Recent clang-9 snapshots double the kernel stack usage when building this file with -O0 -fsanitize=kernel-hwaddress, compared to clang-8 and older snapshots, this changed between commits svn364966 and svn366056: crypto/jitterentropy.c:516:5: error: stack frame size of 2640 bytes in function 'jent_entropy_init' [-Werror,-Wframe-larger-than=] int jent_entropy_init(void) ^ crypto/jitterentropy.c:185:14: error: stack frame size of 2224 bytes in function 'jent_lfsr_time' [-Werror,-Wframe-larger-than=] static __u64 jent_lfsr_time(struct rand_data *ec, __u64 time, __u64 loop_cnt) ^ I prepared a reduced test case in case any clang developers want to take a closer look, but from looking at the earlier output it seems that even with clang-8, something was very wrong here. Turn off any KASAN and UBSAN sanitizing for this file, as that likely clashes with -O0 anyway. Turning off just KASAN avoids the warning already, but I suspect both of these have undesired side-effects for jitterentropy. Link: https://godbolt.org/z/fDcwZ5 Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> --- crypto/Makefile | 2 ++ 1 file changed, 2 insertions(+) diff --git a/crypto/Makefile b/crypto/Makefile index 9479e1a45d8c..176b2623dd68 100644 --- a/crypto/Makefile +++ b/crypto/Makefile @@ -136,6 +136,8 @@ obj-$(CONFIG_CRYPTO_ANSI_CPRNG) += ansi_cprng.o obj-$(CONFIG_CRYPTO_DRBG) += drbg.o obj-$(CONFIG_CRYPTO_JITTERENTROPY) += jitterentropy_rng.o CFLAGS_jitterentropy.o = -O0 +KASAN_SANITIZE_jitterentropy.o = n +UBSAN_SANITIZE_jitterentropy.o = n jitterentropy_rng-y := jitterentropy.o jitterentropy-kcapi.o obj-$(CONFIG_CRYPTO_TEST) += tcrypt.o obj-$(CONFIG_CRYPTO_GHASH) += ghash-generic.o -- 2.20.0