[CRYPTO] Ensure cit_iv is aligned correctly

This patch ensures that cit_iv is aligned according to cra_alignmask
by allocating it as part of the tfm structure.  As a side effect the
crypto layer will also guarantee that the tfm ctx area has enough space
to be aligned by cra_alignmask.  This allows us to remove the extra
space reservation from the Padlock driver.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/crypto/api.c b/crypto/api.c
index 0b583d2..2d8d828 100644 (file)
--- a/crypto/api.c
+++ b/crypto/api.c
@@ -125,20 +125,46 @@ static void crypto_exit_ops(struct crypto_tfm *tfm)
        }
 }
 
+static unsigned int crypto_ctxsize(struct crypto_alg *alg, int flags)
+{
+       unsigned int len;
+
+       switch (alg->cra_flags & CRYPTO_ALG_TYPE_MASK) {
+       default:
+               BUG();
+
+       case CRYPTO_ALG_TYPE_CIPHER:
+               len = crypto_cipher_ctxsize(alg, flags);
+               break;
+               
+       case CRYPTO_ALG_TYPE_DIGEST:
+               len = crypto_digest_ctxsize(alg, flags);
+               break;
+               
+       case CRYPTO_ALG_TYPE_COMPRESS:
+               len = crypto_compress_ctxsize(alg, flags);
+               break;
+       }
+
+       return len + alg->cra_alignmask;
+}
+
 struct crypto_tfm *crypto_alloc_tfm(const char *name, u32 flags)
 {
        struct crypto_tfm *tfm = NULL;
        struct crypto_alg *alg;
+       unsigned int tfm_size;
 
        alg = crypto_alg_mod_lookup(name);
        if (alg == NULL)
                goto out;
-       
-       tfm = kmalloc(sizeof(*tfm) + alg->cra_ctxsize, GFP_KERNEL);
+
+       tfm_size = sizeof(*tfm) + crypto_ctxsize(alg, flags);
+       tfm = kmalloc(tfm_size, GFP_KERNEL);
        if (tfm == NULL)
                goto out_put;
 
-       memset(tfm, 0, sizeof(*tfm) + alg->cra_ctxsize);
+       memset(tfm, 0, tfm_size);
        
        tfm->__crt_alg = alg;
        

diff --git a/crypto/cipher.c b/crypto/cipher.c
index 85eb12f..d3295ce 100644 (file)
--- a/crypto/cipher.c
+++ b/crypto/cipher.c
@@ -41,7 +41,7 @@ static unsigned int crypt_slow(const struct cipher_desc *desc,
                               struct scatter_walk *in,
                               struct scatter_walk *out, unsigned int bsize)
 {
-       unsigned int alignmask = desc->tfm->__crt_alg->cra_alignmask;
+       unsigned int alignmask = crypto_tfm_alg_alignmask(desc->tfm);
        u8 buffer[bsize * 2 + alignmask];
        u8 *src = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
        u8 *dst = src + bsize;
@@ -98,7 +98,7 @@ static int crypt(const struct cipher_desc *desc,
        struct scatter_walk walk_in, walk_out;
        struct crypto_tfm *tfm = desc->tfm;
        const unsigned int bsize = crypto_tfm_alg_blocksize(tfm);
-       unsigned int alignmask = tfm->__crt_alg->cra_alignmask;
+       unsigned int alignmask = crypto_tfm_alg_alignmask(tfm);
        unsigned long buffer = 0;
 
        if (!nbytes)
@@ -399,6 +399,8 @@ int crypto_init_cipher_ops(struct crypto_tfm *tfm)
        }
        
        if (ops->cit_mode == CRYPTO_TFM_MODE_CBC) {
+               unsigned int align;
+               unsigned long addr;
                
                switch (crypto_tfm_alg_blocksize(tfm)) {
                case 8:
@@ -418,9 +420,11 @@ int crypto_init_cipher_ops(struct crypto_tfm *tfm)
                }
                
                ops->cit_ivsize = crypto_tfm_alg_blocksize(tfm);
-               ops->cit_iv = kmalloc(ops->cit_ivsize, GFP_KERNEL);
-               if (ops->cit_iv == NULL)
-                       ret = -ENOMEM;
+               align = crypto_tfm_alg_alignmask(tfm) + 1;
+               addr = (unsigned long)crypto_tfm_ctx(tfm);
+               addr = ALIGN(addr, align);
+               addr += ALIGN(tfm->__crt_alg->cra_ctxsize, align);
+               ops->cit_iv = (void *)addr;
        }
 
 out:   
@@ -429,5 +433,4 @@ out:
 
 void crypto_exit_cipher_ops(struct crypto_tfm *tfm)
 {
-       kfree(tfm->crt_cipher.cit_iv);
 }

diff --git a/crypto/internal.h b/crypto/internal.h
index 83b1b6d..6861287 100644 (file)
--- a/crypto/internal.h
+++ b/crypto/internal.h
@@ -16,6 +16,7 @@
 #include <linux/highmem.h>
 #include <linux/interrupt.h>
 #include <linux/init.h>
+#include <linux/kernel.h>
 #include <asm/kmap_types.h>
 
 extern enum km_type crypto_km_types[];
@@ -61,6 +62,33 @@ static inline void crypto_init_proc(void)
 { }
 #endif
 
+static inline unsigned int crypto_digest_ctxsize(struct crypto_alg *alg,
+                                                int flags)
+{
+       return alg->cra_ctxsize;
+}
+
+static inline unsigned int crypto_cipher_ctxsize(struct crypto_alg *alg,
+                                                int flags)
+{
+       unsigned int len = alg->cra_ctxsize;
+       
+       switch (flags & CRYPTO_TFM_MODE_MASK) {
+       case CRYPTO_TFM_MODE_CBC:
+               len = ALIGN(len, alg->cra_alignmask + 1);
+               len += alg->cra_blocksize;
+               break;
+       }
+
+       return len;
+}
+
+static inline unsigned int crypto_compress_ctxsize(struct crypto_alg *alg,
+                                                  int flags)
+{
+       return alg->cra_ctxsize;
+}
+
 int crypto_init_digest_flags(struct crypto_tfm *tfm, u32 flags);
 int crypto_init_cipher_flags(struct crypto_tfm *tfm, u32 flags);
 int crypto_init_compress_flags(struct crypto_tfm *tfm, u32 flags);

diff --git a/drivers/crypto/padlock-aes.c b/drivers/crypto/padlock-aes.c
index d2745ff..c5b58fa 100644 (file)
--- a/drivers/crypto/padlock-aes.c
+++ b/drivers/crypto/padlock-aes.c
@@ -465,8 +465,7 @@ static struct crypto_alg aes_alg = {
        .cra_name               =       "aes",
        .cra_flags              =       CRYPTO_ALG_TYPE_CIPHER,
        .cra_blocksize          =       AES_BLOCK_SIZE,
-       .cra_ctxsize            =       sizeof(struct aes_ctx) +
-                                       PADLOCK_ALIGNMENT,
+       .cra_ctxsize            =       sizeof(struct aes_ctx),
        .cra_alignmask          =       PADLOCK_ALIGNMENT - 1,
        .cra_module             =       THIS_MODULE,
        .cra_list               =       LIST_HEAD_INIT(aes_alg.cra_list),

diff --git a/include/linux/crypto.h b/include/linux/crypto.h
index ac9d49b..5e2bcc6 100644 (file)
--- a/include/linux/crypto.h
+++ b/include/linux/crypto.h
@@ -288,6 +288,11 @@ static inline unsigned int crypto_tfm_alg_digestsize(struct crypto_tfm *tfm)
        return tfm->__crt_alg->cra_digest.dia_digestsize;
 }
 
+static inline unsigned int crypto_tfm_alg_alignmask(struct crypto_tfm *tfm)
+{
+       return tfm->__crt_alg->cra_alignmask;
+}
+
 static inline void *crypto_tfm_ctx(struct crypto_tfm *tfm)
 {
        return (void *)&tfm[1];