Christian König
2022-Aug-24 14:01 UTC
[PATCH v3 5/9] dma-buf: Move dma_buf_mmap_unlocked() to dynamic locking specification
This should work, but I'm really wondering if this makes a difference for somebody. Anyway the approach is fine with me: Acked-by: Christian K?nig <christian.koenig at amd.com> Regards, Christian. Am 24.08.22 um 12:22 schrieb Dmitry Osipenko:> Move dma_buf_mmap_unlocked() function to the dynamic locking specification > by taking the reservation lock. Neither of the today's drivers take the > reservation lock within the mmap() callback, hence it's safe to enforce > the locking. > > Signed-off-by: Dmitry Osipenko <dmitry.osipenko at collabora.com> > --- > drivers/dma-buf/dma-buf.c | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c > index f358af401360..4556a12bd741 100644 > --- a/drivers/dma-buf/dma-buf.c > +++ b/drivers/dma-buf/dma-buf.c > @@ -1348,6 +1348,8 @@ EXPORT_SYMBOL_NS_GPL(dma_buf_end_cpu_access, DMA_BUF); > int dma_buf_mmap_unlocked(struct dma_buf *dmabuf, struct vm_area_struct *vma, > unsigned long pgoff) > { > + int ret; > + > if (WARN_ON(!dmabuf || !vma)) > return -EINVAL; > > @@ -1368,7 +1370,11 @@ int dma_buf_mmap_unlocked(struct dma_buf *dmabuf, struct vm_area_struct *vma, > vma_set_file(vma, dmabuf->file); > vma->vm_pgoff = pgoff; > > - return dmabuf->ops->mmap(dmabuf, vma); > + dma_resv_lock(dmabuf->resv, NULL); > + ret = dmabuf->ops->mmap(dmabuf, vma); > + dma_resv_unlock(dmabuf->resv); > + > + return ret; > } > EXPORT_SYMBOL_NS_GPL(dma_buf_mmap_unlocked, DMA_BUF); >