fb: push down the BKL in the ioctl handler

Framebuffer is heavily BKL dependant at the moment so just wrap the ioctl
handler in the driver as we push down.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Krzysztof Helt <krzysztof.h1@poczta.fm>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 86 insertions, 55 deletions

diff --git a/drivers/video/fbmem.c b/drivers/video/fbmem.c
index 217c5118ae9e..2a0f013dc37b 100644
--- a/drivers/video/fbmem.c
+++ b/drivers/video/fbmem.c
@@ -1002,101 +1002,132 @@ fb_blank(struct fb_info *info, int blank)
         return ret;
 }
 
-static int 
-fb_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
+static long
+fb_ioctl(struct file *file, unsigned int cmd,
          unsigned long arg)
 {
+        struct inode *inode = file->f_path.dentry->d_inode;
         int fbidx = iminor(inode);
-        struct fb_info *info = registered_fb[fbidx];
-        struct fb_ops *fb = info->fbops;
+        struct fb_info *info;
+        struct fb_ops *fb;
         struct fb_var_screeninfo var;
         struct fb_fix_screeninfo fix;
         struct fb_con2fbmap con2fb;
         struct fb_cmap_user cmap;
         struct fb_event event;
         void __user *argp = (void __user *)arg;
-        int i;
-        
-        if (!fb)
+        long ret = 0;
+
+        lock_kernel();
+        info = registered_fb[fbidx];
+        fb = info->fbops;
+
+        if (!fb) {
+                unlock_kernel();
                 return -ENODEV;
+        }
         switch (cmd) {
         case FBIOGET_VSCREENINFO:
-                return copy_to_user(argp, &info->var,
+                ret = copy_to_user(argp, &info->var,
                                     sizeof(var)) ? -EFAULT : 0;
+                break;
         case FBIOPUT_VSCREENINFO:
-                if (copy_from_user(&var, argp, sizeof(var)))
-                        return -EFAULT;
+                if (copy_from_user(&var, argp, sizeof(var))) {
+                        ret =  -EFAULT;
+                        break;
+                }
                 acquire_console_sem();
                 info->flags |= FBINFO_MISC_USEREVENT;
-                i = fb_set_var(info, &var);
+                ret = fb_set_var(info, &var);
                 info->flags &= ~FBINFO_MISC_USEREVENT;
                 release_console_sem();
-                if (i) return i;
-                if (copy_to_user(argp, &var, sizeof(var)))
-                        return -EFAULT;
-                return 0;
+                if (ret == 0 && copy_to_user(argp, &var, sizeof(var)))
+                        ret = -EFAULT;
+                break;
         case FBIOGET_FSCREENINFO:
-                return copy_to_user(argp, &info->fix,
+                ret = copy_to_user(argp, &info->fix,
                                     sizeof(fix)) ? -EFAULT : 0;
+                break;
         case FBIOPUTCMAP:
                 if (copy_from_user(&cmap, argp, sizeof(cmap)))
-                        return -EFAULT;
-                return (fb_set_user_cmap(&cmap, info));
+                        ret = -EFAULT;
+                else
+                        ret = fb_set_user_cmap(&cmap, info);
+                break;
         case FBIOGETCMAP:
                 if (copy_from_user(&cmap, argp, sizeof(cmap)))
-                        return -EFAULT;
-                return fb_cmap_to_user(&info->cmap, &cmap);
+                        ret = -EFAULT;
+                else
+                        ret = fb_cmap_to_user(&info->cmap, &cmap);
+                break;
         case FBIOPAN_DISPLAY:
-                if (copy_from_user(&var, argp, sizeof(var)))
-                        return -EFAULT;
+                if (copy_from_user(&var, argp, sizeof(var))) {
+                        ret = -EFAULT;
+                        break;
+                }
                 acquire_console_sem();
-                i = fb_pan_display(info, &var);
+                ret = fb_pan_display(info, &var);
                 release_console_sem();
-                if (i)
-                        return i;
-                if (copy_to_user(argp, &var, sizeof(var)))
-                        return -EFAULT;
-                return 0;
+                if (ret == 0 && copy_to_user(argp, &var, sizeof(var)))
+                        ret = -EFAULT;
+                break;
         case FBIO_CURSOR:
-                return -EINVAL;
+                ret = -EINVAL;
+                break;
         case FBIOGET_CON2FBMAP:
                 if (copy_from_user(&con2fb, argp, sizeof(con2fb)))
-                        return -EFAULT;
-                if (con2fb.console < 1 || con2fb.console > MAX_NR_CONSOLES)
-                    return -EINVAL;
-                con2fb.framebuffer = -1;
-                event.info = info;
-                event.data = &con2fb;
-                fb_notifier_call_chain(FB_EVENT_GET_CONSOLE_MAP, &event);
-                return copy_to_user(argp, &con2fb,
+                        ret = -EFAULT;
+                else if (con2fb.console < 1 || con2fb.console > MAX_NR_CONSOLES)
+                        ret = -EINVAL;
+                else {
+                        con2fb.framebuffer = -1;
+                        event.info = info;
+                        event.data = &con2fb;
+                        fb_notifier_call_chain(FB_EVENT_GET_CONSOLE_MAP,
+                                                                &event);
+                        ret = copy_to_user(argp, &con2fb,
                                     sizeof(con2fb)) ? -EFAULT : 0;
+                }
+                break;
         case FBIOPUT_CON2FBMAP:
-                if (copy_from_user(&con2fb, argp, sizeof(con2fb)))
-                        return - EFAULT;
-                if (con2fb.console < 1 || con2fb.console > MAX_NR_CONSOLES)
-                    return -EINVAL;
-                if (con2fb.framebuffer < 0 || con2fb.framebuffer >= FB_MAX)
-                    return -EINVAL;
-                if (!registered_fb[con2fb.framebuffer])
-                    request_module("fb%d", con2fb.framebuffer);
+                if (copy_from_user(&con2fb, argp, sizeof(con2fb))) {
+                        ret = -EFAULT;
+                        break;
+                }
+                if (con2fb.console < 1 || con2fb.console > MAX_NR_CONSOLES) {
+                        ret = -EINVAL;
+                        break;
+                }
+                if (con2fb.framebuffer < 0 || con2fb.framebuffer >= FB_MAX) {
+                        ret = -EINVAL;
+                        break;
+                }
                 if (!registered_fb[con2fb.framebuffer])
-                    return -EINVAL;
+                        request_module("fb%d", con2fb.framebuffer);
+                if (!registered_fb[con2fb.framebuffer]) {
+                        ret = -EINVAL;
+                        break;
+                }
                 event.info = info;
                 event.data = &con2fb;
-                return fb_notifier_call_chain(FB_EVENT_SET_CONSOLE_MAP,
+                ret = fb_notifier_call_chain(FB_EVENT_SET_CONSOLE_MAP,
                                               &event);
+                break;
         case FBIOBLANK:
                 acquire_console_sem();
                 info->flags |= FBINFO_MISC_USEREVENT;
-                i = fb_blank(info, arg);
+                ret = fb_blank(info, arg);
                 info->flags &= ~FBINFO_MISC_USEREVENT;
                 release_console_sem();
-                return i;
+                break;;
         default:
                 if (fb->fb_ioctl == NULL)
-                        return -EINVAL;
-                return fb->fb_ioctl(info, cmd, arg);
+                        ret = -ENOTTY;
+                else
+                        ret = fb->fb_ioctl(info, cmd, arg);
         }
+        unlock_kernel();
+        return ret;
 }
 
 #ifdef CONFIG_COMPAT
@@ -1150,7 +1181,7 @@ static int fb_getput_cmap(struct inode *inode, struct file *file,
             put_user(compat_ptr(data), &cmap->transp))
                 return -EFAULT;
 
-        err = fb_ioctl(inode, file, cmd, (unsigned long) cmap);
+        err = fb_ioctl(file, cmd, (unsigned long) cmap);
 
         if (!err) {
                 if (copy_in_user(&cmap32->start,
@@ -1204,7 +1235,7 @@ static int fb_get_fscreeninfo(struct inode *inode, struct file *file,
 
         old_fs = get_fs();
         set_fs(KERNEL_DS);
-        err = fb_ioctl(inode, file, cmd, (unsigned long) &fix);
+        err = fb_ioctl(file, cmd, (unsigned long) &fix);
         set_fs(old_fs);
 
         if (!err)
@@ -1231,7 +1262,7 @@ fb_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
         case FBIOPUT_CON2FBMAP:
                 arg = (unsigned long) compat_ptr(arg);
         case FBIOBLANK:
-                ret = fb_ioctl(inode, file, cmd, arg);
+                ret = fb_ioctl(file, cmd, arg);
                 break;
 
         case FBIOGET_FSCREENINFO:
@@ -1358,7 +1389,7 @@ static const struct file_operations fb_fops = {
         .owner =        THIS_MODULE,
         .read =         fb_read,
         .write =        fb_write,
-        .ioctl =        fb_ioctl,
+        .unlocked_ioctl = fb_ioctl,
 #ifdef CONFIG_COMPAT
         .compat_ioctl = fb_compat_ioctl,
 #endif