mirrors/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-09-20 01:20:54 +00:00
Code Issues Releases Wiki Activity

pty: Narrow the race on ldisc locking

Browse source 
The pty code has always been buggy on its ldisc handling. The recent
changes made the window for the race much bigger. Pending fixing it
properly which is not at all trivial, at least make the race small again so
we don't disrupt other dev work.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Alan Cox 2009-06-15 16:27:29 +01:00 committed by Linus Torvalds
parent b231125af7
commit cbcb6d66af
1 changed files with 3 additions and 3 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

6
drivers/char/pty.c
View file

@ -104,7 +104,7 @@ static int pty_write(struct tty_struct *tty, const unsigned char *buf,
struct tty_struct *to = tty->link;
int c;
if (!to || tty->stopped)
if (!to || !to->ldisc || tty->stopped)
return 0;
c = to->receive_room;
@ -148,7 +148,7 @@ static int pty_chars_in_buffer(struct tty_struct *tty)
int count;
/* We should get the line discipline lock for "tty->link" */
if (!to || !to->ldisc->ops->chars_in_buffer)
if (!to || !to->ldisc || !to->ldisc->ops->chars_in_buffer)
return 0;
/* The ldisc must report 0 if no characters available to be read */
@ -183,7 +183,7 @@ static void pty_flush_buffer(struct tty_struct *tty)
struct tty_struct *to = tty->link;
unsigned long flags;
if (!to)
if (!to || !to->ldisc)
return;
if (to->ldisc->ops->flush_buffer)