linux下取消页读写保护

Some people modify the page table entry data for read-only pages they
want to modify, but the following functions I have provided are much
simpler, and an example will be provided below.

/* FUNCTION TO DISABLE WRITE PROTECT BIT IN CPU */
static void disable_wp(void)
{
        unsigned int cr0_value;
        
        asm volatile ("movl %%cr0, %0" : "=r" (cr0_value));
        
        /* Disable WP */
        cr0_value &= ~(1 << 16);
        
        asm volatile ("movl %0, %%cr0" :: "r" (cr0_value));

}
        
/* FUNCTION TO RE-ENABLE WRITE PROTECT BIT IN CPU */
static void enable_wp(void)
{
        unsigned int cr0_value;

        asm volatile ("movl %%cr0, %0" : "=r" (cr0_value));

        /* Enable WP */
        cr0_value |= (1 << 16);

        asm volatile ("movl %0, %%cr0" :: "r" (cr0_value));

}
==========================================================================================================================================================
int set_page_rw(long unsigned int _addr)
{
    return set_memory_rw(PAGE_ALIGN(_addr) - PAGE_SIZE, 1);
}

int set_page_ro(long unsigned int _addr)
{
    return set_memory_ro(PAGE_ALIGN(_addr) - PAGE_SIZE, 1);
}