Convert to use vm_insert_range_buggy to map range of kernel memory to user vma.
This driver has ignored vm_pgoff. We could later "fix" these drivers to behave according to the normal vm_pgoff offsetting simply by removing the _buggy suffix on the function name and if that causes regressions, it gives us an easy way to revert. There is an existing bug inside gem_mmap_obj(), where user passed length is not checked against buf->num_pages. For any value of length > buf->num_pages it will end up overrun buf->pages[i], which could lead to a potential bug. This has been addressed by passing buf->num_pages as input to vm_insert_range_buggy() and inside this API error condition is checked which will avoid overrun the page boundary. Signed-off-by: Souptick Joarder <[email protected]> --- drivers/media/common/videobuf2/videobuf2-dma-sg.c | 22 ++++++---------------- 1 file changed, 6 insertions(+), 16 deletions(-) diff --git a/drivers/media/common/videobuf2/videobuf2-dma-sg.c b/drivers/media/common/videobuf2/videobuf2-dma-sg.c index 015e737..ef046b4 100644 --- a/drivers/media/common/videobuf2/videobuf2-dma-sg.c +++ b/drivers/media/common/videobuf2/videobuf2-dma-sg.c @@ -328,28 +328,18 @@ static unsigned int vb2_dma_sg_num_users(void *buf_priv) static int vb2_dma_sg_mmap(void *buf_priv, struct vm_area_struct *vma) { struct vb2_dma_sg_buf *buf = buf_priv; - unsigned long uaddr = vma->vm_start; - unsigned long usize = vma->vm_end - vma->vm_start; - int i = 0; + int err; if (!buf) { printk(KERN_ERR "No memory to map\n"); return -EINVAL; } - do { - int ret; - - ret = vm_insert_page(vma, uaddr, buf->pages[i++]); - if (ret) { - printk(KERN_ERR "Remapping memory, error: %d\n", ret); - return ret; - } - - uaddr += PAGE_SIZE; - usize -= PAGE_SIZE; - } while (usize > 0); - + err = vm_insert_range_buggy(vma, buf->pages, buf->num_pages); + if (err) { + printk(KERN_ERR "Remapping memory, error: %d\n", err); + return err; + } /* * Use common vm_area operations to track buffer refcount. -- 1.9.1
