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authorTheodore Ts'o <tytso@mit.edu>2013-11-03 06:54:51 -0500
committerTheodore Ts'o <tytso@mit.edu>2013-11-03 18:18:48 -0500
commit301f0595c0e788edacc3521c4caa90b4e56ffee1 (patch)
treedf43a0a76d8cfa5783154154a60653a7d51c2d8e /drivers/char
parent40db23e5337d99fda05ee6cd18034b516f8f123d (diff)
downloadlinux-linaro-stable-301f0595c0e788edacc3521c4caa90b4e56ffee1.tar.gz
random: printk notifications for urandom pool initialization
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" <tytso@mit.edu>
Diffstat (limited to 'drivers/char')
-rw-r--r--drivers/char/random.c12
1 files changed, 11 insertions, 1 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c
index 62923138e77a..a19a7a63ec35 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;
}
@@ -1327,7 +1330,14 @@ 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));