On 8 June 2018 at 11:53, Dmitry Vyukov <dvyukov@xxxxxxxxxx> wrote:
> keccakf() is the only function in kernel that uses __optimize() macro.
> __optimize() breaks frame pointer unwinder as optimized code uses RBP,
> and amusingly this always lead to degraded performance as gcc does not
> inline across different optimizations levels, so keccakf() wasn't inlined
> into its callers and keccakf_round() wasn't inlined into keccakf().
>
> Drop __optimize() to resolve both problems.
>
> Signed-off-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
> Fixes: 83dee2ce1ae7 ("crypto: sha3-generic - rewrite KECCAK transform to help the compiler optimize")
> Reported-by: syzbot+37035ccfa9a0a017ffcf@xxxxxxxxxxxxxxxxxxxxxxxxx
> Reported-by: syzbot+e073e4740cfbb3ae200b@xxxxxxxxxxxxxxxxxxxxxxxxx
> Cc: linux-crypto@xxxxxxxxxxxxxxx
> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
> Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
> Cc: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
Acked-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
> ---
> crypto/sha3_generic.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/crypto/sha3_generic.c b/crypto/sha3_generic.c
> index 264ec12c0b9c..7f6735d9003f 100644
> --- a/crypto/sha3_generic.c
> +++ b/crypto/sha3_generic.c
> @@ -152,7 +152,7 @@ static SHA3_INLINE void keccakf_round(u64 st[25])
> st[24] ^= bc[ 4];
> }
>
> -static void __optimize("O3") keccakf(u64 st[25])
> +static void keccakf(u64 st[25])
> {
> int round;
>
> --
> 2.18.0.rc1.242.g61856ae69a-goog
>
