crypto: cryptd - Use refcount_t for refcount

Reference counters are preferred to use refcount_t instead of
atomic_t.
This is because the implementation of refcount_t can prevent
overflows and detect possible use-after-free.
So convert atomic_t ref counters to refcount_t.

Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/crypto/cryptd.c b/crypto/cryptd.c
index 3748f9b..927760b 100644 (file)
--- a/crypto/cryptd.c
+++ b/crypto/cryptd.c
@@ -16,7 +16,7 @@
 #include <crypto/internal/aead.h>
 #include <crypto/internal/skcipher.h>
 #include <crypto/cryptd.h>
-#include <linux/atomic.h>
+#include <linux/refcount.h>
 #include <linux/err.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
@@ -63,7 +63,7 @@ struct aead_instance_ctx {
 };
 
 struct cryptd_skcipher_ctx {
-       atomic_t refcnt;
+       refcount_t refcnt;
        struct crypto_sync_skcipher *child;
 };
 
@@ -72,7 +72,7 @@ struct cryptd_skcipher_request_ctx {
 };
 
 struct cryptd_hash_ctx {
-       atomic_t refcnt;
+       refcount_t refcnt;
        struct crypto_shash *child;
 };
 
@@ -82,7 +82,7 @@ struct cryptd_hash_request_ctx {
 };
 
 struct cryptd_aead_ctx {
-       atomic_t refcnt;
+       refcount_t refcnt;
        struct crypto_aead *child;
 };
 
@@ -127,7 +127,7 @@ static int cryptd_enqueue_request(struct cryptd_queue *queue,
 {
        int cpu, err;
        struct cryptd_cpu_queue *cpu_queue;
-       atomic_t *refcnt;
+       refcount_t *refcnt;
 
        cpu = get_cpu();
        cpu_queue = this_cpu_ptr(queue->cpu_queue);
@@ -140,10 +140,10 @@ static int cryptd_enqueue_request(struct cryptd_queue *queue,
 
        queue_work_on(cpu, cryptd_wq, &cpu_queue->work);
 
-       if (!atomic_read(refcnt))
+       if (!refcount_read(refcnt))
                goto out_put_cpu;
 
-       atomic_inc(refcnt);
+       refcount_inc(refcnt);
 
 out_put_cpu:
        put_cpu();
@@ -270,13 +270,13 @@ static void cryptd_skcipher_complete(struct skcipher_request *req, int err)
        struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
        struct cryptd_skcipher_ctx *ctx = crypto_skcipher_ctx(tfm);
        struct cryptd_skcipher_request_ctx *rctx = skcipher_request_ctx(req);
-       int refcnt = atomic_read(&ctx->refcnt);
+       int refcnt = refcount_read(&ctx->refcnt);
 
        local_bh_disable();
        rctx->complete(&req->base, err);
        local_bh_enable();
 
-       if (err != -EINPROGRESS && refcnt && atomic_dec_and_test(&ctx->refcnt))
+       if (err != -EINPROGRESS && refcnt && refcount_dec_and_test(&ctx->refcnt))
                crypto_free_skcipher(tfm);
 }
 
@@ -521,13 +521,13 @@ static void cryptd_hash_complete(struct ahash_request *req, int err)
        struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
        struct cryptd_hash_ctx *ctx = crypto_ahash_ctx(tfm);
        struct cryptd_hash_request_ctx *rctx = ahash_request_ctx(req);
-       int refcnt = atomic_read(&ctx->refcnt);
+       int refcnt = refcount_read(&ctx->refcnt);
 
        local_bh_disable();
        rctx->complete(&req->base, err);
        local_bh_enable();
 
-       if (err != -EINPROGRESS && refcnt && atomic_dec_and_test(&ctx->refcnt))
+       if (err != -EINPROGRESS && refcnt && refcount_dec_and_test(&ctx->refcnt))
                crypto_free_ahash(tfm);
 }
 
@@ -772,13 +772,13 @@ static void cryptd_aead_crypt(struct aead_request *req,
 
 out:
        ctx = crypto_aead_ctx(tfm);
-       refcnt = atomic_read(&ctx->refcnt);
+       refcnt = refcount_read(&ctx->refcnt);
 
        local_bh_disable();
        compl(&req->base, err);
        local_bh_enable();
 
-       if (err != -EINPROGRESS && refcnt && atomic_dec_and_test(&ctx->refcnt))
+       if (err != -EINPROGRESS && refcnt && refcount_dec_and_test(&ctx->refcnt))
                crypto_free_aead(tfm);
 }
 
@@ -979,7 +979,7 @@ struct cryptd_skcipher *cryptd_alloc_skcipher(const char *alg_name,
        }
 
        ctx = crypto_skcipher_ctx(tfm);
-       atomic_set(&ctx->refcnt, 1);
+       refcount_set(&ctx->refcnt, 1);
 
        return container_of(tfm, struct cryptd_skcipher, base);
 }
@@ -997,7 +997,7 @@ bool cryptd_skcipher_queued(struct cryptd_skcipher *tfm)
 {
        struct cryptd_skcipher_ctx *ctx = crypto_skcipher_ctx(&tfm->base);
 
-       return atomic_read(&ctx->refcnt) - 1;
+       return refcount_read(&ctx->refcnt) - 1;
 }
 EXPORT_SYMBOL_GPL(cryptd_skcipher_queued);
 
@@ -1005,7 +1005,7 @@ void cryptd_free_skcipher(struct cryptd_skcipher *tfm)
 {
        struct cryptd_skcipher_ctx *ctx = crypto_skcipher_ctx(&tfm->base);
 
-       if (atomic_dec_and_test(&ctx->refcnt))
+       if (refcount_dec_and_test(&ctx->refcnt))
                crypto_free_skcipher(&tfm->base);
 }
 EXPORT_SYMBOL_GPL(cryptd_free_skcipher);
@@ -1029,7 +1029,7 @@ struct cryptd_ahash *cryptd_alloc_ahash(const char *alg_name,
        }
 
        ctx = crypto_ahash_ctx(tfm);
-       atomic_set(&ctx->refcnt, 1);
+       refcount_set(&ctx->refcnt, 1);
 
        return __cryptd_ahash_cast(tfm);
 }
@@ -1054,7 +1054,7 @@ bool cryptd_ahash_queued(struct cryptd_ahash *tfm)
 {
        struct cryptd_hash_ctx *ctx = crypto_ahash_ctx(&tfm->base);
 
-       return atomic_read(&ctx->refcnt) - 1;
+       return refcount_read(&ctx->refcnt) - 1;
 }
 EXPORT_SYMBOL_GPL(cryptd_ahash_queued);
 
@@ -1062,7 +1062,7 @@ void cryptd_free_ahash(struct cryptd_ahash *tfm)
 {
        struct cryptd_hash_ctx *ctx = crypto_ahash_ctx(&tfm->base);
 
-       if (atomic_dec_and_test(&ctx->refcnt))
+       if (refcount_dec_and_test(&ctx->refcnt))
                crypto_free_ahash(&tfm->base);
 }
 EXPORT_SYMBOL_GPL(cryptd_free_ahash);
@@ -1086,7 +1086,7 @@ struct cryptd_aead *cryptd_alloc_aead(const char *alg_name,
        }
 
        ctx = crypto_aead_ctx(tfm);
-       atomic_set(&ctx->refcnt, 1);
+       refcount_set(&ctx->refcnt, 1);
 
        return __cryptd_aead_cast(tfm);
 }
@@ -1104,7 +1104,7 @@ bool cryptd_aead_queued(struct cryptd_aead *tfm)
 {
        struct cryptd_aead_ctx *ctx = crypto_aead_ctx(&tfm->base);
 
-       return atomic_read(&ctx->refcnt) - 1;
+       return refcount_read(&ctx->refcnt) - 1;
 }
 EXPORT_SYMBOL_GPL(cryptd_aead_queued);
 
@@ -1112,7 +1112,7 @@ void cryptd_free_aead(struct cryptd_aead *tfm)
 {
        struct cryptd_aead_ctx *ctx = crypto_aead_ctx(&tfm->base);
 
-       if (atomic_dec_and_test(&ctx->refcnt))
+       if (refcount_dec_and_test(&ctx->refcnt))
                crypto_free_aead(&tfm->base);
 }
 EXPORT_SYMBOL_GPL(cryptd_free_aead);