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-rw-r--r--drivers/char/tty_io.c719
1 files changed, 44 insertions, 675 deletions
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index 82f6a8c86332..15e597d03002 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -656,558 +656,6 @@ EXPORT_SYMBOL_GPL(tty_prepare_flip_string_flags);
656 656
657 657
658/** 658/**
659 * tty_set_termios_ldisc - set ldisc field
660 * @tty: tty structure
661 * @num: line discipline number
662 *
663 * This is probably overkill for real world processors but
664 * they are not on hot paths so a little discipline won't do
665 * any harm.
666 *
667 * Locking: takes termios_mutex
668 */
669
670static void tty_set_termios_ldisc(struct tty_struct *tty, int num)
671{
672 mutex_lock(&tty->termios_mutex);
673 tty->termios->c_line = num;
674 mutex_unlock(&tty->termios_mutex);
675}
676
677/*
678 * This guards the refcounted line discipline lists. The lock
679 * must be taken with irqs off because there are hangup path
680 * callers who will do ldisc lookups and cannot sleep.
681 */
682
683static DEFINE_SPINLOCK(tty_ldisc_lock);
684static DECLARE_WAIT_QUEUE_HEAD(tty_ldisc_wait);
685/* Line disc dispatch table */
686static struct tty_ldisc_ops *tty_ldiscs[NR_LDISCS];
687
688/**
689 * tty_register_ldisc - install a line discipline
690 * @disc: ldisc number
691 * @new_ldisc: pointer to the ldisc object
692 *
693 * Installs a new line discipline into the kernel. The discipline
694 * is set up as unreferenced and then made available to the kernel
695 * from this point onwards.
696 *
697 * Locking:
698 * takes tty_ldisc_lock to guard against ldisc races
699 */
700
701int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc)
702{
703 unsigned long flags;
704 int ret = 0;
705
706 if (disc < N_TTY || disc >= NR_LDISCS)
707 return -EINVAL;
708
709 spin_lock_irqsave(&tty_ldisc_lock, flags);
710 tty_ldiscs[disc] = new_ldisc;
711 new_ldisc->num = disc;
712 new_ldisc->refcount = 0;
713 spin_unlock_irqrestore(&tty_ldisc_lock, flags);
714
715 return ret;
716}
717EXPORT_SYMBOL(tty_register_ldisc);
718
719/**
720 * tty_unregister_ldisc - unload a line discipline
721 * @disc: ldisc number
722 * @new_ldisc: pointer to the ldisc object
723 *
724 * Remove a line discipline from the kernel providing it is not
725 * currently in use.
726 *
727 * Locking:
728 * takes tty_ldisc_lock to guard against ldisc races
729 */
730
731int tty_unregister_ldisc(int disc)
732{
733 unsigned long flags;
734 int ret = 0;
735
736 if (disc < N_TTY || disc >= NR_LDISCS)
737 return -EINVAL;
738
739 spin_lock_irqsave(&tty_ldisc_lock, flags);
740 if (tty_ldiscs[disc]->refcount)
741 ret = -EBUSY;
742 else
743 tty_ldiscs[disc] = NULL;
744 spin_unlock_irqrestore(&tty_ldisc_lock, flags);
745
746 return ret;
747}
748EXPORT_SYMBOL(tty_unregister_ldisc);
749
750
751/**
752 * tty_ldisc_try_get - try and reference an ldisc
753 * @disc: ldisc number
754 * @ld: tty ldisc structure to complete
755 *
756 * Attempt to open and lock a line discipline into place. Return
757 * the line discipline refcounted and assigned in ld. On an error
758 * report the error code back
759 */
760
761static int tty_ldisc_try_get(int disc, struct tty_ldisc *ld)
762{
763 unsigned long flags;
764 struct tty_ldisc_ops *ldops;
765 int err = -EINVAL;
766
767 spin_lock_irqsave(&tty_ldisc_lock, flags);
768 ld->ops = NULL;
769 ldops = tty_ldiscs[disc];
770 /* Check the entry is defined */
771 if (ldops) {
772 /* If the module is being unloaded we can't use it */
773 if (!try_module_get(ldops->owner))
774 err = -EAGAIN;
775 else {
776 /* lock it */
777 ldops->refcount++;
778 ld->ops = ldops;
779 err = 0;
780 }
781 }
782 spin_unlock_irqrestore(&tty_ldisc_lock, flags);
783 return err;
784}
785
786/**
787 * tty_ldisc_get - take a reference to an ldisc
788 * @disc: ldisc number
789 * @ld: tty line discipline structure to use
790 *
791 * Takes a reference to a line discipline. Deals with refcounts and
792 * module locking counts. Returns NULL if the discipline is not available.
793 * Returns a pointer to the discipline and bumps the ref count if it is
794 * available
795 *
796 * Locking:
797 * takes tty_ldisc_lock to guard against ldisc races
798 */
799
800static int tty_ldisc_get(int disc, struct tty_ldisc *ld)
801{
802 int err;
803
804 if (disc < N_TTY || disc >= NR_LDISCS)
805 return -EINVAL;
806 err = tty_ldisc_try_get(disc, ld);
807 if (err == -EAGAIN) {
808 request_module("tty-ldisc-%d", disc);
809 err = tty_ldisc_try_get(disc, ld);
810 }
811 return err;
812}
813
814/**
815 * tty_ldisc_put - drop ldisc reference
816 * @disc: ldisc number
817 *
818 * Drop a reference to a line discipline. Manage refcounts and
819 * module usage counts
820 *
821 * Locking:
822 * takes tty_ldisc_lock to guard against ldisc races
823 */
824
825static void tty_ldisc_put(struct tty_ldisc_ops *ld)
826{
827 unsigned long flags;
828 int disc = ld->num;
829
830 BUG_ON(disc < N_TTY || disc >= NR_LDISCS);
831
832 spin_lock_irqsave(&tty_ldisc_lock, flags);
833 ld = tty_ldiscs[disc];
834 BUG_ON(ld->refcount == 0);
835 ld->refcount--;
836 module_put(ld->owner);
837 spin_unlock_irqrestore(&tty_ldisc_lock, flags);
838}
839
840static void * tty_ldiscs_seq_start(struct seq_file *m, loff_t *pos)
841{
842 return (*pos < NR_LDISCS) ? pos : NULL;
843}
844
845static void * tty_ldiscs_seq_next(struct seq_file *m, void *v, loff_t *pos)
846{
847 (*pos)++;
848 return (*pos < NR_LDISCS) ? pos : NULL;
849}
850
851static void tty_ldiscs_seq_stop(struct seq_file *m, void *v)
852{
853}
854
855static int tty_ldiscs_seq_show(struct seq_file *m, void *v)
856{
857 int i = *(loff_t *)v;
858 struct tty_ldisc ld;
859
860 if (tty_ldisc_get(i, &ld) < 0)
861 return 0;
862 seq_printf(m, "%-10s %2d\n", ld.ops->name ? ld.ops->name : "???", i);
863 tty_ldisc_put(ld.ops);
864 return 0;
865}
866
867static const struct seq_operations tty_ldiscs_seq_ops = {
868 .start = tty_ldiscs_seq_start,
869 .next = tty_ldiscs_seq_next,
870 .stop = tty_ldiscs_seq_stop,
871 .show = tty_ldiscs_seq_show,
872};
873
874static int proc_tty_ldiscs_open(struct inode *inode, struct file *file)
875{
876 return seq_open(file, &tty_ldiscs_seq_ops);
877}
878
879const struct file_operations tty_ldiscs_proc_fops = {
880 .owner = THIS_MODULE,
881 .open = proc_tty_ldiscs_open,
882 .read = seq_read,
883 .llseek = seq_lseek,
884 .release = seq_release,
885};
886
887/**
888 * tty_ldisc_assign - set ldisc on a tty
889 * @tty: tty to assign
890 * @ld: line discipline
891 *
892 * Install an instance of a line discipline into a tty structure. The
893 * ldisc must have a reference count above zero to ensure it remains/
894 * The tty instance refcount starts at zero.
895 *
896 * Locking:
897 * Caller must hold references
898 */
899
900static void tty_ldisc_assign(struct tty_struct *tty, struct tty_ldisc *ld)
901{
902 ld->refcount = 0;
903 tty->ldisc = *ld;
904}
905
906/**
907 * tty_ldisc_try - internal helper
908 * @tty: the tty
909 *
910 * Make a single attempt to grab and bump the refcount on
911 * the tty ldisc. Return 0 on failure or 1 on success. This is
912 * used to implement both the waiting and non waiting versions
913 * of tty_ldisc_ref
914 *
915 * Locking: takes tty_ldisc_lock
916 */
917
918static int tty_ldisc_try(struct tty_struct *tty)
919{
920 unsigned long flags;
921 struct tty_ldisc *ld;
922 int ret = 0;
923
924 spin_lock_irqsave(&tty_ldisc_lock, flags);
925 ld = &tty->ldisc;
926 if (test_bit(TTY_LDISC, &tty->flags)) {
927 ld->refcount++;
928 ret = 1;
929 }
930 spin_unlock_irqrestore(&tty_ldisc_lock, flags);
931 return ret;
932}
933
934/**
935 * tty_ldisc_ref_wait - wait for the tty ldisc
936 * @tty: tty device
937 *
938 * Dereference the line discipline for the terminal and take a
939 * reference to it. If the line discipline is in flux then
940 * wait patiently until it changes.
941 *
942 * Note: Must not be called from an IRQ/timer context. The caller
943 * must also be careful not to hold other locks that will deadlock
944 * against a discipline change, such as an existing ldisc reference
945 * (which we check for)
946 *
947 * Locking: call functions take tty_ldisc_lock
948 */
949
950struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *tty)
951{
952 /* wait_event is a macro */
953 wait_event(tty_ldisc_wait, tty_ldisc_try(tty));
954 if (tty->ldisc.refcount == 0)
955 printk(KERN_ERR "tty_ldisc_ref_wait\n");
956 return &tty->ldisc;
957}
958
959EXPORT_SYMBOL_GPL(tty_ldisc_ref_wait);
960
961/**
962 * tty_ldisc_ref - get the tty ldisc
963 * @tty: tty device
964 *
965 * Dereference the line discipline for the terminal and take a
966 * reference to it. If the line discipline is in flux then
967 * return NULL. Can be called from IRQ and timer functions.
968 *
969 * Locking: called functions take tty_ldisc_lock
970 */
971
972struct tty_ldisc *tty_ldisc_ref(struct tty_struct *tty)
973{
974 if (tty_ldisc_try(tty))
975 return &tty->ldisc;
976 return NULL;
977}
978
979EXPORT_SYMBOL_GPL(tty_ldisc_ref);
980
981/**
982 * tty_ldisc_deref - free a tty ldisc reference
983 * @ld: reference to free up
984 *
985 * Undoes the effect of tty_ldisc_ref or tty_ldisc_ref_wait. May
986 * be called in IRQ context.
987 *
988 * Locking: takes tty_ldisc_lock
989 */
990
991void tty_ldisc_deref(struct tty_ldisc *ld)
992{
993 unsigned long flags;
994
995 BUG_ON(ld == NULL);
996
997 spin_lock_irqsave(&tty_ldisc_lock, flags);
998 if (ld->refcount == 0)
999 printk(KERN_ERR "tty_ldisc_deref: no references.\n");
1000 else
1001 ld->refcount--;
1002 if (ld->refcount == 0)
1003 wake_up(&tty_ldisc_wait);
1004 spin_unlock_irqrestore(&tty_ldisc_lock, flags);
1005}
1006
1007EXPORT_SYMBOL_GPL(tty_ldisc_deref);
1008
1009/**
1010 * tty_ldisc_enable - allow ldisc use
1011 * @tty: terminal to activate ldisc on
1012 *
1013 * Set the TTY_LDISC flag when the line discipline can be called
1014 * again. Do necessary wakeups for existing sleepers.
1015 *
1016 * Note: nobody should set this bit except via this function. Clearing
1017 * directly is allowed.
1018 */
1019
1020static void tty_ldisc_enable(struct tty_struct *tty)
1021{
1022 set_bit(TTY_LDISC, &tty->flags);
1023 wake_up(&tty_ldisc_wait);
1024}
1025
1026/**
1027 * tty_ldisc_restore - helper for tty ldisc change
1028 * @tty: tty to recover
1029 * @old: previous ldisc
1030 *
1031 * Restore the previous line discipline or N_TTY when a line discipline
1032 * change fails due to an open error
1033 */
1034
1035static void tty_ldisc_restore(struct tty_struct *tty, struct tty_ldisc *old)
1036{
1037 char buf[64];
1038 struct tty_ldisc new_ldisc;
1039
1040 /* There is an outstanding reference here so this is safe */
1041 tty_ldisc_get(old->ops->num, old);
1042 tty_ldisc_assign(tty, old);
1043 tty_set_termios_ldisc(tty, old->ops->num);
1044 if (old->ops->open && (old->ops->open(tty) < 0)) {
1045 tty_ldisc_put(old->ops);
1046 /* This driver is always present */
1047 if (tty_ldisc_get(N_TTY, &new_ldisc) < 0)
1048 panic("n_tty: get");
1049 tty_ldisc_assign(tty, &new_ldisc);
1050 tty_set_termios_ldisc(tty, N_TTY);
1051 if (new_ldisc.ops->open) {
1052 int r = new_ldisc.ops->open(tty);
1053 if (r < 0)
1054 panic("Couldn't open N_TTY ldisc for "
1055 "%s --- error %d.",
1056 tty_name(tty, buf), r);
1057 }
1058 }
1059}
1060
1061/**
1062 * tty_set_ldisc - set line discipline
1063 * @tty: the terminal to set
1064 * @ldisc: the line discipline
1065 *
1066 * Set the discipline of a tty line. Must be called from a process
1067 * context.
1068 *
1069 * Locking: takes tty_ldisc_lock.
1070 * called functions take termios_mutex
1071 */
1072
1073static int tty_set_ldisc(struct tty_struct *tty, int ldisc)
1074{
1075 int retval;
1076 struct tty_ldisc o_ldisc, new_ldisc;
1077 int work;
1078 unsigned long flags;
1079 struct tty_struct *o_tty;
1080
1081restart:
1082 /* This is a bit ugly for now but means we can break the 'ldisc
1083 is part of the tty struct' assumption later */
1084 retval = tty_ldisc_get(ldisc, &new_ldisc);
1085 if (retval)
1086 return retval;
1087
1088 /*
1089 * Problem: What do we do if this blocks ?
1090 */
1091
1092 tty_wait_until_sent(tty, 0);
1093
1094 if (tty->ldisc.ops->num == ldisc) {
1095 tty_ldisc_put(new_ldisc.ops);
1096 return 0;
1097 }
1098
1099 /*
1100 * No more input please, we are switching. The new ldisc
1101 * will update this value in the ldisc open function
1102 */
1103
1104 tty->receive_room = 0;
1105
1106 o_ldisc = tty->ldisc;
1107 o_tty = tty->link;
1108
1109 /*
1110 * Make sure we don't change while someone holds a
1111 * reference to the line discipline. The TTY_LDISC bit
1112 * prevents anyone taking a reference once it is clear.
1113 * We need the lock to avoid racing reference takers.
1114 */
1115
1116 spin_lock_irqsave(&tty_ldisc_lock, flags);
1117 if (tty->ldisc.refcount || (o_tty && o_tty->ldisc.refcount)) {
1118 if (tty->ldisc.refcount) {
1119 /* Free the new ldisc we grabbed. Must drop the lock
1120 first. */
1121 spin_unlock_irqrestore(&tty_ldisc_lock, flags);
1122 tty_ldisc_put(o_ldisc.ops);
1123 /*
1124 * There are several reasons we may be busy, including
1125 * random momentary I/O traffic. We must therefore
1126 * retry. We could distinguish between blocking ops
1127 * and retries if we made tty_ldisc_wait() smarter.
1128 * That is up for discussion.
1129 */
1130 if (wait_event_interruptible(tty_ldisc_wait, tty->ldisc.refcount == 0) < 0)
1131 return -ERESTARTSYS;
1132 goto restart;
1133 }
1134 if (o_tty && o_tty->ldisc.refcount) {
1135 spin_unlock_irqrestore(&tty_ldisc_lock, flags);
1136 tty_ldisc_put(o_tty->ldisc.ops);
1137 if (wait_event_interruptible(tty_ldisc_wait, o_tty->ldisc.refcount == 0) < 0)
1138 return -ERESTARTSYS;
1139 goto restart;
1140 }
1141 }
1142 /*
1143 * If the TTY_LDISC bit is set, then we are racing against
1144 * another ldisc change
1145 */
1146 if (!test_bit(TTY_LDISC, &tty->flags)) {
1147 struct tty_ldisc *ld;
1148 spin_unlock_irqrestore(&tty_ldisc_lock, flags);
1149 tty_ldisc_put(new_ldisc.ops);
1150 ld = tty_ldisc_ref_wait(tty);
1151 tty_ldisc_deref(ld);
1152 goto restart;
1153 }
1154
1155 clear_bit(TTY_LDISC, &tty->flags);
1156 if (o_tty)
1157 clear_bit(TTY_LDISC, &o_tty->flags);
1158 spin_unlock_irqrestore(&tty_ldisc_lock, flags);
1159
1160 /*
1161 * From this point on we know nobody has an ldisc
1162 * usage reference, nor can they obtain one until
1163 * we say so later on.
1164 */
1165
1166 work = cancel_delayed_work(&tty->buf.work);
1167 /*
1168 * Wait for ->hangup_work and ->buf.work handlers to terminate
1169 * MUST NOT hold locks here.
1170 */
1171 flush_scheduled_work();
1172 /* Shutdown the current discipline. */
1173 if (o_ldisc.ops->close)
1174 (o_ldisc.ops->close)(tty);
1175
1176 /* Now set up the new line discipline. */
1177 tty_ldisc_assign(tty, &new_ldisc);
1178 tty_set_termios_ldisc(tty, ldisc);
1179 if (new_ldisc.ops->open)
1180 retval = (new_ldisc.ops->open)(tty);
1181 if (retval < 0) {
1182 tty_ldisc_put(new_ldisc.ops);
1183 tty_ldisc_restore(tty, &o_ldisc);
1184 }
1185 /* At this point we hold a reference to the new ldisc and a
1186 a reference to the old ldisc. If we ended up flipping back
1187 to the existing ldisc we have two references to it */
1188
1189 if (tty->ldisc.ops->num != o_ldisc.ops->num && tty->ops->set_ldisc)
1190 tty->ops->set_ldisc(tty);
1191
1192 tty_ldisc_put(o_ldisc.ops);
1193
1194 /*
1195 * Allow ldisc referencing to occur as soon as the driver
1196 * ldisc callback completes.
1197 */
1198
1199 tty_ldisc_enable(tty);
1200 if (o_tty)
1201 tty_ldisc_enable(o_tty);
1202
1203 /* Restart it in case no characters kick it off. Safe if
1204 already running */
1205 if (work)
1206 schedule_delayed_work(&tty->buf.work, 1);
1207 return retval;
1208}
1209
1210/**
1211 * get_tty_driver - find device of a tty 659 * get_tty_driver - find device of a tty
1212 * @dev_t: device identifier 660 * @dev_t: device identifier
1213 * @index: returns the index of the tty 661 * @index: returns the index of the tty
@@ -2193,7 +1641,6 @@ static int init_dev(struct tty_driver *driver, int idx,
2193 struct ktermios *tp, **tp_loc, *o_tp, **o_tp_loc; 1641 struct ktermios *tp, **tp_loc, *o_tp, **o_tp_loc;
2194 struct ktermios *ltp, **ltp_loc, *o_ltp, **o_ltp_loc; 1642 struct ktermios *ltp, **ltp_loc, *o_ltp, **o_ltp_loc;
2195 int retval = 0; 1643 int retval = 0;
2196 struct tty_ldisc *ld;
2197 1644
2198 /* check whether we're reopening an existing tty */ 1645 /* check whether we're reopening an existing tty */
2199 if (driver->flags & TTY_DRIVER_DEVPTS_MEM) { 1646 if (driver->flags & TTY_DRIVER_DEVPTS_MEM) {
@@ -2342,25 +1789,12 @@ static int init_dev(struct tty_driver *driver, int idx,
2342 * If we fail here just call release_tty to clean up. No need 1789 * If we fail here just call release_tty to clean up. No need
2343 * to decrement the use counts, as release_tty doesn't care. 1790 * to decrement the use counts, as release_tty doesn't care.
2344 */ 1791 */
2345
2346 ld = &tty->ldisc;
2347 1792
2348 if (ld->ops->open) { 1793 retval = tty_ldisc_setup(tty, o_tty);
2349 retval = (ld->ops->open)(tty); 1794
2350 if (retval) 1795 if (retval)
2351 goto release_mem_out; 1796 goto release_mem_out;
2352 } 1797 goto success;
2353 if (o_tty && o_tty->ldisc.ops->open) {
2354 retval = (o_tty->ldisc.ops->open)(o_tty);
2355 if (retval) {
2356 if (ld->ops->close)
2357 (ld->ops->close)(tty);
2358 goto release_mem_out;
2359 }
2360 tty_ldisc_enable(o_tty);
2361 }
2362 tty_ldisc_enable(tty);
2363 goto success;
2364 1798
2365 /* 1799 /*
2366 * This fast open can be used if the tty is already open. 1800 * This fast open can be used if the tty is already open.
@@ -2498,12 +1932,10 @@ static void release_tty(struct tty_struct *tty, int idx)
2498static void release_dev(struct file *filp) 1932static void release_dev(struct file *filp)
2499{ 1933{
2500 struct tty_struct *tty, *o_tty; 1934 struct tty_struct *tty, *o_tty;
2501 struct tty_ldisc ld;
2502 int pty_master, tty_closing, o_tty_closing, do_sleep; 1935 int pty_master, tty_closing, o_tty_closing, do_sleep;
2503 int devpts; 1936 int devpts;
2504 int idx; 1937 int idx;
2505 char buf[64]; 1938 char buf[64];
2506 unsigned long flags;
2507 1939
2508 tty = (struct tty_struct *)filp->private_data; 1940 tty = (struct tty_struct *)filp->private_data;
2509 if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, 1941 if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode,
@@ -2705,56 +2137,9 @@ static void release_dev(struct file *filp)
2705 printk(KERN_DEBUG "freeing tty structure..."); 2137 printk(KERN_DEBUG "freeing tty structure...");
2706#endif 2138#endif
2707 /* 2139 /*
2708 * Prevent flush_to_ldisc() from rescheduling the work for later. Then 2140 * Ask the line discipline code to release its structures
2709 * kill any delayed work. As this is the final close it does not
2710 * race with the set_ldisc code path.
2711 */ 2141 */
2712 clear_bit(TTY_LDISC, &tty->flags); 2142 tty_ldisc_release(tty, o_tty);
2713 cancel_delayed_work(&tty->buf.work);
2714
2715 /*
2716 * Wait for ->hangup_work and ->buf.work handlers to terminate
2717 */
2718
2719 flush_scheduled_work();
2720
2721 /*
2722 * Wait for any short term users (we know they are just driver
2723 * side waiters as the file is closing so user count on the file
2724 * side is zero.
2725 */
2726 spin_lock_irqsave(&tty_ldisc_lock, flags);
2727 while (tty->ldisc.refcount) {
2728 spin_unlock_irqrestore(&tty_ldisc_lock, flags);
2729 wait_event(tty_ldisc_wait, tty->ldisc.refcount == 0);
2730 spin_lock_irqsave(&tty_ldisc_lock, flags);
2731 }
2732 spin_unlock_irqrestore(&tty_ldisc_lock, flags);
2733 /*
2734 * Shutdown the current line discipline, and reset it to N_TTY.
2735 *
2736 * FIXME: this MUST get fixed for the new reflocking
2737 */
2738 if (tty->ldisc.ops->close)
2739 (tty->ldisc.ops->close)(tty);
2740 tty_ldisc_put(tty->ldisc.ops);
2741
2742 /*
2743 * Switch the line discipline back
2744 */
2745 WARN_ON(tty_ldisc_get(N_TTY, &ld));
2746 tty_ldisc_assign(tty, &ld);
2747 tty_set_termios_ldisc(tty, N_TTY);
2748 if (o_tty) {
2749 /* FIXME: could o_tty be in setldisc here ? */
2750 clear_bit(TTY_LDISC, &o_tty->flags);
2751 if (o_tty->ldisc.ops->close)
2752 (o_tty->ldisc.ops->close)(o_tty);
2753 tty_ldisc_put(o_tty->ldisc.ops);
2754 WARN_ON(tty_ldisc_get(N_TTY, &ld));
2755 tty_ldisc_assign(o_tty, &ld);
2756 tty_set_termios_ldisc(o_tty, N_TTY);
2757 }
2758 /* 2143 /*
2759 * The release_tty function takes care of the details of clearing 2144 * The release_tty function takes care of the details of clearing
2760 * the slots and preserving the termios structure. 2145 * the slots and preserving the termios structure.
@@ -3464,16 +2849,29 @@ static int tiocsetd(struct tty_struct *tty, int __user *p)
3464 2849
3465static int send_break(struct tty_struct *tty, unsigned int duration) 2850static int send_break(struct tty_struct *tty, unsigned int duration)
3466{ 2851{
3467 if (tty_write_lock(tty, 0) < 0) 2852 int retval;
3468 return -EINTR; 2853
3469 tty->ops->break_ctl(tty, -1); 2854 if (tty->ops->break_ctl == NULL)
3470 if (!signal_pending(current)) 2855 return 0;
3471 msleep_interruptible(duration); 2856
3472 tty->ops->break_ctl(tty, 0); 2857 if (tty->driver->flags & TTY_DRIVER_HARDWARE_BREAK)
3473 tty_write_unlock(tty); 2858 retval = tty->ops->break_ctl(tty, duration);
3474 if (signal_pending(current)) 2859 else {
3475 return -EINTR; 2860 /* Do the work ourselves */
3476 return 0; 2861 if (tty_write_lock(tty, 0) < 0)
2862 return -EINTR;
2863 retval = tty->ops->break_ctl(tty, -1);
2864 if (retval)
2865 goto out;
2866 if (!signal_pending(current))
2867 msleep_interruptible(duration);
2868 retval = tty->ops->break_ctl(tty, 0);
2869out:
2870 tty_write_unlock(tty);
2871 if (signal_pending(current))
2872 retval = -EINTR;
2873 }
2874 return retval;
3477} 2875}
3478 2876
3479/** 2877/**
@@ -3564,36 +2962,6 @@ long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
3564 tty->driver->subtype == PTY_TYPE_MASTER) 2962 tty->driver->subtype == PTY_TYPE_MASTER)
3565 real_tty = tty->link; 2963 real_tty = tty->link;
3566 2964
3567 /*
3568 * Break handling by driver
3569 */
3570
3571 retval = -EINVAL;
3572
3573 if (!tty->ops->break_ctl) {
3574 switch (cmd) {
3575 case TIOCSBRK:
3576 case TIOCCBRK:
3577 if (tty->ops->ioctl)
3578 retval = tty->ops->ioctl(tty, file, cmd, arg);
3579 if (retval != -EINVAL && retval != -ENOIOCTLCMD)
3580 printk(KERN_WARNING "tty: driver %s needs updating to use break_ctl\n", tty->driver->name);
3581 return retval;
3582
3583 /* These two ioctl's always return success; even if */
3584 /* the driver doesn't support them. */
3585 case TCSBRK:
3586 case TCSBRKP:
3587 if (!tty->ops->ioctl)
3588 return 0;
3589 retval = tty->ops->ioctl(tty, file, cmd, arg);
3590 if (retval != -EINVAL && retval != -ENOIOCTLCMD)
3591 printk(KERN_WARNING "tty: driver %s needs updating to use break_ctl\n", tty->driver->name);
3592 if (retval == -ENOIOCTLCMD)
3593 retval = 0;
3594 return retval;
3595 }
3596 }
3597 2965
3598 /* 2966 /*
3599 * Factor out some common prep work 2967 * Factor out some common prep work
@@ -3615,6 +2983,9 @@ long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
3615 break; 2983 break;
3616 } 2984 }
3617 2985
2986 /*
2987 * Now do the stuff.
2988 */
3618 switch (cmd) { 2989 switch (cmd) {
3619 case TIOCSTI: 2990 case TIOCSTI:
3620 return tiocsti(tty, p); 2991 return tiocsti(tty, p);
@@ -3658,12 +3029,11 @@ long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
3658 */ 3029 */
3659 case TIOCSBRK: /* Turn break on, unconditionally */ 3030 case TIOCSBRK: /* Turn break on, unconditionally */
3660 if (tty->ops->break_ctl) 3031 if (tty->ops->break_ctl)
3661 tty->ops->break_ctl(tty, -1); 3032 return tty->ops->break_ctl(tty, -1);
3662 return 0; 3033 return 0;
3663
3664 case TIOCCBRK: /* Turn break off, unconditionally */ 3034 case TIOCCBRK: /* Turn break off, unconditionally */
3665 if (tty->ops->break_ctl) 3035 if (tty->ops->break_ctl)
3666 tty->ops->break_ctl(tty, 0); 3036 return tty->ops->break_ctl(tty, 0);
3667 return 0; 3037 return 0;
3668 case TCSBRK: /* SVID version: non-zero arg --> no break */ 3038 case TCSBRK: /* SVID version: non-zero arg --> no break */
3669 /* non-zero arg means wait for all output data 3039 /* non-zero arg means wait for all output data
@@ -3962,12 +3332,9 @@ EXPORT_SYMBOL(tty_flip_buffer_push);
3962 3332
3963static void initialize_tty_struct(struct tty_struct *tty) 3333static void initialize_tty_struct(struct tty_struct *tty)
3964{ 3334{
3965 struct tty_ldisc ld;
3966 memset(tty, 0, sizeof(struct tty_struct)); 3335 memset(tty, 0, sizeof(struct tty_struct));
3967 tty->magic = TTY_MAGIC; 3336 tty->magic = TTY_MAGIC;
3968 if (tty_ldisc_get(N_TTY, &ld) < 0) 3337 tty_ldisc_init(tty);
3969 panic("n_tty: init_tty");
3970 tty_ldisc_assign(tty, &ld);
3971 tty->session = NULL; 3338 tty->session = NULL;
3972 tty->pgrp = NULL; 3339 tty->pgrp = NULL;
3973 tty->overrun_time = jiffies; 3340 tty->overrun_time = jiffies;
@@ -4045,7 +3412,7 @@ struct device *tty_register_device(struct tty_driver *driver, unsigned index,
4045 else 3412 else
4046 tty_line_name(driver, index, name); 3413 tty_line_name(driver, index, name);
4047 3414
4048 return device_create(tty_class, device, dev, name); 3415 return device_create_drvdata(tty_class, device, dev, NULL, name);
4049} 3416}
4050 3417
4051/** 3418/**
@@ -4280,7 +3647,7 @@ void __init console_init(void)
4280 initcall_t *call; 3647 initcall_t *call;
4281 3648
4282 /* Setup the default TTY line discipline. */ 3649 /* Setup the default TTY line discipline. */
4283 (void) tty_register_ldisc(N_TTY, &tty_ldisc_N_TTY); 3650 tty_ldisc_begin();
4284 3651
4285 /* 3652 /*
4286 * set up the console device so that later boot sequences can 3653 * set up the console device so that later boot sequences can
@@ -4323,20 +3690,22 @@ static int __init tty_init(void)
4323 if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) || 3690 if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) ||
4324 register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0) 3691 register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0)
4325 panic("Couldn't register /dev/tty driver\n"); 3692 panic("Couldn't register /dev/tty driver\n");
4326 device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), "tty"); 3693 device_create_drvdata(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL,
3694 "tty");
4327 3695
4328 cdev_init(&console_cdev, &console_fops); 3696 cdev_init(&console_cdev, &console_fops);
4329 if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) || 3697 if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) ||
4330 register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0) 3698 register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0)
4331 panic("Couldn't register /dev/console driver\n"); 3699 panic("Couldn't register /dev/console driver\n");
4332 device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 1), "console"); 3700 device_create_drvdata(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 1), NULL,
3701 "console");
4333 3702
4334#ifdef CONFIG_UNIX98_PTYS 3703#ifdef CONFIG_UNIX98_PTYS
4335 cdev_init(&ptmx_cdev, &ptmx_fops); 3704 cdev_init(&ptmx_cdev, &ptmx_fops);
4336 if (cdev_add(&ptmx_cdev, MKDEV(TTYAUX_MAJOR, 2), 1) || 3705 if (cdev_add(&ptmx_cdev, MKDEV(TTYAUX_MAJOR, 2), 1) ||
4337 register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0) 3706 register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0)
4338 panic("Couldn't register /dev/ptmx driver\n"); 3707 panic("Couldn't register /dev/ptmx driver\n");
4339 device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), "ptmx"); 3708 device_create_drvdata(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx");
4340#endif 3709#endif
4341 3710
4342#ifdef CONFIG_VT 3711#ifdef CONFIG_VT
@@ -4344,7 +3713,7 @@ static int __init tty_init(void)
4344 if (cdev_add(&vc0_cdev, MKDEV(TTY_MAJOR, 0), 1) || 3713 if (cdev_add(&vc0_cdev, MKDEV(TTY_MAJOR, 0), 1) ||
4345 register_chrdev_region(MKDEV(TTY_MAJOR, 0), 1, "/dev/vc/0") < 0) 3714 register_chrdev_region(MKDEV(TTY_MAJOR, 0), 1, "/dev/vc/0") < 0)
4346 panic("Couldn't register /dev/tty0 driver\n"); 3715 panic("Couldn't register /dev/tty0 driver\n");
4347 device_create(tty_class, NULL, MKDEV(TTY_MAJOR, 0), "tty0"); 3716 device_create_drvdata(tty_class, NULL, MKDEV(TTY_MAJOR, 0), NULL, "tty0");
4348 3717
4349 vty_init(); 3718 vty_init();
4350#endif 3719#endif
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-26 04:20:18 -0500