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authorHerbert Xu <herbert@gondor.apana.org.au>2014-12-23 16:40:19 +1100
committerHerbert Xu <herbert@gondor.apana.org.au>2014-12-26 08:33:35 +1100
commitac3a497f13e42a99ed6fe188ebf2dcc39eb7ac20 (patch)
tree6c06a3de482d03a83d7a7c6ad8ea32f099c9530c /drivers/char/hw_random
parent15b66cd54291186011f733cc750263f320b8a0a4 (diff)
hwrng: core - Do not register device opportunistically
Currently we only register the device when a valid RNG is added. However the way it's done is buggy because we test whether there is a current RNG to determine whether we need to register. As the current RNG may be missing due to a reinitialisation error this can lead to a reregistration of the device. As the device already has to handle a NULL current RNG anyway, let's just register the device always and remove the complexity. 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.c23
1 files changed, 12 insertions, 11 deletions
diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c
index 42827fd5f38d..1d342f0cb0c1 100644
--- a/drivers/char/hw_random/core.c
+++ b/drivers/char/hw_random/core.c
@@ -372,14 +372,14 @@ static DEVICE_ATTR(rng_available, S_IRUGO,
NULL);
-static void unregister_miscdev(void)
+static void __exit unregister_miscdev(void)
{
device_remove_file(rng_miscdev.this_device, &dev_attr_rng_available);
device_remove_file(rng_miscdev.this_device, &dev_attr_rng_current);
misc_deregister(&rng_miscdev);
}
-static int register_miscdev(void)
+static int __init register_miscdev(void)
{
int err;
@@ -484,12 +484,6 @@ int hwrng_register(struct hwrng *rng)
if (err)
goto out_unlock;
set_current_rng(rng);
-
- err = register_miscdev();
- if (err) {
- drop_current_rng();
- goto out_unlock;
- }
}
list_add_tail(&rng->list, &rng_list);
@@ -530,7 +524,6 @@ void hwrng_unregister(struct hwrng *rng)
if (list_empty(&rng_list)) {
mutex_unlock(&rng_mutex);
- unregister_miscdev();
if (hwrng_fill)
kthread_stop(hwrng_fill);
} else
@@ -540,16 +533,24 @@ void hwrng_unregister(struct hwrng *rng)
}
EXPORT_SYMBOL_GPL(hwrng_unregister);
-static void __exit hwrng_exit(void)
+static int __init hwrng_modinit(void)
+{
+ return register_miscdev();
+}
+
+static void __exit hwrng_modexit(void)
{
mutex_lock(&rng_mutex);
BUG_ON(current_rng);
kfree(rng_buffer);
kfree(rng_fillbuf);
mutex_unlock(&rng_mutex);
+
+ unregister_miscdev();
}
-module_exit(hwrng_exit);
+module_init(hwrng_modinit);
+module_exit(hwrng_modexit);
MODULE_DESCRIPTION("H/W Random Number Generator (RNG) driver");
MODULE_LICENSE("GPL");