Commit 27f3733a authored by Dmitry Osipenko's avatar Dmitry Osipenko
Browse files

dma-buf/heaps: 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 checks to the dma-buf mmaping callbacks to ensure
that the locking assumptions won't regress in the future.

Suggested-by: default avatarDaniel Vetter <daniel@ffwll.ch>
Signed-off-by: default avatarDmitry Osipenko <dmitry.osipenko@collabora.com>
Acked-by: default avatarChristian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221110201349.351294-5-dmitry.osipenko@collabora.com
parent aa3f9989

drivers/dma-buf/heaps/cma_heap.c

+3 −0
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 
#include <linux/dma-buf.h>

#include <linux/dma-heap.h>

#include <linux/dma-map-ops.h>

#include <linux/dma-resv.h>

#include <linux/err.h>

#include <linux/highmem.h>

#include <linux/io.h>
@@ -182,6 +183,8 @@ static int cma_heap_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma) 
{

	struct cma_heap_buffer *buffer = dmabuf->priv;



	dma_resv_assert_held(dmabuf->resv);



	if ((vma->vm_flags & (VM_SHARED | VM_MAYSHARE)) == 0)

		return -EINVAL;

drivers/dma-buf/heaps/system_heap.c

+3 −0
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 
#include <linux/dma-buf.h>

#include <linux/dma-mapping.h>

#include <linux/dma-heap.h>

#include <linux/dma-resv.h>

#include <linux/err.h>

#include <linux/highmem.h>

#include <linux/mm.h>
@@ -201,6 +202,8 @@ static int system_heap_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma) 
	struct sg_page_iter piter;

	int ret;



	dma_resv_assert_held(dmabuf->resv);



	for_each_sgtable_page(table, &piter, vma->vm_pgoff) {

		struct page *page = sg_page_iter_page(&piter);