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authorHerbert Xu <herbert@gondor.apana.org.au>2014-12-23 16:40:22 +1100
committerHerbert Xu <herbert@gondor.apana.org.au>2014-12-26 08:33:36 +1100
commit90ac41bd40ad0571a10826eb26d53c84bd791f29 (patch)
tree47637b48bcfd4f4a284417184e5f15e1b747d837 /drivers/char/hw_random
parentff77c150f71b761dcf29b9d1947df3165d2dc83e (diff)
hwrng: core - Move hwrng_init call into set_current_rng
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 <herbert@gondor.apana.org.au>
Diffstat (limited to 'drivers/char/hw_random')
-rw-r--r--drivers/char/hw_random/core.c30
1 files changed, 16 insertions, 14 deletions
diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c
index 787ef42a77b9..32a8a867f7f8 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);
}
}