5.15-stable review patch. If anyone has any objections, please let me know.
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From: Ville Syrjälä ville.syrjala@linux.intel.com
[ Upstream commit 426c89aa203bcec9d9cf6eea36735eafa1b1f099 ]
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: Alex Deucher alexander.deucher@amd.com Cc: Harry Wentland harry.wentland@amd.com Cc: Leo Li sunpeng.li@amd.com Cc: Rodrigo Siqueira Rodrigo.Siqueira@amd.com Cc: amd-gfx@lists.freedesktop.org Reviewed-by: Harry Wentland harry.wentland@amd.com Signed-off-by: Ville Syrjälä ville.syrjala@linux.intel.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Stable-dep-of: 79f3e38f60e5 ("drm/amd/display: Preserve original aspect ratio in create stream") Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c | 4 ++-- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 6 +++--- 2 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c index c777aff164b76..654f99f4107ea 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c @@ -625,7 +625,7 @@ amdgpu_connector_fixup_lcd_native_mode(struct drm_encoder *encoder, if (mode->type & DRM_MODE_TYPE_PREFERRED) { if (mode->hdisplay != native_mode->hdisplay || mode->vdisplay != native_mode->vdisplay) - memcpy(native_mode, mode, sizeof(*mode)); + drm_mode_copy(native_mode, mode); } }
@@ -634,7 +634,7 @@ amdgpu_connector_fixup_lcd_native_mode(struct drm_encoder *encoder, list_for_each_entry_safe(mode, t, &connector->probed_modes, head) { if (mode->hdisplay == native_mode->hdisplay && mode->vdisplay == native_mode->vdisplay) { - *native_mode = *mode; + drm_mode_copy(native_mode, mode); drm_mode_set_crtcinfo(native_mode, CRTC_INTERLACE_HALVE_V); DRM_DEBUG_KMS("Determined LVDS native mode details from EDID\n"); break; diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c index 7385efe699f88..9356decd14513 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -6219,7 +6219,7 @@ get_highest_refresh_rate_mode(struct amdgpu_dm_connector *aconnector, } }
- aconnector->freesync_vid_base = *m_pref; + drm_mode_copy(&aconnector->freesync_vid_base, m_pref); return m_pref; }
@@ -6333,8 +6333,8 @@ create_stream_for_sink(struct amdgpu_dm_connector *aconnector, is_freesync_video_mode(&mode, aconnector); if (recalculate_timing) { freesync_mode = get_highest_refresh_rate_mode(aconnector, false); - saved_mode = mode; - mode = *freesync_mode; + drm_mode_copy(&saved_mode, &mode); + drm_mode_copy(&mode, freesync_mode); } else { decide_crtc_timing_for_drm_display_mode( &mode, preferred_mode, scale);