[v2.6.34-stable 149/165] random: Adjust the number of loops when initializing

[Paul Gortmaker]

From: "H. Peter Anvin" <hpa@xxxxxxxxxxxxxxx>

                   -------------------
    This is a commit scheduled for the next v2.6.34 longterm release.
    http://git.kernel.org/?p=linux/kernel/git/paulg/longterm-queue-2.6.34.git
    If you see a problem with using this for longterm, please comment.
                   -------------------

commit 2dac8e54f988ab58525505d7ef982493374433c3 upstream.

When we are initializing using arch_get_random_long() we only need to
loop enough times to touch all the bytes in the buffer; using
poolwords for that does twice the number of operations necessary on a
64-bit machine, since in the random number generator code "word" means
32 bits.

Signed-off-by: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx>
Cc: "Theodore Ts'o" <tytso@xxxxxxx>
Link: http://lkml.kernel.org/r/1324589281-31931-1-git-send-email-tytso@xxxxxxx
Signed-off-by: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx>
---
 drivers/char/random.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/char/random.c b/drivers/char/random.c
index 4874f55..fce764d 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -968,7 +968,7 @@ static void init_std_data(struct entropy_store *r)
 
 	now = ktime_get_real();
 	mix_pool_bytes(r, &now, sizeof(now));
-	for (i = r->poolinfo->poolwords; i; i--) {
+	for (i = r->poolinfo->POOLBYTES; i > 0; i -= sizeof flags) {
 		if (!arch_get_random_long(&flags))
 			break;
 		mix_pool_bytes(r, &flags, sizeof(flags));
-- 
1.7.12.rc2

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