Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 401 insertions, 0 deletions

diff --git a/drivers/tty/vt/selection.c b/drivers/tty/vt/selection.c
new file mode 100644
index 000000000..34a0e529c
--- /dev/null
+++ b/drivers/tty/vt/selection.c
@@ -0,0 +1,401 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * This module exports the functions:
+ *
+ *     'int set_selection(struct tiocl_selection __user *, struct tty_struct *)'
+ *     'void clear_selection(void)'
+ *     'int paste_selection(struct tty_struct *)'
+ *     'int sel_loadlut(char __user *)'
+ *
+ * Now that /dev/vcs exists, most of this can disappear again.
+ */
+
+#include <linux/module.h>
+#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 <linux/uaccess.h>
+
+#include <linux/kbd_kern.h>
+#include <linux/vt_kern.h>
+#include <linux/consolemap.h>
+#include <linux/selection.h>
+#include <linux/tiocl.h>
+#include <linux/console.h>
+#include <linux/tty_flip.h>
+
+#include <linux/sched/signal.h>
+
+/* Don't take this from <ctype.h>: 011-015 on the screen aren't spaces */
+#define isspace(c)	((c) == ' ')
+
+extern void poke_blanked_console(void);
+
+/* 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 DEFINE_MUTEX(sel_lock);
+
+/* clear_selection, highlight and highlight_pointer can be called
+   from interrupt (via scrollback/front) */
+
+/* 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);
+}
+
+/* use complementary color to show the pointer */
+static inline void highlight_pointer(const int where)
+{
+	complement_pos(sel_cons, where);
+}
+
+static u32
+sel_pos(int n)
+{
+	if (use_unicode)
+		return screen_glyph_unicode(sel_cons, n / 2);
+	return inverse_translate(sel_cons, screen_glyph(sel_cons, n),
+				0);
+}
+
+/**
+ *	clear_selection		-	remove current selection
+ *
+ *	Remove the current selection highlight, if any from the console
+ *	holding the selection. 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;
+	}
+}
+
+bool vc_is_sel(struct vc_data *vc)
+{
+	return vc == sel_cons;
+}
+
+/*
+ * User settable table: what characters are to be considered alphabetic?
+ * 128 bits. Locked by the console lock.
+ */
+static u32 inwordLut[]={
+  0x00000000, /* control chars     */
+  0x03FFE000, /* digits and "-./"  */
+  0x87FFFFFE, /* uppercase and '_' */
+  0x07FFFFFE, /* lowercase         */
+};
+
+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
+ *
+ *	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.
+ */
+int sel_loadlut(char __user *p)
+{
+	u32 tmplut[ARRAY_SIZE(inwordLut)];
+	if (copy_from_user(tmplut, (u32 __user *)(p+4), sizeof(inwordLut)))
+		return -EFAULT;
+	memcpy(inwordLut, tmplut, sizeof(inwordLut));
+	return 0;
+}
+
+/* does screen address p correspond to character at LH/RH edge of screen? */
+static inline int atedge(const int p, int size_row)
+{
+	return (!(p % size_row)	|| !((p + 2) % size_row));
+}
+
+/* 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******* */
+		p[0] = c;
+		return 1;
+	} else if (c < 0x800) {
+		/* 110***** 10****** */
+		p[0] = 0xc0 | (c >> 6);
+		p[1] = 0x80 | (c & 0x3f);
+		return 2;
+	} 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
+ *
+ *	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
+ */
+static int __set_selection(const struct tiocl_selection __user *sel, struct tty_struct *tty)
+{
+	struct vc_data *vc = vc_cons[fg_console].d;
+	int new_sel_start, new_sel_end, spc;
+	struct tiocl_selection v;
+	char *bp, *obp;
+	int i, ps, pe, multiplier;
+	u32 c;
+	int mode, ret = 0;
+
+	poke_blanked_console();
+	if (copy_from_user(&v, sel, sizeof(*sel)))
+		return -EFAULT;
+
+	v.xs = min_t(u16, v.xs - 1, vc->vc_cols - 1);
+	v.ys = min_t(u16, v.ys - 1, vc->vc_rows - 1);
+	v.xe = min_t(u16, v.xe - 1, vc->vc_cols - 1);
+	v.ye = min_t(u16, v.ye - 1, vc->vc_rows - 1);
+	ps = v.ys * vc->vc_size_row + (v.xs << 1);
+	pe = v.ye * vc->vc_size_row + (v.xe << 1);
+
+	if (v.sel_mode == TIOCL_SELCLEAR) {
+		/* useful for screendump without selection highlights */
+		clear_selection();
+		return 0;
+	}
+
+	if (mouse_reporting() && (v.sel_mode & TIOCL_SELMOUSEREPORT)) {
+		mouse_report(tty, v.sel_mode & TIOCL_SELBUTTONMASK, v.xs, v.ys);
+		return 0;
+	}
+
+	if (ps > pe)	/* make sel_start <= sel_end */
+		swap(ps, pe);
+
+	if (sel_cons != vc_cons[fg_console].d) {
+		clear_selection();
+		sel_cons = vc_cons[fg_console].d;
+	}
+	mode = vt_do_kdgkbmode(fg_console);
+	if (mode == K_UNICODE)
+		use_unicode = 1;
+	else
+		use_unicode = 0;
+
+	switch (v.sel_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 = 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;
+	}
+
+	/* remove the pointer */
+	highlight_pointer(-1);
+
+	/* 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))) {
+		for (pe = new_sel_end + 2; ; pe += 2)
+			if (!isspace(sel_pos(pe)) ||
+			    atedge(pe, vc->vc_size_row))
+				break;
+		if (isspace(sel_pos(pe)))
+			new_sel_end = pe;
+	}
+	if (sel_start == -1)	/* no current selection */
+		highlight(new_sel_start, new_sel_end);
+	else if (new_sel_start == sel_start)
+	{
+		if (new_sel_end == 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				/* contract from right */
+			highlight(new_sel_end + 2, sel_end);
+	}
+	else if (new_sel_end == sel_end)
+	{
+		if (new_sel_start < sel_start)	/* extend to left */
+			highlight(new_sel_start, sel_start - 2);
+		else				/* contract from left */
+			highlight(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;
+
+	/* Allocate a new buffer before freeing the old one ... */
+	multiplier = use_unicode ? 4 : 1;  /* chars can take up to 4 bytes */
+	bp = kmalloc_array((sel_end - sel_start) / 2 + 1, multiplier,
+			   GFP_KERNEL);
+	if (!bp) {
+		printk(KERN_WARNING "selection: kmalloc() failed\n");
+		clear_selection();
+		return -ENOMEM;
+	}
+	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;
+		}
+	}
+	sel_buffer_lth = bp - sel_buffer;
+
+	return ret;
+}
+
+int set_selection(const struct tiocl_selection __user *v, struct tty_struct *tty)
+{
+	int ret;
+
+	mutex_lock(&sel_lock);
+	console_lock();
+	ret = __set_selection(v, tty);
+	console_unlock();
+	mutex_unlock(&sel_lock);
+
+	return ret;
+}
+
+/* Insert the contents of the selection buffer into the
+ * queue of the tty associated with the current console.
+ * Invoked by ioctl().
+ *
+ * Locking: called without locks. Calls the ldisc wrongly with
+ * unsafe methods,
+ */
+int paste_selection(struct tty_struct *tty)
+{
+	struct vc_data *vc = tty->driver_data;
+	int	pasted = 0;
+	unsigned int count;
+	struct  tty_ldisc *ld;
+	DECLARE_WAITQUEUE(wait, current);
+	int ret = 0;
+
+	console_lock();
+	poke_blanked_console();
+	console_unlock();
+
+	ld = tty_ldisc_ref_wait(tty);
+	if (!ld)
+		return -EIO;	/* ldisc was hung up */
+	tty_buffer_lock_exclusive(&vc->port);
+
+	add_wait_queue(&vc->paste_wait, &wait);
+	mutex_lock(&sel_lock);
+	while (sel_buffer && sel_buffer_lth > pasted) {
+		set_current_state(TASK_INTERRUPTIBLE);
+		if (signal_pending(current)) {
+			ret = -EINTR;
+			break;
+		}
+		if (tty_throttled(tty)) {
+			mutex_unlock(&sel_lock);
+			schedule();
+			mutex_lock(&sel_lock);
+			continue;
+		}
+		__set_current_state(TASK_RUNNING);
+		count = sel_buffer_lth - pasted;
+		count = tty_ldisc_receive_buf(ld, sel_buffer + pasted, NULL,
+					      count);
+		pasted += count;
+	}
+	mutex_unlock(&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 ret;
+}