From bfe981a0952880df43d08a050bf3ae44aaebd795 Mon Sep 17 00:00:00 2001 From: Daniel Thompson Date: Tue, 22 Dec 2015 19:36:44 -0200 Subject: drm: prime: Honour O_RDWR during prime-handle-to-fd MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Currently DRM_IOCTL_PRIME_HANDLE_TO_FD rejects all flags except (DRM|O)_CLOEXEC making it difficult (maybe impossible) for userspace to mmap() the resulting dma-buf even when this is supported by the DRM driver. It is trivial to relax the restriction and permit read/write access. This is safe because the flags are seldom touched by drm; mostly they are passed verbatim to dma_buf calls. v3 (Tiago): removed unused flags variable from drm_prime_handle_to_fd_ioctl. Reviewed-by: Chris Wilson Signed-off-by: Daniel Thompson Signed-off-by: Tiago Vignatti Reviewed-by: Stéphane Marchesin Signed-off-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/1450820214-12509-2-git-send-email-tiago.vignatti@intel.com --- drivers/gpu/drm/drm_prime.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) (limited to 'drivers/gpu/drm') diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c index 27aa7183b20b..df6cdc76a16e 100644 --- a/drivers/gpu/drm/drm_prime.c +++ b/drivers/gpu/drm/drm_prime.c @@ -329,7 +329,7 @@ static const struct dma_buf_ops drm_gem_prime_dmabuf_ops = { * drm_gem_prime_export - helper library implementation of the export callback * @dev: drm_device to export from * @obj: GEM object to export - * @flags: flags like DRM_CLOEXEC + * @flags: flags like DRM_CLOEXEC and DRM_RDWR * * This is the implementation of the gem_prime_export functions for GEM drivers * using the PRIME helpers. @@ -628,7 +628,6 @@ int drm_prime_handle_to_fd_ioctl(struct drm_device *dev, void *data, struct drm_file *file_priv) { struct drm_prime_handle *args = data; - uint32_t flags; if (!drm_core_check_feature(dev, DRIVER_PRIME)) return -EINVAL; @@ -637,14 +636,11 @@ int drm_prime_handle_to_fd_ioctl(struct drm_device *dev, void *data, return -ENOSYS; /* check flags are valid */ - if (args->flags & ~DRM_CLOEXEC) + if (args->flags & ~(DRM_CLOEXEC | DRM_RDWR)) return -EINVAL; - /* we only want to pass DRM_CLOEXEC which is == O_CLOEXEC */ - flags = args->flags & DRM_CLOEXEC; - return dev->driver->prime_handle_to_fd(dev, file_priv, - args->handle, flags, &args->fd); + args->handle, args->flags, &args->fd); } int drm_prime_fd_to_handle_ioctl(struct drm_device *dev, void *data, -- cgit v1.2.3