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hwrng: core - Move hwrng_init call into set_current_rng

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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>
This commit is contained in:
Herbert Xu 2014-12-23 16:40:22 +11:00
parent ff77c150f7
commit 90ac41bd40
1 changed files with 16 additions and 14 deletions
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30
drivers/char/hw_random/core.c
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@ -71,6 +71,7 @@ MODULE_PARM_DESC(default_quality,
"default entropy content of hwrng per mill"); "default entropy content of hwrng per mill");
static void drop_current_rng(void); static void drop_current_rng(void);
static int hwrng_init(struct hwrng *rng);
static void start_khwrngd(void); static void start_khwrngd(void);
static inline int rng_get_data(struct hwrng *rng, u8 *buffer, size_t size, 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); 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)); BUG_ON(!mutex_is_locked(&rng_mutex));
err = hwrng_init(rng);
if (err)
return err;
drop_current_rng(); drop_current_rng();
current_rng = rng; current_rng = rng;
return 0;
} }
static void drop_current_rng(void) static void drop_current_rng(void)
@ -149,7 +159,7 @@ static void put_rng(struct hwrng *rng)
mutex_unlock(&rng_mutex); 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)) if (kref_get_unless_zero(&rng->ref))
goto skip_init; goto skip_init;
@ -310,15 +320,9 @@ static ssize_t hwrng_attr_current_store(struct device *dev,
err = -ENODEV; err = -ENODEV;
list_for_each_entry(rng, &rng_list, list) { list_for_each_entry(rng, &rng_list, list) {
if (strcmp(rng->name, buf) == 0) { 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; err = 0;
if (rng != current_rng)
err = set_current_rng(rng);
break; break;
} }
} }
@ -481,10 +485,9 @@ int hwrng_register(struct hwrng *rng)
old_rng = current_rng; old_rng = current_rng;
err = 0; err = 0;
if (!old_rng) { if (!old_rng) {
err = hwrng_init(rng); err = set_current_rng(rng);
if (err) if (err)
goto out_unlock; goto out_unlock;
set_current_rng(rng);
} }
list_add_tail(&rng->list, &rng_list); 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); tail = list_entry(rng_list.prev, struct hwrng, list);
if (hwrng_init(tail) == 0) set_current_rng(tail);
set_current_rng(tail);
} }
} }