v4.19.13 snapshot.
diff --git a/drivers/tty/vt/selection.c b/drivers/tty/vt/selection.c
new file mode 100644
index 0000000..07496c7
--- /dev/null
+++ b/drivers/tty/vt/selection.c
@@ -0,0 +1,369 @@
+// 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/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>
+
+/* 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;
+
+/* 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;
+ }
+}
+
+/*
+ * 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
+ */
+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;
+
+ 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 0;
+}
+
+/* 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);
+
+ 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);
+ while (sel_buffer && sel_buffer_lth > pasted) {
+ set_current_state(TASK_INTERRUPTIBLE);
+ if (tty_throttled(tty)) {
+ schedule();
+ continue;
+ }
+ __set_current_state(TASK_RUNNING);
+ count = sel_buffer_lth - pasted;
+ count = tty_ldisc_receive_buf(ld, sel_buffer + pasted, NULL,
+ count);
+ pasted += count;
+ }
+ remove_wait_queue(&vc->paste_wait, &wait);
+ __set_current_state(TASK_RUNNING);
+
+ tty_buffer_unlock_exclusive(&vc->port);
+ tty_ldisc_deref(ld);
+ return 0;
+}