diff options
Diffstat (limited to 'drivers/char/vt_ioctl.c')
| -rw-r--r-- | drivers/char/vt_ioctl.c | 19 |
1 files changed, 12 insertions, 7 deletions
diff --git a/drivers/char/vt_ioctl.c b/drivers/char/vt_ioctl.c index c6f6f420973..7a61a2a9aaf 100644 --- a/drivers/char/vt_ioctl.c +++ b/drivers/char/vt_ioctl.c @@ -770,6 +770,7 @@ int vt_ioctl(struct tty_struct *tty, struct file * file, /* * Switching-from response */ + acquire_console_sem(); if (vc->vt_newvt >= 0) { if (arg == 0) /* @@ -784,7 +785,6 @@ int vt_ioctl(struct tty_struct *tty, struct file * file, * complete the switch. */ int newvt; - acquire_console_sem(); newvt = vc->vt_newvt; vc->vt_newvt = -1; i = vc_allocate(newvt); @@ -798,7 +798,6 @@ int vt_ioctl(struct tty_struct *tty, struct file * file, * other console switches.. */ complete_change_console(vc_cons[newvt].d); - release_console_sem(); } } @@ -810,9 +809,12 @@ int vt_ioctl(struct tty_struct *tty, struct file * file, /* * If it's just an ACK, ignore it */ - if (arg != VT_ACKACQ) + if (arg != VT_ACKACQ) { + release_console_sem(); return -EINVAL; + } } + release_console_sem(); return 0; @@ -1030,7 +1032,7 @@ static DECLARE_WAIT_QUEUE_HEAD(vt_activate_queue); /* * Sleeps until a vt is activated, or the task is interrupted. Returns - * 0 if activation, -EINTR if interrupted. + * 0 if activation, -EINTR if interrupted by a signal handler. */ int vt_waitactive(int vt) { @@ -1055,7 +1057,7 @@ int vt_waitactive(int vt) break; } release_console_sem(); - retval = -EINTR; + retval = -ERESTARTNOHAND; if (signal_pending(current)) break; schedule(); @@ -1208,15 +1210,18 @@ void change_console(struct vc_data *new_vc) /* * Send the signal as privileged - kill_pid() will * tell us if the process has gone or something else - * is awry + * is awry. + * + * We need to set vt_newvt *before* sending the signal or we + * have a race. */ + vc->vt_newvt = new_vc->vc_num; if (kill_pid(vc->vt_pid, vc->vt_mode.relsig, 1) == 0) { /* * It worked. Mark the vt to switch to and * return. The process needs to send us a * VT_RELDISP ioctl to complete the switch. */ - vc->vt_newvt = new_vc->vc_num; return; } |