From: Ville Syrjälä ville.syrjala@linux.intel.com
This function performs a battery of sanity checks on the requested framebuffer layout. Drivers can call it from their fb_create hook.
Signed-off-by: Ville Syrjälä ville.syrjala@linux.intel.com --- drivers/gpu/drm/drm_crtc_helper.c | 70 +++++++++++++++++++++++++++++++++++++ include/drm/drm_crtc_helper.h | 2 + 2 files changed, 72 insertions(+), 0 deletions(-)
diff --git a/drivers/gpu/drm/drm_crtc_helper.c b/drivers/gpu/drm/drm_crtc_helper.c index 1528068..af5a8f0 100644 --- a/drivers/gpu/drm/drm_crtc_helper.c +++ b/drivers/gpu/drm/drm_crtc_helper.c @@ -1154,3 +1154,73 @@ int drm_format_vert_chroma_subsampling(uint32_t format) } } EXPORT_SYMBOL(drm_format_vert_chroma_subsampling); + +/** + * drm_framebuffer_check - check the framebuffer layout + * @r: cmd from ioctl + * @size: BO size + * + * RETURNS: + * Zero on success, error code on failure. + */ +int drm_framebuffer_check(const struct drm_mode_fb_cmd2 *r, unsigned int size) +{ + struct { + unsigned int start, end; + } ranges[4]; + unsigned int required_size = 0; + int hsub = drm_format_horz_chroma_subsampling(r->pixel_format); + int vsub = drm_format_vert_chroma_subsampling(r->pixel_format); + int num_planes = drm_format_num_planes(r->pixel_format); + int i, j; + + if (r->width == 0 || r->height == 0) + return -EINVAL; + + /* Keep things safe for s15.16 fixed point math. */ + if (r->width > 0x7fff || r->height > 0x7fff) + return -EINVAL; + + if (r->width % hsub || r->height % vsub) + return -EINVAL; + + for (i = 0; i < num_planes; i++) { + unsigned int height = r->height / (i != 0 ? vsub : 1); + unsigned int width = r->width / (i != 0 ? hsub : 1); + unsigned int size = r->pitches[i] * height; + unsigned int cpp = drm_format_plane_cpp(r->pixel_format, i); + unsigned int min_pitch = cpp * width; + + if (size < r->pitches[i] || size < height) + return -EINVAL; + + if (min_pitch < width || min_pitch < cpp) + return -EINVAL; + + if (r->pitches[i] < min_pitch) + return -EINVAL; + + ranges[i].start = r->offsets[i]; + ranges[i].end = ranges[i].start + size; + + if (ranges[i].end < ranges[i].start) + return -EINVAL; + + required_size = max(required_size, ranges[i].end); + } + + if (size < required_size) + return -EINVAL; + + /* Check for overlapping ranges */ + for (i = 0; i < num_planes; i++) { + for (j = i + 1; j < num_planes; j++) { + if (ranges[i].start < ranges[j].end && + ranges[j].start < ranges[i].end) + return -EINVAL; + } + } + + return 0; +} +EXPORT_SYMBOL(drm_framebuffer_check); diff --git a/include/drm/drm_crtc_helper.h b/include/drm/drm_crtc_helper.h index 25d46b8..4d2a53a 100644 --- a/include/drm/drm_crtc_helper.h +++ b/include/drm/drm_crtc_helper.h @@ -151,5 +151,7 @@ extern int drm_format_num_planes(uint32_t format); extern int drm_format_plane_cpp(uint32_t format, int plane); extern int drm_format_horz_chroma_subsampling(uint32_t format); extern int drm_format_vert_chroma_subsampling(uint32_t format); +extern int drm_framebuffer_check(const struct drm_mode_fb_cmd2 *r, + unsigned int size);
#endif