Commit bfe981a0 authored by Daniel Thompson's avatar Daniel Thompson Committed by Daniel Vetter

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: default avatarChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: default avatarDaniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: default avatarTiago Vignatti <tiago.vignatti@intel.com>
Reviewed-by: default avatarStéphane Marchesin <marcheu@chromium.org>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1450820214-12509-2-git-send-email-tiago.vignatti@intel.com
parent 10c1b618
...@@ -329,7 +329,7 @@ static const struct dma_buf_ops drm_gem_prime_dmabuf_ops = { ...@@ -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 * drm_gem_prime_export - helper library implementation of the export callback
* @dev: drm_device to export from * @dev: drm_device to export from
* @obj: GEM object to export * @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 * This is the implementation of the gem_prime_export functions for GEM drivers
* using the PRIME helpers. * using the PRIME helpers.
...@@ -628,7 +628,6 @@ int drm_prime_handle_to_fd_ioctl(struct drm_device *dev, void *data, ...@@ -628,7 +628,6 @@ int drm_prime_handle_to_fd_ioctl(struct drm_device *dev, void *data,
struct drm_file *file_priv) struct drm_file *file_priv)
{ {
struct drm_prime_handle *args = data; struct drm_prime_handle *args = data;
uint32_t flags;
if (!drm_core_check_feature(dev, DRIVER_PRIME)) if (!drm_core_check_feature(dev, DRIVER_PRIME))
return -EINVAL; return -EINVAL;
...@@ -637,14 +636,11 @@ int drm_prime_handle_to_fd_ioctl(struct drm_device *dev, void *data, ...@@ -637,14 +636,11 @@ int drm_prime_handle_to_fd_ioctl(struct drm_device *dev, void *data,
return -ENOSYS; return -ENOSYS;
/* check flags are valid */ /* check flags are valid */
if (args->flags & ~DRM_CLOEXEC) if (args->flags & ~(DRM_CLOEXEC | DRM_RDWR))
return -EINVAL; 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, 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, int drm_prime_fd_to_handle_ioctl(struct drm_device *dev, void *data,
......
...@@ -669,6 +669,7 @@ struct drm_set_client_cap { ...@@ -669,6 +669,7 @@ struct drm_set_client_cap {
__u64 value; __u64 value;
}; };
#define DRM_RDWR O_RDWR
#define DRM_CLOEXEC O_CLOEXEC #define DRM_CLOEXEC O_CLOEXEC
struct drm_prime_handle { struct drm_prime_handle {
__u32 handle; __u32 handle;
......
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