linux-kernel - [PATCH] n_tty: Clarify copy_from_read

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Message-Id: <1446993310-7681-1-git-send-email-peter@hurleysoftware.com>
Date:	Sun,  8 Nov 2015 09:35:09 -0500
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] n_tty: Clarify copy_from_read_buf()

Add a temporary for the computed source address and substitute
where appropriate. No functional change.

Signed-off-by: Peter Hurley <peter@...leysoftware.com>
---
 drivers/tty/n_tty.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index b2b01d5..bc613b8 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -2014,11 +2014,11 @@ static int copy_from_read_buf(struct tty_struct *tty,
 	n = min(head - ldata->read_tail, N_TTY_BUF_SIZE - tail);
 	n = min(*nr, n);
 	if (n) {
-		retval = copy_to_user(*b, read_buf_addr(ldata, tail), n);
+		const unsigned char *from = read_buf_addr(ldata, tail);
+		retval = copy_to_user(*b, from, n);
 		n -= retval;
-		is_eof = n == 1 && read_buf(ldata, tail) == EOF_CHAR(tty);
-		tty_audit_add_data(tty, read_buf_addr(ldata, tail), n,
-				ldata->icanon);
+		is_eof = n == 1 && *from == EOF_CHAR(tty);
+		tty_audit_add_data(tty, from, n, ldata->icanon);
 		smp_store_release(&ldata->read_tail, ldata->read_tail + n);
 		/* Turn single EOF into zero-length read */
 		if (L_EXTPROC(tty) && ldata->icanon && is_eof &&
-- 
2.6.3

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