[PATCH] shield fbdev operations with console semaphore

This fixes the fbdev ioctl's and fbcon cursor management with the
console semaphore, which is the best we can do at this point in 2.6,
thus fixing a bunch of races where we could have, for example, tried to
blit while changing mode, etc..

diff --git a/drivers/video/console/fbcon.c b/drivers/video/console/fbcon.c
index 11422933cf1506b7f9307f299791ba122cab4961..50fe17ea95dd21676da845aeb12cdc7742291f9a 100644 (file)
--- a/drivers/video/console/fbcon.c
+++ b/drivers/video/console/fbcon.c
@@ -198,8 +198,10 @@ static void fb_flashcursor(void *private)
        /* Test to see if the cursor is erased but still on */
        if (!info || (info->cursor.rop == ROP_COPY))
                return;
+       acquire_console_sem();
        info->cursor.enable ^= 1;
        info->fbops->fb_cursor(info, &info->cursor);
+       release_console_sem();
 }
 
 #if (defined(__arm__) && defined(IRQ_VSYNCPULSE)) || defined(CONFIG_ATARI) || defined(CONFIG_MAC)
@@ -226,8 +228,7 @@ static void cursor_timer_handler(unsigned long dev_addr)
        struct fb_info *info = (struct fb_info *) dev_addr;
        
        schedule_work(&info->queue);    
-       cursor_timer.expires = jiffies + HZ / 5;
-       add_timer(&cursor_timer);
+       mod_timer(&cursor_timer, jiffies + HZ/5);
 }
 
 int __init fb_console_setup(char *this_opt)
@@ -676,7 +677,7 @@ static const char *fbcon_startup(void)
        if (!info->queue.func) {
                INIT_WORK(&info->queue, fb_flashcursor, info);
                
-               cursor_timer.expires = jiffies + HZ / 50;
+               cursor_timer.expires = jiffies + HZ / 5;
                cursor_timer.data = (unsigned long ) info;
                add_timer(&cursor_timer);
        }

diff --git a/drivers/video/fbmem.c b/drivers/video/fbmem.c
index bff474679be9d14a63fe5d913d16ff606fa90a78..4dea35376d2c20f08131730142f285ff0d4bce01 100644 (file)
--- a/drivers/video/fbmem.c
+++ b/drivers/video/fbmem.c
@@ -27,6 +27,7 @@
 #include <linux/init.h>
 #include <linux/linux_logo.h>
 #include <linux/proc_fs.h>
+#include <linux/console.h>
 #ifdef CONFIG_KMOD
 #include <linux/kmod.h>
 #endif
@@ -979,7 +980,7 @@ fb_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
        struct fb_con2fbmap con2fb;
 #endif
        struct fb_cmap cmap;
-       int i;
+       int i, rc;
        
        if (!fb)
                return -ENODEV;
@@ -990,7 +991,9 @@ fb_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
        case FBIOPUT_VSCREENINFO:
                if (copy_from_user(&var, (void *) arg, sizeof(var)))
                        return -EFAULT;
+               acquire_console_sem();
                i = fb_set_var(info, &var);
+               release_console_sem();
                if (i) return i;
                if (copy_to_user((void *) arg, &var, sizeof(var)))
                        return -EFAULT;
@@ -1009,13 +1012,19 @@ fb_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
        case FBIOPAN_DISPLAY:
                if (copy_from_user(&var, (void *) arg, sizeof(var)))
                        return -EFAULT;
-               if ((i = fb_pan_display(info, &var)))
+               acquire_console_sem();
+               i = fb_pan_display(info, &var);
+               release_console_sem();
+               if (i)
                        return i;
                if (copy_to_user((void *) arg, &var, sizeof(var)))
                        return -EFAULT;
                return 0;
        case FBIO_CURSOR:
-               return (fb_cursor(info, (struct fb_cursor *) arg));
+               acquire_console_sem();
+               rc = fb_cursor(info, (struct fb_cursor *) arg);
+               release_console_sem();
+               return rc;
 #ifdef CONFIG_FRAMEBUFFER_CONSOLE
        case FBIOGET_CON2FBMAP:
                if (copy_from_user(&con2fb, (void *)arg, sizeof(con2fb)))
@@ -1045,7 +1054,10 @@ fb_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
                return 0;
 #endif /* CONFIG_FRAMEBUFFER_CONSOLE */
        case FBIOBLANK:
-               return fb_blank(info, arg);
+               acquire_console_sem();
+               i = fb_blank(info, arg);
+               release_console_sem();
+               return i;
        default:
                if (fb->fb_ioctl == NULL)
                        return -EINVAL;