We shouldn't vunmap more then we vmap, but if we do, make sure we complain loudly.

Cc: Sumit Semwal sumit.semwal@linaro.org Cc: Liam Mark lmark@codeaurora.org Cc: Laura Abbott labbott@kernel.org Cc: Brian Starkey Brian.Starkey@arm.com Cc: Hridya Valsaraju hridya@google.com Cc: Suren Baghdasaryan surenb@google.com Cc: Sandeep Patil sspatil@google.com Cc: Daniel Mentz danielmentz@google.com Cc: Chris Goldsworthy cgoldswo@codeaurora.org Cc: Ørjan Eide orjan.eide@arm.com Cc: Robin Murphy robin.murphy@arm.com Cc: Ezequiel Garcia ezequiel@collabora.com Cc: Simon Ser contact@emersion.fr Cc: James Jones jajones@nvidia.com Cc: linux-media@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Suggested-by: Suren Baghdasaryan surenb@google.com Signed-off-by: John Stultz john.stultz@linaro.org --- drivers/dma-buf/heaps/cma_heap.c | 1 + drivers/dma-buf/heaps/system_heap.c | 1 + 2 files changed, 2 insertions(+)

diff --git a/drivers/dma-buf/heaps/cma_heap.c b/drivers/dma-buf/heaps/cma_heap.c index 364fc2f3e499..0c76cbc3fb11 100644 --- a/drivers/dma-buf/heaps/cma_heap.c +++ b/drivers/dma-buf/heaps/cma_heap.c @@ -232,6 +232,7 @@ static void cma_heap_vunmap(struct dma_buf *dmabuf, struct dma_buf_map *map) struct cma_heap_buffer *buffer = dmabuf->priv;

mutex_lock(&buffer->lock); + WARN_ON(buffer->vmap_cnt == 0); if (!--buffer->vmap_cnt) { vunmap(buffer->vaddr); buffer->vaddr = NULL; diff --git a/drivers/dma-buf/heaps/system_heap.c b/drivers/dma-buf/heaps/system_heap.c index 405351aad2a8..2321c91891f6 100644 --- a/drivers/dma-buf/heaps/system_heap.c +++ b/drivers/dma-buf/heaps/system_heap.c @@ -273,6 +273,7 @@ static void system_heap_vunmap(struct dma_buf *dmabuf, struct dma_buf_map *map) struct system_heap_buffer *buffer = dmabuf->priv;

mutex_lock(&buffer->lock); + WARN_ON(buffer->vmap_cnt == 0); if (!--buffer->vmap_cnt) { vunmap(buffer->vaddr); buffer->vaddr = NULL;

Every heap needs to create a dmabuf and then export it to a fd via dma_buf_fd(), so to consolidate things a bit, have the heaps just return a struct dmabuf * and let the top level dma_heap_buffer_alloc() call handle creating the fd via dma_buf_fd().

Cc: Sumit Semwal sumit.semwal@linaro.org Cc: Liam Mark lmark@codeaurora.org Cc: Laura Abbott labbott@kernel.org Cc: Brian Starkey Brian.Starkey@arm.com Cc: Hridya Valsaraju hridya@google.com Cc: Suren Baghdasaryan surenb@google.com Cc: Sandeep Patil sspatil@google.com Cc: Daniel Mentz danielmentz@google.com Cc: Chris Goldsworthy cgoldswo@codeaurora.org Cc: Ørjan Eide orjan.eide@arm.com Cc: Robin Murphy robin.murphy@arm.com Cc: Ezequiel Garcia ezequiel@collabora.com Cc: Simon Ser contact@emersion.fr Cc: James Jones jajones@nvidia.com Cc: linux-media@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Signed-off-by: John Stultz john.stultz@linaro.org --- drivers/dma-buf/dma-heap.c | 14 +++++++++++++- drivers/dma-buf/heaps/cma_heap.c | 22 +++++++--------------- drivers/dma-buf/heaps/system_heap.c | 21 +++++++-------------- include/linux/dma-heap.h | 12 ++++++------ 4 files changed, 33 insertions(+), 36 deletions(-)

diff --git a/drivers/dma-buf/dma-heap.c b/drivers/dma-buf/dma-heap.c index afd22c9dbdcf..6b5db954569f 100644 --- a/drivers/dma-buf/dma-heap.c +++ b/drivers/dma-buf/dma-heap.c @@ -52,6 +52,9 @@ static int dma_heap_buffer_alloc(struct dma_heap *heap, size_t len, unsigned int fd_flags, unsigned int heap_flags) { + struct dma_buf *dmabuf; + int fd; + /* * Allocations from all heaps have to begin * and end on page boundaries. @@ -60,7 +63,16 @@ static int dma_heap_buffer_alloc(struct dma_heap *heap, size_t len, if (!len) return -EINVAL;

- return heap->ops->allocate(heap, len, fd_flags, heap_flags); + dmabuf = heap->ops->allocate(heap, len, fd_flags, heap_flags); + if (IS_ERR(dmabuf)) + return PTR_ERR(dmabuf); + + fd = dma_buf_fd(dmabuf, fd_flags); + if (fd < 0) { + dma_buf_put(dmabuf); + /* just return, as put will call release and that will free */ + } + return fd; }

static int dma_heap_open(struct inode *inode, struct file *file) diff --git a/drivers/dma-buf/heaps/cma_heap.c b/drivers/dma-buf/heaps/cma_heap.c index 0c76cbc3fb11..985c41ffd85b 100644 --- a/drivers/dma-buf/heaps/cma_heap.c +++ b/drivers/dma-buf/heaps/cma_heap.c @@ -272,10 +272,10 @@ static const struct dma_buf_ops cma_heap_buf_ops = { .release = cma_heap_dma_buf_release, };

-static int cma_heap_allocate(struct dma_heap *heap, - unsigned long len, - unsigned long fd_flags, - unsigned long heap_flags) +static struct dma_buf *cma_heap_allocate(struct dma_heap *heap, + unsigned long len, + unsigned long fd_flags, + unsigned long heap_flags) { struct cma_heap *cma_heap = dma_heap_get_drvdata(heap); struct cma_heap_buffer *buffer; @@ -290,7 +290,7 @@ static int cma_heap_allocate(struct dma_heap *heap,

buffer = kzalloc(sizeof(*buffer), GFP_KERNEL); if (!buffer) - return -ENOMEM; + return ERR_PTR(-ENOMEM);

INIT_LIST_HEAD(&buffer->attachments); mutex_init(&buffer->lock); @@ -349,15 +349,7 @@ static int cma_heap_allocate(struct dma_heap *heap, ret = PTR_ERR(dmabuf); goto free_pages; } - - ret = dma_buf_fd(dmabuf, fd_flags); - if (ret < 0) { - dma_buf_put(dmabuf); - /* just return, as put will call release and that will free */ - return ret; - } - - return ret; + return dmabuf;

free_pages: kfree(buffer->pages); @@ -366,7 +358,7 @@ static int cma_heap_allocate(struct dma_heap *heap, free_buffer: kfree(buffer);

- return ret; + return ERR_PTR(ret); }

static const struct dma_heap_ops cma_heap_ops = { diff --git a/drivers/dma-buf/heaps/system_heap.c b/drivers/dma-buf/heaps/system_heap.c index 2321c91891f6..7b154424aeb3 100644 --- a/drivers/dma-buf/heaps/system_heap.c +++ b/drivers/dma-buf/heaps/system_heap.c @@ -332,10 +332,10 @@ static struct page *alloc_largest_available(unsigned long size, return NULL; }

-static int system_heap_allocate(struct dma_heap *heap, - unsigned long len, - unsigned long fd_flags, - unsigned long heap_flags) +static struct dma_buf *system_heap_allocate(struct dma_heap *heap, + unsigned long len, + unsigned long fd_flags, + unsigned long heap_flags) { struct system_heap_buffer *buffer; DEFINE_DMA_BUF_EXPORT_INFO(exp_info); @@ -350,7 +350,7 @@ static int system_heap_allocate(struct dma_heap *heap,

buffer = kzalloc(sizeof(*buffer), GFP_KERNEL); if (!buffer) - return -ENOMEM; + return ERR_PTR(-ENOMEM);

INIT_LIST_HEAD(&buffer->attachments); mutex_init(&buffer->lock); @@ -400,14 +400,7 @@ static int system_heap_allocate(struct dma_heap *heap, ret = PTR_ERR(dmabuf); goto free_pages; } - - ret = dma_buf_fd(dmabuf, fd_flags); - if (ret < 0) { - dma_buf_put(dmabuf); - /* just return, as put will call release and that will free */ - return ret; - } - return ret; + return dmabuf;

free_pages: for_each_sgtable_sg(table, sg, i) { @@ -421,7 +414,7 @@ static int system_heap_allocate(struct dma_heap *heap, __free_pages(page, compound_order(page)); kfree(buffer);

- return ret; + return ERR_PTR(ret); }

static const struct dma_heap_ops system_heap_ops = { diff --git a/include/linux/dma-heap.h b/include/linux/dma-heap.h index 454e354d1ffb..5bc5c946af58 100644 --- a/include/linux/dma-heap.h +++ b/include/linux/dma-heap.h @@ -16,15 +16,15 @@ struct dma_heap;

/** * struct dma_heap_ops - ops to operate on a given heap - * @allocate: allocate dmabuf and return fd + * @allocate: allocate dmabuf and return struct dma_buf ptr * - * allocate returns dmabuf fd on success, -errno on error. + * allocate returns dmabuf on success, ERR_PTR(-errno) on error. */ struct dma_heap_ops { - int (*allocate)(struct dma_heap *heap, - unsigned long len, - unsigned long fd_flags, - unsigned long heap_flags); + struct dma_buf *(*allocate)(struct dma_heap *heap, + unsigned long len, + unsigned long fd_flags, + unsigned long heap_flags); };

/**

Hi John,

On Wed, 20 Jan 2021 at 02:15, John Stultz john.stultz@linaro.org wrote:

If we abort from the allocation due to a fatal_signal_pending(), be sure we report an error so any return code paths don't trip over the fact that the allocation didn't succeed.

Thanks for the patch; LGTM, will push into drm-misc-next.

Cc: Sumit Semwal sumit.semwal@linaro.org Cc: Liam Mark lmark@codeaurora.org Cc: Laura Abbott labbott@kernel.org Cc: Brian Starkey Brian.Starkey@arm.com Cc: Hridya Valsaraju hridya@google.com Cc: Suren Baghdasaryan surenb@google.com Cc: Sandeep Patil sspatil@google.com Cc: Daniel Mentz danielmentz@google.com Cc: Chris Goldsworthy cgoldswo@codeaurora.org Cc: Ørjan Eide orjan.eide@arm.com Cc: Robin Murphy robin.murphy@arm.com Cc: Ezequiel Garcia ezequiel@collabora.com Cc: Simon Ser contact@emersion.fr Cc: James Jones jajones@nvidia.com Cc: linux-media@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Suggested-by: Suren Baghdasaryan surenb@google.com Signed-off-by: John Stultz john.stultz@linaro.org

---

drivers/dma-buf/heaps/system_heap.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/dma-buf/heaps/system_heap.c b/drivers/dma-buf/heaps/system_heap.c index 17e0e9a68baf..405351aad2a8 100644 --- a/drivers/dma-buf/heaps/system_heap.c +++ b/drivers/dma-buf/heaps/system_heap.c @@ -363,8 +363,10 @@ static int system_heap_allocate(struct dma_heap *heap, * Avoid trying to allocate memory if the process * has been killed by SIGKILL */

•           if (fatal_signal_pending(current))
  

•           if (fatal_signal_pending(current)) {
  

•                   ret = -EINTR;
                    goto free_buffer;
  

•           }
  
            page = alloc_largest_available(size_remaining, max_order);
            if (!page)
  

-- 2.17.1

Best, Sumit.