[CRYPTO]: Added CRYPTO_TFM_REQ_MAY_SLEEP flag

The crypto layer currently uses in_atomic() to determine whether it is
allowed to sleep.  This is incorrect since spin locks don't always cause
in_atomic() to return true.

Instead of that, this patch returns to an earlier idea of a per-tfm flag
which determines whether sleeping is allowed.  Unlike the earlier version,
the default is to not allow sleeping.  This ensures that no existing code
can break.

As usual, this flag may either be set through crypto_alloc_tfm(), or
just before a specific crypto operation.

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 b4728811ce3b1570e7ee2806644692d099c32cdf..959c4e5f264f42ed831720149b3627d9a9e6300c 100644 (file)
--- a/crypto/api.c
+++ b/crypto/api.c
@@ -66,7 +66,8 @@ static inline struct crypto_alg *crypto_alg_mod_lookup(const char *name)
 
 static int crypto_init_flags(struct crypto_tfm *tfm, u32 flags)
 {
-       tfm->crt_flags = 0;
+       tfm->crt_flags = flags & CRYPTO_TFM_REQ_MASK;
+       flags &= ~CRYPTO_TFM_REQ_MASK;
        
        switch (crypto_tfm_alg_type(tfm)) {
        case CRYPTO_ALG_TYPE_CIPHER:

diff --git a/crypto/cipher.c b/crypto/cipher.c
index 8da644364cb4225824575ec4813741b9d46d7041..3df47f93c9db01e0a19da8af237ab800ae9d34b1 100644 (file)
--- a/crypto/cipher.c
+++ b/crypto/cipher.c
@@ -377,11 +377,7 @@ static int nocrypt_iv(struct crypto_tfm *tfm,
 int crypto_init_cipher_flags(struct crypto_tfm *tfm, u32 flags)
 {
        u32 mode = flags & CRYPTO_TFM_MODE_MASK;
-       
        tfm->crt_cipher.cit_mode = mode ? mode : CRYPTO_TFM_MODE_ECB;
-       if (flags & CRYPTO_TFM_REQ_WEAK_KEY)
-               tfm->crt_flags = CRYPTO_TFM_REQ_WEAK_KEY;
-       
        return 0;
 }
 

diff --git a/crypto/internal.h b/crypto/internal.h
index 37515beafc8ce44ff501d15d617968248656b59f..37aa652ce5ce6f89e4738ac07dd770b8df4a6ac9 100644 (file)
--- a/crypto/internal.h
+++ b/crypto/internal.h
@@ -17,6 +17,7 @@
 #include <linux/interrupt.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
+#include <linux/slab.h>
 #include <asm/kmap_types.h>
 
 extern enum km_type crypto_km_types[];
@@ -38,7 +39,7 @@ static inline void crypto_kunmap(void *vaddr, int out)
 
 static inline void crypto_yield(struct crypto_tfm *tfm)
 {
-       if (!in_atomic())
+       if (tfm->crt_flags & CRYPTO_TFM_REQ_MAY_SLEEP)
                cond_resched();
 }
 

diff --git a/include/linux/crypto.h b/include/linux/crypto.h
index 5e2bcc636a02fd4d7a383e661b7661d6ac916169..3c89df6e7768451acf625236790753f2ab7f5139 100644 (file)
--- a/include/linux/crypto.h
+++ b/include/linux/crypto.h
@@ -45,6 +45,7 @@
 #define CRYPTO_TFM_MODE_CTR            0x00000008
 
 #define CRYPTO_TFM_REQ_WEAK_KEY                0x00000100
+#define CRYPTO_TFM_REQ_MAY_SLEEP       0x00000200
 #define CRYPTO_TFM_RES_WEAK_KEY                0x00100000
 #define CRYPTO_TFM_RES_BAD_KEY_LEN     0x00200000
 #define CRYPTO_TFM_RES_BAD_KEY_SCHED   0x00400000