From: Arnd Bergmann <arnd@xxxxxxxx> With KASAN enabled, clang fails to optimize the inline version of vdec_vp9_slice_map_counts_eob_coef() properly, leading to kilobytes of temporary values spilled to the stack: drivers/media/platform/mediatek/vcodec/decoder/vdec/vdec_vp9_req_lat_if.c:1526:12: error: stack frame size (2160) exceeds limit (2048) in 'vdec_vp9_slice_update_prob' [-Werror,-Wframe-larger-than] This seems to affect all versions of clang including the latest (clang-20), but the degree of stack overhead is different per release. Marking the function as noinline_for_stack is harmless here and avoids the problem completely. Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> --- I have not come to a conclusion on how exactly clang fails to do this right, but can provide the .config and/or preprocessed source files and command line if we think this should be fixed in clang. --- .../mediatek/vcodec/decoder/vdec/vdec_vp9_req_lat_if.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/media/platform/mediatek/vcodec/decoder/vdec/vdec_vp9_req_lat_if.c b/drivers/media/platform/mediatek/vcodec/decoder/vdec/vdec_vp9_req_lat_if.c index eea709d93820..47c302745c1d 100644 --- a/drivers/media/platform/mediatek/vcodec/decoder/vdec/vdec_vp9_req_lat_if.c +++ b/drivers/media/platform/mediatek/vcodec/decoder/vdec/vdec_vp9_req_lat_if.c @@ -1188,7 +1188,8 @@ static int vdec_vp9_slice_setup_lat(struct vdec_vp9_slice_instance *instance, return ret; } -static +/* clang stack usage explodes if this is inlined */ +static noinline_for_stack void vdec_vp9_slice_map_counts_eob_coef(unsigned int i, unsigned int j, unsigned int k, struct vdec_vp9_slice_frame_counts *counts, struct v4l2_vp9_frame_symbol_counts *counts_helper) -- 2.39.5
