diff options
author | 2016-04-11 10:41:07 +0300 | |
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committer | 2016-04-13 08:17:18 +0300 | |
commit | e09b41010ba33a20a87472ee821fa407a5b8da36 (patch) | |
tree | d10dc367189862e7ca5c592f033dc3726e1df4e3 /kernel/drivers/char/random.c | |
parent | f93b97fd65072de626c074dbe099a1fff05ce060 (diff) |
These changes are the raw update to linux-4.4.6-rt14. Kernel sources
are taken from kernel.org, and rt patch from the rt wiki download page.
During the rebasing, the following patch collided:
Force tick interrupt and get rid of softirq magic(I70131fb85).
Collisions have been removed because its logic was found on the
source already.
Change-Id: I7f57a4081d9deaa0d9ccfc41a6c8daccdee3b769
Signed-off-by: José Pekkarinen <jose.pekkarinen@nokia.com>
Diffstat (limited to 'kernel/drivers/char/random.c')
-rw-r--r-- | kernel/drivers/char/random.c | 80 |
1 files changed, 79 insertions, 1 deletions
diff --git a/kernel/drivers/char/random.c b/kernel/drivers/char/random.c index eb47efec2..29abd5fa5 100644 --- a/kernel/drivers/char/random.c +++ b/kernel/drivers/char/random.c @@ -409,6 +409,9 @@ static DECLARE_WAIT_QUEUE_HEAD(random_write_wait); static DECLARE_WAIT_QUEUE_HEAD(urandom_init_wait); static struct fasync_struct *fasync; +static DEFINE_SPINLOCK(random_ready_list_lock); +static LIST_HEAD(random_ready_list); + /********************************************************************** * * OS independent entropy store. Here are the functions which handle @@ -589,6 +592,22 @@ static void fast_mix(struct fast_pool *f) f->count++; } +static void process_random_ready_list(void) +{ + unsigned long flags; + struct random_ready_callback *rdy, *tmp; + + spin_lock_irqsave(&random_ready_list_lock, flags); + list_for_each_entry_safe(rdy, tmp, &random_ready_list, list) { + struct module *owner = rdy->owner; + + list_del_init(&rdy->list); + rdy->func(rdy); + module_put(owner); + } + spin_unlock_irqrestore(&random_ready_list_lock, flags); +} + /* * Credit (or debit) the entropy store with n bits of entropy. * Use credit_entropy_bits_safe() if the value comes from userspace @@ -660,7 +679,8 @@ retry: r->entropy_total = 0; if (r == &nonblocking_pool) { prandom_reseed_late(); - wake_up_interruptible(&urandom_init_wait); + process_random_ready_list(); + wake_up_all(&urandom_init_wait); pr_notice("random: %s pool is initialized\n", r->name); } } @@ -1241,6 +1261,64 @@ void get_random_bytes(void *buf, int nbytes) EXPORT_SYMBOL(get_random_bytes); /* + * Add a callback function that will be invoked when the nonblocking + * pool is initialised. + * + * returns: 0 if callback is successfully added + * -EALREADY if pool is already initialised (callback not called) + * -ENOENT if module for callback is not alive + */ +int add_random_ready_callback(struct random_ready_callback *rdy) +{ + struct module *owner; + unsigned long flags; + int err = -EALREADY; + + if (likely(nonblocking_pool.initialized)) + return err; + + owner = rdy->owner; + if (!try_module_get(owner)) + return -ENOENT; + + spin_lock_irqsave(&random_ready_list_lock, flags); + if (nonblocking_pool.initialized) + goto out; + + owner = NULL; + + list_add(&rdy->list, &random_ready_list); + err = 0; + +out: + spin_unlock_irqrestore(&random_ready_list_lock, flags); + + module_put(owner); + + return err; +} +EXPORT_SYMBOL(add_random_ready_callback); + +/* + * Delete a previously registered readiness callback function. + */ +void del_random_ready_callback(struct random_ready_callback *rdy) +{ + unsigned long flags; + struct module *owner = NULL; + + spin_lock_irqsave(&random_ready_list_lock, flags); + if (!list_empty(&rdy->list)) { + list_del_init(&rdy->list); + owner = rdy->owner; + } + spin_unlock_irqrestore(&random_ready_list_lock, flags); + + module_put(owner); +} +EXPORT_SYMBOL(del_random_ready_callback); + +/* * This function will use the architecture-specific hardware random * number generator if it is available. The arch-specific hw RNG will * almost certainly be faster than what we can do in software, but it |