cregit-Linux how code gets into the kernel

Release 4.11 drivers/tty/vt/selection.c

Directory: drivers/tty/vt
/*
 * 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); }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)2996.67%150.00%
Roman Zippel13.33%150.00%
Total30100.00%2100.00%

/* use complementary color to show the pointer */
static inline void highlight_pointer(const int where) { complement_pos(sel_cons, where); }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)1794.44%150.00%
Roman Zippel15.56%150.00%
Total18100.00%2100.00%


static u16 sel_pos(int n) { return inverse_translate(sel_cons, screen_glyph(sel_cons, n), use_unicode); }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)2187.50%266.67%
Jan Engelhardt312.50%133.33%
Total24100.00%3100.00%

/** * 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; } }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)3497.14%150.00%
Alan Cox12.86%150.00%
Total35100.00%2100.00%

/* * User settable table: what characters are to be considered alphabetic? * 256 bits. Locked by the console lock. */ 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 u16 c) { return c > 0xff || (( inwordLut[c>>5] >> (c & 0x1F) ) & 1); }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)2880.00%150.00%
Jan Engelhardt720.00%150.00%
Total35100.00%2100.00%

/** * 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[8]; if (copy_from_user(tmplut, (u32 __user *)(p+4), 32)) return -EFAULT; memcpy(inwordLut, tmplut, 32); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)2242.31%350.00%
Alan Cox2242.31%116.67%
Al Viro611.54%116.67%
Linus Torvalds23.85%116.67%
Total52100.00%6100.00%

/* 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)); }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)35100.00%2100.00%
Total35100.00%2100.00%

/* constrain v such that v <= u */
static inline unsigned short limit(const unsigned short v, const unsigned short u) { return (v > u) ? u : v; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)29100.00%2100.00%
Total29100.00%2100.00%

/* stores the char in UTF8 and returns the number of bytes used (1-3) */
static int store_utf8(u16 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 { /* 1110**** 10****** 10****** */ p[0] = 0xe0 | (c >> 12); p[1] = 0x80 | ((c >> 6) & 0x3f); p[2] = 0x80 | (c & 0x3f); return 3; } }

Contributors

PersonTokensPropCommitsCommitProp
Jan Engelhardt121100.00%1100.00%
Total121100.00%1100.00%

/** * 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 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; 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; } mode = vt_do_kdgkbmode(fg_console); if (mode == K_UNICODE) use_unicode = 1; else use_unicode = 0; 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 ... */ 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"); 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; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)76181.56%746.67%
Christoph Hellwig646.86%16.67%
Jan Engelhardt394.18%16.67%
Andrew Morton343.64%16.67%
Alan Cox212.25%16.67%
Linus Torvalds70.75%16.67%
Mikulas Patocka40.43%16.67%
Jesper Juhl20.21%16.67%
Al Viro10.11%16.67%
Total933100.00%15100.00%

/* 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; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)10660.57%628.57%
Peter Hurley3318.86%523.81%
Alan Cox1810.29%29.52%
Andrew Morton42.29%14.76%
Roman Zippel42.29%14.76%
Milind Arun Choudhary31.71%14.76%
Torben Hohn21.14%14.76%
Arnd Bergmann21.14%14.76%
Linus Torvalds10.57%14.76%
Mika Kukkonen10.57%14.76%
Jiri Slaby10.57%14.76%
Total175100.00%21100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)118773.18%1634.78%
Jan Engelhardt17810.97%12.17%
Alan Cox694.25%613.04%
Christoph Hellwig674.13%12.17%
Andrew Morton442.71%24.35%
Peter Hurley362.22%510.87%
Linus Torvalds120.74%48.70%
Al Viro70.43%12.17%
Roman Zippel60.37%24.35%
Mikulas Patocka40.25%12.17%
Milind Arun Choudhary30.18%12.17%
Torben Hohn20.12%12.17%
Arnd Bergmann20.12%12.17%
Jesper Juhl20.12%12.17%
Mika Kukkonen10.06%12.17%
Jiri Slaby10.06%12.17%
Jovi Zhang10.06%12.17%
Total1622100.00%46100.00%
Directory: drivers/tty/vt
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