kernel-ark/drivers/char/selection.c
Alan Cox ca9bda00b4 [PATCH] tty locking on resize
The current kernel serializes console resizes but does not serialize the
resize against the tty structure updates.  This means that while two
parallel resizes cannot mess up the console you can get incorrect results
reported.

Secondly while doing this I added vc_lock_resize() to lock and resize the
console.  This leaves all knowledge of the console_sem in the vt/console
driver and kicks it out of the tty layer, which is good

Thirdly while doing this I decided I couldn't stand "disallocate" any
longer so I switched it to "deallocate".

Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Paul Fulghum <paulkf@microgate.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29 09:18:12 -07:00

307 lines
7.8 KiB
C

/*
* linux/drivers/char/selection.c
*
* 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 <asm/uaccess.h>
#include <linux/vt_kern.h>
#include <linux/consolemap.h>
#include <linux/selection.h>
#include <linux/tiocl.h>
#include <linux/console.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);
/* Variables for selection control. */
/* Use a dynamic buffer, instead of static (Dec 1994) */
struct vc_data *sel_cons; /* must not be deallocated */
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 unsigned char
sel_pos(int n)
{
return inverse_translate(sel_cons, screen_glyph(sel_cons, n));
}
/* remove the current selection highlight, if any,
from the console holding the selection. */
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?
* 256 bits
*/
static u32 inwordLut[8]={
0x00000000, /* control chars */
0x03FF0000, /* digits */
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 unsigned char c) {
return ( inwordLut[c>>5] >> (c & 0x1F) ) & 1;
}
/* set inwordLut contents. Invoked by ioctl(). */
int sel_loadlut(char __user *p)
{
return copy_from_user(inwordLut, (u32 __user *)(p+4), 32) ? -EFAULT : 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));
}
/* constrain v such that v <= u */
static inline unsigned short limit(const unsigned short v, const unsigned short u)
{
return (v > u) ? u : v;
}
/* set the current selection. Invoked by ioctl() or by kernel code. */
int set_selection(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;
poke_blanked_console();
{ unsigned short xs, ys, xe, ye;
if (!access_ok(VERIFY_READ, 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;
}
if (sel_cons != vc_cons[fg_console].d) {
clear_selection();
sel_cons = vc_cons[fg_console].d;
}
switch (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 ... */
bp = kmalloc((sel_end-sel_start)/2+1, 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) {
*bp = sel_pos(i);
if (!isspace(*bp++))
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().
*/
int paste_selection(struct tty_struct *tty)
{
struct vc_data *vc = (struct vc_data *)tty->driver_data;
int pasted = 0;
unsigned int count;
struct tty_ldisc *ld;
DECLARE_WAITQUEUE(wait, current);
acquire_console_sem();
poke_blanked_console();
release_console_sem();
ld = tty_ldisc_ref_wait(tty);
add_wait_queue(&vc->paste_wait, &wait);
while (sel_buffer && sel_buffer_lth > pasted) {
set_current_state(TASK_INTERRUPTIBLE);
if (test_bit(TTY_THROTTLED, &tty->flags)) {
schedule();
continue;
}
count = sel_buffer_lth - pasted;
count = min(count, tty->receive_room);
tty->ldisc.receive_buf(tty, sel_buffer + pasted, NULL, count);
pasted += count;
}
remove_wait_queue(&vc->paste_wait, &wait);
current->state = TASK_RUNNING;
tty_ldisc_deref(ld);
return 0;
}