diff options
| -rw-r--r-- | crypto/skcipher.c | 62 |
1 files changed, 15 insertions, 47 deletions
diff --git a/crypto/skcipher.c b/crypto/skcipher.c index 8749c44f98a2..887cbce8f78d 100644 --- a/crypto/skcipher.c +++ b/crypto/skcipher.c @@ -63,16 +63,6 @@ static inline gfp_t skcipher_walk_gfp(struct skcipher_walk *walk) return walk->flags & SKCIPHER_WALK_SLEEP ? GFP_KERNEL : GFP_ATOMIC; } -/* Get a spot of the specified length that does not straddle a page. - * The caller needs to ensure that there is enough space for this operation. - */ -static inline u8 *skcipher_get_spot(u8 *start, unsigned int len) -{ - u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK); - - return max(start, end_page); -} - static inline struct skcipher_alg *__crypto_skcipher_alg( struct crypto_alg *alg) { @@ -81,10 +71,8 @@ static inline struct skcipher_alg *__crypto_skcipher_alg( static int skcipher_done_slow(struct skcipher_walk *walk, unsigned int bsize) { - u8 *addr; + u8 *addr = PTR_ALIGN(walk->buffer, walk->alignmask + 1); - addr = (u8 *)ALIGN((unsigned long)walk->buffer, walk->alignmask + 1); - addr = skcipher_get_spot(addr, bsize); scatterwalk_copychunks(addr, &walk->out, bsize, 1); return 0; } @@ -183,33 +171,22 @@ EXPORT_SYMBOL_GPL(skcipher_walk_done); static int skcipher_next_slow(struct skcipher_walk *walk, unsigned int bsize) { unsigned alignmask = walk->alignmask; - unsigned a; unsigned n; u8 *buffer; if (!walk->buffer) walk->buffer = walk->page; buffer = walk->buffer; - if (buffer) - goto ok; - - /* Start with the minimum alignment of kmalloc. */ - a = crypto_tfm_ctx_alignment() - 1; - n = bsize; - - /* Minimum size to align buffer by alignmask. */ - n += alignmask & ~a; - - /* Minimum size to ensure buffer does not straddle a page. */ - n += (bsize - 1) & ~(alignmask | a); - - buffer = kzalloc(n, skcipher_walk_gfp(walk)); - if (!buffer) - return skcipher_walk_done(walk, -ENOMEM); - walk->buffer = buffer; -ok: + if (!buffer) { + /* Min size for a buffer of bsize bytes aligned to alignmask */ + n = bsize + (alignmask & ~(crypto_tfm_ctx_alignment() - 1)); + + buffer = kzalloc(n, skcipher_walk_gfp(walk)); + if (!buffer) + return skcipher_walk_done(walk, -ENOMEM); + walk->buffer = buffer; + } walk->dst.virt.addr = PTR_ALIGN(buffer, alignmask + 1); - walk->dst.virt.addr = skcipher_get_spot(walk->dst.virt.addr, bsize); walk->src.virt.addr = walk->dst.virt.addr; scatterwalk_copychunks(walk->src.virt.addr, &walk->in, bsize, 0); @@ -296,30 +273,21 @@ slow_path: static int skcipher_copy_iv(struct skcipher_walk *walk) { - unsigned a = crypto_tfm_ctx_alignment() - 1; unsigned alignmask = walk->alignmask; unsigned ivsize = walk->ivsize; - unsigned bs = walk->stride; - unsigned aligned_bs; + unsigned aligned_stride = ALIGN(walk->stride, alignmask + 1); unsigned size; u8 *iv; - aligned_bs = ALIGN(bs, alignmask + 1); - - /* Minimum size to align buffer by alignmask. */ - size = alignmask & ~a; - - size += aligned_bs + ivsize; - - /* Minimum size to ensure buffer does not straddle a page. */ - size += (bs - 1) & ~(alignmask | a); + /* Min size for a buffer of stride + ivsize, aligned to alignmask */ + size = aligned_stride + ivsize + + (alignmask & ~(crypto_tfm_ctx_alignment() - 1)); walk->buffer = kmalloc(size, skcipher_walk_gfp(walk)); if (!walk->buffer) return -ENOMEM; - iv = PTR_ALIGN(walk->buffer, alignmask + 1); - iv = skcipher_get_spot(iv, bs) + aligned_bs; + iv = PTR_ALIGN(walk->buffer, alignmask + 1) + aligned_stride; walk->iv = memcpy(iv, walk->iv, walk->ivsize); return 0; |