From 85e2d61e49768f85346fe7ff133625eabf0946fe Mon Sep 17 00:00:00 2001 From: Matt Roper Date: Tue, 18 Dec 2018 09:51:58 -0800 Subject: [PATCH] drm/i915: Validate userspace-provided color management LUT's (v4) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit We currently program userspace-provided gamma and degamma LUT's into our hardware without really checking to see whether they satisfy our hardware's rules. We should try to catch tables that are invalid for our hardware early and reject the atomic transaction. All of our platforms that accept a degamma LUT expect that the entries in the LUT are always flat or increasing, never decreasing. Also, our GLK and ICL platforms only accept degamma tables with r=g=b entries; so we should also add the relevant checks for that in anticipation of degamma support landing for those platforms. v2: - Use new API (single check function with bitmask of tests to apply) - Call helper for our gamma table as well (with no additional tests specified) so that the table size will be validated. v3: - Don't call on the gamma table since the LUT size is already tested at property blob upload and we don't have any additional hardware constraints for that LUT. v4: - Apply equal color channel check on gen10 as well; the bspec has some strange tagging for CNL platforms, but this appears to apply there as well. (Ville) Cc: Uma Shankar Cc: Swati Sharma Cc: Ville Syrjälä Signed-off-by: Matt Roper Reviewed-by: Uma Shankar Link: https://patchwork.freedesktop.org/patch/msgid/20181218175158.5739-1-matthew.d.roper@intel.com --- drivers/gpu/drm/i915/intel_color.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/drivers/gpu/drm/i915/intel_color.c b/drivers/gpu/drm/i915/intel_color.c index 299eb7858adc..bc7589656a8f 100644 --- a/drivers/gpu/drm/i915/intel_color.c +++ b/drivers/gpu/drm/i915/intel_color.c @@ -609,10 +609,26 @@ int intel_color_check(struct intel_crtc_state *crtc_state) { struct drm_i915_private *dev_priv = to_i915(crtc_state->base.crtc->dev); size_t gamma_length, degamma_length; + uint32_t tests = DRM_COLOR_LUT_NON_DECREASING; degamma_length = INTEL_INFO(dev_priv)->color.degamma_lut_size; gamma_length = INTEL_INFO(dev_priv)->color.gamma_lut_size; + /* + * All of our platforms mandate that the degamma curve be + * non-decreasing. Additionally, GLK and gen11 only accept a single + * value for red, green, and blue in the degamma table. Make sure + * userspace didn't try to pass us something we can't handle. + * + * We don't have any extra hardware constraints on the gamma table, + * so no need to explicitly check it. + */ + if (IS_GEMINILAKE(dev_priv) || INTEL_GEN(dev_priv) >= 10) + tests |= DRM_COLOR_LUT_EQUAL_CHANNELS; + + if (drm_color_lut_check(crtc_state->base.degamma_lut, tests) != 0) + return -EINVAL; + /* * We allow both degamma & gamma luts at the right size or * NULL.