Commit 4c6ab3ee authored by Herbert Xu's avatar Herbert Xu
Browse files

crypto: padlock-sha - Fix stack alignment 



The PadLock hardware requires the output buffer for SHA to be
128-bit aligned.  We currentply place the buffer on the stack,
and ask gcc to align it to 128 bits.  That doesn't work on i386
because the kernel stack is only aligned to 32 bits.  This patch
changes the code to align the buffer by hand so that the hardware
doesn't fault on unaligned buffers.

Reported-by: default avatarSéguier Régis <rguier@e-teleport.net>
Tested-by: default avatarSéguier Régis <rguier@e-teleport.net>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 78f28b7c

drivers/crypto/padlock-sha.c

+12 −2
Original line number Diff line number Diff line
@@ -24,6 +24,12 @@ 
#include <asm/i387.h>

#include "padlock.h"



#ifdef CONFIG_64BIT

#define STACK_ALIGN 16

#else

#define STACK_ALIGN 4

#endif



struct padlock_sha_desc {

	struct shash_desc fallback;

};
@@ -64,7 +70,9 @@ static int padlock_sha1_finup(struct shash_desc *desc, const u8 *in, 
	/* We can't store directly to *out as it may be unaligned. */

	/* BTW Don't reduce the buffer size below 128 Bytes!

	 *     PadLock microcode needs it that big. */

	char result[128] __attribute__ ((aligned(PADLOCK_ALIGNMENT)));

	char buf[128 + PADLOCK_ALIGNMENT - STACK_ALIGN] __attribute__

		((aligned(STACK_ALIGN)));

	char *result = PTR_ALIGN(&buf[0], PADLOCK_ALIGNMENT);

	struct padlock_sha_desc *dctx = shash_desc_ctx(desc);

	struct sha1_state state;

	unsigned int space;
@@ -128,7 +136,9 @@ static int padlock_sha256_finup(struct shash_desc *desc, const u8 *in, 
	/* We can't store directly to *out as it may be unaligned. */

	/* BTW Don't reduce the buffer size below 128 Bytes!

	 *     PadLock microcode needs it that big. */

	char result[128] __attribute__ ((aligned(PADLOCK_ALIGNMENT)));

	char buf[128 + PADLOCK_ALIGNMENT - STACK_ALIGN] __attribute__

		((aligned(STACK_ALIGN)));

	char *result = PTR_ALIGN(&buf[0], PADLOCK_ALIGNMENT);

	struct padlock_sha_desc *dctx = shash_desc_ctx(desc);

	struct sha256_state state;

	unsigned int space;

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