From: Andy Lutomirski luto@kernel.org
commit c6f1deb158789abba02a7eba600747843eeb3a57 upstream.
/dev/random and getrandom() never warn. Split the meat of urandom_read() into urandom_read_nowarn() and leave the warning code in urandom_read().
This has no effect on kernel behavior, but it makes subsequent patches more straightforward. It also makes the fact that getrandom() never warns more obvious.
Signed-off-by: Andy Lutomirski luto@kernel.org Link: https://lore.kernel.org/r/c87ab200588de746431d9f916501ef11e5242b13.157708852... Signed-off-by: Theodore Ts'o tytso@mit.edu Signed-off-by: Jason A. Donenfeld Jason@zx2c4.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/char/random.c | 21 +++++++++++++++------ 1 file changed, 15 insertions(+), 6 deletions(-)
--- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -2015,11 +2015,22 @@ random_read(struct file *file, char __us }
static ssize_t +urandom_read_nowarn(struct file *file, char __user *buf, size_t nbytes, + loff_t *ppos) +{ + int ret; + + nbytes = min_t(size_t, nbytes, INT_MAX >> (ENTROPY_SHIFT + 3)); + ret = extract_crng_user(buf, nbytes); + trace_urandom_read(8 * nbytes, 0, ENTROPY_BITS(&input_pool)); + return ret; +} + +static ssize_t urandom_read(struct file *file, char __user *buf, size_t nbytes, loff_t *ppos) { unsigned long flags; static int maxwarn = 10; - int ret;
if (!crng_ready() && maxwarn > 0) { maxwarn--; @@ -2031,10 +2042,8 @@ urandom_read(struct file *file, char __u crng_init_cnt = 0; spin_unlock_irqrestore(&primary_crng.lock, flags); } - nbytes = min_t(size_t, nbytes, INT_MAX >> (ENTROPY_SHIFT + 3)); - ret = extract_crng_user(buf, nbytes); - trace_urandom_read(8 * nbytes, 0, ENTROPY_BITS(&input_pool)); - return ret; + + return urandom_read_nowarn(file, buf, nbytes, ppos); }
static unsigned int @@ -2194,7 +2203,7 @@ SYSCALL_DEFINE3(getrandom, char __user * if (unlikely(ret)) return ret; } - return urandom_read(NULL, buf, count, NULL); + return urandom_read_nowarn(NULL, buf, count, NULL); }
/********************************************************************