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authorDmitry Osipenko <dmitry.osipenko@collabora.com>2022-11-10 23:13:46 +0300
committerDmitry Osipenko <dmitry.osipenko@collabora.com>2022-11-11 23:49:50 +0300
commitaa3f99896443ea26e115f08757008d14430876f9 (patch)
tree096a598843768f8afc75a7cae5c40b959bb3e234 /drivers/dma-buf
parent39ce252918712180f5a64853920a320981dac94b (diff)
downloadlinux-aa3f99896443ea26e115f08757008d14430876f9.tar.bz2
udmabuf: Assert held reservation lock for dma-buf mmapping
When userspace mmaps dma-buf's fd, the dma-buf reservation lock must be held. Add locking sanity check to the dma-buf mmaping callback to ensure that the locking assumption won't regress in the future. Suggested-by: Daniel Vetter <daniel@ffwll.ch> Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> Acked-by: Christian König <christian.koenig@amd.com> Link: https://patchwork.freedesktop.org/patch/msgid/20221110201349.351294-4-dmitry.osipenko@collabora.com
Diffstat (limited to 'drivers/dma-buf')
-rw-r--r--drivers/dma-buf/udmabuf.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c
index 2bcdb935a3ac..283816fbd72f 100644
--- a/drivers/dma-buf/udmabuf.c
+++ b/drivers/dma-buf/udmabuf.c
@@ -2,6 +2,7 @@
#include <linux/cred.h>
#include <linux/device.h>
#include <linux/dma-buf.h>
+#include <linux/dma-resv.h>
#include <linux/highmem.h>
#include <linux/init.h>
#include <linux/kernel.h>
@@ -49,6 +50,8 @@ static int mmap_udmabuf(struct dma_buf *buf, struct vm_area_struct *vma)
{
struct udmabuf *ubuf = buf->priv;
+ dma_resv_assert_held(buf->resv);
+
if ((vma->vm_flags & (VM_SHARED | VM_MAYSHARE)) == 0)
return -EINVAL;