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Commit5d8c3e836f("drm/amd/display: fix array-bounds error in dc_stream_remove_writeback()") tried to fix an array bounds error seen with gcc 12.0. Unfortunately, that results in another array bounds error, seen with older versions of gcc. Building csky:allmodconfig ... failed -------------- Error log: drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_stream.c: In function 'dc_stream_remove_writeback': drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_stream.c:527:83: error: array subscript 1 is above array bounds of 'struct dc_writeback_info[1]' [-Werror=array-bounds] 527 | stream->writeback_info[j] = stream->writeback_info[i]; | ~~~~~~~~~~~~~~~~~~~~~~^~~ In file included from drivers/gpu/drm/amd/amdgpu/../display/dc/dc.h:1269, from drivers/gpu/drm/amd/amdgpu/../display/dc/inc/core_types.h:29, from drivers/gpu/drm/amd/amdgpu/../display/dc/basics/dc_common.h:29, from drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_stream.c:27: drivers/gpu/drm/amd/amdgpu/../display/dc/dc_stream.h:241:34: note: while referencing 'writeback_info' 241 | struct dc_writeback_info writeback_info[MAX_DWB_PIPES]; We could check both i and j for overflow to fix the problem. That would, however, be not make much sense since it is known and provable that j <= i. Also, the check introduced with commit5d8c3e836fdoes not really add value since it checks if j < MAX_DWB_PIPES. Since it is known that j <= i, it would make more sense to check if i < MAX_DWB_PIPES. Unfortunately, that does not help to solve the problem observed here: gcc still complains. To solve the problem, replace the subsequent check for 'i != j' with 'j < i'. This is identical to the original check since we know that j <= i, and it makes all versions of gcc happy. Drop the check introduced with commit5d8c3e836fsince it is not really useful and does not solve the problem. Cc: Aurabindo Pillai <aurabindo.pillai@amd.com> Cc: Hamza Mahfooz <hamza.mahfooz@amd.com> Fixes:5d8c3e836f("drm/amd/display: fix array-bounds error in dc_stream_remove_writeback()") Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Linux kernel
============
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