From 4c6ab3ee4cdb86cbd4e9400dd22fad7701cbe795 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Mon, 21 Sep 2009 23:21:53 -0700 Subject: [PATCH] crypto: padlock-sha - Fix stack alignment MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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: Séguier Régis Tested-by: Séguier Régis Signed-off-by: Herbert Xu --- drivers/crypto/padlock-sha.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/drivers/crypto/padlock-sha.c b/drivers/crypto/padlock-sha.c index 76cb6b345e7..0af80577dc7 100644 --- a/drivers/crypto/padlock-sha.c +++ b/drivers/crypto/padlock-sha.c @@ -24,6 +24,12 @@ #include #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;