linux-kernel - [RESEND][PATCH 02/15] tty: audit: Never audit packet mode

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Date:	Sat,  9 Jan 2016 20:58:55 -0800
From:	Peter Hurley <peter@...leysoftware.com>
To:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc:	Jiri Slaby <jslaby@...e.cz>, linux-audit@...hat.com,
	linux-kernel@...r.kernel.org,
	Peter Hurley <peter@...leysoftware.com>
Subject: [RESEND][PATCH 02/15] tty: audit: Never audit packet mode

tty audit never logs pty master reads, but packet mode only works for
pty masters, so tty_audit_add_data() was never logging packet mode
anyway.

Don't audit packet mode data. As those are the lone call sites, remove
tty_put_user().

Signed-off-by: Peter Hurley <peter@...leysoftware.com>
---
 drivers/tty/n_tty.c | 17 ++++-------------
 1 file changed, 4 insertions(+), 13 deletions(-)

diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index 90eca26..eeae6bc 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -153,15 +153,6 @@ static inline unsigned char *echo_buf_addr(struct n_tty_data *ldata, size_t i)
 	return &ldata->echo_buf[i & (N_TTY_BUF_SIZE - 1)];
 }
 
-static inline int tty_put_user(struct tty_struct *tty, unsigned char x,
-			       unsigned char __user *ptr)
-{
-	struct n_tty_data *ldata = tty->disc_data;
-
-	tty_audit_add_data(tty, &x, 1, ldata->icanon);
-	return put_user(x, ptr);
-}
-
 static int tty_copy_to_user(struct tty_struct *tty, void __user *to,
 			    size_t tail, size_t n)
 {
@@ -2203,11 +2194,11 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
 			cs = tty->link->ctrl_status;
 			tty->link->ctrl_status = 0;
 			spin_unlock_irq(&tty->link->ctrl_lock);
-			if (tty_put_user(tty, cs, b++)) {
+			if (put_user(cs, b)) {
 				retval = -EFAULT;
-				b--;
 				break;
 			}
+			b++;
 			nr--;
 			break;
 		}
@@ -2253,11 +2244,11 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
 
 			/* Deal with packet mode. */
 			if (packet && b == buf) {
-				if (tty_put_user(tty, TIOCPKT_DATA, b++)) {
+				if (put_user(TIOCPKT_DATA, b)) {
 					retval = -EFAULT;
-					b--;
 					break;
 				}
+				b++;
 				nr--;
 			}
 
-- 
2.7.0