From: Arnd Bergmann arnd@arndb.de
[ Upstream commit 473971187d6727609951858c63bf12b0307ef015 ]
The same bug that gcc hit in the past is apparently now showing up with clang, which decides to inline __serpent_setkey_sbox:
crypto/serpent_generic.c:268:5: error: stack frame size of 2112 bytes in function '__serpent_setkey' [-Werror,-Wframe-larger-than=]
Marking it 'noinline' reduces the stack usage from 2112 bytes to 192 and 96 bytes, respectively, and seems to generate more useful object code.
Fixes: c871c10e4ea7 ("crypto: serpent - improve __serpent_setkey with UBSAN") Signed-off-by: Arnd Bergmann arnd@arndb.de Reviewed-by: Eric Biggers ebiggers@kernel.org Signed-off-by: Herbert Xu herbert@gondor.apana.org.au Signed-off-by: Sasha Levin sashal@kernel.org --- crypto/serpent_generic.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/crypto/serpent_generic.c b/crypto/serpent_generic.c index 16f612b6dbca..a9cc0b2aa0d6 100644 --- a/crypto/serpent_generic.c +++ b/crypto/serpent_generic.c @@ -225,7 +225,13 @@ x4 ^= x2; \ })
-static void __serpent_setkey_sbox(u32 r0, u32 r1, u32 r2, u32 r3, u32 r4, u32 *k) +/* + * both gcc and clang have misoptimized this function in the past, + * producing horrible object code from spilling temporary variables + * on the stack. Forcing this part out of line avoids that. + */ +static noinline void __serpent_setkey_sbox(u32 r0, u32 r1, u32 r2, + u32 r3, u32 r4, u32 *k) { k += 100; S3(r3, r4, r0, r1, r2); store_and_load_keys(r1, r2, r4, r3, 28, 24);