// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) 1992 obz under the linux copyright * * Dynamic diacritical handling - aeb@cwi.nl - Dec 1993 * Dynamic keymap and string allocation - aeb@cwi.nl - May 1994 * Restrict VT switching via ioctl() - grif@cs.ucr.edu - Dec 1995 * Some code moved for less code duplication - Andi Kleen - Mar 1997 * Check put/get_user, cleanups - acme@conectiva.com.br - Jun 2001 */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include bool vt_dont_switch; static inline bool vt_in_use(unsigned int i) { const struct vc_data *vc = vc_cons[i].d; /* * console_lock must be held to prevent the vc from being deallocated * while we're checking whether it's in-use. */ WARN_CONSOLE_UNLOCKED(); return vc && kref_read(&vc->port.kref) > 1; } static inline bool vt_busy(int i) { if (vt_in_use(i)) return true; if (i == fg_console) return true; if (vc_is_sel(vc_cons[i].d)) return true; return false; } /* * Console (vt and kd) routines, as defined by USL SVR4 manual, and by * experimentation and study of X386 SYSV handling. * * One point of difference: SYSV vt's are /dev/vtX, which X >= 0, and * /dev/console is a separate ttyp. Under Linux, /dev/tty0 is /dev/console, * and the vc start at /dev/ttyX, X >= 1. We maintain that here, so we will * always treat our set of vt as numbered 1..MAX_NR_CONSOLES (corresponding to * ttys 0..MAX_NR_CONSOLES-1). Explicitly naming VT 0 is illegal, but using * /dev/tty0 (fg_console) as a target is legal, since an implicit aliasing * to the current console is done by the main ioctl code. */ #ifdef CONFIG_X86 #include #endif static void complete_change_console(struct vc_data *vc); /* * User space VT_EVENT handlers */ struct vt_event_wait { struct list_head list; struct vt_event event; int done; }; static LIST_HEAD(vt_events); static DEFINE_SPINLOCK(vt_event_lock); static DECLARE_WAIT_QUEUE_HEAD(vt_event_waitqueue); /** * vt_event_post * @event: the event that occurred * @old: old console * @new: new console * * Post an VT event to interested VT handlers */ void vt_event_post(unsigned int event, unsigned int old, unsigned int new) { struct list_head *pos, *head; unsigned long flags; int wake = 0; spin_lock_irqsave(&vt_event_lock, flags); head = &vt_events; list_for_each(pos, head) { struct vt_event_wait *ve = list_entry(pos, struct vt_event_wait, list); if (!(ve->event.event & event)) continue; ve->event.event = event; /* kernel view is consoles 0..n-1, user space view is console 1..n with 0 meaning current, so we must bias */ ve->event.oldev = old + 1; ve->event.newev = new + 1; wake = 1; ve->done = 1; } spin_unlock_irqrestore(&vt_event_lock, flags); if (wake) wake_up_interruptible(&vt_event_waitqueue); } static void __vt_event_queue(struct vt_event_wait *vw) { unsigned long flags; /* Prepare the event */ INIT_LIST_HEAD(&vw->list); vw->done = 0; /* Queue our event */ spin_lock_irqsave(&vt_event_lock, flags); list_add(&vw->list, &vt_events); spin_unlock_irqrestore(&vt_event_lock, flags); } static void __vt_event_wait(struct vt_event_wait *vw) { /* Wait for it to pass */ wait_event_interruptible(vt_event_waitqueue, vw->done); } static void __vt_event_dequeue(struct vt_event_wait *vw) { unsigned long flags; /* Dequeue it */ spin_lock_irqsave(&vt_event_lock, flags); list_del(&vw->list); spin_unlock_irqrestore(&vt_event_lock, flags); } /** * vt_event_wait - wait for an event * @vw: our event * * Waits for an event to occur which completes our vt_event_wait * structure. On return the structure has wv->done set to 1 for success * or 0 if some event such as a signal ended the wait. */ static void vt_event_wait(struct vt_event_wait *vw) { __vt_event_queue(vw); __vt_event_wait(vw); __vt_event_dequeue(vw); } /** * vt_event_wait_ioctl - event ioctl handler * @event: argument to ioctl (the event) * * Implement the VT_WAITEVENT ioctl using the VT event interface */ static int vt_event_wait_ioctl(struct vt_event __user *event) { struct vt_event_wait vw; if (copy_from_user(&vw.event, event, sizeof(struct vt_event))) return -EFAULT; /* Highest supported event for now */ if (vw.event.event & ~VT_MAX_EVENT) return -EINVAL; vt_event_wait(&vw); /* If it occurred report it */ if (vw.done) { if (copy_to_user(event, &vw.event, sizeof(struct vt_event))) return -EFAULT; return 0; } return -EINTR; } /** * vt_waitactive - active console wait * @n: new console * * Helper for event waits. Used to implement the legacy * event waiting ioctls in terms of events */ int vt_waitactive(int n) { struct vt_event_wait vw; do { vw.event.event = VT_EVENT_SWITCH; __vt_event_queue(&vw); if (n == fg_console + 1) { __vt_event_dequeue(&vw); break; } __vt_event_wait(&vw); __vt_event_dequeue(&vw); if (vw.done == 0) return -EINTR; } while (vw.event.newev != n); return 0; } /* * these are the valid i/o ports we're allowed to change. they map all the * video ports */ #define GPFIRST 0x3b4 #define GPLAST 0x3df #define GPNUM (GPLAST - GPFIRST + 1) /* * currently, setting the mode from KD_TEXT to KD_GRAPHICS doesn't do a whole * lot. i'm not sure if it should do any restoration of modes or what... * * XXX It should at least call into the driver, fbdev's definitely need to * restore their engine state. --BenH * * Called with the console lock held. */ static int vt_kdsetmode(struct vc_data *vc, unsigned long mode) { switch (mode) { case KD_GRAPHICS: break; case KD_TEXT0: case KD_TEXT1: mode = KD_TEXT; fallthrough; case KD_TEXT: break; default: return -EINVAL; } if (vc->vc_mode == mode) return 0; vc->vc_mode = mode; if (vc->vc_num != fg_console) return 0; /* explicitly blank/unblank the screen if switching modes */ if (mode == KD_TEXT) do_unblank_screen(1); else do_blank_screen(1); return 0; } static int vt_k_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg, bool perm) { struct vc_data *vc = tty->driver_data; void __user *up = (void __user *)arg; unsigned int console = vc->vc_num; int ret; switch (cmd) { case KIOCSOUND: if (!perm) return -EPERM; /* * The use of PIT_TICK_RATE is historic, it used to be * the platform-dependent CLOCK_TICK_RATE between 2.6.12 * and 2.6.36, which was a minor but unfortunate ABI * change. kd_mksound is locked by the input layer. */ if (arg) arg = PIT_TICK_RATE / arg; kd_mksound(arg, 0); break; case KDMKTONE: if (!perm) return -EPERM; { unsigned int ticks, count; /* * Generate the tone for the appropriate number of ticks. * If the time is zero, turn off sound ourselves. */ ticks = msecs_to_jiffies((arg >> 16) & 0xffff); count = ticks ? (arg & 0xffff) : 0; if (count) count = PIT_TICK_RATE / count; kd_mksound(count, ticks); break; } case KDGKBTYPE: /* * this is naïve. */ return put_user(KB_101, (char __user *)arg); /* * These cannot be implemented on any machine that implements * ioperm() in user level (such as Alpha PCs) or not at all. * * XXX: you should never use these, just call ioperm directly.. */ #ifdef CONFIG_X86 case KDADDIO: case KDDELIO: /* * KDADDIO and KDDELIO may be able to add ports beyond what * we reject here, but to be safe... * * These are locked internally via sys_ioperm */ if (arg < GPFIRST || arg > GPLAST) return -EINVAL; return ksys_ioperm(arg, 1, (cmd == KDADDIO)) ? -ENXIO : 0; case KDENABIO: case KDDISABIO: return ksys_ioperm(GPFIRST, GPNUM, (cmd == KDENABIO)) ? -ENXIO : 0; #endif /* Linux m68k/i386 interface for setting the keyboard delay/repeat rate */ case KDKBDREP: { struct kbd_repeat kbrep; if (!capable(CAP_SYS_TTY_CONFIG)) return -EPERM; if (copy_from_user(&kbrep, up, sizeof(struct kbd_repeat))) return -EFAULT; ret = kbd_rate(&kbrep); if (ret) return ret; if (copy_to_user(up, &kbrep, sizeof(struct kbd_repeat))) return -EFAULT; break; } case KDSETMODE: if (!perm) return -EPERM; console_lock(); ret = vt_kdsetmode(vc, arg); console_unlock(); return ret; case KDGETMODE: return put_user(vc->vc_mode, (int __user *)arg); case KDMAPDISP: case KDUNMAPDISP: /* * these work like a combination of mmap and KDENABIO. * this could be easily finished. */ return -EINVAL; case KDSKBMODE: if (!perm) return -EPERM; ret = vt_do_kdskbmode(console, arg); if (ret) return ret; tty_ldisc_flush(tty); break; case KDGKBMODE: return put_user(vt_do_kdgkbmode(console), (int __user *)arg); /* this could be folded into KDSKBMODE, but for compatibility reasons it is not so easy to fold KDGKBMETA into KDGKBMODE */ case KDSKBMETA: return vt_do_kdskbmeta(console, arg); case KDGKBMETA: /* FIXME: should review whether this is worth locking */ return put_user(vt_do_kdgkbmeta(console), (int __user *)arg); case KDGETKEYCODE: case KDSETKEYCODE: if(!capable(CAP_SYS_TTY_CONFIG)) perm = 0; return vt_do_kbkeycode_ioctl(cmd, up, perm); case KDGKBENT: case KDSKBENT: return vt_do_kdsk_ioctl(cmd, up, perm, console); case KDGKBSENT: case KDSKBSENT: return vt_do_kdgkb_ioctl(cmd, up, perm); /* Diacritical processing. Handled in keyboard.c as it has to operate on the keyboard locks and structures */ case KDGKBDIACR: case KDGKBDIACRUC: case KDSKBDIACR: case KDSKBDIACRUC: return vt_do_diacrit(cmd, up, perm); /* the ioctls below read/set the flags usually shown in the leds */ /* don't use them - they will go away without warning */ case KDGKBLED: case KDSKBLED: case KDGETLED: case KDSETLED: return vt_do_kdskled(console, cmd, arg, perm); /* * A process can indicate its willingness to accept signals * generated by pressing an appropriate key combination. * Thus, one can have a daemon that e.g. spawns a new console * upon a keypress and then changes to it. * See also the kbrequest field of inittab(5). */ case KDSIGACCEPT: if (!perm || !capable(CAP_KILL)) return -EPERM; if (!valid_signal(arg) || arg < 1 || arg == SIGKILL) return -EINVAL; spin_lock_irq(&vt_spawn_con.lock); put_pid(vt_spawn_con.pid); vt_spawn_con.pid = get_pid(task_pid(current)); vt_spawn_con.sig = arg; spin_unlock_irq(&vt_spawn_con.lock); break; case KDFONTOP: { struct console_font_op op; if (copy_from_user(&op, up, sizeof(op))) return -EFAULT; if (!perm && op.op != KD_FONT_OP_GET) return -EPERM; ret = con_font_op(vc, &op); if (ret) return ret; if (copy_to_user(up, &op, sizeof(op))) return -EFAULT; break; } default: return -ENOIOCTLCMD; } return 0; } static inline int do_unimap_ioctl(int cmd, struct unimapdesc __user *user_ud, bool perm, struct vc_data *vc) { struct unimapdesc tmp; if (copy_from_user(&tmp, user_ud, sizeof tmp)) return -EFAULT; switch (cmd) { case PIO_UNIMAP: if (!perm) return -EPERM; return con_set_unimap(vc, tmp.entry_ct, tmp.entries); case GIO_UNIMAP: if (!perm && fg_console != vc->vc_num) return -EPERM; return con_get_unimap(vc, tmp.entry_ct, &(user_ud->entry_ct), tmp.entries); } return 0; } static int vt_io_ioctl(struct vc_data *vc, unsigned int cmd, void __user *up, bool perm) { switch (cmd) { case PIO_CMAP: if (!perm) return -EPERM; return con_set_cmap(up); case GIO_CMAP: return con_get_cmap(up); case PIO_SCRNMAP: if (!perm) return -EPERM; return con_set_trans_old(up); case GIO_SCRNMAP: return con_get_trans_old(up); case PIO_UNISCRNMAP: if (!perm) return -EPERM; return con_set_trans_new(up); case GIO_UNISCRNMAP: return con_get_trans_new(up); case PIO_UNIMAPCLR: if (!perm) return -EPERM; con_clear_unimap(vc); break; case PIO_UNIMAP: case GIO_UNIMAP: return do_unimap_ioctl(cmd, up, perm, vc); default: return -ENOIOCTLCMD; } return 0; } static int vt_reldisp(struct vc_data *vc, unsigned int swtch) { int newvt, ret; if (vc->vt_mode.mode != VT_PROCESS) return -EINVAL; /* Switched-to response */ if (vc->vt_newvt < 0) { /* If it's just an ACK, ignore it */ return swtch == VT_ACKACQ ? 0 : -EINVAL; } /* Switching-from response */ if (swtch == 0) { /* Switch disallowed, so forget we were trying to do it. */ vc->vt_newvt = -1; return 0; } /* The current vt has been released, so complete the switch. */ newvt = vc->vt_newvt; vc->vt_newvt = -1; ret = vc_allocate(newvt); if (ret) return ret; /* * When we actually do the console switch, make sure we are atomic with * respect to other console switches.. */ complete_change_console(vc_cons[newvt].d); return 0; } static int vt_setactivate(struct vt_setactivate __user *sa) { struct vt_setactivate vsa; struct vc_data *nvc; int ret; if (copy_from_user(&vsa, sa, sizeof(vsa))) return -EFAULT; if (vsa.console == 0 || vsa.console > MAX_NR_CONSOLES) return -ENXIO; vsa.console--; vsa.console = array_index_nospec(vsa.console, MAX_NR_CONSOLES); console_lock(); ret = vc_allocate(vsa.console); if (ret) { console_unlock(); return ret; } /* * This is safe providing we don't drop the console sem between * vc_allocate and finishing referencing nvc. */ nvc = vc_cons[vsa.console].d; nvc->vt_mode = vsa.mode; nvc->vt_mode.frsig = 0; put_pid(nvc->vt_pid); nvc->vt_pid = get_pid(task_pid(current)); console_unlock(); /* Commence switch and lock */ /* Review set_console locks */ set_console(vsa.console); return 0; } /* deallocate a single console, if possible (leave 0) */ static int vt_disallocate(unsigned int vc_num) { struct vc_data *vc = NULL; int ret = 0; console_lock(); if (vt_busy(vc_num)) ret = -EBUSY; else if (vc_num) vc = vc_deallocate(vc_num); console_unlock(); if (vc && vc_num >= MIN_NR_CONSOLES) tty_port_put(&vc->port); return ret; } /* deallocate all unused consoles, but leave 0 */ static void vt_disallocate_all(void) { struct vc_data *vc[MAX_NR_CONSOLES]; int i; console_lock(); for (i = 1; i < MAX_NR_CONSOLES; i++) if (!vt_busy(i)) vc[i] = vc_deallocate(i); else vc[i] = NULL; console_unlock(); for (i = 1; i < MAX_NR_CONSOLES; i++) { if (vc[i] && i >= MIN_NR_CONSOLES) tty_port_put(&vc[i]->port); } } static int vt_resizex(struct vc_data *vc, struct vt_consize __user *cs) { struct vt_consize v; int i; if (copy_from_user(&v, cs, sizeof(struct vt_consize))) return -EFAULT; /* FIXME: Should check the copies properly */ if (!v.v_vlin) v.v_vlin = vc->vc_scan_lines; if (v.v_clin) { int rows = v.v_vlin / v.v_clin; if (v.v_rows != rows) { if (v.v_rows) /* Parameters don't add up */ return -EINVAL; v.v_rows = rows; } } if (v.v_vcol && v.v_ccol) { int cols = v.v_vcol / v.v_ccol; if (v.v_cols != cols) { if (v.v_cols) return -EINVAL; v.v_cols = cols; } } if (v.v_clin > 32) return -EINVAL; for (i = 0; i < MAX_NR_CONSOLES; i++) { struct vc_data *vcp; if (!vc_cons[i].d) continue; console_lock(); vcp = vc_cons[i].d; if (vcp) { int ret; int save_scan_lines = vcp->vc_scan_lines; int save_cell_height = vcp->vc_cell_height; if (v.v_vlin) vcp->vc_scan_lines = v.v_vlin; if (v.v_clin) vcp->vc_cell_height = v.v_clin; vcp->vc_resize_user = 1; ret = vc_resize(vcp, v.v_cols, v.v_rows); if (ret) { vcp->vc_scan_lines = save_scan_lines; vcp->vc_cell_height = save_cell_height; console_unlock(); return ret; } } console_unlock(); } return 0; } /* * We handle the console-specific ioctl's here. We allow the * capability to modify any console, not just the fg_console. */ int vt_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg) { struct vc_data *vc = tty->driver_data; void __user *up = (void __user *)arg; int i, perm; int ret; /* * To have permissions to do most of the vt ioctls, we either have * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG. */ perm = 0; if (current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG)) perm = 1; ret = vt_k_ioctl(tty, cmd, arg, perm); if (ret != -ENOIOCTLCMD) return ret; ret = vt_io_ioctl(vc, cmd, up, perm); if (ret != -ENOIOCTLCMD) return ret; switch (cmd) { case TIOCLINUX: return tioclinux(tty, arg); case VT_SETMODE: { struct vt_mode tmp; if (!perm) return -EPERM; if (copy_from_user(&tmp, up, sizeof(struct vt_mode))) return -EFAULT; if (tmp.mode != VT_AUTO && tmp.mode != VT_PROCESS) return -EINVAL; console_lock(); vc->vt_mode = tmp; /* the frsig is ignored, so we set it to 0 */ vc->vt_mode.frsig = 0; put_pid(vc->vt_pid); vc->vt_pid = get_pid(task_pid(current)); /* no switch is required -- saw@shade.msu.ru */ vc->vt_newvt = -1; console_unlock(); break; } case VT_GETMODE: { struct vt_mode tmp; int rc; console_lock(); memcpy(&tmp, &vc->vt_mode, sizeof(struct vt_mode)); console_unlock(); rc = copy_to_user(up, &tmp, sizeof(struct vt_mode)); if (rc) return -EFAULT; break; } /* * Returns global vt state. Note that VT 0 is always open, since * it's an alias for the current VT, and people can't use it here. * We cannot return state for more than 16 VTs, since v_state is short. */ case VT_GETSTATE: { struct vt_stat __user *vtstat = up; unsigned short state, mask; if (put_user(fg_console + 1, &vtstat->v_active)) return -EFAULT; state = 1; /* /dev/tty0 is always open */ console_lock(); /* required by vt_in_use() */ for (i = 0, mask = 2; i < MAX_NR_CONSOLES && mask; ++i, mask <<= 1) if (vt_in_use(i)) state |= mask; console_unlock(); return put_user(state, &vtstat->v_state); } /* * Returns the first available (non-opened) console. */ case VT_OPENQRY: console_lock(); /* required by vt_in_use() */ for (i = 0; i < MAX_NR_CONSOLES; ++i) if (!vt_in_use(i)) break; console_unlock(); i = i < MAX_NR_CONSOLES ? (i+1) : -1; return put_user(i, (int __user *)arg); /* * ioctl(fd, VT_ACTIVATE, num) will cause us to switch to vt # num, * with num >= 1 (switches to vt 0, our console, are not allowed, just * to preserve sanity). */ case VT_ACTIVATE: if (!perm) return -EPERM; if (arg == 0 || arg > MAX_NR_CONSOLES) return -ENXIO; arg--; arg = array_index_nospec(arg, MAX_NR_CONSOLES); console_lock(); ret = vc_allocate(arg); console_unlock(); if (ret) return ret; set_console(arg); break; case VT_SETACTIVATE: if (!perm) return -EPERM; return vt_setactivate(up); /* * wait until the specified VT has been activated */ case VT_WAITACTIVE: if (!perm) return -EPERM; if (arg == 0 || arg > MAX_NR_CONSOLES) return -ENXIO; return vt_waitactive(arg); /* * If a vt is under process control, the kernel will not switch to it * immediately, but postpone the operation until the process calls this * ioctl, allowing the switch to complete. * * According to the X sources this is the behavior: * 0: pending switch-from not OK * 1: pending switch-from OK * 2: completed switch-to OK */ case VT_RELDISP: if (!perm) return -EPERM; console_lock(); ret = vt_reldisp(vc, arg); console_unlock(); return ret; /* * Disallocate memory associated to VT (but leave VT1) */ case VT_DISALLOCATE: if (arg > MAX_NR_CONSOLES) return -ENXIO; if (arg == 0) { vt_disallocate_all(); break; } arg = array_index_nospec(arg - 1, MAX_NR_CONSOLES); return vt_disallocate(arg); case VT_RESIZE: { struct vt_sizes __user *vtsizes = up; struct vc_data *vc; ushort ll,cc; if (!perm) return -EPERM; if (get_user(ll, &vtsizes->v_rows) || get_user(cc, &vtsizes->v_cols)) return -EFAULT; console_lock(); for (i = 0; i < MAX_NR_CONSOLES; i++) { vc = vc_cons[i].d; if (vc) { vc->vc_resize_user = 1; /* FIXME: review v tty lock */ vc_resize(vc_cons[i].d, cc, ll); } } console_unlock(); break; } case VT_RESIZEX: if (!perm) return -EPERM; return vt_resizex(vc, up); case VT_LOCKSWITCH: if (!capable(CAP_SYS_TTY_CONFIG)) return -EPERM; vt_dont_switch = true; break; case VT_UNLOCKSWITCH: if (!capable(CAP_SYS_TTY_CONFIG)) return -EPERM; vt_dont_switch = false; break; case VT_GETHIFONTMASK: return put_user(vc->vc_hi_font_mask, (unsigned short __user *)arg); case VT_WAITEVENT: return vt_event_wait_ioctl((struct vt_event __user *)arg); default: return -ENOIOCTLCMD; } return 0; } void reset_vc(struct vc_data *vc) { vc->vc_mode = KD_TEXT; vt_reset_unicode(vc->vc_num); vc->vt_mode.mode = VT_AUTO; vc->vt_mode.waitv = 0; vc->vt_mode.relsig = 0; vc->vt_mode.acqsig = 0; vc->vt_mode.frsig = 0; put_pid(vc->vt_pid); vc->vt_pid = NULL; vc->vt_newvt = -1; reset_palette(vc); } void vc_SAK(struct work_struct *work) { struct vc *vc_con = container_of(work, struct vc, SAK_work); struct vc_data *vc; struct tty_struct *tty; console_lock(); vc = vc_con->d; if (vc) { /* FIXME: review tty ref counting */ tty = vc->port.tty; /* * SAK should also work in all raw modes and reset * them properly. */ if (tty) __do_SAK(tty); reset_vc(vc); } console_unlock(); } #ifdef CONFIG_COMPAT struct compat_console_font_op { compat_uint_t op; /* operation code KD_FONT_OP_* */ compat_uint_t flags; /* KD_FONT_FLAG_* */ compat_uint_t width, height; /* font size */ compat_uint_t charcount; compat_caddr_t data; /* font data with height fixed to 32 */ }; static inline int compat_kdfontop_ioctl(struct compat_console_font_op __user *fontop, int perm, struct console_font_op *op, struct vc_data *vc) { int i; if (copy_from_user(op, fontop, sizeof(struct compat_console_font_op))) return -EFAULT; if (!perm && op->op != KD_FONT_OP_GET) return -EPERM; op->data = compat_ptr(((struct compat_console_font_op *)op)->data); i = con_font_op(vc, op); if (i) return i; ((struct compat_console_font_op *)op)->data = (unsigned long)op->data; if (copy_to_user(fontop, op, sizeof(struct compat_console_font_op))) return -EFAULT; return 0; } struct compat_unimapdesc { unsigned short entry_ct; compat_caddr_t entries; }; static inline int compat_unimap_ioctl(unsigned int cmd, struct compat_unimapdesc __user *user_ud, int perm, struct vc_data *vc) { struct compat_unimapdesc tmp; struct unipair __user *tmp_entries; if (copy_from_user(&tmp, user_ud, sizeof tmp)) return -EFAULT; tmp_entries = compat_ptr(tmp.entries); switch (cmd) { case PIO_UNIMAP: if (!perm) return -EPERM; return con_set_unimap(vc, tmp.entry_ct, tmp_entries); case GIO_UNIMAP: if (!perm && fg_console != vc->vc_num) return -EPERM; return con_get_unimap(vc, tmp.entry_ct, &(user_ud->entry_ct), tmp_entries); } return 0; } long vt_compat_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg) { struct vc_data *vc = tty->driver_data; struct console_font_op op; /* used in multiple places here */ void __user *up = compat_ptr(arg); int perm; /* * To have permissions to do most of the vt ioctls, we either have * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG. */ perm = 0; if (current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG)) perm = 1; switch (cmd) { /* * these need special handlers for incompatible data structures */ case KDFONTOP: return compat_kdfontop_ioctl(up, perm, &op, vc); case PIO_UNIMAP: case GIO_UNIMAP: return compat_unimap_ioctl(cmd, up, perm, vc); /* * all these treat 'arg' as an integer */ case KIOCSOUND: case KDMKTONE: #ifdef CONFIG_X86 case KDADDIO: case KDDELIO: #endif case KDSETMODE: case KDMAPDISP: case KDUNMAPDISP: case KDSKBMODE: case KDSKBMETA: case KDSKBLED: case KDSETLED: case KDSIGACCEPT: case VT_ACTIVATE: case VT_WAITACTIVE: case VT_RELDISP: case VT_DISALLOCATE: case VT_RESIZE: case VT_RESIZEX: return vt_ioctl(tty, cmd, arg); /* * the rest has a compatible data structure behind arg, * but we have to convert it to a proper 64 bit pointer. */ default: return vt_ioctl(tty, cmd, (unsigned long)up); } } #endif /* CONFIG_COMPAT */ /* * Performs the back end of a vt switch. Called under the console * semaphore. */ static void complete_change_console(struct vc_data *vc) { unsigned char old_vc_mode; int old = fg_console; last_console = fg_console; /* * If we're switching, we could be going from KD_GRAPHICS to * KD_TEXT mode or vice versa, which means we need to blank or * unblank the screen later. */ old_vc_mode = vc_cons[fg_console].d->vc_mode; switch_screen(vc); /* * This can't appear below a successful kill_pid(). If it did, * then the *blank_screen operation could occur while X, having * received acqsig, is waking up on another processor. This * condition can lead to overlapping accesses to the VGA range * and the framebuffer (causing system lockups). * * To account for this we duplicate this code below only if the * controlling process is gone and we've called reset_vc. */ if (old_vc_mode != vc->vc_mode) { if (vc->vc_mode == KD_TEXT) do_unblank_screen(1); else do_blank_screen(1); } /* * If this new console is under process control, send it a signal * telling it that it has acquired. Also check if it has died and * clean up (similar to logic employed in change_console()) */ if (vc->vt_mode.mode == VT_PROCESS) { /* * Send the signal as privileged - kill_pid() will * tell us if the process has gone or something else * is awry */ if (kill_pid(vc->vt_pid, vc->vt_mode.acqsig, 1) != 0) { /* * The controlling process has died, so we revert back to * normal operation. In this case, we'll also change back * to KD_TEXT mode. I'm not sure if this is strictly correct * but it saves the agony when the X server dies and the screen * remains blanked due to KD_GRAPHICS! It would be nice to do * this outside of VT_PROCESS but there is no single process * to account for and tracking tty count may be undesirable. */ reset_vc(vc); if (old_vc_mode != vc->vc_mode) { if (vc->vc_mode == KD_TEXT) do_unblank_screen(1); else do_blank_screen(1); } } } /* * Wake anyone waiting for their VT to activate */ vt_event_post(VT_EVENT_SWITCH, old, vc->vc_num); return; } /* * Performs the front-end of a vt switch */ void change_console(struct vc_data *new_vc) { struct vc_data *vc; if (!new_vc || new_vc->vc_num == fg_console || vt_dont_switch) return; /* * If this vt is in process mode, then we need to handshake with * that process before switching. Essentially, we store where that * vt wants to switch to and wait for it to tell us when it's done * (via VT_RELDISP ioctl). * * We also check to see if the controlling process still exists. * If it doesn't, we reset this vt to auto mode and continue. * This is a cheap way to track process control. The worst thing * that can happen is: we send a signal to a process, it dies, and * the switch gets "lost" waiting for a response; hopefully, the * user will try again, we'll detect the process is gone (unless * the user waits just the right amount of time :-) and revert the * vt to auto control. */ vc = vc_cons[fg_console].d; if (vc->vt_mode.mode == VT_PROCESS) { /* * Send the signal as privileged - kill_pid() will * tell us if the process has gone or something else * 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. */ return; } /* * The controlling process has died, so we revert back to * normal operation. In this case, we'll also change back * to KD_TEXT mode. I'm not sure if this is strictly correct * but it saves the agony when the X server dies and the screen * remains blanked due to KD_GRAPHICS! It would be nice to do * this outside of VT_PROCESS but there is no single process * to account for and tracking tty count may be undesirable. */ reset_vc(vc); /* * Fall through to normal (VT_AUTO) handling of the switch... */ } /* * Ignore all switches in KD_GRAPHICS+VT_AUTO mode */ if (vc->vc_mode == KD_GRAPHICS) return; complete_change_console(new_vc); } /* Perform a kernel triggered VT switch for suspend/resume */ static int disable_vt_switch; int vt_move_to_console(unsigned int vt, int alloc) { int prev; console_lock(); /* Graphics mode - up to X */ if (disable_vt_switch) { console_unlock(); return 0; } prev = fg_console; if (alloc && vc_allocate(vt)) { /* we can't have a free VC for now. Too bad, * we don't want to mess the screen for now. */ console_unlock(); return -ENOSPC; } if (set_console(vt)) { /* * We're unable to switch to the SUSPEND_CONSOLE. * Let the calling function know so it can decide * what to do. */ console_unlock(); return -EIO; } console_unlock(); if (vt_waitactive(vt + 1)) { pr_debug("Suspend: Can't switch VCs."); return -EINTR; } return prev; } /* * Normally during a suspend, we allocate a new console and switch to it. * When we resume, we switch back to the original console. This switch * can be slow, so on systems where the framebuffer can handle restoration * of video registers anyways, there's little point in doing the console * switch. This function allows you to disable it by passing it '0'. */ void pm_set_vt_switch(int do_switch) { console_lock(); disable_vt_switch = !do_switch; console_unlock(); } EXPORT_SYMBOL(pm_set_vt_switch);