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vt:tackle kbd_table

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Keyboard struct lifetime is easy, but the locking is not and is completely
ignored by the existing code. Tackle this one head on

- Make the kbd_table private so we can run down all direct users
- Hoick the relevant ioctl handlers into the keyboard layer
- Lock them with the keyboard lock so they don't change mid keypress
- Add helpers for things like console stop/start so we isolate the poking
  around properly
- Tweak the braille console so it still builds

There are a couple of FIXME locking cases left for ioctls that are so hideous
they should be addressed in a later patch. After this patch the kbd_table is
private and all the keyboard jiggery pokery is in one place.

This update fixes speakup and also a memory leak in the original.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Alan Cox
2012-02-28 14:49:23 +00:00
committed by Greg Kroah-Hartman
parent 0fb8379dab
commit 079c9534a9
10 changed files with 660 additions and 377 deletions
Download Patch File Download Diff File Expand all files Collapse all files

325
drivers/tty/vt/vt_ioctl.c
View File

@@ -195,232 +195,7 @@ int vt_waitactive(int n)
#define GPLAST 0x3df
#define GPNUM (GPLAST - GPFIRST + 1)
#define i (tmp.kb_index)
#define s (tmp.kb_table)
#define v (tmp.kb_value)
static inline int
do_kdsk_ioctl(int cmd, struct kbentry __user *user_kbe, int perm, struct kbd_struct *kbd)
{
struct kbentry tmp;
ushort *key_map, val, ov;
if (copy_from_user(&tmp, user_kbe, sizeof(struct kbentry)))
return -EFAULT;
if (!capable(CAP_SYS_TTY_CONFIG))
perm = 0;
switch (cmd) {
case KDGKBENT:
key_map = key_maps[s];
if (key_map) {
val = U(key_map[i]);
if (kbd->kbdmode != VC_UNICODE && KTYP(val) >= NR_TYPES)
val = K_HOLE;
} else
val = (i ? K_HOLE : K_NOSUCHMAP);
return put_user(val, &user_kbe->kb_value);
case KDSKBENT:
if (!perm)
return -EPERM;
if (!i && v == K_NOSUCHMAP) {
/* deallocate map */
key_map = key_maps[s];
if (s && key_map) {
key_maps[s] = NULL;
if (key_map[0] == U(K_ALLOCATED)) {
kfree(key_map);
keymap_count--;
}
}
break;
}
if (KTYP(v) < NR_TYPES) {
if (KVAL(v) > max_vals[KTYP(v)])
return -EINVAL;
} else
if (kbd->kbdmode != VC_UNICODE)
return -EINVAL;
/* ++Geert: non-PC keyboards may generate keycode zero */
#if !defined(__mc68000__) && !defined(__powerpc__)
/* assignment to entry 0 only tests validity of args */
if (!i)
break;
#endif
if (!(key_map = key_maps[s])) {
int j;
if (keymap_count >= MAX_NR_OF_USER_KEYMAPS &&
!capable(CAP_SYS_RESOURCE))
return -EPERM;
key_map = kmalloc(sizeof(plain_map),
GFP_KERNEL);
if (!key_map)
return -ENOMEM;
key_maps[s] = key_map;
key_map[0] = U(K_ALLOCATED);
for (j = 1; j < NR_KEYS; j++)
key_map[j] = U(K_HOLE);
keymap_count++;
}
ov = U(key_map[i]);
if (v == ov)
break; /* nothing to do */
/*
* Attention Key.
*/
if (((ov == K_SAK) || (v == K_SAK)) && !capable(CAP_SYS_ADMIN))
return -EPERM;
key_map[i] = U(v);
if (!s && (KTYP(ov) == KT_SHIFT || KTYP(v) == KT_SHIFT))
compute_shiftstate();
break;
}
return 0;
}
#undef i
#undef s
#undef v
static inline int
do_kbkeycode_ioctl(int cmd, struct kbkeycode __user *user_kbkc, int perm)
{
struct kbkeycode tmp;
int kc = 0;
if (copy_from_user(&tmp, user_kbkc, sizeof(struct kbkeycode)))
return -EFAULT;
switch (cmd) {
case KDGETKEYCODE:
kc = getkeycode(tmp.scancode);
if (kc >= 0)
kc = put_user(kc, &user_kbkc->keycode);
break;
case KDSETKEYCODE:
if (!perm)
return -EPERM;
kc = setkeycode(tmp.scancode, tmp.keycode);
break;
}
return kc;
}
static inline int
do_kdgkb_ioctl(int cmd, struct kbsentry __user *user_kdgkb, int perm)
{
struct kbsentry *kbs;
char *p;
u_char *q;
u_char __user *up;
int sz;
int delta;
char *first_free, *fj, *fnw;
int i, j, k;
int ret;
if (!capable(CAP_SYS_TTY_CONFIG))
perm = 0;
kbs = kmalloc(sizeof(*kbs), GFP_KERNEL);
if (!kbs) {
ret = -ENOMEM;
goto reterr;
}
/* we mostly copy too much here (512bytes), but who cares ;) */
if (copy_from_user(kbs, user_kdgkb, sizeof(struct kbsentry))) {
ret = -EFAULT;
goto reterr;
}
kbs->kb_string[sizeof(kbs->kb_string)-1] = '\0';
i = kbs->kb_func;
switch (cmd) {
case KDGKBSENT:
sz = sizeof(kbs->kb_string) - 1; /* sz should have been
a struct member */
up = user_kdgkb->kb_string;
p = func_table[i];
if(p)
for ( ; *p && sz; p++, sz--)
if (put_user(*p, up++)) {
ret = -EFAULT;
goto reterr;
}
if (put_user('\0', up)) {
ret = -EFAULT;
goto reterr;
}
kfree(kbs);
return ((p && *p) ? -EOVERFLOW : 0);
case KDSKBSENT:
if (!perm) {
ret = -EPERM;
goto reterr;
}
q = func_table[i];
first_free = funcbufptr + (funcbufsize - funcbufleft);
for (j = i+1; j < MAX_NR_FUNC && !func_table[j]; j++)
;
if (j < MAX_NR_FUNC)
fj = func_table[j];
else
fj = first_free;
delta = (q ? -strlen(q) : 1) + strlen(kbs->kb_string);
if (delta <= funcbufleft) { /* it fits in current buf */
if (j < MAX_NR_FUNC) {
memmove(fj + delta, fj, first_free - fj);
for (k = j; k < MAX_NR_FUNC; k++)
if (func_table[k])
func_table[k] += delta;
}
if (!q)
func_table[i] = fj;
funcbufleft -= delta;
} else { /* allocate a larger buffer */
sz = 256;
while (sz < funcbufsize - funcbufleft + delta)
sz <<= 1;
fnw = kmalloc(sz, GFP_KERNEL);
if(!fnw) {
ret = -ENOMEM;
goto reterr;
}
if (!q)
func_table[i] = fj;
if (fj > funcbufptr)
memmove(fnw, funcbufptr, fj - funcbufptr);
for (k = 0; k < j; k++)
if (func_table[k])
func_table[k] = fnw + (func_table[k] - funcbufptr);
if (first_free > fj) {
memmove(fnw + (fj - funcbufptr) + delta, fj, first_free - fj);
for (k = j; k < MAX_NR_FUNC; k++)
if (func_table[k])
func_table[k] = fnw + (func_table[k] - funcbufptr) + delta;
}
if (funcbufptr != func_buf)
kfree(funcbufptr);
funcbufptr = fnw;
funcbufleft = funcbufleft - delta + sz - funcbufsize;
funcbufsize = sz;
}
strcpy(func_table[i], kbs->kb_string);
break;
}
ret = 0;
reterr:
kfree(kbs);
return ret;
}
static inline int
do_fontx_ioctl(int cmd, struct consolefontdesc __user *user_cfd, int perm, struct console_font_op *op)
@@ -497,7 +272,6 @@ int vt_ioctl(struct tty_struct *tty,
{
struct vc_data *vc = tty->driver_data;
struct console_font_op op; /* used in multiple places here */
struct kbd_struct * kbd;
unsigned int console;
unsigned char ucval;
unsigned int uival;
@@ -523,7 +297,6 @@ int vt_ioctl(struct tty_struct *tty,
if (current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG))
perm = 1;
kbd = kbd_table + console;
switch (cmd) {
case TIOCLINUX:
ret = tioclinux(tty, arg);
@@ -565,7 +338,8 @@ int vt_ioctl(struct tty_struct *tty,
* this is naive.
*/
ucval = KB_101;
goto setchar;
ret = put_user(ucval, (char __user *)arg);
break;
/*
* These cannot be implemented on any machine that implements
@@ -670,68 +444,25 @@ int vt_ioctl(struct tty_struct *tty,
case KDSKBMODE:
if (!perm)
goto eperm;
switch(arg) {
case K_RAW:
kbd->kbdmode = VC_RAW;
break;
case K_MEDIUMRAW:
kbd->kbdmode = VC_MEDIUMRAW;
break;
case K_XLATE:
kbd->kbdmode = VC_XLATE;
compute_shiftstate();
break;
case K_UNICODE:
kbd->kbdmode = VC_UNICODE;
compute_shiftstate();
break;
case K_OFF:
kbd->kbdmode = VC_OFF;
break;
default:
ret = -EINVAL;
goto out;
}
tty_ldisc_flush(tty);
ret = vt_do_kdskbmode(console, arg);
if (ret == 0)
tty_ldisc_flush(tty);
break;
case KDGKBMODE:
switch (kbd->kbdmode) {
case VC_RAW:
uival = K_RAW;
break;
case VC_MEDIUMRAW:
uival = K_MEDIUMRAW;
break;
case VC_UNICODE:
uival = K_UNICODE;
break;
case VC_OFF:
uival = K_OFF;
break;
default:
uival = K_XLATE;
break;
}
goto setint;
uival = vt_do_kdgkbmode(console);
ret = put_user(uival, (int __user *)arg);
break;
/* this could be folded into KDSKBMODE, but for compatibility
reasons it is not so easy to fold KDGKBMETA into KDGKBMODE */
case KDSKBMETA:
switch(arg) {
case K_METABIT:
clr_vc_kbd_mode(kbd, VC_META);
break;
case K_ESCPREFIX:
set_vc_kbd_mode(kbd, VC_META);
break;
default:
ret = -EINVAL;
}
ret = vt_do_kdskbmeta(console, arg);
break;
case KDGKBMETA:
uival = (vc_kbd_mode(kbd, VC_META) ? K_ESCPREFIX : K_METABIT);
/* FIXME: should review whether this is worth locking */
uival = vt_do_kdgkbmeta(console);
setint:
ret = put_user(uival, (int __user *)arg);
break;
@@ -740,17 +471,17 @@ int vt_ioctl(struct tty_struct *tty,
case KDSETKEYCODE:
if(!capable(CAP_SYS_TTY_CONFIG))
perm = 0;
ret = do_kbkeycode_ioctl(cmd, up, perm);
ret = vt_do_kbkeycode_ioctl(cmd, up, perm);
break;
case KDGKBENT:
case KDSKBENT:
ret = do_kdsk_ioctl(cmd, up, perm, kbd);
ret = vt_do_kdsk_ioctl(cmd, up, perm, console);
break;
case KDGKBSENT:
case KDSKBSENT:
ret = do_kdgkb_ioctl(cmd, up, perm);
ret = vt_do_kdgkb_ioctl(cmd, up, perm);
break;
/* Diacritical processing. Handled in keyboard.c as it has
@@ -765,33 +496,10 @@ int vt_ioctl(struct tty_struct *tty,
/* the ioctls below read/set the flags usually shown in the leds */
/* don't use them - they will go away without warning */
case KDGKBLED:
ucval = kbd->ledflagstate | (kbd->default_ledflagstate << 4);
goto setchar;
case KDSKBLED:
if (!perm)
goto eperm;
if (arg & ~0x77) {
ret = -EINVAL;
break;
}
kbd->ledflagstate = (arg & 7);
kbd->default_ledflagstate = ((arg >> 4) & 7);
set_leds();
break;
/* the ioctls below only set the lights, not the functions */
/* for those, see KDGKBLED and KDSKBLED above */
case KDGETLED:
ucval = getledstate();
setchar:
ret = put_user(ucval, (char __user *)arg);
break;
case KDSETLED:
if (!perm)
goto eperm;
setledstate(kbd, arg);
ret = vt_do_kdskled(console, cmd, arg, perm);
break;
/*
@@ -1286,7 +994,7 @@ eperm:
void reset_vc(struct vc_data *vc)
{
vc->vc_mode = KD_TEXT;
kbd_table[vc->vc_num].kbdmode = default_utf8 ? VC_UNICODE : VC_XLATE;
vt_reset_unicode(vc->vc_num);
vc->vt_mode.mode = VT_AUTO;
vc->vt_mode.waitv = 0;
vc->vt_mode.relsig = 0;
@@ -1309,6 +1017,7 @@ void vc_SAK(struct work_struct *work)
console_lock();
vc = vc_con->d;
if (vc) {
/* FIXME: review tty ref counting */
tty = vc->port.tty;
/*
* SAK should also work in all raw modes and reset