linux-kernel - [PATCH v2 01/14] serial: core: Document and assert lock requirements for irq helpers

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: <1410375996-4693-2-git-send-email-peter@hurleysoftware.com>
Date:	Wed, 10 Sep 2014 15:06:23 -0400
From:	Peter Hurley <peter@...leysoftware.com>
To:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc:	Jiri Slaby <jslaby@...e.cz>,
	One Thousand Gnomes <gnomes@...rguk.ukuu.org.uk>,
	linux-kernel@...r.kernel.org, linux-serial@...r.kernel.org,
	Peter Hurley <peter@...leysoftware.com>
Subject: [PATCH v2 01/14] serial: core: Document and assert lock requirements for irq helpers

The serial core provides two helper functions, uart_handle_dcd_change()
and uart_handle_cts_change(), for UART drivers to use at interrupt
time. The serial core expects the UART driver to hold the uart port lock
when calling these helpers to prevent state corruption.

If lockdep enabled, trigger a warning if the uart port lock is not held
when calling these helper functions.

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

diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 732d386..0567b65 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -2731,6 +2731,8 @@ EXPORT_SYMBOL(uart_match_port);
  *	uart_handle_dcd_change - handle a change of carrier detect state
  *	@uport: uart_port structure for the open port
  *	@status: new carrier detect status, nonzero if active
+ *
+ *	Caller must hold uport->lock
  */
 void uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
 {
@@ -2738,6 +2740,8 @@ void uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
 	struct tty_struct *tty = port->tty;
 	struct tty_ldisc *ld;
 
+	lockdep_assert_held_once(&uport->lock);
+
 	if (tty) {
 		ld = tty_ldisc_ref(tty);
 		if (ld) {
@@ -2762,12 +2766,16 @@ EXPORT_SYMBOL_GPL(uart_handle_dcd_change);
  *	uart_handle_cts_change - handle a change of clear-to-send state
  *	@uport: uart_port structure for the open port
  *	@status: new clear to send status, nonzero if active
+ *
+ *	Caller must hold uport->lock
  */
 void uart_handle_cts_change(struct uart_port *uport, unsigned int status)
 {
 	struct tty_port *port = &uport->state->port;
 	struct tty_struct *tty = port->tty;
 
+	lockdep_assert_held_once(&uport->lock);
+
 	uport->icount.cts++;
 
 	if (tty_port_cts_enabled(port)) {
-- 
2.1.0

--
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/