Commit 47397118 authored Jun 18, 2019 by Arnd Bergmann Committed by Herbert Xu Jun 27, 2019

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: c871c10e ("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>

parent 149c4e6e

crypto/serpent_generic.c

+7 −1

Original line number	Diff line number	Diff line
		@@ -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);

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