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authorAlan Cox <alan@lxorguk.ukuu.org.uk>2008-04-30 00:53:59 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-04-30 08:29:45 -0700
commit978e595f88a1fba5869aa42a4af4fba36f33ecac (patch)
tree60848f49949c5b7b518621ee36cdc6d500244539 /drivers/char/tty_ioctl.c
parentac0e4b7d319bf284bb64bc7e1c051417386b34a4 (diff)
downloadlinux-978e595f88a1fba5869aa42a4af4fba36f33ecac.tar.bz2
tty/serial: lay the foundations for the next set of reworks
- Stop drivers calling their own flush method indirectly, it obfuscates code and it will change soon anyway - A few more lock_kernel paths temporarily needed in some driver internal waiting code - Remove private put_char method that does a write call for one char - we have that anyway - Most but not yet all of the termios copy under lock fixing (some has other dependencies to follow) - Note a few locking bugs in drivers found in the process - Kill remaining [ab]users of TIOCG/SSOFTCAR in the driver, these must go to fix the termios locking Signed-off-by: Alan Cox <alan@redhat.com> Cc: Jiri Slaby <jirislaby@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/char/tty_ioctl.c')
-rw-r--r--drivers/char/tty_ioctl.c14
1 files changed, 12 insertions, 2 deletions
diff --git a/drivers/char/tty_ioctl.c b/drivers/char/tty_ioctl.c
index d769e43f73fb..8c4bf3e48d5b 100644
--- a/drivers/char/tty_ioctl.c
+++ b/drivers/char/tty_ioctl.c
@@ -396,7 +396,7 @@ EXPORT_SYMBOL(tty_termios_hw_change);
static void change_termios(struct tty_struct *tty, struct ktermios *new_termios)
{
int canon_change;
- struct ktermios old_termios = *tty->termios;
+ struct ktermios old_termios;
struct tty_ldisc *ld;
unsigned long flags;
@@ -408,7 +408,7 @@ static void change_termios(struct tty_struct *tty, struct ktermios *new_termios)
/* FIXME: we need to decide on some locking/ordering semantics
for the set_termios notification eventually */
mutex_lock(&tty->termios_mutex);
-
+ old_termios = *tty->termios;
*tty->termios = *new_termios;
unset_locked_termios(tty->termios, &old_termios, tty->termios_locked);
canon_change = (old_termios.c_lflag ^ tty->termios->c_lflag) & ICANON;
@@ -480,7 +480,9 @@ static int set_termios(struct tty_struct *tty, void __user *arg, int opt)
if (retval)
return retval;
+ mutex_lock(&tty->termios_mutex);
memcpy(&tmp_termios, tty->termios, sizeof(struct ktermios));
+ mutex_unlock(&tty->termios_mutex);
if (opt & TERMIOS_TERMIO) {
if (user_termio_to_kernel_termios(&tmp_termios,
@@ -666,12 +668,14 @@ static int get_tchars(struct tty_struct *tty, struct tchars __user *tchars)
{
struct tchars tmp;
+ mutex_lock(&tty->termios_mutex);
tmp.t_intrc = tty->termios->c_cc[VINTR];
tmp.t_quitc = tty->termios->c_cc[VQUIT];
tmp.t_startc = tty->termios->c_cc[VSTART];
tmp.t_stopc = tty->termios->c_cc[VSTOP];
tmp.t_eofc = tty->termios->c_cc[VEOF];
tmp.t_brkc = tty->termios->c_cc[VEOL2]; /* what is brkc anyway? */
+ mutex_unlock(&tty->termios_mutex);
return copy_to_user(tchars, &tmp, sizeof(tmp)) ? -EFAULT : 0;
}
@@ -681,12 +685,14 @@ static int set_tchars(struct tty_struct *tty, struct tchars __user *tchars)
if (copy_from_user(&tmp, tchars, sizeof(tmp)))
return -EFAULT;
+ mutex_lock(&tty->termios_mutex);
tty->termios->c_cc[VINTR] = tmp.t_intrc;
tty->termios->c_cc[VQUIT] = tmp.t_quitc;
tty->termios->c_cc[VSTART] = tmp.t_startc;
tty->termios->c_cc[VSTOP] = tmp.t_stopc;
tty->termios->c_cc[VEOF] = tmp.t_eofc;
tty->termios->c_cc[VEOL2] = tmp.t_brkc; /* what is brkc anyway? */
+ mutex_unlock(&tty->termios_mutex);
return 0;
}
#endif
@@ -696,6 +702,7 @@ static int get_ltchars(struct tty_struct *tty, struct ltchars __user *ltchars)
{
struct ltchars tmp;
+ mutex_lock(&tty->termios_mutex);
tmp.t_suspc = tty->termios->c_cc[VSUSP];
/* what is dsuspc anyway? */
tmp.t_dsuspc = tty->termios->c_cc[VSUSP];
@@ -704,6 +711,7 @@ static int get_ltchars(struct tty_struct *tty, struct ltchars __user *ltchars)
tmp.t_flushc = tty->termios->c_cc[VEOL2];
tmp.t_werasc = tty->termios->c_cc[VWERASE];
tmp.t_lnextc = tty->termios->c_cc[VLNEXT];
+ mutex_unlock(&tty->termios_mutex);
return copy_to_user(ltchars, &tmp, sizeof(tmp)) ? -EFAULT : 0;
}
@@ -714,6 +722,7 @@ static int set_ltchars(struct tty_struct *tty, struct ltchars __user *ltchars)
if (copy_from_user(&tmp, ltchars, sizeof(tmp)))
return -EFAULT;
+ mutex_lock(&tty->termios_mutex);
tty->termios->c_cc[VSUSP] = tmp.t_suspc;
/* what is dsuspc anyway? */
tty->termios->c_cc[VEOL2] = tmp.t_dsuspc;
@@ -722,6 +731,7 @@ static int set_ltchars(struct tty_struct *tty, struct ltchars __user *ltchars)
tty->termios->c_cc[VEOL2] = tmp.t_flushc;
tty->termios->c_cc[VWERASE] = tmp.t_werasc;
tty->termios->c_cc[VLNEXT] = tmp.t_lnextc;
+ mutex_unlock(&tty->termios_mutex);
return 0;
}
#endif