From: Daniel Thompson Date: Tue, 22 Dec 2015 21:36:44 +0000 (-0200) Subject: UPSTREAM: drm: prime: Honour O_RDWR during prime-handle-to-fd X-Git-Tag: firefly_0821_release~2819 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=ed5594204426d3fe4e32f9a4099755bd49ca0d1e;p=firefly-linux-kernel-4.4.55.git UPSTREAM: drm: prime: Honour O_RDWR during prime-handle-to-fd 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 (cherry picked from commit bfe981a0952880df43d08a050bf3ae44aaebd795) Signed-off-by: Brian Norris Change-Id: Ieb3c547b1a08bd9c90fe72e0a1df1757d100aa8e Reviewed-on: https://chrome-internal-review.googlesource.com/255266 Tested-by: Brian Norris Reviewed-by: Doug Anderson Signed-off-by: Caesar Wang --- diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c index 9f935f55d74c..21eda25e6522 100644 --- a/drivers/gpu/drm/drm_prime.c +++ b/drivers/gpu/drm/drm_prime.c @@ -333,7 +333,7 @@ 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. @@ -632,7 +632,6 @@ 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; @@ -641,14 +640,11 @@ 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, diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h index 3801584a0c53..ad8223e3e0b2 100644 --- a/include/uapi/drm/drm.h +++ b/include/uapi/drm/drm.h @@ -668,6 +668,7 @@ struct drm_set_client_cap { __u64 value; }; +#define DRM_RDWR O_RDWR #define DRM_CLOEXEC O_CLOEXEC struct drm_prime_handle { __u32 handle;