On Thu, Jul 18, 2019 at 6:50 AM Arnd Bergmann <arnd@xxxxxxxx> wrote: > > Clang sometimes makes very different inlining decisions from gcc. > In case of the aegis crypto algorithms, it decides to turn the innermost > primitives (and, xor, ...) into separate functions but inline most of > the rest. > > This results in a huge amount of variables spilled on the stack, leading > to rather slow execution as well as kernel stack usage beyond the 32-bit > warning limit when CONFIG_KASAN is enabled: > > crypto/aegis256.c:123:13: warning: stack frame size of 648 bytes in function 'crypto_aegis256_encrypt_chunk' [-Wframe-larger-than=] > crypto/aegis256.c:366:13: warning: stack frame size of 1264 bytes in function 'crypto_aegis256_crypt' [-Wframe-larger-than=] > crypto/aegis256.c:187:13: warning: stack frame size of 656 bytes in function 'crypto_aegis256_decrypt_chunk' [-Wframe-larger-than=] > crypto/aegis128l.c:135:13: warning: stack frame size of 832 bytes in function 'crypto_aegis128l_encrypt_chunk' [-Wframe-larger-than=] > crypto/aegis128l.c:415:13: warning: stack frame size of 1480 bytes in function 'crypto_aegis128l_crypt' [-Wframe-larger-than=] > crypto/aegis128l.c:218:13: warning: stack frame size of 848 bytes in function 'crypto_aegis128l_decrypt_chunk' [-Wframe-larger-than=] > crypto/aegis128.c:116:13: warning: stack frame size of 584 bytes in function 'crypto_aegis128_encrypt_chunk' [-Wframe-larger-than=] > crypto/aegis128.c:351:13: warning: stack frame size of 1064 bytes in function 'crypto_aegis128_crypt' [-Wframe-larger-than=] > crypto/aegis128.c:177:13: warning: stack frame size of 592 bytes in function 'crypto_aegis128_decrypt_chunk' [-Wframe-larger-than=] > > Forcing the primitives to all get inlined avoids the issue and the > resulting code is similar to what gcc produces. > > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> > --- > crypto/aegis.h | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/crypto/aegis.h b/crypto/aegis.h > index 41a3090cda8e..efed7251c49d 100644 > --- a/crypto/aegis.h > +++ b/crypto/aegis.h > @@ -34,21 +34,21 @@ static const union aegis_block crypto_aegis_const[2] = { > } }, > }; > > -static void crypto_aegis_block_xor(union aegis_block *dst, > +static __always_inline void crypto_aegis_block_xor(union aegis_block *dst, `static inline` would be more concise and expand to the same attribute, IIRC. Not sure if that's worth sending a v2. But for now, thanks for the patch and: Acked-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> -- Thanks, ~Nick Desaulniers