When building ARCH=arm64 allmodconfig with clang, there is a warning about high stack usage in avs_path_create(), which breaks the build due to CONFIG_WERROR=y:
sound/soc/intel/avs/path.c:815:18: error: stack frame size (2176) exceeds limit (2048) in 'avs_path_create' [-Werror,-Wframe-larger-than] struct avs_path *avs_path_create(struct avs_dev *adev, u32 dma_id, ^ 1 error generated.
This warning is also visible with allmodconfig on other architectures. The minimum set of configs that triggers this on top of ARCH=arm64 allnoconfig:
CONFIG_COMPILE_TEST=y CONFIG_FORTIFY_SOURCE=y CONFIG_KASAN=y CONFIG_PCI=y CONFIG_SOUND=y CONFIG_SND=y CONFIG_SND_SOC=y CONFIG_SND_SOC_INTEL_AVS=y
When CONFIG_FORTIFY_SOURCE is enabled, memcmp() (called from guid_equal()) becomes a wrapper to do compile time checking, which interacts poorly with inlining plus CONFIG_KASAN=y.
With ARCH=arm64 allmodconfig + CONFIG_KASAN=n + CONFIG_FRAME_WARN=128, the stack usage is much better:
sound/soc/intel/avs/path.c:815:18: warning: stack frame size (624) exceeds limit (128) in 'avs_path_create' [-Wframe-larger-than] struct avs_path *avs_path_create(struct avs_dev *adev, u32 dma_id, ^ sound/soc/intel/avs/path.c:873:5: warning: stack frame size (144) exceeds limit (128) in 'avs_path_bind' [-Wframe-larger-than] int avs_path_bind(struct avs_path *path) ^ 2 warnings generated.
To avoid this warning, mark avs_path_module_type_create() as noinline_for_stack, which redistributes the stack usage across multiple functions, regardless of CONFIG_KASAN.
With ARCH=arm64 allmodconfig + CONFIG_FRAME_WARN=128, the warnings show:
avs_path_create(): 192 avs_path_bind(): 272 avs_path_module_type_create(): 416 avs_mux_create(): 160 avs_updown_mix_create(): 160 avs_aec_create(): 176 avs_asrc_create(): 144
With ARCH=arm64 allmodconfig + CONFIG_FRAME_WARN=128 + CONFIG_KASAN=n, the warnings show:
avs_path_create(): 192 avs_path_bind(): 144 avs_path_module_type_create(): 416 avs_mux_create(): 176 avs_updown_mix_create(): 176 avs_src_create(): 144 avs_aec_create(): 192 avs_asrc_create(): 144 avs_wov_create(): 144
Link: https://github.com/ClangBuiltLinux/linux/issues/1642 Signed-off-by: Nathan Chancellor nathan@kernel.org --- sound/soc/intel/avs/path.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/sound/soc/intel/avs/path.c b/sound/soc/intel/avs/path.c index 3d46dd5e5bc4..ec2aa0001f91 100644 --- a/sound/soc/intel/avs/path.c +++ b/sound/soc/intel/avs/path.c @@ -449,7 +449,8 @@ static int avs_modext_create(struct avs_dev *adev, struct avs_path_module *mod) return ret; }
-static int avs_path_module_type_create(struct avs_dev *adev, struct avs_path_module *mod) +static noinline_for_stack int avs_path_module_type_create(struct avs_dev *adev, + struct avs_path_module *mod) { const guid_t *type = &mod->template->cfg_ext->type;
base-commit: ff6992735ade75aae3e35d16b17da1008d753d28