Adding upstream version 6.1.76.upstream/6.1.76

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

1 files changed, 421 insertions, 0 deletions

diff --git a/drivers/tty/vt/selection.c b/drivers/tty/vt/selection.c
new file mode 100644
index 000000000..6ef22f01c
--- /dev/null
+++ b/drivers/tty/vt/selection.c
@@ -0,0 +1,421 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * This module exports the functions:
+ *
+ *     '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 *)'
+ *
+ * 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 is_space_on_vt(c)	((c) == ' ')
+
+/* FIXME: all this needs locking */
+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) */
+
+/* set reverse video on characters s-e of console with selection. */
+static inline void highlight(const int s, const int e)
+{
+	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(vc_sel.cons, where);
+}
+
+static u32
+sel_pos(int n, bool 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
+ *
+ *	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 (vc_sel.start != -1) {
+		highlight(vc_sel.start, vc_sel.end);
+		vc_sel.start = -1;
+	}
+}
+EXPORT_SYMBOL_GPL(clear_selection);
+
+bool vc_is_sel(struct vc_data *vc)
+{
+	return vc == 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);
+}
+
+/**
+ *	sel_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_user	-	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
+ */
+int set_selection_user(const struct tiocl_selection __user *sel,
+		       struct tty_struct *tty)
+{
+	struct tiocl_selection v;
+
+	if (copy_from_user(&v, sel, sizeof(*sel)))
+		return -EFAULT;
+
+	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();
+		return -ENOMEM;
+	}
+	kfree(vc_sel.buffer);
+	vc_sel.buffer = bp;
+
+	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;
+			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 */
+	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) &&
+		is_space_on_vt(sel_pos(new_sel_end, unicode))) {
+		for (pe = new_sel_end + 2; ; pe += 2)
+			if (!is_space_on_vt(sel_pos(pe, unicode)) ||
+			    atedge(pe, vc->vc_size_row))
+				break;
+		if (is_space_on_vt(sel_pos(pe, unicode)))
+			new_sel_end = pe;
+	}
+	if (vc_sel.start == -1)	/* no current selection */
+		highlight(new_sel_start, new_sel_end);
+	else if (new_sel_start == vc_sel.start)
+	{
+		if (new_sel_end == vc_sel.end)	/* no action required */
+			return 0;
+		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, vc_sel.end);
+	}
+	else if (new_sel_end == vc_sel.end)
+	{
+		if (new_sel_start < vc_sel.start) /* extend to left */
+			highlight(new_sel_start, vc_sel.start - 2);
+		else				/* contract from left */
+			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);
+	}
+	vc_sel.start = new_sel_start;
+	vc_sel.end = new_sel_end;
+
+	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 0;
+	}
+
+	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);
+
+	if (mouse_reporting() && (v->sel_mode & TIOCL_SELMOUSEREPORT)) {
+		mouse_report(tty, v->sel_mode & TIOCL_SELBUTTONMASK, v->xs,
+			     v->ys);
+		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)
+{
+	int ret;
+
+	mutex_lock(&vc_sel.lock);
+	console_lock();
+	ret = vc_selection(vc_cons[fg_console].d, v, tty);
+	console_unlock();
+	mutex_unlock(&vc_sel.lock);
+
+	return ret;
+}
+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().
+ *
+ * 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(&vc_sel.lock);
+	while (vc_sel.buffer && vc_sel.buf_len > pasted) {
+		set_current_state(TASK_INTERRUPTIBLE);
+		if (signal_pending(current)) {
+			ret = -EINTR;
+			break;
+		}
+		if (tty_throttled(tty)) {
+			mutex_unlock(&vc_sel.lock);
+			schedule();
+			mutex_lock(&vc_sel.lock);
+			continue;
+		}
+		__set_current_state(TASK_RUNNING);
+		count = vc_sel.buf_len - pasted;
+		count = tty_ldisc_receive_buf(ld, vc_sel.buffer + pasted, NULL,
+					      count);
+		pasted += count;
+	}
+	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 ret;
+}
+EXPORT_SYMBOL_GPL(paste_selection);