| Message ID | 1889464.W6X1COIBGJ@tauon (mailing list archive) |
|---|---|
| State | RFC |
| Delegated to: | Herbert Xu |
| Headers | show |
On Tue, May 19, 2015 at 04:36:58PM +0200, Stephan Mueller wrote: > diff --git a/drivers/char/random.c b/drivers/char/random.c > index 9cd6968..6f71354 100644 > --- a/drivers/char/random.c > +++ b/drivers/char/random.c > @@ -1245,6 +1245,20 @@ void get_random_bytes(void *buf, int nbytes) > EXPORT_SYMBOL(get_random_bytes); > > /* > + * Equivalent function to get_random_bytes with the difference that this > + * function blocks the request until the nonblocking_pool is initialized. > + */ > +void get_blocking_random_bytes(void *buf, int nbytes) > +{ > + if (unlikely(nonblocking_pool.initialized == 0)) > + wait_event_interruptible(urandom_init_wait, > + nonblocking_pool.initialized); > + extract_entropy(&nonblocking_pool, buf, nbytes, 0, 0); > +} > +EXPORT_SYMBOL(get_blocking_random_bytes); You still need to handle the case where wait_event_interruptible returns an error. Otherwise this looks fine. Thanks,
Am Mittwoch, 20. Mai 2015, 06:55:33 schrieb Herbert Xu: Hi Herbert, > >You still need to handle the case where wait_event_interruptible >returns an error. Otherwise this looks fine. Thank you. I would suggest to add a while loop around the call that sets up the wait if it terminated with ERESTARTSYS. This way we can maintain a void function that is almost identical to the get_random_bytes function. Ciao Stephan -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/char/random.c b/drivers/char/random.c index 9cd6968..6f71354 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -1245,6 +1245,20 @@ void get_random_bytes(void *buf, int nbytes) EXPORT_SYMBOL(get_random_bytes); /* + * Equivalent function to get_random_bytes with the difference that this + * function blocks the request until the nonblocking_pool is initialized. + */ +void get_blocking_random_bytes(void *buf, int nbytes) +{ + if (unlikely(nonblocking_pool.initialized == 0)) + wait_event_interruptible(urandom_init_wait, + nonblocking_pool.initialized); + extract_entropy(&nonblocking_pool, buf, nbytes, 0, 0); +} +EXPORT_SYMBOL(get_blocking_random_bytes); + + +/* * 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 diff --git a/include/linux/random.h b/include/linux/random.h index b05856e..0926d78 100644 --- a/include/linux/random.h +++ b/include/linux/random.h @@ -14,6 +14,7 @@ extern void add_input_randomness(unsigned int type, unsigned int code, extern void add_interrupt_randomness(int irq, int irq_flags); extern void get_random_bytes(void *buf, int nbytes); +extern void get_blocking_random_bytes(void *buf, int nbytes); extern void get_random_bytes_arch(void *buf, int nbytes); void generate_random_uuid(unsigned char uuid_out[16]);