From 3d1ab66e043f2a143e4d93242de7710a9c98c829 Mon Sep 17 00:00:00 2001 From: Jani Nikula Date: Wed, 29 Jun 2022 12:27:52 +0300 Subject: [PATCH] drm/edid: add drm_edid_raw() to access the raw EDID data MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Unfortunately, there are still plenty of interfaces around that require a struct edid pointer, and it's impossible to change them all at once. Add an accessor to the raw EDID data to help the transition. While there are no such cases now, be defensive against raw EDID extension count indicating bigger EDID than is actually allocated. Signed-off-by: Jani Nikula Reviewed-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/fb55d0b580d556bf2b8e58070239657ac9cb4b2f.1656494768.git.jani.nikula@intel.com --- drivers/gpu/drm/drm_edid.c | 26 ++++++++++++++++++++++++++ include/drm/drm_edid.h | 1 + 2 files changed, 27 insertions(+) diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c index 41b3de5..1c761e1 100644 --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -2359,6 +2359,32 @@ struct edid *drm_do_get_edid(struct drm_connector *connector, } EXPORT_SYMBOL_GPL(drm_do_get_edid); +/** + * drm_edid_raw - Get a pointer to the raw EDID data. + * @drm_edid: drm_edid container + * + * Get a pointer to the raw EDID data. + * + * This is for transition only. Avoid using this like the plague. + * + * Return: Pointer to raw EDID data. + */ +const struct edid *drm_edid_raw(const struct drm_edid *drm_edid) +{ + if (!drm_edid || !drm_edid->size) + return NULL; + + /* + * Do not return pointers where relying on EDID extension count would + * lead to buffer overflow. + */ + if (WARN_ON(edid_size(drm_edid->edid) > drm_edid->size)) + return NULL; + + return drm_edid->edid; +} +EXPORT_SYMBOL(drm_edid_raw); + /* Allocate struct drm_edid container *without* duplicating the edid data */ static const struct drm_edid *_drm_edid_alloc(const void *edid, size_t size) { diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h index aeb2fa9..2181977 100644 --- a/include/drm/drm_edid.h +++ b/include/drm/drm_edid.h @@ -597,6 +597,7 @@ drm_display_mode_from_cea_vic(struct drm_device *dev, const struct drm_edid *drm_edid_alloc(const void *edid, size_t size); const struct drm_edid *drm_edid_dup(const struct drm_edid *drm_edid); void drm_edid_free(const struct drm_edid *drm_edid); +const struct edid *drm_edid_raw(const struct drm_edid *drm_edid); const struct drm_edid *drm_edid_read(struct drm_connector *connector); const struct drm_edid *drm_edid_read_ddc(struct drm_connector *connector, struct i2c_adapter *adapter); -- 2.7.4