PAX补丁导致nvidia显卡驱动编译不了的解决办法

用的gentoo-hardened的内核，结果安装nvidia的显卡驱动，编译内核的时候报错，错误如下：

/tmp/selfgz22986/NVIDIA-Linux-x86-280.13/kernel/nv-procfs.c: In function 'nv_register_procfs':
/tmp/selfgz22986/NVIDIA-Linux-x86-280.13/kernel/nv-procfs.c:710:5: error: assignment of read-only variable 'nv_procfs_registry_fops'
/tmp/selfgz22986/NVIDIA-Linux-x86-280.13/kernel/nv-procfs.c:711:5: error: assignment of read-only variable 'nv_procfs_registry_fops'

但察看代码，nv_procfs_registry_fops就是一个很普通的静态外部变量啊！在nv_register_procfs里面修改了下read和write的值

static struct file_operations nv_procfs_registry_fops = {
    .open    = nv_procfs_open_registry,
    .release = nv_procfs_close_registry,
};

int nv_register_procfs(void)
{

    ...................

    /*
     * entry->proc_fops originally points to a constant
     * structure, so to add more methods for the
     * binary registry write path, we need to replace the
     * said entry->proc_fops with a new fops structure.
     * However, in preparation for this, we need to preserve
     * the procfs read() and write() operations.
     */

    nv_procfs_registry_fops.read = entry->proc_fops->read;
    nv_procfs_registry_fops.write = entry->proc_fops->write;

    ..................

}

开始觉得很奇怪，这也不行的话，那C语言不就用不了了啊！

后来在网上搜到这个

http://forums.grsecurity.net/viewtopic.php?t=2716&p=11009

是PAX的错，里面给了一个补丁，主要就是在改写 nv_procfs_registry_fops的前后加了pax_open_kernel和pax_close_kernel。

补丁主要内容如下：

- nv_procfs_registry_fops.read = entry->proc_fops->read;

- nv_procfs_registry_fops.write = entry->proc_fops->write;

+ pax_open_kernel();

+ *(void **)&nv_procfs_registry_fops.read = entry->proc_fops->read;

+ *(void **)&nv_procfs_registry_fops.write = entry->proc_fops->write;

+ pax_close_kernel();