[PATCH 5/5] hwrng: core - Move hwrng_init call into set_current_rng

[Herbert Xu]

We always do hwrng_init in set_current_rng.  In fact, our current
reference count system relies on this.  So make this explicit by
moving hwrng_init into set_current_rng.

Signed-off-by: Herbert Xu <herb...@gondor.apana.org.au>
---

 drivers/char/hw_random/core.c |   30 ++++++++++++++++--------------
 1 file changed, 16 insertions(+), 14 deletions(-)

diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c
index 787ef42..32a8a86 100644
--- a/drivers/char/hw_random/core.c
+++ b/drivers/char/hw_random/core.c
@@ -71,6 +71,7 @@ MODULE_PARM_DESC(default_quality,
                 "default entropy content of hwrng per mill");
 
 static void drop_current_rng(void);
+static int hwrng_init(struct hwrng *rng);
 static void start_khwrngd(void);
 
 static inline int rng_get_data(struct hwrng *rng, u8 *buffer, size_t size,
@@ -103,11 +104,20 @@ static inline void cleanup_rng(struct kref *kref)
        complete(&rng->cleanup_done);
 }
 
-static void set_current_rng(struct hwrng *rng)
+static int set_current_rng(struct hwrng *rng)
 {
+       int err;
+
        BUG_ON(!mutex_is_locked(&rng_mutex));
+
+       err = hwrng_init(rng);
+       if (err)
+               return err;
+
        drop_current_rng();
        current_rng = rng;
+
+       return 0;
 }
 
 static void drop_current_rng(void)
@@ -149,7 +159,7 @@ static void put_rng(struct hwrng *rng)
        mutex_unlock(&rng_mutex);
 }
 
-static inline int hwrng_init(struct hwrng *rng)
+static int hwrng_init(struct hwrng *rng)
 {
        if (kref_get_unless_zero(&rng->ref))
                goto skip_init;
@@ -310,15 +320,9 @@ static ssize_t hwrng_attr_current_store(struct device *dev,
        err = -ENODEV;
        list_for_each_entry(rng, &rng_list, list) {
                if (strcmp(rng->name, buf) == 0) {
-                       if (rng == current_rng) {
-                               err = 0;
-                               break;
-                       }
-                       err = hwrng_init(rng);
-                       if (err)
-                               break;
-                       set_current_rng(rng);
                        err = 0;
+                       if (rng != current_rng)
+                               err = set_current_rng(rng);
                        break;
                }
        }
@@ -481,10 +485,9 @@ int hwrng_register(struct hwrng *rng)
        old_rng = current_rng;
        err = 0;
        if (!old_rng) {
-               err = hwrng_init(rng);
+               err = set_current_rng(rng);
                if (err)
                        goto out_unlock;
-               set_current_rng(rng);
        }
        list_add_tail(&rng->list, &rng_list);
 
@@ -518,8 +521,7 @@ void hwrng_unregister(struct hwrng *rng)
 
                        tail = list_entry(rng_list.prev, struct hwrng, list);
 
-                       if (hwrng_init(tail) == 0)
-                               set_current_rng(tail);
+                       set_current_rng(tail);
                }
        }
 
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/