On Mon, 2016-10-10 at 10:37 -0700, Eric Biggers wrote: > On Mon, Oct 10, 2016 at 10:29:55AM -0700, Joe Perches wrote: > > On Mon, 2016-10-10 at 10:15 -0700, Eric Biggers wrote: > > > The per-transform 'consts' array is accessed as __be64 in > > > crypto_cmac_digest_setkey() but was only guaranteed to be aligned to > > > __alignof__(long). Fix this by aligning it to __alignof__(__be64). > > [] > > > diff --git a/crypto/cmac.c b/crypto/cmac.c > > [] > > > @@ -57,7 +57,8 @@ static int crypto_cmac_digest_setkey(struct crypto_shash *parent, > > > unsigned long alignmask = crypto_shash_alignmask(parent); > > > struct cmac_tfm_ctx *ctx = crypto_shash_ctx(parent); > > > unsigned int bs = crypto_shash_blocksize(parent); > > > - __be64 *consts = PTR_ALIGN((void *)ctx->ctx, alignmask + 1); > > > + __be64 *consts = PTR_ALIGN((void *)ctx->ctx, > > > + (alignmask | (__alignof__(__be64) - 1)) + 1); > > > > > > Using a bitwise or looks very odd there. Perhaps: > > > > min(alignmask + 1, __alignof__(__be64)) > > > > > Alignment has to be a power of 2. From the code I've read, crypto drivers work > with alignment a lot and use bitwise OR to mean "the more restrictive of these > alignmasks". So I believe the way it's written is the preferred style. > > Eric Hey Eric. I don't see any PTR_ALIGN uses in crypto/ or drivers/crypto/ that use a bitwise or, just mask + 1, but I believe the effect is the same. Anyway, your choice, but I think using min is clearer. cheers, Joe -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
