svn commit: r282645 - head/sys/dev/vt
Hans Petter Selasky
hselasky at FreeBSD.org
Fri May 8 16:19:02 UTC 2015
Author: hselasky
Date: Fri May 8 16:19:01 2015
New Revision: 282645
URL: https://svnweb.freebsd.org/changeset/base/282645
Log:
Prevent switching to NULL or own window in the "vt_proc_window_switch"
function. This fixes an issue where X11 keyboard input can appear
stuck. The cause of the problem is a duplicate TTY device window
switch IOCTL during boot, which leaves the "vt_switch_timer" running,
because the current window is already selected. While at it factor out
some NULL checks.
PR: 200032
Differential Revision: https://reviews.freebsd.org/D2480
Reported by: several people
MFC after: 1 week
Reviewed by: emaste
Modified:
head/sys/dev/vt/vt_core.c
Modified: head/sys/dev/vt/vt_core.c
==============================================================================
--- head/sys/dev/vt/vt_core.c Fri May 8 16:18:11 2015 (r282644)
+++ head/sys/dev/vt/vt_core.c Fri May 8 16:19:01 2015 (r282645)
@@ -451,12 +451,35 @@ vt_proc_window_switch(struct vt_window *
struct vt_device *vd;
int ret;
+ /* Prevent switching to NULL */
+ if (vw == NULL) {
+ DPRINTF(30, "%s: Cannot switch: vw is NULL.", __func__);
+ return (EINVAL);
+ }
vd = vw->vw_device;
curvw = vd->vd_curwindow;
+ /* Check if virtual terminal is locked */
if (curvw->vw_flags & VWF_VTYLOCK)
return (EBUSY);
+ /* Check if switch already in progress */
+ if (curvw->vw_flags & VWF_SWWAIT_REL) {
+ /* Check if switching to same window */
+ if (curvw->vw_switch_to == vw) {
+ DPRINTF(30, "%s: Switch in progress to same vw.", __func__);
+ return (0); /* success */
+ }
+ DPRINTF(30, "%s: Switch in progress to different vw.", __func__);
+ return (EBUSY);
+ }
+
+ /* Avoid switching to already selected window */
+ if (vw == curvw) {
+ DPRINTF(30, "%s: Cannot switch: vw == curvw.", __func__);
+ return (0); /* success */
+ }
+
/* Ask current process permission to switch away. */
if (curvw->vw_smode.mode == VT_PROCESS) {
DPRINTF(30, "%s: VT_PROCESS ", __func__);
@@ -664,8 +687,7 @@ vt_scrollmode_kbdevent(struct vt_window
if (console == 0) {
if (c >= F_SCR && c <= MIN(L_SCR, F_SCR + VT_MAXWINDOWS - 1)) {
vw = vd->vd_windows[c - F_SCR];
- if (vw != NULL)
- vt_proc_window_switch(vw);
+ vt_proc_window_switch(vw);
return;
}
VT_LOCK(vd);
@@ -750,8 +772,7 @@ vt_processkey(keyboard_t *kbd, struct vt
if (c >= F_SCR && c <= MIN(L_SCR, F_SCR + VT_MAXWINDOWS - 1)) {
vw = vd->vd_windows[c - F_SCR];
- if (vw != NULL)
- vt_proc_window_switch(vw);
+ vt_proc_window_switch(vw);
return (0);
}
@@ -760,15 +781,13 @@ vt_processkey(keyboard_t *kbd, struct vt
/* Switch to next VT. */
c = (vw->vw_number + 1) % VT_MAXWINDOWS;
vw = vd->vd_windows[c];
- if (vw != NULL)
- vt_proc_window_switch(vw);
+ vt_proc_window_switch(vw);
return (0);
case PREV:
/* Switch to previous VT. */
c = (vw->vw_number - 1) % VT_MAXWINDOWS;
vw = vd->vd_windows[c];
- if (vw != NULL)
- vt_proc_window_switch(vw);
+ vt_proc_window_switch(vw);
return (0);
case SLK: {
vt_save_kbd_state(vw, kbd);
@@ -2774,8 +2793,7 @@ vt_resume(struct vt_device *vd)
if (vt_suspendswitch == 0)
return;
- /* Switch back to saved window */
- if (vd->vd_savedwindow != NULL)
- vt_proc_window_switch(vd->vd_savedwindow);
+ /* Switch back to saved window, if any */
+ vt_proc_window_switch(vd->vd_savedwindow);
vd->vd_savedwindow = NULL;
}
More information about the svn-src-all
mailing list