Print a notification to the console when the nonblocking pool is initialized. Also printk a warning when a process tries reading from /dev/urandom before it is fully initialized.
Signed-off-by: "Theodore Ts'o" <[email protected]> --- drivers/char/random.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/drivers/char/random.c b/drivers/char/random.c index b578c03..f553600 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -655,6 +655,9 @@ retry: r->entropy_total += nbits; if (!r->initialized && nbits > 0) { if (r->entropy_total > 128) { + if (r == &nonblocking_pool) + pr_notice("random: %s pool is initialized\n", + r->name); r->initialized = 1; r->entropy_total = 0; } @@ -1334,7 +1337,14 @@ random_read(struct file *file, char __user *buf, size_t nbytes, loff_t *ppos) static ssize_t urandom_read(struct file *file, char __user *buf, size_t nbytes, loff_t *ppos) { - int ret = extract_entropy_user(&nonblocking_pool, buf, nbytes); + int ret; + + if (unlikely(nonblocking_pool.initialized == 0)) + printk_once(KERN_NOTICE "random: %s urandom read " + "with %d bits of entropy available\n", + current->comm, nonblocking_pool.entropy_total); + + ret = extract_entropy_user(&nonblocking_pool, buf, nbytes); trace_urandom_read(8 * nbytes, ENTROPY_BITS(&nonblocking_pool), ENTROPY_BITS(&input_pool)); -- 1.7.12.rc0.22.gcdd159b -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
