diff options
| author | Gerd Hoffmann <kraxel@redhat.com> | 2018-09-11 16:42:10 +0300 |
|---|---|---|
| committer | Gerd Hoffmann <kraxel@redhat.com> | 2018-09-12 09:21:30 +0300 |
| commit | dc4716d75154b36cb115d2a1871655ed0f2e10b2 (patch) | |
| tree | 08e9f359c5a529671e46b3405b3651475b8ce261 | |
| parent | 68d2f70efe2d622483c5cde7c27179a695285fb0 (diff) | |
| download | linux-dc4716d75154b36cb115d2a1871655ed0f2e10b2.tar.xz | |
udmabuf: rework limits
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@redhat.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20180911134216.9760-8-kraxel@redhat.com
| -rw-r--r-- | drivers/dma-buf/udmabuf.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c index 51cc585faab9..e32c381eca7d 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); |