From 392a546dc8368d1745f9891ef3f8f7c380de8650 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Sun, 3 Nov 2013 18:24:08 -0500 Subject: [PATCH] random: add debugging code to detect early use of get_random_bytes() Signed-off-by: "Theodore Ts'o" --- drivers/char/random.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/char/random.c b/drivers/char/random.c index 0894d86253fd..cdf4cfb2da4d 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -280,6 +280,8 @@ #define SEC_XFER_SIZE 512 #define EXTRACT_SIZE 10 +#define DEBUG_RANDOM_BOOT 0 + #define LONGS(x) (((x) + sizeof(unsigned long) - 1)/sizeof(unsigned long)) /* @@ -1177,6 +1179,13 @@ static ssize_t extract_entropy_user(struct entropy_store *r, void __user *buf, */ void get_random_bytes(void *buf, int nbytes) { +#if DEBUG_RANDOM_BOOT > 0 + if (unlikely(nonblocking_pool.initialized == 0)) + printk(KERN_NOTICE "random: %pF get_random_bytes called " + "with %d bits of entropy available\n", + (void *) _RET_IP_, + nonblocking_pool.entropy_total); +#endif trace_get_random_bytes(nbytes, _RET_IP_); extract_entropy(&nonblocking_pool, buf, nbytes, 0, 0); } -- 2.34.1