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Message-ID: <20080220203533.66ecc951@core>
Date: Wed, 20 Feb 2008 20:35:33 +0000
From: Alan Cox <alan@...rguk.ukuu.org.uk>
To: akpm@...l.org, linux-kernel@...r.kernel.org
Subject: [PATCH] vt_ioctl: Prepare for BKL push down
This one could do with some eyeballs on it. In theory it simply wraps the
ioctl handler in lock/unlock_kernel ready for the lock/unlocks to be
pushed into specific switch values. To do that means changing the code to
return via a common exit path not all over the place as it does now,
hence the big diff
Signed-off-by: Alan Cox <alan@...hat.com>
diff -u --new-file --recursive --exclude-from /usr/src/exclude linux.vanilla-2.6.25-rc2-mm1/drivers/char/vt_ioctl.c linux-2.6.25-rc2-mm1/drivers/char/vt_ioctl.c
--- linux.vanilla-2.6.25-rc2-mm1/drivers/char/vt_ioctl.c 2008-02-19 11:01:43.000000000 +0000
+++ linux-2.6.25-rc2-mm1/drivers/char/vt_ioctl.c 2008-02-20 11:49:34.000000000 +0000
@@ -373,11 +373,17 @@
unsigned char ucval;
void __user *up = (void __user *)arg;
int i, perm;
-
+ int ret = 0;
+
console = vc->vc_num;
+
+ lock_kernel();
- if (!vc_cons_allocated(console)) /* impossible? */
- return -ENOIOCTLCMD;
+ if (!vc_cons_allocated(console)) { /* impossible? */
+ ret = -ENOIOCTLCMD;
+ goto out;
+ }
+
/*
* To have permissions to do most of the vt ioctls, we either have
@@ -391,15 +397,15 @@
switch (cmd) {
case KIOCSOUND:
if (!perm)
- return -EPERM;
+ goto eperm;
if (arg)
arg = CLOCK_TICK_RATE / arg;
kd_mksound(arg, 0);
- return 0;
+ break;
case KDMKTONE:
if (!perm)
- return -EPERM;
+ goto eperm;
{
unsigned int ticks, count;
@@ -412,7 +418,7 @@
if (count)
count = CLOCK_TICK_RATE / count;
kd_mksound(count, ticks);
- return 0;
+ break;
}
case KDGKBTYPE:
@@ -435,14 +441,18 @@
* KDADDIO and KDDELIO may be able to add ports beyond what
* we reject here, but to be safe...
*/
- if (arg < GPFIRST || arg > GPLAST)
- return -EINVAL;
- return sys_ioperm(arg, 1, (cmd == KDADDIO)) ? -ENXIO : 0;
+ if (arg < GPFIRST || arg > GPLAST) {
+ ret = -EINVAL;
+ break;
+ }
+ ret = sys_ioperm(arg, 1, (cmd == KDADDIO)) ? -ENXIO : 0;
+ break;
case KDENABIO:
case KDDISABIO:
- return sys_ioperm(GPFIRST, GPNUM,
+ ret = sys_ioperm(GPFIRST, GPNUM,
(cmd == KDENABIO)) ? -ENXIO : 0;
+ break;
#endif
/* Linux m68k/i386 interface for setting the keyboard delay/repeat rate */
@@ -450,19 +460,20 @@
case KDKBDREP:
{
struct kbd_repeat kbrep;
- int err;
if (!capable(CAP_SYS_TTY_CONFIG))
- return -EPERM;
+ goto eperm;
- if (copy_from_user(&kbrep, up, sizeof(struct kbd_repeat)))
- return -EFAULT;
- err = kbd_rate(&kbrep);
- if (err)
- return err;
+ if (copy_from_user(&kbrep, up, sizeof(struct kbd_repeat))) {
+ ret = -EFAULT;
+ break;
+ }
+ ret = kbd_rate(&kbrep);
+ if (ret)
+ break;
if (copy_to_user(up, &kbrep, sizeof(struct kbd_repeat)))
- return -EFAULT;
- return 0;
+ ret = -EFAULT;
+ break;
}
case KDSETMODE:
@@ -475,7 +486,7 @@
* need to restore their engine state. --BenH
*/
if (!perm)
- return -EPERM;
+ goto eperm;
switch (arg) {
case KD_GRAPHICS:
break;
@@ -485,13 +496,14 @@
case KD_TEXT:
break;
default:
- return -EINVAL;
+ ret = -EINVAL;
+ goto out;
}
if (vc->vc_mode == (unsigned char) arg)
- return 0;
+ break;
vc->vc_mode = (unsigned char) arg;
if (console != fg_console)
- return 0;
+ break;
/*
* explicitly blank/unblank the screen if switching modes
*/
@@ -501,7 +513,7 @@
else
do_blank_screen(1);
release_console_sem();
- return 0;
+ break;
case KDGETMODE:
ucval = vc->vc_mode;
@@ -513,11 +525,12 @@
* these work like a combination of mmap and KDENABIO.
* this could be easily finished.
*/
- return -EINVAL;
+ ret = -EINVAL;
+ break;
case KDSKBMODE:
if (!perm)
- return -EPERM;
+ goto eperm;
switch(arg) {
case K_RAW:
kbd->kbdmode = VC_RAW;
@@ -534,10 +547,11 @@
compute_shiftstate();
break;
default:
- return -EINVAL;
+ ret = -EINVAL;
+ goto out;
}
tty_ldisc_flush(tty);
- return 0;
+ break;
case KDGKBMODE:
ucval = ((kbd->kbdmode == VC_RAW) ? K_RAW :
@@ -557,28 +571,32 @@
set_vc_kbd_mode(kbd, VC_META);
break;
default:
- return -EINVAL;
+ ret = -EINVAL;
}
- return 0;
+ break;
case KDGKBMETA:
ucval = (vc_kbd_mode(kbd, VC_META) ? K_ESCPREFIX : K_METABIT);
setint:
- return put_user(ucval, (int __user *)arg);
+ ret = put_user(ucval, (int __user *)arg);
+ break;
case KDGETKEYCODE:
case KDSETKEYCODE:
if(!capable(CAP_SYS_TTY_CONFIG))
- perm=0;
- return do_kbkeycode_ioctl(cmd, up, perm);
+ perm = 0;
+ ret = do_kbkeycode_ioctl(cmd, up, perm);
+ break;
case KDGKBENT:
case KDSKBENT:
- return do_kdsk_ioctl(cmd, up, perm, kbd);
+ ret = do_kdsk_ioctl(cmd, up, perm, kbd);
+ break;
case KDGKBSENT:
case KDSKBSENT:
- return do_kdgkb_ioctl(cmd, up, perm);
+ ret = do_kdgkb_ioctl(cmd, up, perm);
+ break;
case KDGKBDIACR:
{
@@ -586,26 +604,31 @@
struct kbdiacr diacr;
int i;
- if (put_user(accent_table_size, &a->kb_cnt))
- return -EFAULT;
+ if (put_user(accent_table_size, &a->kb_cnt)) {
+ ret = -EFAULT;
+ break;
+ }
for (i = 0; i < accent_table_size; i++) {
diacr.diacr = conv_uni_to_8bit(accent_table[i].diacr);
diacr.base = conv_uni_to_8bit(accent_table[i].base);
diacr.result = conv_uni_to_8bit(accent_table[i].result);
- if (copy_to_user(a->kbdiacr + i, &diacr, sizeof(struct kbdiacr)))
- return -EFAULT;
+ if (copy_to_user(a->kbdiacr + i, &diacr, sizeof(struct kbdiacr))) {
+ ret = -EFAULT;
+ break;
+ }
}
- return 0;
+ break;
}
case KDGKBDIACRUC:
{
struct kbdiacrsuc __user *a = up;
if (put_user(accent_table_size, &a->kb_cnt))
- return -EFAULT;
- if (copy_to_user(a->kbdiacruc, accent_table, accent_table_size*sizeof(struct kbdiacruc)))
- return -EFAULT;
- return 0;
+ ret = -EFAULT;
+ else if (copy_to_user(a->kbdiacruc, accent_table,
+ accent_table_size*sizeof(struct kbdiacruc)))
+ ret = -EFAULT;
+ break;
}
case KDSKBDIACR:
@@ -616,20 +639,26 @@
int i;
if (!perm)
- return -EPERM;
- if (get_user(ct,&a->kb_cnt))
- return -EFAULT;
- if (ct >= MAX_DIACR)
- return -EINVAL;
+ goto eperm;
+ if (get_user(ct,&a->kb_cnt)) {
+ ret = -EFAULT;
+ break;
+ }
+ if (ct >= MAX_DIACR) {
+ ret = -EINVAL;
+ break;
+ }
accent_table_size = ct;
for (i = 0; i < ct; i++) {
- if (copy_from_user(&diacr, a->kbdiacr + i, sizeof(struct kbdiacr)))
- return -EFAULT;
+ if (copy_from_user(&diacr, a->kbdiacr + i, sizeof(struct kbdiacr))) {
+ ret = -EFAULT;
+ break;
+ }
accent_table[i].diacr = conv_8bit_to_uni(diacr.diacr);
accent_table[i].base = conv_8bit_to_uni(diacr.base);
accent_table[i].result = conv_8bit_to_uni(diacr.result);
}
- return 0;
+ break;
}
case KDSKBDIACRUC:
@@ -638,15 +667,19 @@
unsigned int ct;
if (!perm)
- return -EPERM;
- if (get_user(ct,&a->kb_cnt))
- return -EFAULT;
- if (ct >= MAX_DIACR)
- return -EINVAL;
+ goto eperm;
+ if (get_user(ct,&a->kb_cnt)) {
+ ret = -EFAULT;
+ break;
+ }
+ if (ct >= MAX_DIACR) {
+ ret = -EINVAL;
+ break;
+ }
accent_table_size = ct;
if (copy_from_user(accent_table, a->kbdiacruc, ct*sizeof(struct kbdiacruc)))
- return -EFAULT;
- return 0;
+ ret = -EFAULT;
+ break;
}
/* the ioctls below read/set the flags usually shown in the leds */
@@ -657,26 +690,29 @@
case KDSKBLED:
if (!perm)
- return -EPERM;
- if (arg & ~0x77)
- return -EINVAL;
+ goto eperm;
+ if (arg & ~0x77) {
+ ret = -EINVAL;
+ break;
+ }
kbd->ledflagstate = (arg & 7);
kbd->default_ledflagstate = ((arg >> 4) & 7);
set_leds();
- return 0;
+ break;
/* the ioctls below only set the lights, not the functions */
/* for those, see KDGKBLED and KDSKBLED above */
case KDGETLED:
ucval = getledstate();
setchar:
- return put_user(ucval, (char __user *)arg);
+ ret = put_user(ucval, (char __user *)arg);
+ break;
case KDSETLED:
if (!perm)
- return -EPERM;
+ goto eperm;
setledstate(kbd, arg);
- return 0;
+ break;
/*
* A process can indicate its willingness to accept signals
@@ -688,16 +724,17 @@
case KDSIGACCEPT:
{
if (!perm || !capable(CAP_KILL))
- return -EPERM;
+ goto eperm;
if (!valid_signal(arg) || arg < 1 || arg == SIGKILL)
- return -EINVAL;
-
- spin_lock_irq(&vt_spawn_con.lock);
- put_pid(vt_spawn_con.pid);
- vt_spawn_con.pid = get_pid(task_pid(current));
- vt_spawn_con.sig = arg;
- spin_unlock_irq(&vt_spawn_con.lock);
- return 0;
+ ret = -EINVAL;
+ else {
+ spin_lock_irq(&vt_spawn_con.lock);
+ put_pid(vt_spawn_con.pid);
+ vt_spawn_con.pid = get_pid(task_pid(current));
+ vt_spawn_con.sig = arg;
+ spin_unlock_irq(&vt_spawn_con.lock);
+ }
+ break;
}
case VT_SETMODE:
@@ -705,11 +742,15 @@
struct vt_mode tmp;
if (!perm)
- return -EPERM;
- if (copy_from_user(&tmp, up, sizeof(struct vt_mode)))
- return -EFAULT;
- if (tmp.mode != VT_AUTO && tmp.mode != VT_PROCESS)
- return -EINVAL;
+ goto eperm;
+ if (copy_from_user(&tmp, up, sizeof(struct vt_mode))) {
+ ret = -EFAULT;
+ goto out;
+ }
+ if (tmp.mode != VT_AUTO && tmp.mode != VT_PROCESS) {
+ ret = -EINVAL;
+ goto out;
+ }
acquire_console_sem();
vc->vt_mode = tmp;
/* the frsig is ignored, so we set it to 0 */
@@ -719,7 +760,7 @@
/* no switch is required -- saw@...de.msu.ru */
vc->vt_newvt = -1;
release_console_sem();
- return 0;
+ break;
}
case VT_GETMODE:
@@ -732,7 +773,9 @@
release_console_sem();
rc = copy_to_user(up, &tmp, sizeof(struct vt_mode));
- return rc ? -EFAULT : 0;
+ if (rc)
+ ret = -EFAULT;
+ break;
}
/*
@@ -746,12 +789,16 @@
unsigned short state, mask;
if (put_user(fg_console + 1, &vtstat->v_active))
- return -EFAULT;
- state = 1; /* /dev/tty0 is always open */
- for (i = 0, mask = 2; i < MAX_NR_CONSOLES && mask; ++i, mask <<= 1)
- if (VT_IS_IN_USE(i))
- state |= mask;
- return put_user(state, &vtstat->v_state);
+ ret = -EFAULT;
+ else {
+ state = 1; /* /dev/tty0 is always open */
+ for (i = 0, mask = 2; i < MAX_NR_CONSOLES && mask;
+ ++i, mask <<= 1)
+ if (VT_IS_IN_USE(i))
+ state |= mask;
+ ret = put_user(state, &vtstat->v_state);
+ }
+ break;
}
/*
@@ -771,27 +818,31 @@
*/
case VT_ACTIVATE:
if (!perm)
- return -EPERM;
+ goto eperm;
if (arg == 0 || arg > MAX_NR_CONSOLES)
- return -ENXIO;
- arg--;
- acquire_console_sem();
- i = vc_allocate(arg);
- release_console_sem();
- if (i)
- return i;
- set_console(arg);
- return 0;
+ ret = -ENXIO;
+ else {
+ arg--;
+ acquire_console_sem();
+ ret = vc_allocate(arg);
+ release_console_sem();
+ if (ret)
+ break;
+ set_console(arg);
+ }
+ break;
/*
* wait until the specified VT has been activated
*/
case VT_WAITACTIVE:
if (!perm)
- return -EPERM;
+ goto eperm;
if (arg == 0 || arg > MAX_NR_CONSOLES)
- return -ENXIO;
- return vt_waitactive(arg-1);
+ ret = -ENXIO;
+ else
+ ret = vt_waitactive(arg - 1);
+ break;
/*
* If a vt is under process control, the kernel will not switch to it
@@ -805,10 +856,12 @@
*/
case VT_RELDISP:
if (!perm)
- return -EPERM;
- if (vc->vt_mode.mode != VT_PROCESS)
- return -EINVAL;
+ goto eperm;
+ if (vc->vt_mode.mode != VT_PROCESS) {
+ ret = -EINVAL;
+ break;
+ }
/*
* Switching-from response
*/
@@ -829,10 +882,10 @@
int newvt;
newvt = vc->vt_newvt;
vc->vt_newvt = -1;
- i = vc_allocate(newvt);
- if (i) {
+ ret = vc_allocate(newvt);
+ if (ret) {
release_console_sem();
- return i;
+ break;
}
/*
* When we actually do the console switch,
@@ -841,31 +894,27 @@
*/
complete_change_console(vc_cons[newvt].d);
}
- }
-
- /*
- * Switched-to response
- */
- else
- {
+ } else {
+ /*
+ * Switched-to response
+ */
/*
* If it's just an ACK, ignore it
*/
- if (arg != VT_ACKACQ) {
- release_console_sem();
- return -EINVAL;
- }
+ if (arg != VT_ACKACQ)
+ ret = -EINVAL;
}
release_console_sem();
-
- return 0;
+ break;
/*
* Disallocate memory associated to VT (but leave VT1)
*/
case VT_DISALLOCATE:
- if (arg > MAX_NR_CONSOLES)
- return -ENXIO;
+ if (arg > MAX_NR_CONSOLES) {
+ ret = -ENXIO;
+ break;
+ }
if (arg == 0) {
/* deallocate all unused consoles, but leave 0 */
acquire_console_sem();
@@ -877,14 +926,14 @@
/* deallocate a single console, if possible */
arg--;
if (VT_BUSY(arg))
- return -EBUSY;
- if (arg) { /* leave 0 */
+ ret = -EBUSY;
+ else if (arg) { /* leave 0 */
acquire_console_sem();
vc_deallocate(arg);
release_console_sem();
}
}
- return 0;
+ break;
case VT_RESIZE:
{
@@ -893,21 +942,21 @@
ushort ll,cc;
if (!perm)
- return -EPERM;
+ goto eperm;
if (get_user(ll, &vtsizes->v_rows) ||
get_user(cc, &vtsizes->v_cols))
- return -EFAULT;
-
- for (i = 0; i < MAX_NR_CONSOLES; i++) {
- vc = vc_cons[i].d;
-
- if (vc) {
- vc->vc_resize_user = 1;
- vc_lock_resize(vc_cons[i].d, cc, ll);
+ ret = -EFAULT;
+ else {
+ for (i = 0; i < MAX_NR_CONSOLES; i++) {
+ vc = vc_cons[i].d;
+
+ if (vc) {
+ vc->vc_resize_user = 1;
+ vc_lock_resize(vc_cons[i].d, cc, ll);
+ }
}
}
-
- return 0;
+ break;
}
case VT_RESIZEX:
@@ -915,10 +964,13 @@
struct vt_consize __user *vtconsize = up;
ushort ll,cc,vlin,clin,vcol,ccol;
if (!perm)
- return -EPERM;
+ goto eperm;
if (!access_ok(VERIFY_READ, vtconsize,
- sizeof(struct vt_consize)))
- return -EFAULT;
+ sizeof(struct vt_consize))) {
+ ret = -EFAULT;
+ break;
+ }
+ /* FIXME: Should check the copies properly */
__get_user(ll, &vtconsize->v_rows);
__get_user(cc, &vtconsize->v_cols);
__get_user(vlin, &vtconsize->v_vlin);
@@ -928,21 +980,28 @@
vlin = vlin ? vlin : vc->vc_scan_lines;
if (clin) {
if (ll) {
- if (ll != vlin/clin)
- return -EINVAL; /* Parameters don't add up */
+ if (ll != vlin/clin) {
+ /* Parameters don't add up */
+ ret = -EINVAL;
+ break;
+ }
} else
ll = vlin/clin;
}
if (vcol && ccol) {
if (cc) {
- if (cc != vcol/ccol)
- return -EINVAL;
+ if (cc != vcol/ccol) {
+ ret = -EINVAL;
+ break;
+ }
} else
cc = vcol/ccol;
}
- if (clin > 32)
- return -EINVAL;
+ if (clin > 32) {
+ ret = -EINVAL;
+ break;
+ }
for (i = 0; i < MAX_NR_CONSOLES; i++) {
if (!vc_cons[i].d)
@@ -956,19 +1015,20 @@
vc_resize(vc_cons[i].d, cc, ll);
release_console_sem();
}
- return 0;
+ break;
}
case PIO_FONT: {
if (!perm)
- return -EPERM;
+ goto eperm;
op.op = KD_FONT_OP_SET;
op.flags = KD_FONT_FLAG_OLD | KD_FONT_FLAG_DONT_RECALC; /* Compatibility */
op.width = 8;
op.height = 0;
op.charcount = 256;
op.data = up;
- return con_font_op(vc_cons[fg_console].d, &op);
+ ret = con_font_op(vc_cons[fg_console].d, &op);
+ break;
}
case GIO_FONT: {
@@ -978,100 +1038,124 @@
op.height = 32;
op.charcount = 256;
op.data = up;
- return con_font_op(vc_cons[fg_console].d, &op);
+ ret = con_font_op(vc_cons[fg_console].d, &op);
+ break;
}
case PIO_CMAP:
if (!perm)
- return -EPERM;
- return con_set_cmap(up);
+ ret = -EPERM;
+ else
+ ret = con_set_cmap(up);
+ break;
case GIO_CMAP:
- return con_get_cmap(up);
+ ret = con_get_cmap(up);
+ break;
case PIO_FONTX:
case GIO_FONTX:
- return do_fontx_ioctl(cmd, up, perm, &op);
+ ret = do_fontx_ioctl(cmd, up, perm, &op);
+ break;
case PIO_FONTRESET:
{
if (!perm)
- return -EPERM;
+ goto eperm;
#ifdef BROKEN_GRAPHICS_PROGRAMS
/* With BROKEN_GRAPHICS_PROGRAMS defined, the default
font is not saved. */
- return -ENOSYS;
+ ret = -ENOSYS;
+ break;
#else
{
op.op = KD_FONT_OP_SET_DEFAULT;
op.data = NULL;
- i = con_font_op(vc_cons[fg_console].d, &op);
- if (i)
- return i;
+ ret = con_font_op(vc_cons[fg_console].d, &op);
+ if (ret)
+ break;
con_set_default_unimap(vc_cons[fg_console].d);
- return 0;
+ break;
}
#endif
}
case KDFONTOP: {
- if (copy_from_user(&op, up, sizeof(op)))
- return -EFAULT;
+ if (copy_from_user(&op, up, sizeof(op))) {
+ ret = -EFAULT;
+ break;
+ }
if (!perm && op.op != KD_FONT_OP_GET)
- return -EPERM;
- i = con_font_op(vc, &op);
- if (i) return i;
+ goto eperm;
+ ret = con_font_op(vc, &op);
+ if (ret)
+ break;
if (copy_to_user(up, &op, sizeof(op)))
- return -EFAULT;
- return 0;
+ ret = -EFAULT;
+ break;
}
case PIO_SCRNMAP:
if (!perm)
- return -EPERM;
- return con_set_trans_old(up);
+ ret = -EPERM;
+ else
+ ret = con_set_trans_old(up);
+ break;
case GIO_SCRNMAP:
- return con_get_trans_old(up);
+ ret = con_get_trans_old(up);
+ break;
case PIO_UNISCRNMAP:
if (!perm)
- return -EPERM;
- return con_set_trans_new(up);
+ ret = -EPERM;
+ else
+ ret = con_set_trans_new(up);
+ break;
case GIO_UNISCRNMAP:
- return con_get_trans_new(up);
+ ret = con_get_trans_new(up);
+ break;
case PIO_UNIMAPCLR:
{ struct unimapinit ui;
if (!perm)
- return -EPERM;
- i = copy_from_user(&ui, up, sizeof(struct unimapinit));
- if (i) return -EFAULT;
- con_clear_unimap(vc, &ui);
- return 0;
+ goto eperm;
+ ret = copy_from_user(&ui, up, sizeof(struct unimapinit));
+ if (!ret)
+ con_clear_unimap(vc, &ui);
+ break;
}
case PIO_UNIMAP:
case GIO_UNIMAP:
- return do_unimap_ioctl(cmd, up, perm, vc);
+ ret = do_unimap_ioctl(cmd, up, perm, vc);
+ break;
case VT_LOCKSWITCH:
if (!capable(CAP_SYS_TTY_CONFIG))
- return -EPERM;
+ goto eperm;
vt_dont_switch = 1;
- return 0;
+ break;
case VT_UNLOCKSWITCH:
if (!capable(CAP_SYS_TTY_CONFIG))
- return -EPERM;
+ goto eperm;
vt_dont_switch = 0;
- return 0;
+ break;
case VT_GETHIFONTMASK:
- return put_user(vc->vc_hi_font_mask, (unsigned short __user *)arg);
+ ret = put_user(vc->vc_hi_font_mask,
+ (unsigned short __user *)arg);
+ break;
default:
- return -ENOIOCTLCMD;
+ ret = -ENOIOCTLCMD;
}
+out:
+ unlock_kernel();
+ return ret;
+eperm:
+ ret = -EPERM;
+ goto out;
}
/*
--
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