linux-kernel - [PATCH 07/11] random: simplify accounting code slightly

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20131107235859.GJ16018@ringworld.MIT.EDU>
Date:	Thu, 7 Nov 2013 18:58:59 -0500
From:	Greg Price <price@....EDU>
To:	"Theodore Ts'o" <tytso@....edu>
Cc:	linux-kernel@...r.kernel.org, Jiri Kosina <jkosina@...e.cz>
Subject: [PATCH 07/11] random: simplify accounting code slightly

This commit makes the very boring simplifications so that the next
commit, which is a little trickier, is isolated and easy to review.
No change in behavior here at all.

Cc: "Theodore Ts'o" <tytso@....edu>
Cc: Jiri Kosina <jkosina@...e.cz>
Signed-off-by: Greg Price <price@....edu>
---
 drivers/char/random.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/drivers/char/random.c b/drivers/char/random.c
index 8ec4a9a..8824e8d 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -858,18 +858,16 @@ static size_t account(struct entropy_store *r, size_t nbytes, int min,
 retry:
 		entropy_count = orig = ACCESS_ONCE(r->entropy_count);
 		/* If limited, never pull more than available */
-		if (r->limit && nbytes + reserved >= entropy_count / 8)
-			nbytes = entropy_count/8 - reserved;
+		if (r->limit)
+			nbytes = min_t(size_t, nbytes, entropy_count/8 - reserved);
 
 		if (entropy_count / 8 >= nbytes + reserved) {
 			entropy_count -= nbytes*8;
-			if (cmpxchg(&r->entropy_count, orig, entropy_count) != orig)
-				goto retry;
 		} else {
 			entropy_count = reserved;
-			if (cmpxchg(&r->entropy_count, orig, entropy_count) != orig)
-				goto retry;
 		}
+		if (cmpxchg(&r->entropy_count, orig, entropy_count) != orig)
+			goto retry;
 
 		if (entropy_count < random_write_wakeup_thresh)
 			wakeup_write = 1;
-- 
1.8.3.2

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/