list[i].size >> PAGE_SHIFT; + if (ubuf->pagecount > pglimit) + goto err_free_ubuf; } ubuf->pages = kmalloc_array(ubuf->pagecount, sizeof(struct page *), GFP_KERNEL); @@ -227,7 +233,7 @@ static long udmabuf_ioctl_create_list(struct file *filp, unsigned long arg) if (copy_from_user(&head, (void __user *)arg, sizeof(head))) return -EFAULT; - if (head.count > 1024) + if (head.count > list_limit) return -EINVAL; lsize = sizeof(struct udmabuf_create_item) * head.count; list = memdup_user((void __user *)(arg + sizeof(head)), lsize); -- 2.9.3

5 years, 7 months

[PATCH v2 06/13] udmabuf: add MEMFD_CREATE dependency

by Gerd Hoffmann

udmabuf builds without it, but if userspace can not create memfd handles in the first place it is rather pointless to include it, except for test builds. Signed-off-by: Gerd Hoffmann <kraxel(a)redhat.com> Acked-by: Daniel Vetter <daniel.vetter(a)ffwll.ch> --- drivers/dma-buf/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/dma-buf/Kconfig b/drivers/dma-buf/Kconfig index 338129eb12..2e5a0faa2c 100644 --- a/drivers/dma-buf/Kconfig +++ b/drivers/dma-buf/Kconfig @@ -34,6 +34,7 @@ config UDMABUF bool "userspace dmabuf misc driver" default n depends on DMA_SHARED_BUFFER + depends on MEMFD_CREATE || COMPILE_TEST help A driver to let userspace turn memfd regions into dma-bufs. Qemu can use this to create host dmabufs for guest framebuffers. -- 2.9.3

5 years, 7 months

[PATCH v2 04/13] udmabuf: constify udmabuf_ops

by Gerd Hoffmann

5 years, 7 months

[PATCH v2 03/13] udmabuf: use pgoff_t for pagecount

by Gerd Hoffmann

5 years, 7 months

[PATCH v2 02/13] udmabuf: improve map_udmabuf error handling

by Gerd Hoffmann

5 years, 7 months

[PATCH v2 01/13] udmabuf: sort headers, drop uapi/ path prefix

by Gerd Hoffmann

5 years, 7 months

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Linaro-mm-sig September 2018