linux-kernel - [PATCH v2 10/15] tty: audit: Remove false memory optimization

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Message-Id: <1452408939-19380-11-git-send-email-peter@hurleysoftware.com>
Date:	Sat,  9 Jan 2016 22:55:34 -0800
From:	Peter Hurley <peter@...leysoftware.com>
To:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc:	Jiri Slaby <jslaby@...e.cz>, linux-kernel@...r.kernel.org,
	Peter Hurley <peter@...leysoftware.com>
Subject: [PATCH v2 10/15] tty: audit: Remove false memory optimization

The tty audit buffer is allocated at first use and not freed until
the process exits. If tty audit is turned off after the audit buffer
has been allocated, no effort is made to release the buffer.
So re-checking if tty audit has just been turned off when tty audit
was just on is false optimization; the likelihood of triggering this
condition is exceedingly small.

Signed-off-by: Peter Hurley <peter@...leysoftware.com>
---
 drivers/tty/tty_audit.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/drivers/tty/tty_audit.c b/drivers/tty/tty_audit.c
index 3d90f88..7943984 100644
--- a/drivers/tty/tty_audit.c
+++ b/drivers/tty/tty_audit.c
@@ -200,8 +200,7 @@ int tty_audit_push(void)
  *	tty_audit_buf_get	-	Get an audit buffer.
  *
  *	Get an audit buffer, allocate it if necessary.  Return %NULL
- *	if TTY auditing is disabled or out of memory.  Otherwise, return a new
- *	reference to the buffer.
+ *	if out of memory.  Otherwise, return a new reference to the buffer.
  */
 static struct tty_audit_buf *tty_audit_buf_get(void)
 {
@@ -224,9 +223,6 @@ static struct tty_audit_buf *tty_audit_buf_get(void)
 		return NULL;
 	}
 
-	if (~current->signal->audit_tty & AUDIT_TTY_ENABLE)
-		goto out;
-
 	spin_lock_irqsave(&current->sighand->siglock, flags);
 	buf = current->signal->tty_audit_buf;
 	if (!buf) {
-- 
2.7.0