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v6.8
  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * This module exports the functions:
  4 *
  5 *     'int set_selection_user(struct tiocl_selection __user *,
  6 *			       struct tty_struct *)'
  7 *     'int set_selection_kernel(struct tiocl_selection *, struct tty_struct *)'
  8 *     'void clear_selection(void)'
  9 *     'int paste_selection(struct tty_struct *)'
 10 *     'int sel_loadlut(char __user *)'
 11 *
 12 * Now that /dev/vcs exists, most of this can disappear again.
 13 */
 14
 15#include <linux/module.h>
 16#include <linux/tty.h>
 17#include <linux/sched.h>
 18#include <linux/mm.h>
 19#include <linux/mutex.h>
 20#include <linux/slab.h>
 21#include <linux/types.h>
 22
 23#include <linux/uaccess.h>
 24
 25#include <linux/kbd_kern.h>
 26#include <linux/vt_kern.h>
 27#include <linux/consolemap.h>
 28#include <linux/selection.h>
 29#include <linux/tiocl.h>
 30#include <linux/console.h>
 31#include <linux/tty_flip.h>
 32
 33#include <linux/sched/signal.h>
 34
 35/* Don't take this from <ctype.h>: 011-015 on the screen aren't spaces */
 36#define is_space_on_vt(c)	((c) == ' ')
 37
 38/* FIXME: all this needs locking */
 39static struct vc_selection {
 40	struct mutex lock;
 41	struct vc_data *cons;			/* must not be deallocated */
 42	char *buffer;
 43	unsigned int buf_len;
 44	volatile int start;			/* cleared by clear_selection */
 45	int end;
 46} vc_sel = {
 47	.lock = __MUTEX_INITIALIZER(vc_sel.lock),
 48	.start = -1,
 49};
 50
 51/* clear_selection, highlight and highlight_pointer can be called
 52   from interrupt (via scrollback/front) */
 53
 54/* set reverse video on characters s-e of console with selection. */
 55static inline void highlight(const int s, const int e)
 56{
 57	invert_screen(vc_sel.cons, s, e-s+2, true);
 58}
 59
 60/* use complementary color to show the pointer */
 61static inline void highlight_pointer(const int where)
 62{
 63	complement_pos(vc_sel.cons, where);
 64}
 65
 66static u32
 67sel_pos(int n, bool unicode)
 68{
 69	if (unicode)
 70		return screen_glyph_unicode(vc_sel.cons, n / 2);
 71	return inverse_translate(vc_sel.cons, screen_glyph(vc_sel.cons, n),
 72			false);
 73}
 74
 75/**
 76 *	clear_selection		-	remove current selection
 77 *
 78 *	Remove the current selection highlight, if any from the console
 79 *	holding the selection. The caller must hold the console lock.
 80 */
 81void clear_selection(void)
 82{
 83	highlight_pointer(-1); /* hide the pointer */
 84	if (vc_sel.start != -1) {
 85		highlight(vc_sel.start, vc_sel.end);
 86		vc_sel.start = -1;
 87	}
 88}
 89EXPORT_SYMBOL_GPL(clear_selection);
 90
 91bool vc_is_sel(struct vc_data *vc)
 92{
 93	return vc == vc_sel.cons;
 94}
 95
 96/*
 97 * User settable table: what characters are to be considered alphabetic?
 98 * 128 bits. Locked by the console lock.
 99 */
100static u32 inwordLut[]={
101  0x00000000, /* control chars     */
102  0x03FFE000, /* digits and "-./"  */
103  0x87FFFFFE, /* uppercase and '_' */
104  0x07FFFFFE, /* lowercase         */
105};
106
107static inline int inword(const u32 c)
108{
109	return c > 0x7f || (( inwordLut[c>>5] >> (c & 0x1F) ) & 1);
110}
111
112/**
113 *	sel_loadlut()		-	load the LUT table
114 *	@p: user table
115 *
116 *	Load the LUT table from user space. The caller must hold the console
117 *	lock. Make a temporary copy so a partial update doesn't make a mess.
118 */
119int sel_loadlut(char __user *p)
120{
121	u32 tmplut[ARRAY_SIZE(inwordLut)];
122	if (copy_from_user(tmplut, (u32 __user *)(p+4), sizeof(inwordLut)))
123		return -EFAULT;
124	memcpy(inwordLut, tmplut, sizeof(inwordLut));
125	return 0;
126}
127
128/* does screen address p correspond to character at LH/RH edge of screen? */
129static inline int atedge(const int p, int size_row)
130{
131	return (!(p % size_row)	|| !((p + 2) % size_row));
132}
133
134/* stores the char in UTF8 and returns the number of bytes used (1-4) */
135static int store_utf8(u32 c, char *p)
136{
137	if (c < 0x80) {
138		/*  0******* */
139		p[0] = c;
140		return 1;
141	} else if (c < 0x800) {
142		/* 110***** 10****** */
143		p[0] = 0xc0 | (c >> 6);
144		p[1] = 0x80 | (c & 0x3f);
145		return 2;
146	} else if (c < 0x10000) {
147		/* 1110**** 10****** 10****** */
148		p[0] = 0xe0 | (c >> 12);
149		p[1] = 0x80 | ((c >> 6) & 0x3f);
150		p[2] = 0x80 | (c & 0x3f);
151		return 3;
152	} else if (c < 0x110000) {
153		/* 11110*** 10****** 10****** 10****** */
154		p[0] = 0xf0 | (c >> 18);
155		p[1] = 0x80 | ((c >> 12) & 0x3f);
156		p[2] = 0x80 | ((c >> 6) & 0x3f);
157		p[3] = 0x80 | (c & 0x3f);
158		return 4;
159	} else {
160		/* outside Unicode, replace with U+FFFD */
161		p[0] = 0xef;
162		p[1] = 0xbf;
163		p[2] = 0xbd;
164		return 3;
165	}
166}
167
168/**
169 *	set_selection_user	-	set the current selection.
170 *	@sel: user selection info
171 *	@tty: the console tty
172 *
173 *	Invoked by the ioctl handle for the vt layer.
174 *
175 *	The entire selection process is managed under the console_lock. It's
176 *	 a lot under the lock but its hardly a performance path
177 */
178int set_selection_user(const struct tiocl_selection __user *sel,
179		       struct tty_struct *tty)
180{
181	struct tiocl_selection v;
182
183	if (copy_from_user(&v, sel, sizeof(*sel)))
184		return -EFAULT;
185
186	return set_selection_kernel(&v, tty);
187}
188
189static int vc_selection_store_chars(struct vc_data *vc, bool unicode)
190{
191	char *bp, *obp;
192	unsigned int i;
193
194	/* Allocate a new buffer before freeing the old one ... */
195	/* chars can take up to 4 bytes with unicode */
196	bp = kmalloc_array((vc_sel.end - vc_sel.start) / 2 + 1, unicode ? 4 : 1,
197			   GFP_KERNEL | __GFP_NOWARN);
198	if (!bp) {
199		printk(KERN_WARNING "selection: kmalloc() failed\n");
200		clear_selection();
201		return -ENOMEM;
202	}
203	kfree(vc_sel.buffer);
204	vc_sel.buffer = bp;
205
206	obp = bp;
207	for (i = vc_sel.start; i <= vc_sel.end; i += 2) {
208		u32 c = sel_pos(i, unicode);
209		if (unicode)
210			bp += store_utf8(c, bp);
211		else
212			*bp++ = c;
213		if (!is_space_on_vt(c))
214			obp = bp;
215		if (!((i + 2) % vc->vc_size_row)) {
216			/* strip trailing blanks from line and add newline,
217			   unless non-space at end of line. */
218			if (obp != bp) {
219				bp = obp;
220				*bp++ = '\r';
221			}
222			obp = bp;
223		}
224	}
225	vc_sel.buf_len = bp - vc_sel.buffer;
226
227	return 0;
228}
229
230static int vc_do_selection(struct vc_data *vc, unsigned short mode, int ps,
231		int pe)
232{
233	int new_sel_start, new_sel_end, spc;
234	bool unicode = vt_do_kdgkbmode(fg_console) == K_UNICODE;
235
236	switch (mode) {
237	case TIOCL_SELCHAR:	/* character-by-character selection */
238		new_sel_start = ps;
239		new_sel_end = pe;
240		break;
241	case TIOCL_SELWORD:	/* word-by-word selection */
242		spc = is_space_on_vt(sel_pos(ps, unicode));
243		for (new_sel_start = ps; ; ps -= 2) {
244			if ((spc && !is_space_on_vt(sel_pos(ps, unicode))) ||
245			    (!spc && !inword(sel_pos(ps, unicode))))
246				break;
247			new_sel_start = ps;
248			if (!(ps % vc->vc_size_row))
249				break;
250		}
251
252		spc = is_space_on_vt(sel_pos(pe, unicode));
253		for (new_sel_end = pe; ; pe += 2) {
254			if ((spc && !is_space_on_vt(sel_pos(pe, unicode))) ||
255			    (!spc && !inword(sel_pos(pe, unicode))))
256				break;
257			new_sel_end = pe;
258			if (!((pe + 2) % vc->vc_size_row))
259				break;
260		}
261		break;
262	case TIOCL_SELLINE:	/* line-by-line selection */
263		new_sel_start = rounddown(ps, vc->vc_size_row);
264		new_sel_end = rounddown(pe, vc->vc_size_row) +
265			vc->vc_size_row - 2;
266		break;
267	case TIOCL_SELPOINTER:
268		highlight_pointer(pe);
269		return 0;
270	default:
271		return -EINVAL;
272	}
273
274	/* remove the pointer */
275	highlight_pointer(-1);
276
277	/* select to end of line if on trailing space */
278	if (new_sel_end > new_sel_start &&
279		!atedge(new_sel_end, vc->vc_size_row) &&
280		is_space_on_vt(sel_pos(new_sel_end, unicode))) {
281		for (pe = new_sel_end + 2; ; pe += 2)
282			if (!is_space_on_vt(sel_pos(pe, unicode)) ||
283			    atedge(pe, vc->vc_size_row))
284				break;
285		if (is_space_on_vt(sel_pos(pe, unicode)))
286			new_sel_end = pe;
287	}
288	if (vc_sel.start == -1)	/* no current selection */
289		highlight(new_sel_start, new_sel_end);
290	else if (new_sel_start == vc_sel.start)
291	{
292		if (new_sel_end == vc_sel.end)	/* no action required */
293			return 0;
294		else if (new_sel_end > vc_sel.end)	/* extend to right */
295			highlight(vc_sel.end + 2, new_sel_end);
296		else				/* contract from right */
297			highlight(new_sel_end + 2, vc_sel.end);
298	}
299	else if (new_sel_end == vc_sel.end)
300	{
301		if (new_sel_start < vc_sel.start) /* extend to left */
302			highlight(new_sel_start, vc_sel.start - 2);
303		else				/* contract from left */
304			highlight(vc_sel.start, new_sel_start - 2);
305	}
306	else	/* some other case; start selection from scratch */
307	{
308		clear_selection();
309		highlight(new_sel_start, new_sel_end);
310	}
311	vc_sel.start = new_sel_start;
312	vc_sel.end = new_sel_end;
313
314	return vc_selection_store_chars(vc, unicode);
315}
316
317static int vc_selection(struct vc_data *vc, struct tiocl_selection *v,
318		struct tty_struct *tty)
319{
320	int ps, pe;
321
322	poke_blanked_console();
323
324	if (v->sel_mode == TIOCL_SELCLEAR) {
325		/* useful for screendump without selection highlights */
326		clear_selection();
327		return 0;
328	}
329
330	v->xs = min_t(u16, v->xs - 1, vc->vc_cols - 1);
331	v->ys = min_t(u16, v->ys - 1, vc->vc_rows - 1);
332	v->xe = min_t(u16, v->xe - 1, vc->vc_cols - 1);
333	v->ye = min_t(u16, v->ye - 1, vc->vc_rows - 1);
334
335	if (mouse_reporting() && (v->sel_mode & TIOCL_SELMOUSEREPORT)) {
336		mouse_report(tty, v->sel_mode & TIOCL_SELBUTTONMASK, v->xs,
337			     v->ys);
338		return 0;
339	}
340
341	ps = v->ys * vc->vc_size_row + (v->xs << 1);
342	pe = v->ye * vc->vc_size_row + (v->xe << 1);
343	if (ps > pe)	/* make vc_sel.start <= vc_sel.end */
344		swap(ps, pe);
345
346	if (vc_sel.cons != vc) {
347		clear_selection();
348		vc_sel.cons = vc;
349	}
350
351	return vc_do_selection(vc, v->sel_mode, ps, pe);
352}
353
354int set_selection_kernel(struct tiocl_selection *v, struct tty_struct *tty)
355{
356	int ret;
357
358	mutex_lock(&vc_sel.lock);
359	console_lock();
360	ret = vc_selection(vc_cons[fg_console].d, v, tty);
361	console_unlock();
362	mutex_unlock(&vc_sel.lock);
363
364	return ret;
365}
366EXPORT_SYMBOL_GPL(set_selection_kernel);
367
368/* Insert the contents of the selection buffer into the
369 * queue of the tty associated with the current console.
370 * Invoked by ioctl().
371 *
372 * Locking: called without locks. Calls the ldisc wrongly with
373 * unsafe methods,
374 */
375int paste_selection(struct tty_struct *tty)
376{
377	struct vc_data *vc = tty->driver_data;
378	int	pasted = 0;
379	size_t count;
380	struct  tty_ldisc *ld;
381	DECLARE_WAITQUEUE(wait, current);
382	int ret = 0;
383
384	console_lock();
385	poke_blanked_console();
386	console_unlock();
387
388	ld = tty_ldisc_ref_wait(tty);
389	if (!ld)
390		return -EIO;	/* ldisc was hung up */
391	tty_buffer_lock_exclusive(&vc->port);
392
393	add_wait_queue(&vc->paste_wait, &wait);
394	mutex_lock(&vc_sel.lock);
395	while (vc_sel.buffer && vc_sel.buf_len > pasted) {
396		set_current_state(TASK_INTERRUPTIBLE);
397		if (signal_pending(current)) {
398			ret = -EINTR;
399			break;
400		}
401		if (tty_throttled(tty)) {
402			mutex_unlock(&vc_sel.lock);
403			schedule();
404			mutex_lock(&vc_sel.lock);
405			continue;
406		}
407		__set_current_state(TASK_RUNNING);
408		count = vc_sel.buf_len - pasted;
409		count = tty_ldisc_receive_buf(ld, vc_sel.buffer + pasted, NULL,
410					      count);
411		pasted += count;
412	}
413	mutex_unlock(&vc_sel.lock);
414	remove_wait_queue(&vc->paste_wait, &wait);
415	__set_current_state(TASK_RUNNING);
416
417	tty_buffer_unlock_exclusive(&vc->port);
418	tty_ldisc_deref(ld);
419	return ret;
420}
421EXPORT_SYMBOL_GPL(paste_selection);
v5.9
  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * This module exports the functions:
  4 *
  5 *     'int set_selection_user(struct tiocl_selection __user *,
  6 *			       struct tty_struct *)'
  7 *     'int set_selection_kernel(struct tiocl_selection *, struct tty_struct *)'
  8 *     'void clear_selection(void)'
  9 *     'int paste_selection(struct tty_struct *)'
 10 *     'int sel_loadlut(char __user *)'
 11 *
 12 * Now that /dev/vcs exists, most of this can disappear again.
 13 */
 14
 15#include <linux/module.h>
 16#include <linux/tty.h>
 17#include <linux/sched.h>
 18#include <linux/mm.h>
 19#include <linux/mutex.h>
 20#include <linux/slab.h>
 21#include <linux/types.h>
 22
 23#include <linux/uaccess.h>
 24
 25#include <linux/kbd_kern.h>
 26#include <linux/vt_kern.h>
 27#include <linux/consolemap.h>
 28#include <linux/selection.h>
 29#include <linux/tiocl.h>
 30#include <linux/console.h>
 31#include <linux/tty_flip.h>
 32
 33#include <linux/sched/signal.h>
 34
 35/* Don't take this from <ctype.h>: 011-015 on the screen aren't spaces */
 36#define isspace(c)	((c) == ' ')
 37
 38/* FIXME: all this needs locking */
 39static struct vc_selection {
 40	struct mutex lock;
 41	struct vc_data *cons;			/* must not be deallocated */
 42	char *buffer;
 43	unsigned int buf_len;
 44	volatile int start;			/* cleared by clear_selection */
 45	int end;
 46} vc_sel = {
 47	.lock = __MUTEX_INITIALIZER(vc_sel.lock),
 48	.start = -1,
 49};
 50
 51/* clear_selection, highlight and highlight_pointer can be called
 52   from interrupt (via scrollback/front) */
 53
 54/* set reverse video on characters s-e of console with selection. */
 55static inline void highlight(const int s, const int e)
 56{
 57	invert_screen(vc_sel.cons, s, e-s+2, 1);
 58}
 59
 60/* use complementary color to show the pointer */
 61static inline void highlight_pointer(const int where)
 62{
 63	complement_pos(vc_sel.cons, where);
 64}
 65
 66static u32
 67sel_pos(int n, bool unicode)
 68{
 69	if (unicode)
 70		return screen_glyph_unicode(vc_sel.cons, n / 2);
 71	return inverse_translate(vc_sel.cons, screen_glyph(vc_sel.cons, n), 0);
 
 72}
 73
 74/**
 75 *	clear_selection		-	remove current selection
 76 *
 77 *	Remove the current selection highlight, if any from the console
 78 *	holding the selection. The caller must hold the console lock.
 79 */
 80void clear_selection(void)
 81{
 82	highlight_pointer(-1); /* hide the pointer */
 83	if (vc_sel.start != -1) {
 84		highlight(vc_sel.start, vc_sel.end);
 85		vc_sel.start = -1;
 86	}
 87}
 88EXPORT_SYMBOL_GPL(clear_selection);
 89
 90bool vc_is_sel(struct vc_data *vc)
 91{
 92	return vc == vc_sel.cons;
 93}
 94
 95/*
 96 * User settable table: what characters are to be considered alphabetic?
 97 * 128 bits. Locked by the console lock.
 98 */
 99static u32 inwordLut[]={
100  0x00000000, /* control chars     */
101  0x03FFE000, /* digits and "-./"  */
102  0x87FFFFFE, /* uppercase and '_' */
103  0x07FFFFFE, /* lowercase         */
104};
105
106static inline int inword(const u32 c)
107{
108	return c > 0x7f || (( inwordLut[c>>5] >> (c & 0x1F) ) & 1);
109}
110
111/**
112 *	set loadlut		-	load the LUT table
113 *	@p: user table
114 *
115 *	Load the LUT table from user space. The caller must hold the console
116 *	lock. Make a temporary copy so a partial update doesn't make a mess.
117 */
118int sel_loadlut(char __user *p)
119{
120	u32 tmplut[ARRAY_SIZE(inwordLut)];
121	if (copy_from_user(tmplut, (u32 __user *)(p+4), sizeof(inwordLut)))
122		return -EFAULT;
123	memcpy(inwordLut, tmplut, sizeof(inwordLut));
124	return 0;
125}
126
127/* does screen address p correspond to character at LH/RH edge of screen? */
128static inline int atedge(const int p, int size_row)
129{
130	return (!(p % size_row)	|| !((p + 2) % size_row));
131}
132
133/* stores the char in UTF8 and returns the number of bytes used (1-4) */
134static int store_utf8(u32 c, char *p)
135{
136	if (c < 0x80) {
137		/*  0******* */
138		p[0] = c;
139		return 1;
140	} else if (c < 0x800) {
141		/* 110***** 10****** */
142		p[0] = 0xc0 | (c >> 6);
143		p[1] = 0x80 | (c & 0x3f);
144		return 2;
145	} else if (c < 0x10000) {
146		/* 1110**** 10****** 10****** */
147		p[0] = 0xe0 | (c >> 12);
148		p[1] = 0x80 | ((c >> 6) & 0x3f);
149		p[2] = 0x80 | (c & 0x3f);
150		return 3;
151	} else if (c < 0x110000) {
152		/* 11110*** 10****** 10****** 10****** */
153		p[0] = 0xf0 | (c >> 18);
154		p[1] = 0x80 | ((c >> 12) & 0x3f);
155		p[2] = 0x80 | ((c >> 6) & 0x3f);
156		p[3] = 0x80 | (c & 0x3f);
157		return 4;
158	} else {
159		/* outside Unicode, replace with U+FFFD */
160		p[0] = 0xef;
161		p[1] = 0xbf;
162		p[2] = 0xbd;
163		return 3;
164	}
165}
166
167/**
168 *	set_selection_user	-	set the current selection.
169 *	@sel: user selection info
170 *	@tty: the console tty
171 *
172 *	Invoked by the ioctl handle for the vt layer.
173 *
174 *	The entire selection process is managed under the console_lock. It's
175 *	 a lot under the lock but its hardly a performance path
176 */
177int set_selection_user(const struct tiocl_selection __user *sel,
178		       struct tty_struct *tty)
179{
180	struct tiocl_selection v;
181
182	if (copy_from_user(&v, sel, sizeof(*sel)))
183		return -EFAULT;
184
185	return set_selection_kernel(&v, tty);
186}
187
188static int vc_selection_store_chars(struct vc_data *vc, bool unicode)
189{
190	char *bp, *obp;
191	unsigned int i;
192
193	/* Allocate a new buffer before freeing the old one ... */
194	/* chars can take up to 4 bytes with unicode */
195	bp = kmalloc_array((vc_sel.end - vc_sel.start) / 2 + 1, unicode ? 4 : 1,
196			   GFP_KERNEL | __GFP_NOWARN);
197	if (!bp) {
198		printk(KERN_WARNING "selection: kmalloc() failed\n");
199		clear_selection();
200		return -ENOMEM;
201	}
202	kfree(vc_sel.buffer);
203	vc_sel.buffer = bp;
204
205	obp = bp;
206	for (i = vc_sel.start; i <= vc_sel.end; i += 2) {
207		u32 c = sel_pos(i, unicode);
208		if (unicode)
209			bp += store_utf8(c, bp);
210		else
211			*bp++ = c;
212		if (!isspace(c))
213			obp = bp;
214		if (!((i + 2) % vc->vc_size_row)) {
215			/* strip trailing blanks from line and add newline,
216			   unless non-space at end of line. */
217			if (obp != bp) {
218				bp = obp;
219				*bp++ = '\r';
220			}
221			obp = bp;
222		}
223	}
224	vc_sel.buf_len = bp - vc_sel.buffer;
225
226	return 0;
227}
228
229static int vc_do_selection(struct vc_data *vc, unsigned short mode, int ps,
230		int pe)
231{
232	int new_sel_start, new_sel_end, spc;
233	bool unicode = vt_do_kdgkbmode(fg_console) == K_UNICODE;
234
235	switch (mode) {
236	case TIOCL_SELCHAR:	/* character-by-character selection */
237		new_sel_start = ps;
238		new_sel_end = pe;
239		break;
240	case TIOCL_SELWORD:	/* word-by-word selection */
241		spc = isspace(sel_pos(ps, unicode));
242		for (new_sel_start = ps; ; ps -= 2) {
243			if ((spc && !isspace(sel_pos(ps, unicode))) ||
244			    (!spc && !inword(sel_pos(ps, unicode))))
245				break;
246			new_sel_start = ps;
247			if (!(ps % vc->vc_size_row))
248				break;
249		}
250
251		spc = isspace(sel_pos(pe, unicode));
252		for (new_sel_end = pe; ; pe += 2) {
253			if ((spc && !isspace(sel_pos(pe, unicode))) ||
254			    (!spc && !inword(sel_pos(pe, unicode))))
255				break;
256			new_sel_end = pe;
257			if (!((pe + 2) % vc->vc_size_row))
258				break;
259		}
260		break;
261	case TIOCL_SELLINE:	/* line-by-line selection */
262		new_sel_start = rounddown(ps, vc->vc_size_row);
263		new_sel_end = rounddown(pe, vc->vc_size_row) +
264			vc->vc_size_row - 2;
265		break;
266	case TIOCL_SELPOINTER:
267		highlight_pointer(pe);
268		return 0;
269	default:
270		return -EINVAL;
271	}
272
273	/* remove the pointer */
274	highlight_pointer(-1);
275
276	/* select to end of line if on trailing space */
277	if (new_sel_end > new_sel_start &&
278		!atedge(new_sel_end, vc->vc_size_row) &&
279		isspace(sel_pos(new_sel_end, unicode))) {
280		for (pe = new_sel_end + 2; ; pe += 2)
281			if (!isspace(sel_pos(pe, unicode)) ||
282			    atedge(pe, vc->vc_size_row))
283				break;
284		if (isspace(sel_pos(pe, unicode)))
285			new_sel_end = pe;
286	}
287	if (vc_sel.start == -1)	/* no current selection */
288		highlight(new_sel_start, new_sel_end);
289	else if (new_sel_start == vc_sel.start)
290	{
291		if (new_sel_end == vc_sel.end)	/* no action required */
292			return 0;
293		else if (new_sel_end > vc_sel.end)	/* extend to right */
294			highlight(vc_sel.end + 2, new_sel_end);
295		else				/* contract from right */
296			highlight(new_sel_end + 2, vc_sel.end);
297	}
298	else if (new_sel_end == vc_sel.end)
299	{
300		if (new_sel_start < vc_sel.start) /* extend to left */
301			highlight(new_sel_start, vc_sel.start - 2);
302		else				/* contract from left */
303			highlight(vc_sel.start, new_sel_start - 2);
304	}
305	else	/* some other case; start selection from scratch */
306	{
307		clear_selection();
308		highlight(new_sel_start, new_sel_end);
309	}
310	vc_sel.start = new_sel_start;
311	vc_sel.end = new_sel_end;
312
313	return vc_selection_store_chars(vc, unicode);
314}
315
316static int vc_selection(struct vc_data *vc, struct tiocl_selection *v,
317		struct tty_struct *tty)
318{
319	int ps, pe;
320
321	poke_blanked_console();
322
323	if (v->sel_mode == TIOCL_SELCLEAR) {
324		/* useful for screendump without selection highlights */
325		clear_selection();
326		return 0;
327	}
328
329	v->xs = min_t(u16, v->xs - 1, vc->vc_cols - 1);
330	v->ys = min_t(u16, v->ys - 1, vc->vc_rows - 1);
331	v->xe = min_t(u16, v->xe - 1, vc->vc_cols - 1);
332	v->ye = min_t(u16, v->ye - 1, vc->vc_rows - 1);
333
334	if (mouse_reporting() && (v->sel_mode & TIOCL_SELMOUSEREPORT)) {
335		mouse_report(tty, v->sel_mode & TIOCL_SELBUTTONMASK, v->xs,
336			     v->ys);
337		return 0;
338	}
339
340	ps = v->ys * vc->vc_size_row + (v->xs << 1);
341	pe = v->ye * vc->vc_size_row + (v->xe << 1);
342	if (ps > pe)	/* make vc_sel.start <= vc_sel.end */
343		swap(ps, pe);
344
345	if (vc_sel.cons != vc) {
346		clear_selection();
347		vc_sel.cons = vc;
348	}
349
350	return vc_do_selection(vc, v->sel_mode, ps, pe);
351}
352
353int set_selection_kernel(struct tiocl_selection *v, struct tty_struct *tty)
354{
355	int ret;
356
357	mutex_lock(&vc_sel.lock);
358	console_lock();
359	ret = vc_selection(vc_cons[fg_console].d, v, tty);
360	console_unlock();
361	mutex_unlock(&vc_sel.lock);
362
363	return ret;
364}
365EXPORT_SYMBOL_GPL(set_selection_kernel);
366
367/* Insert the contents of the selection buffer into the
368 * queue of the tty associated with the current console.
369 * Invoked by ioctl().
370 *
371 * Locking: called without locks. Calls the ldisc wrongly with
372 * unsafe methods,
373 */
374int paste_selection(struct tty_struct *tty)
375{
376	struct vc_data *vc = tty->driver_data;
377	int	pasted = 0;
378	unsigned int count;
379	struct  tty_ldisc *ld;
380	DECLARE_WAITQUEUE(wait, current);
381	int ret = 0;
382
383	console_lock();
384	poke_blanked_console();
385	console_unlock();
386
387	ld = tty_ldisc_ref_wait(tty);
388	if (!ld)
389		return -EIO;	/* ldisc was hung up */
390	tty_buffer_lock_exclusive(&vc->port);
391
392	add_wait_queue(&vc->paste_wait, &wait);
393	mutex_lock(&vc_sel.lock);
394	while (vc_sel.buffer && vc_sel.buf_len > pasted) {
395		set_current_state(TASK_INTERRUPTIBLE);
396		if (signal_pending(current)) {
397			ret = -EINTR;
398			break;
399		}
400		if (tty_throttled(tty)) {
401			mutex_unlock(&vc_sel.lock);
402			schedule();
403			mutex_lock(&vc_sel.lock);
404			continue;
405		}
406		__set_current_state(TASK_RUNNING);
407		count = vc_sel.buf_len - pasted;
408		count = tty_ldisc_receive_buf(ld, vc_sel.buffer + pasted, NULL,
409					      count);
410		pasted += count;
411	}
412	mutex_unlock(&vc_sel.lock);
413	remove_wait_queue(&vc->paste_wait, &wait);
414	__set_current_state(TASK_RUNNING);
415
416	tty_buffer_unlock_exclusive(&vc->port);
417	tty_ldisc_deref(ld);
418	return ret;
419}
420EXPORT_SYMBOL_GPL(paste_selection);