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fb: convert lock/unlock_kernel() into local fb mutex 

Change lock_kernel()/unlock_kernel() to local fb mutex.  Each frame buffer
instance has its own mutex.

The one line try_to_load() function is unrolled to request_module() in two
places for readability.

[righi.andrea@gmail.com: fb: fix NULL pointer BUG dereference in fb_open()]
Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: Andrea Righi <righi.andrea@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Krzysztof Helt 2008-10-18 20:27:51 -07:00 committed by Linus Torvalds
parent e53677113e
commit 3e680aae4e
2 changed files with 21 additions and 19 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

39
drivers/video/fbmem.c
View File

@ -1018,12 +1018,12 @@ fb_ioctl(struct file *file, unsigned int cmd,
void __user *argp = (void __user *)arg;
long ret = 0;
lock_kernel();
info = registered_fb[fbidx];
mutex_lock(&info->lock);
fb = info->fbops;
if (!fb) {
unlock_kernel();
mutex_unlock(&info->lock);
return -ENODEV;
}
switch (cmd) {
@ -1126,7 +1126,7 @@ fb_ioctl(struct file *file, unsigned int cmd,
else
ret = fb->fb_ioctl(info, cmd, arg);
}
unlock_kernel();
mutex_unlock(&info->lock);
return ret;
}
@ -1253,7 +1253,7 @@ fb_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
struct fb_ops *fb = info->fbops;
long ret = -ENOIOCTLCMD;
lock_kernel();
mutex_lock(&info->lock);
switch(cmd) {
case FBIOGET_VSCREENINFO:
case FBIOPUT_VSCREENINFO:
@ -1279,7 +1279,7 @@ fb_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
ret = fb->fb_compat_ioctl(info, cmd, arg);
break;
}
unlock_kernel();
mutex_unlock(&info->lock);
return ret;
}
#endif
@ -1301,13 +1301,13 @@ fb_mmap(struct file *file, struct vm_area_struct * vma)
return -ENODEV;
if (fb->fb_mmap) {
int res;
lock_kernel();
mutex_lock(&info->lock);
res = fb->fb_mmap(info, vma);
unlock_kernel();
mutex_unlock(&info->lock);
return res;
}
lock_kernel();
mutex_lock(&info->lock);
/* frame buffer memory */
start = info->fix.smem_start;
@ -1316,13 +1316,13 @@ fb_mmap(struct file *file, struct vm_area_struct * vma)
/* memory mapped io */
off -= len;
if (info->var.accel_flags) {
unlock_kernel();
mutex_unlock(&info->lock);
return -EINVAL;
}
start = info->fix.mmio_start;
len = PAGE_ALIGN((start & ~PAGE_MASK) + info->fix.mmio_len);
}
unlock_kernel();
mutex_unlock(&info->lock);
start &= PAGE_MASK;
if ((vma->vm_end - vma->vm_start + off) > len)
return -EINVAL;
@ -1346,13 +1346,13 @@ fb_open(struct inode *inode, struct file *file)
if (fbidx >= FB_MAX)
return -ENODEV;
lock_kernel();
if (!(info = registered_fb[fbidx]))
info = registered_fb[fbidx];
if (!info)
request_module("fb%d", fbidx);
if (!(info = registered_fb[fbidx])) {
res = -ENODEV;
goto out;
}
info = registered_fb[fbidx];
if (!info)
return -ENODEV;
mutex_lock(&info->lock);
if (!try_module_get(info->fbops->owner)) {
res = -ENODEV;
goto out;
@ -1368,7 +1368,7 @@ fb_open(struct inode *inode, struct file *file)
fb_deferred_io_open(info, inode, file);
#endif
out:
unlock_kernel();
mutex_unlock(&info->lock);
return res;
}
@ -1377,11 +1377,11 @@ fb_release(struct inode *inode, struct file *file)
{
struct fb_info * const info = file->private_data;
lock_kernel();
mutex_lock(&info->lock);
if (info->fbops->fb_release)
info->fbops->fb_release(info,1);
module_put(info->fbops->owner);
unlock_kernel();
mutex_unlock(&info->lock);
return 0;
}
@ -1460,6 +1460,7 @@ register_framebuffer(struct fb_info *fb_info)
if (!registered_fb[i])
break;
fb_info->node = i;
mutex_init(&fb_info->lock);
fb_info->dev = device_create(fb_class, fb_info->device,
MKDEV(FB_MAJOR, i), NULL, "fb%d", i);

1
include/linux/fb.h
View File

@ -808,6 +808,7 @@ struct fb_tile_ops {
struct fb_info {
int node;
int flags;
struct mutex lock; /* Lock for open/release/ioctl funcs */
struct fb_var_screeninfo var; /* Current var */
struct fb_fix_screeninfo fix; /* Current fix */
struct fb_monspecs monspecs; /* Current Monitor specs */