[PATCH v2] lib/crypto: blake2b: Limit frame size workaround to GCC

[Thorsten Blum <thorsten.blum@linux.dev>]

The GCC regression only affected i386 and has been fixed since GCC 12.2.
However, modern GCC versions still generate large stack frames on other
architectures (e.g., 3440 bytes for blake2b_compress_generic() on m68k
with GCC 15.1.0). Clang handles these functions efficiently and should
work fine with the default warning threshold.

Limit the frame size workaround to GCC only.

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
---
Changes in v2:
- Restrict frame size workaround to GCC independent of its version or
  the architecture
- Update patch title and description
- Link to v1: https://lore.kernel.org/lkml/20251122105530.441350-2-thorsten.blum@linux.dev/
---
 lib/crypto/Makefile | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/lib/crypto/Makefile b/lib/crypto/Makefile
index b5346cebbb55..95a48393ffb4 100644
--- a/lib/crypto/Makefile
+++ b/lib/crypto/Makefile
@@ -33,7 +33,9 @@ obj-$(CONFIG_CRYPTO_LIB_GF128MUL)		+= gf128mul.o
 
 obj-$(CONFIG_CRYPTO_LIB_BLAKE2B) += libblake2b.o
 libblake2b-y := blake2b.o
+ifeq ($(CONFIG_CC_IS_GCC),y)
 CFLAGS_blake2b.o := -Wframe-larger-than=4096 #  https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105930
+endif # CONFIG_CC_IS_GCC
 ifeq ($(CONFIG_CRYPTO_LIB_BLAKE2B_ARCH),y)
 CFLAGS_blake2b.o += -I$(src)/$(SRCARCH)
 libblake2b-$(CONFIG_ARM) += arm/blake2b-neon-core.o
-- 
2.51.1