From fe25510fc23031f1a3c1b42edd37067d1989a9f6 Mon Sep 17 00:00:00 2001 From: Keith Packard Date: Sat, 17 Dec 2016 20:58:36 -0800 Subject: altos/arm: Align data so that gcc 5.4 doesn't do byte-accesses. Add -Wcast-align Gcc 5.4.1 tracks alignment of data through assignments, so that a uint32_t pointer which comes from byte-aligned uint8_t data: extern uint8_t foo[]; uint32_t *q = (void *) foo; Fetches and stores through this pointer are done bytewise. This is slow (meh), but if q references a device register, things to bad very quickly. This patch works around this bug in the compiler by adding __attribute__((aligned(4))) tags to some variables, or changing them from uint8_t to uint32_t. Places doing this will now be caught as I've added -Wcast-align to the compiler flags. That required adding (void *) casts, after the relevant code was checked to make sure the compiler could tell that the addresses were aligned. Signed-off-by: Keith Packard --- src/aes/ao_aes.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) (limited to 'src/aes') diff --git a/src/aes/ao_aes.c b/src/aes/ao_aes.c index a04174c6..fd90c5bf 100644 --- a/src/aes/ao_aes.c +++ b/src/aes/ao_aes.c @@ -359,10 +359,10 @@ void xrijndaelDecrypt(word32 block[], roundkey *rkk) #endif uint8_t ao_aes_mutex; -static uint8_t key[16]; +static word32 key[16/4]; static roundkey rkk; -static uint8_t iv[16]; +static word32 iv[16/4]; void ao_aes_set_mode(enum ao_aes_mode mode) @@ -389,10 +389,11 @@ ao_aes_run(__xdata uint8_t *in, __xdata uint8_t *out) { uint8_t i; + uint8_t *_iv = (uint8_t *) iv; for (i = 0; i < 16; i++) - iv[i] ^= in[i]; - xrijndaelEncrypt((word32 *) iv, &rkk); + _iv[i] ^= in[i]; + xrijndaelEncrypt(iv, &rkk); if (out) memcpy(out, iv, 16); } -- cgit v1.2.3