From: Arnd Bergmann arnd@arndb.de
[ Upstream commit 0c0408e86dbe8f44d4b27bf42130e8ac905361d6 ]
When building for ARMv7-M, clang-9 or higher tries to unroll some loops, which ends up confusing the register allocator to the point of generating rather bad code and using more than the warning limit for stack frames:
warning: stack frame size of 1200 bytes in function 'blake2b_compress' [-Wframe-larger-than=]
Forcing it to not unroll the final loop avoids this problem.
Fixes: 91d689337fe8 ("crypto: blake2b - add blake2b generic implementation") Signed-off-by: Arnd Bergmann arnd@arndb.de Reviewed-by: Nathan Chancellor natechancellor@gmail.com Signed-off-by: Herbert Xu herbert@gondor.apana.org.au Signed-off-by: Sasha Levin sashal@kernel.org --- crypto/blake2b_generic.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/crypto/blake2b_generic.c b/crypto/blake2b_generic.c index 1d262374fa4e..0ffd8d92e308 100644 --- a/crypto/blake2b_generic.c +++ b/crypto/blake2b_generic.c @@ -129,7 +129,9 @@ static void blake2b_compress(struct blake2b_state *S, ROUND(9); ROUND(10); ROUND(11); - +#ifdef CONFIG_CC_IS_CLANG +#pragma nounroll /* https://bugs.llvm.org/show_bug.cgi?id=45803 */ +#endif for (i = 0; i < 8; ++i) S->h[i] = S->h[i] ^ v[i] ^ v[i + 8]; }