From 442cf8e22ba25a77cb9092d78733fdbac9844e50 Mon Sep 17 00:00:00 2001 From: Ville Syrjälä Date: Mon, 7 Nov 2022 21:25:45 +0200 Subject: drm/sti: Use drm_mode_copy() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit struct drm_display_mode embeds a list head, so overwriting the full struct with another one will corrupt the list (if the destination mode is on a list). Use drm_mode_copy() instead which explicitly preserves the list head of the destination mode. Even if we know the destination mode is not on any list using drm_mode_copy() seems decent as it sets a good example. Bad examples of not using it might eventually get copied into code where preserving the list head actually matters. Obviously one case not covered here is when the mode itself is embedded in a larger structure and the whole structure is copied. But if we are careful when copying into modes embedded in structures I think we can be a little more reassured that bogus list heads haven't been propagated in. @is_mode_copy@ @@ drm_mode_copy(...) { ... } @depends on !is_mode_copy@ struct drm_display_mode *mode; expression E, S; @@ ( - *mode = E + drm_mode_copy(mode, &E) | - memcpy(mode, E, S) + drm_mode_copy(mode, E) ) @depends on !is_mode_copy@ struct drm_display_mode mode; expression E; @@ ( - mode = E + drm_mode_copy(&mode, &E) | - memcpy(&mode, E, S) + drm_mode_copy(&mode, E) ) @@ struct drm_display_mode *mode; @@ - &*mode + mode Cc: Alain Volmat Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20221107192545.9896-8-ville.syrjala@linux.intel.com Reviewed-by: Daniel Vetter --- drivers/gpu/drm/sti/sti_hdmi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/gpu/drm/sti/sti_hdmi.c') diff --git a/drivers/gpu/drm/sti/sti_hdmi.c b/drivers/gpu/drm/sti/sti_hdmi.c index cb82622877d2..fcc2194869d6 100644 --- a/drivers/gpu/drm/sti/sti_hdmi.c +++ b/drivers/gpu/drm/sti/sti_hdmi.c @@ -941,7 +941,7 @@ static void sti_hdmi_set_mode(struct drm_bridge *bridge, DRM_DEBUG_DRIVER("\n"); /* Copy the drm display mode in the connector local structure */ - memcpy(&hdmi->mode, mode, sizeof(struct drm_display_mode)); + drm_mode_copy(&hdmi->mode, mode); /* Update clock framerate according to the selected mode */ ret = clk_set_rate(hdmi->clk_pix, mode->clock * 1000); -- cgit v1.2.3