diff options
| -rw-r--r-- | include/linux/net.h | 21 | ||||
| -rw-r--r-- | include/linux/once.h | 24 | ||||
| -rw-r--r-- | lib/Makefile | 3 | ||||
| -rw-r--r-- | lib/once.c | 54 | ||||
| -rw-r--r-- | net/core/utils.c | 49 |
5 files changed, 84 insertions, 67 deletions
diff --git a/include/linux/net.h b/include/linux/net.h index 049d4b03c4c4..70ac5e28e6b7 100644 --- a/include/linux/net.h +++ b/include/linux/net.h @@ -24,7 +24,8 @@ #include <linux/fcntl.h> /* For O_CLOEXEC and O_NONBLOCK */ #include <linux/kmemcheck.h> #include <linux/rcupdate.h> -#include <linux/jump_label.h> +#include <linux/once.h> + #include <uapi/linux/net.h> struct poll_table_struct; @@ -250,22 +251,8 @@ do { \ } while (0) #endif -bool __net_get_random_once(void *buf, int nbytes, bool *done, - struct static_key *done_key); - -#define net_get_random_once(buf, nbytes) \ - ({ \ - bool ___ret = false; \ - static bool ___done = false; \ - static struct static_key ___once_key = \ - STATIC_KEY_INIT_TRUE; \ - if (static_key_true(&___once_key)) \ - ___ret = __net_get_random_once(buf, \ - nbytes, \ - &___done, \ - &___once_key); \ - ___ret; \ - }) +#define net_get_random_once(buf, nbytes) \ + get_random_once((buf), (nbytes)) int kernel_sendmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec, size_t num, size_t len); diff --git a/include/linux/once.h b/include/linux/once.h new file mode 100644 index 000000000000..2a83b538dd6a --- /dev/null +++ b/include/linux/once.h @@ -0,0 +1,24 @@ +#ifndef _LINUX_ONCE_H +#define _LINUX_ONCE_H + +#include <linux/types.h> +#include <linux/jump_label.h> + +bool __get_random_once(void *buf, int nbytes, bool *done, + struct static_key *once_key); + +#define get_random_once(buf, nbytes) \ + ({ \ + bool ___ret = false; \ + static bool ___done = false; \ + static struct static_key ___once_key = \ + STATIC_KEY_INIT_TRUE; \ + if (static_key_true(&___once_key)) \ + ___ret = __get_random_once((buf), \ + (nbytes), \ + &___done, \ + &___once_key); \ + ___ret; \ + }) + +#endif /* _LINUX_ONCE_H */ diff --git a/lib/Makefile b/lib/Makefile index 13a7c6ae3fec..8de3b012eac7 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -26,7 +26,8 @@ obj-y += bcd.o div64.o sort.o parser.o halfmd4.o debug_locks.o random32.o \ bust_spinlocks.o kasprintf.o bitmap.o scatterlist.o \ gcd.o lcm.o list_sort.o uuid.o flex_array.o iov_iter.o clz_ctz.o \ bsearch.o find_bit.o llist.o memweight.o kfifo.o \ - percpu-refcount.o percpu_ida.o rhashtable.o reciprocal_div.o + percpu-refcount.o percpu_ida.o rhashtable.o reciprocal_div.o \ + once.o obj-y += string_helpers.o obj-$(CONFIG_TEST_STRING_HELPERS) += test-string_helpers.o obj-y += hexdump.o diff --git a/lib/once.c b/lib/once.c new file mode 100644 index 000000000000..2d5a7de17aba --- /dev/null +++ b/lib/once.c @@ -0,0 +1,54 @@ +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/once.h> +#include <linux/random.h> + +struct __random_once_work { + struct work_struct work; + struct static_key *key; +}; + +static void __random_once_deferred(struct work_struct *w) +{ + struct __random_once_work *work; + + work = container_of(w, struct __random_once_work, work); + BUG_ON(!static_key_enabled(work->key)); + static_key_slow_dec(work->key); + kfree(work); +} + +static void __random_once_disable_jump(struct static_key *key) +{ + struct __random_once_work *w; + + w = kmalloc(sizeof(*w), GFP_ATOMIC); + if (!w) + return; + + INIT_WORK(&w->work, __random_once_deferred); + w->key = key; + schedule_work(&w->work); +} + +bool __get_random_once(void *buf, int nbytes, bool *done, + struct static_key *once_key) +{ + static DEFINE_SPINLOCK(lock); + unsigned long flags; + + spin_lock_irqsave(&lock, flags); + if (*done) { + spin_unlock_irqrestore(&lock, flags); + return false; + } + + get_random_bytes(buf, nbytes); + *done = true; + spin_unlock_irqrestore(&lock, flags); + + __random_once_disable_jump(once_key); + + return true; +} +EXPORT_SYMBOL(__get_random_once); diff --git a/net/core/utils.c b/net/core/utils.c index 3dffce953c39..3d17ca8b4744 100644 --- a/net/core/utils.c +++ b/net/core/utils.c @@ -348,52 +348,3 @@ void inet_proto_csum_replace_by_diff(__sum16 *sum, struct sk_buff *skb, } } EXPORT_SYMBOL(inet_proto_csum_replace_by_diff); - -struct __net_random_once_work { - struct work_struct work; - struct static_key *key; -}; - -static void __net_random_once_deferred(struct work_struct *w) -{ - struct __net_random_once_work *work = - container_of(w, struct __net_random_once_work, work); - BUG_ON(!static_key_enabled(work->key)); - static_key_slow_dec(work->key); - kfree(work); -} - -static void __net_random_once_disable_jump(struct static_key *key) -{ - struct __net_random_once_work *w; - - w = kmalloc(sizeof(*w), GFP_ATOMIC); - if (!w) - return; - - INIT_WORK(&w->work, __net_random_once_deferred); - w->key = key; - schedule_work(&w->work); -} - -bool __net_get_random_once(void *buf, int nbytes, bool *done, - struct static_key *once_key) -{ - static DEFINE_SPINLOCK(lock); - unsigned long flags; - - spin_lock_irqsave(&lock, flags); - if (*done) { - spin_unlock_irqrestore(&lock, flags); - return false; - } - - get_random_bytes(buf, nbytes); - *done = true; - spin_unlock_irqrestore(&lock, flags); - - __net_random_once_disable_jump(once_key); - - return true; -} -EXPORT_SYMBOL(__net_get_random_once); |