6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Arnd Bergmann arnd@arndb.de
commit 8b55f8818900c99dd4f55a59a103f5b29e41eb2c upstream.
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@arndb.de Reviewed-by: Nathan Chancellor nathan@kernel.org Signed-off-by: Sebastian Fricke sebastian.fricke@collabora.com Signed-off-by: Mauro Carvalho Chehab mchehab+huawei@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/media/platform/mediatek/vcodec/decoder/vdec/vdec_vp9_req_lat_if.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- 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 @@ -1189,7 +1189,8 @@ err: 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)