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Commit f84be2bd authored by Hannes Frederic Sowa's avatar Hannes Frederic Sowa Committed by David S. Miller
Browse files

net: make net_get_random_once irq safe 



I initial build non irq safe version of net_get_random_once because I
would liked to have the freedom to defer even the extraction process of
get_random_bytes until the nonblocking pool is fully seeded.

I don't think this is a good idea anymore and thus this patch makes
net_get_random_once irq safe. Now someone using net_get_random_once does
not need to care from where it is called.

Cc: David S. Miller <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: default avatarHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 974daef7

include/linux/net.h

+0 −1
Original line number Diff line number Diff line
@@ -250,7 +250,6 @@ bool __net_get_random_once(void *buf, int nbytes, bool *done, 
#define ___NET_RANDOM_STATIC_KEY_INIT STATIC_KEY_INIT_FALSE

#endif /* HAVE_JUMP_LABEL */



/* BE CAREFUL: this function is not interrupt safe */

#define net_get_random_once(buf, nbytes)				\

	({								\

		bool ___ret = false;					\

net/core/utils.c

+4 −3
Original line number Diff line number Diff line
@@ -370,16 +370,17 @@ bool __net_get_random_once(void *buf, int nbytes, bool *done, 
			   struct static_key *done_key)

{

	static DEFINE_SPINLOCK(lock);

	unsigned long flags;



	spin_lock_bh(&lock);

	spin_lock_irqsave(&lock, flags);

	if (*done) {

		spin_unlock_bh(&lock);

		spin_unlock_irqrestore(&lock, flags);

		return false;

	}



	get_random_bytes(buf, nbytes);

	*done = true;

	spin_unlock_bh(&lock);

	spin_unlock_irqrestore(&lock, flags);



	__net_random_once_disable_jump(done_key);