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authorArnd Bergmann <arnd@arndb.de>2019-06-18 13:19:42 +0200
committerHerbert Xu <herbert@gondor.apana.org.au>2019-06-27 14:28:01 +0800
commit473971187d6727609951858c63bf12b0307ef015 (patch)
tree7aced6bb5402810d105b25f07090ccad78200644
parent149c4e6ef7788d58b9c05eed9fb85e0f5a2c3456 (diff)
downloadlinux-473971187d6727609951858c63bf12b0307ef015.tar.bz2
crypto: serpent - mark __serpent_setkey_sbox noinline
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>
-rw-r--r--crypto/serpent_generic.c8
1 files changed, 7 insertions, 1 deletions
diff --git a/crypto/serpent_generic.c b/crypto/serpent_generic.c
index f2f549330d2b..e133006b2217 100644
--- a/crypto/serpent_generic.c
+++ b/crypto/serpent_generic.c
@@ -229,7 +229,13 @@
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);