1 files changed, 290 insertions, 199 deletions

diff --git a/drivers/tty/vt/selection.c b/drivers/tty/vt/selection.c
index 60b7b6926059..13f4e48b4142 100644
--- a/drivers/tty/vt/selection.c
+++ b/drivers/tty/vt/selection.c
@@ -1,10 +1,13 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * This module exports the functions:
  *
- *     'int set_selection(struct tiocl_selection __user *, struct tty_struct *)'
+ *     'int set_selection_user(struct tiocl_selection __user *,
+ *			       struct tty_struct *)'
+ *     'int set_selection_kernel(struct tiocl_selection *, struct tty_struct *)'
  *     'void clear_selection(void)'
  *     'int paste_selection(struct tty_struct *)'
- *     'int sel_loadlut(char __user *)'
+ *     'int sel_loadlut(u32 __user *)'
  *
  * Now that /dev/vcs exists, most of this can disappear again.
  */
@@ -13,10 +16,11 @@
 #include <linux/tty.h>
 #include <linux/sched.h>
 #include <linux/mm.h>
+#include <linux/mutex.h>
 #include <linux/slab.h>
 #include <linux/types.h>
 
-#include <asm/uaccess.h>
+#include <linux/uaccess.h>
 
 #include <linux/kbd_kern.h>
 #include <linux/vt_kern.h>
@@ -24,21 +28,25 @@
 #include <linux/selection.h>
 #include <linux/tiocl.h>
 #include <linux/console.h>
+#include <linux/tty_flip.h>
 
-/* Don't take this from <ctype.h>: 011-015 on the screen aren't spaces */
-#define isspace(c)	((c) == ' ')
+#include <linux/sched/signal.h>
 
-extern void poke_blanked_console(void);
+/* Don't take this from <ctype.h>: 011-015 on the screen aren't spaces */
+#define is_space_on_vt(c)	((c) == ' ')
 
 /* FIXME: all this needs locking */
-/* Variables for selection control. */
-/* Use a dynamic buffer, instead of static (Dec 1994) */
-struct vc_data *sel_cons;		/* must not be deallocated */
-static int use_unicode;
-static volatile int sel_start = -1; 	/* cleared by clear_selection */
-static int sel_end;
-static int sel_buffer_lth;
-static char *sel_buffer;
+static struct vc_selection {
+	struct mutex lock;
+	struct vc_data *cons;			/* must not be deallocated */
+	char *buffer;
+	unsigned int buf_len;
+	volatile int start;			/* cleared by clear_selection */
+	int end;
+} vc_sel = {
+	.lock = __MUTEX_INITIALIZER(vc_sel.lock),
+	.start = -1,
+};
 
 /* clear_selection, highlight and highlight_pointer can be called
    from interrupt (via scrollback/front) */
@@ -46,69 +54,82 @@ static char *sel_buffer;
 /* set reverse video on characters s-e of console with selection. */
 static inline void highlight(const int s, const int e)
 {
-	invert_screen(sel_cons, s, e-s+2, 1);
+	invert_screen(vc_sel.cons, s, e-s+2, true);
 }
 
 /* use complementary color to show the pointer */
 static inline void highlight_pointer(const int where)
 {
-	complement_pos(sel_cons, where);
+	complement_pos(vc_sel.cons, where);
 }
 
-static u16
-sel_pos(int n)
+static u32
+sel_pos(int n, bool unicode)
 {
-	return inverse_translate(sel_cons, screen_glyph(sel_cons, n),
-				use_unicode);
+	if (unicode)
+		return screen_glyph_unicode(vc_sel.cons, n / 2);
+	return inverse_translate(vc_sel.cons, screen_glyph(vc_sel.cons, n),
+			false);
 }
 
 /**
- *	clear_selection		-	remove current selection
+ * clear_selection - remove current selection
+ *
+ * Remove the current selection highlight, if any from the console holding the
+ * selection.
  *
- *	Remove the current selection highlight, if any from the console
- *	holding the selection. The caller must hold the console lock.
+ * Locking: The caller must hold the console lock.
  */
 void clear_selection(void)
 {
 	highlight_pointer(-1); /* hide the pointer */
-	if (sel_start != -1) {
-		highlight(sel_start, sel_end);
-		sel_start = -1;
+	if (vc_sel.start != -1) {
+		highlight(vc_sel.start, vc_sel.end);
+		vc_sel.start = -1;
 	}
 }
+EXPORT_SYMBOL_GPL(clear_selection);
+
+bool vc_is_sel(const struct vc_data *vc)
+{
+	return vc == vc_sel.cons;
+}
 
 /*
  * User settable table: what characters are to be considered alphabetic?
- * 256 bits. Locked by the console lock.
+ * 128 bits. Locked by the console lock.
  */
-static u32 inwordLut[8]={
+static u32 inwordLut[]={
   0x00000000, /* control chars     */
-  0x03FF0000, /* digits            */
+  0x03FFE000, /* digits and "-./"  */
   0x87FFFFFE, /* uppercase and '_' */
   0x07FFFFFE, /* lowercase         */
-  0x00000000,
-  0x00000000,
-  0xFF7FFFFF, /* latin-1 accented letters, not multiplication sign */
-  0xFF7FFFFF  /* latin-1 accented letters, not division sign */
 };
 
-static inline int inword(const u16 c) {
-	return c > 0xff || (( inwordLut[c>>5] >> (c & 0x1F) ) & 1);
+static inline int inword(const u32 c)
+{
+	return c > 0x7f || (( inwordLut[c>>5] >> (c & 0x1F) ) & 1);
 }
 
 /**
- *	set loadlut		-	load the LUT table
- *	@p: user table
+ * sel_loadlut() - load the LUT table
+ * @lut: user table
+ *
+ * Load the LUT table from user space. Make a temporary copy so a partial
+ * update doesn't make a mess.
  *
- *	Load the LUT table from user space. The caller must hold the console
- *	lock. Make a temporary copy so a partial update doesn't make a mess.
+ * Locking: The console lock is acquired.
  */
-int sel_loadlut(char __user *p)
+int sel_loadlut(u32 __user *lut)
 {
-	u32 tmplut[8];
-	if (copy_from_user(tmplut, (u32 __user *)(p+4), 32))
+	u32 tmplut[ARRAY_SIZE(inwordLut)];
+
+	if (copy_from_user(tmplut, lut, sizeof(inwordLut)))
 		return -EFAULT;
-	memcpy(inwordLut, tmplut, 32);
+
+	guard(console_lock)();
+	memcpy(inwordLut, tmplut, sizeof(inwordLut));
+
 	return 0;
 }
 
@@ -118,14 +139,8 @@ static inline int atedge(const int p, int size_row)
 	return (!(p % size_row)	|| !((p + 2) % size_row));
 }
 
-/* constrain v such that v <= u */
-static inline unsigned short limit(const unsigned short v, const unsigned short u)
-{
-	return (v > u) ? u : v;
-}
-
-/* stores the char in UTF8 and returns the number of bytes used (1-3) */
-static int store_utf8(u16 c, char *p)
+/* stores the char in UTF8 and returns the number of bytes used (1-4) */
+static int store_utf8(u32 c, char *p)
 {
 	if (c < 0x80) {
 		/*  0******* */
@@ -136,120 +151,145 @@ static int store_utf8(u16 c, char *p)
 		p[0] = 0xc0 | (c >> 6);
 		p[1] = 0x80 | (c & 0x3f);
 		return 2;
-    	} else {
+	} else if (c < 0x10000) {
 		/* 1110**** 10****** 10****** */
 		p[0] = 0xe0 | (c >> 12);
 		p[1] = 0x80 | ((c >> 6) & 0x3f);
 		p[2] = 0x80 | (c & 0x3f);
 		return 3;
-    	}
+	} else if (c < 0x110000) {
+		/* 11110*** 10****** 10****** 10****** */
+		p[0] = 0xf0 | (c >> 18);
+		p[1] = 0x80 | ((c >> 12) & 0x3f);
+		p[2] = 0x80 | ((c >> 6) & 0x3f);
+		p[3] = 0x80 | (c & 0x3f);
+		return 4;
+	} else {
+		/* outside Unicode, replace with U+FFFD */
+		p[0] = 0xef;
+		p[1] = 0xbf;
+		p[2] = 0xbd;
+		return 3;
+	}
 }
 
 /**
- *	set_selection		- 	set the current selection.
- *	@sel: user selection info
- *	@tty: the console tty
+ * set_selection_user - set the current selection.
+ * @sel: user selection info
+ * @tty: the console tty
  *
- *	Invoked by the ioctl handle for the vt layer.
+ * Invoked by the ioctl handle for the vt layer.
  *
- *	The entire selection process is managed under the console_lock. It's
- *	 a lot under the lock but its hardly a performance path
+ * Locking: The entire selection process is managed under the console_lock.
+ * It's a lot under the lock but its hardly a performance path.
  */
-int set_selection(const struct tiocl_selection __user *sel, struct tty_struct *tty)
+int set_selection_user(const struct tiocl_selection __user *sel,
+		       struct tty_struct *tty)
 {
-	struct vc_data *vc = vc_cons[fg_console].d;
-	int sel_mode, new_sel_start, new_sel_end, spc;
-	char *bp, *obp;
-	int i, ps, pe, multiplier;
-	u16 c;
-	int mode;
-
-	poke_blanked_console();
-
-	{ unsigned short xs, ys, xe, ye;
+	struct tiocl_selection v;
 
-	  if (!access_ok(VERIFY_READ, sel, sizeof(*sel)))
+	if (copy_from_user(&v, sel, sizeof(*sel)))
 		return -EFAULT;
-	  __get_user(xs, &sel->xs);
-	  __get_user(ys, &sel->ys);
-	  __get_user(xe, &sel->xe);
-	  __get_user(ye, &sel->ye);
-	  __get_user(sel_mode, &sel->sel_mode);
-	  xs--; ys--; xe--; ye--;
-	  xs = limit(xs, vc->vc_cols - 1);
-	  ys = limit(ys, vc->vc_rows - 1);
-	  xe = limit(xe, vc->vc_cols - 1);
-	  ye = limit(ye, vc->vc_rows - 1);
-	  ps = ys * vc->vc_size_row + (xs << 1);
-	  pe = ye * vc->vc_size_row + (xe << 1);
-
-	  if (sel_mode == TIOCL_SELCLEAR) {
-	      /* useful for screendump without selection highlights */
-	      clear_selection();
-	      return 0;
-	  }
-
-	  if (mouse_reporting() && (sel_mode & TIOCL_SELMOUSEREPORT)) {
-	      mouse_report(tty, sel_mode & TIOCL_SELBUTTONMASK, xs, ys);
-	      return 0;
-	  }
-        }
-
-	if (ps > pe)	/* make sel_start <= sel_end */
-	{
-		int tmp = ps;
-		ps = pe;
-		pe = tmp;
+
+	/*
+	 * TIOCL_SELCLEAR and TIOCL_SELPOINTER are OK to use without
+	 * CAP_SYS_ADMIN as they do not modify the selection.
+	 */
+	switch (v.sel_mode) {
+	case TIOCL_SELCLEAR:
+	case TIOCL_SELPOINTER:
+		break;
+	default:
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
 	}
 
-	if (sel_cons != vc_cons[fg_console].d) {
+	return set_selection_kernel(&v, tty);
+}
+
+static int vc_selection_store_chars(struct vc_data *vc, bool unicode)
+{
+	char *bp, *obp;
+	unsigned int i;
+
+	/* Allocate a new buffer before freeing the old one ... */
+	/* chars can take up to 4 bytes with unicode */
+	bp = kmalloc_array((vc_sel.end - vc_sel.start) / 2 + 1, unicode ? 4 : 1,
+			   GFP_KERNEL | __GFP_NOWARN);
+	if (!bp) {
+		printk(KERN_WARNING "selection: kmalloc() failed\n");
 		clear_selection();
-		sel_cons = vc_cons[fg_console].d;
+		return -ENOMEM;
 	}
-	mode = vt_do_kdgkbmode(fg_console);
-	if (mode == K_UNICODE)
-		use_unicode = 1;
-	else
-		use_unicode = 0;
+	kfree(vc_sel.buffer);
+	vc_sel.buffer = bp;
 
-	switch (sel_mode)
-	{
-		case TIOCL_SELCHAR:	/* character-by-character selection */
+	obp = bp;
+	for (i = vc_sel.start; i <= vc_sel.end; i += 2) {
+		u32 c = sel_pos(i, unicode);
+		if (unicode)
+			bp += store_utf8(c, bp);
+		else
+			*bp++ = c;
+		if (!is_space_on_vt(c))
+			obp = bp;
+		if (!((i + 2) % vc->vc_size_row)) {
+			/* strip trailing blanks from line and add newline,
+			   unless non-space at end of line. */
+			if (obp != bp) {
+				bp = obp;
+				*bp++ = '\r';
+			}
+			obp = bp;
+		}
+	}
+	vc_sel.buf_len = bp - vc_sel.buffer;
+
+	return 0;
+}
+
+static int vc_do_selection(struct vc_data *vc, unsigned short mode, int ps,
+		int pe)
+{
+	int new_sel_start, new_sel_end, spc;
+	bool unicode = vt_do_kdgkbmode(fg_console) == K_UNICODE;
+
+	switch (mode) {
+	case TIOCL_SELCHAR:	/* character-by-character selection */
+		new_sel_start = ps;
+		new_sel_end = pe;
+		break;
+	case TIOCL_SELWORD:	/* word-by-word selection */
+		spc = is_space_on_vt(sel_pos(ps, unicode));
+		for (new_sel_start = ps; ; ps -= 2) {
+			if ((spc && !is_space_on_vt(sel_pos(ps, unicode))) ||
+			    (!spc && !inword(sel_pos(ps, unicode))))
+				break;
 			new_sel_start = ps;
+			if (!(ps % vc->vc_size_row))
+				break;
+		}
+
+		spc = is_space_on_vt(sel_pos(pe, unicode));
+		for (new_sel_end = pe; ; pe += 2) {
+			if ((spc && !is_space_on_vt(sel_pos(pe, unicode))) ||
+			    (!spc && !inword(sel_pos(pe, unicode))))
+				break;
 			new_sel_end = pe;
-			break;
-		case TIOCL_SELWORD:	/* word-by-word selection */
-			spc = isspace(sel_pos(ps));
-			for (new_sel_start = ps; ; ps -= 2)
-			{
-				if ((spc && !isspace(sel_pos(ps))) ||
-				    (!spc && !inword(sel_pos(ps))))
-					break;
-				new_sel_start = ps;
-				if (!(ps % vc->vc_size_row))
-					break;
-			}
-			spc = isspace(sel_pos(pe));
-			for (new_sel_end = pe; ; pe += 2)
-			{
-				if ((spc && !isspace(sel_pos(pe))) ||
-				    (!spc && !inword(sel_pos(pe))))
-					break;
-				new_sel_end = pe;
-				if (!((pe + 2) % vc->vc_size_row))
-					break;
-			}
-			break;
-		case TIOCL_SELLINE:	/* line-by-line selection */
-			new_sel_start = ps - ps % vc->vc_size_row;
-			new_sel_end = pe + vc->vc_size_row
-				    - pe % vc->vc_size_row - 2;
-			break;
-		case TIOCL_SELPOINTER:
-			highlight_pointer(pe);
-			return 0;
-		default:
-			return -EINVAL;
+			if (!((pe + 2) % vc->vc_size_row))
+				break;
+		}
+		break;
+	case TIOCL_SELLINE:	/* line-by-line selection */
+		new_sel_start = rounddown(ps, vc->vc_size_row);
+		new_sel_end = rounddown(pe, vc->vc_size_row) +
+			vc->vc_size_row - 2;
+		break;
+	case TIOCL_SELPOINTER:
+		highlight_pointer(pe);
+		return 0;
+	default:
+		return -EINVAL;
 	}
 
 	/* remove the pointer */
@@ -258,74 +298,89 @@ int set_selection(const struct tiocl_selection __user *sel, struct tty_struct *t
 	/* select to end of line if on trailing space */
 	if (new_sel_end > new_sel_start &&
 		!atedge(new_sel_end, vc->vc_size_row) &&
-		isspace(sel_pos(new_sel_end))) {
+		is_space_on_vt(sel_pos(new_sel_end, unicode))) {
 		for (pe = new_sel_end + 2; ; pe += 2)
-			if (!isspace(sel_pos(pe)) ||
+			if (!is_space_on_vt(sel_pos(pe, unicode)) ||
 			    atedge(pe, vc->vc_size_row))
 				break;
-		if (isspace(sel_pos(pe)))
+		if (is_space_on_vt(sel_pos(pe, unicode)))
 			new_sel_end = pe;
 	}
-	if (sel_start == -1)	/* no current selection */
+	if (vc_sel.start == -1)	/* no current selection */
 		highlight(new_sel_start, new_sel_end);
-	else if (new_sel_start == sel_start)
+	else if (new_sel_start == vc_sel.start)
 	{
-		if (new_sel_end == sel_end)	/* no action required */
+		if (new_sel_end == vc_sel.end)	/* no action required */
 			return 0;
-		else if (new_sel_end > sel_end)	/* extend to right */
-			highlight(sel_end + 2, new_sel_end);
+		else if (new_sel_end > vc_sel.end)	/* extend to right */
+			highlight(vc_sel.end + 2, new_sel_end);
 		else				/* contract from right */
-			highlight(new_sel_end + 2, sel_end);
+			highlight(new_sel_end + 2, vc_sel.end);
 	}
-	else if (new_sel_end == sel_end)
+	else if (new_sel_end == vc_sel.end)
 	{
-		if (new_sel_start < sel_start)	/* extend to left */
-			highlight(new_sel_start, sel_start - 2);
+		if (new_sel_start < vc_sel.start) /* extend to left */
+			highlight(new_sel_start, vc_sel.start - 2);
 		else				/* contract from left */
-			highlight(sel_start, new_sel_start - 2);
+			highlight(vc_sel.start, new_sel_start - 2);
 	}
 	else	/* some other case; start selection from scratch */
 	{
 		clear_selection();
 		highlight(new_sel_start, new_sel_end);
 	}
-	sel_start = new_sel_start;
-	sel_end = new_sel_end;
+	vc_sel.start = new_sel_start;
+	vc_sel.end = new_sel_end;
 
-	/* Allocate a new buffer before freeing the old one ... */
-	multiplier = use_unicode ? 3 : 1;  /* chars can take up to 3 bytes */
-	bp = kmalloc(((sel_end-sel_start)/2+1)*multiplier, GFP_KERNEL);
-	if (!bp) {
-		printk(KERN_WARNING "selection: kmalloc() failed\n");
+	return vc_selection_store_chars(vc, unicode);
+}
+
+static int vc_selection(struct vc_data *vc, struct tiocl_selection *v,
+		struct tty_struct *tty)
+{
+	int ps, pe;
+
+	poke_blanked_console();
+
+	if (v->sel_mode == TIOCL_SELCLEAR) {
+		/* useful for screendump without selection highlights */
 		clear_selection();
-		return -ENOMEM;
+		return 0;
 	}
-	kfree(sel_buffer);
-	sel_buffer = bp;
 
-	obp = bp;
-	for (i = sel_start; i <= sel_end; i += 2) {
-		c = sel_pos(i);
-		if (use_unicode)
-			bp += store_utf8(c, bp);
-		else
-			*bp++ = c;
-		if (!isspace(c))
-			obp = bp;
-		if (! ((i + 2) % vc->vc_size_row)) {
-			/* strip trailing blanks from line and add newline,
-			   unless non-space at end of line. */
-			if (obp != bp) {
-				bp = obp;
-				*bp++ = '\r';
-			}
-			obp = bp;
-		}
+	/* Historically 0 => max value */
+	v->xs = umin(v->xs - 1, vc->vc_cols - 1);
+	v->ys = umin(v->ys - 1, vc->vc_rows - 1);
+	v->xe = umin(v->xe - 1, vc->vc_cols - 1);
+	v->ye = umin(v->ye - 1, vc->vc_rows - 1);
+
+	if (mouse_reporting() && (v->sel_mode & TIOCL_SELMOUSEREPORT)) {
+		mouse_report(tty, v->sel_mode & TIOCL_SELBUTTONMASK, v->xs,
+			     v->ys);
+		return 0;
 	}
-	sel_buffer_lth = bp - sel_buffer;
-	return 0;
+
+	ps = v->ys * vc->vc_size_row + (v->xs << 1);
+	pe = v->ye * vc->vc_size_row + (v->xe << 1);
+	if (ps > pe)	/* make vc_sel.start <= vc_sel.end */
+		swap(ps, pe);
+
+	if (vc_sel.cons != vc) {
+		clear_selection();
+		vc_sel.cons = vc;
+	}
+
+	return vc_do_selection(vc, v->sel_mode, ps, pe);
 }
 
+int set_selection_kernel(struct tiocl_selection *v, struct tty_struct *tty)
+{
+	guard(mutex)(&vc_sel.lock);
+	guard(console_lock)();
+	return vc_selection(vc_cons[fg_console].d, v, tty);
+}
+EXPORT_SYMBOL_GPL(set_selection_kernel);
+
 /* Insert the contents of the selection buffer into the
  * queue of the tty associated with the current console.
  * Invoked by ioctl().
@@ -337,32 +392,68 @@ int paste_selection(struct tty_struct *tty)
 {
 	struct vc_data *vc = tty->driver_data;
 	int	pasted = 0;
-	unsigned int count;
+	size_t count;
 	struct  tty_ldisc *ld;
 	DECLARE_WAITQUEUE(wait, current);
+	int ret = 0;
 
-	console_lock();
-	poke_blanked_console();
-	console_unlock();
+	bool bp = vc->vc_bracketed_paste;
+	static const char bracketed_paste_start[] = "\033[200~";
+	static const char bracketed_paste_end[]   = "\033[201~";
+	const char *bps = bp ? bracketed_paste_start : NULL;
+	const char *bpe = bp ? bracketed_paste_end : NULL;
+
+	scoped_guard(console_lock)
+		poke_blanked_console();
 
 	ld = tty_ldisc_ref_wait(tty);
+	if (!ld)
+		return -EIO;	/* ldisc was hung up */
+	tty_buffer_lock_exclusive(&vc->port);
 
-	/* FIXME: this is completely unsafe */
 	add_wait_queue(&vc->paste_wait, &wait);
-	while (sel_buffer && sel_buffer_lth > pasted) {
+	mutex_lock(&vc_sel.lock);
+	while (vc_sel.buffer && (vc_sel.buf_len > pasted || bpe)) {
 		set_current_state(TASK_INTERRUPTIBLE);
-		if (test_bit(TTY_THROTTLED, &tty->flags)) {
+		if (signal_pending(current)) {
+			ret = -EINTR;
+			break;
+		}
+		if (tty_throttled(tty)) {
+			mutex_unlock(&vc_sel.lock);
 			schedule();
+			mutex_lock(&vc_sel.lock);
 			continue;
 		}
-		count = sel_buffer_lth - pasted;
-		count = min(count, tty->receive_room);
-		ld->ops->receive_buf(tty, sel_buffer + pasted, NULL, count);
-		pasted += count;
+		__set_current_state(TASK_RUNNING);
+
+		if (bps) {
+			bps += tty_ldisc_receive_buf(ld, bps, NULL, strlen(bps));
+			if (*bps != '\0')
+				continue;
+			bps = NULL;
+		}
+
+		count = vc_sel.buf_len - pasted;
+		if (count) {
+			pasted += tty_ldisc_receive_buf(ld, vc_sel.buffer + pasted,
+							NULL, count);
+			if (vc_sel.buf_len > pasted)
+				continue;
+		}
+
+		if (bpe) {
+			bpe += tty_ldisc_receive_buf(ld, bpe, NULL, strlen(bpe));
+			if (*bpe == '\0')
+				bpe = NULL;
+		}
 	}
+	mutex_unlock(&vc_sel.lock);
 	remove_wait_queue(&vc->paste_wait, &wait);
 	__set_current_state(TASK_RUNNING);
 
+	tty_buffer_unlock_exclusive(&vc->port);
 	tty_ldisc_deref(ld);
-	return 0;
+	return ret;
 }
+EXPORT_SYMBOL_GPL(paste_selection);