MemoryAddress/wuli.c at master · sixfish/MemoryAddress · GitHub

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#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <asm/pgtable.h>
#include <asm/page.h>


MODULE_LICENSE("GPL");
static int pid;
static unsigned long va;


module_param(pid,int,0644);
module_param(va,ulong,0644);


static int find_pgd_init(void)
{
unsigned long pa = 0;
struct task_struct *pcb_tmp = NULL;
pgd_t *pgd_tmp = NULL;
pud_t *pud_tmp = NULL;
pmd_t *pmd_tmp = NULL;
pte_t *pte_tmp = NULL;


printk(KERN_INFO"PAGE_OFFSET = 0x%lx\n",PAGE_OFFSET);
printk(KERN_INFO"PGDIR_SHIFT = %d\n",PGDIR_SHIFT);
printk(KERN_INFO"PUD_SHIFT = %d\n",PUD_SHIFT);
printk(KERN_INFO"PMD_SHIFT = %d\n",PMD_SHIFT);
printk(KERN_INFO"PAGE_SHIFT = %d\n",PAGE_SHIFT);


printk(KERN_INFO"PTRS_PER_PGD = %d\n",PTRS_PER_PGD);
printk(KERN_INFO"PTRS_PER_PUD = %d\n",PTRS_PER_PUD);
printk(KERN_INFO"PTRS_PER_PMD = %d\n",PTRS_PER_PMD);
printk(KERN_INFO"PTRS_PER_PTE = %d\n",PTRS_PER_PTE);


printk(KERN_INFO"PAGE_MASK = 0x%lx\n",PAGE_MASK);


if(!(pcb_tmp = find_task_by_vpid(pid))) {
printk(KERN_INFO"Can't find the task %d .\n",pid);
return 0;
}
printk(KERN_INFO"pgd = 0x%p\n",pcb_tmp->mm->pgd);
/* 判断给出的地址va是否合法(va<vm_end)*/
if(!find_vma(pcb_tmp->mm,va)){
printk(KERN_INFO"virt_addr 0x%lx not available.\n",va);
return 0;
}
pgd_tmp = pgd_offset(pcb_tmp->mm,va);
printk(KERN_INFO"pgd_tmp = 0x%p\n",pgd_tmp);
printk(KERN_INFO"pgd_val(*pgd_tmp) = 0x%lx\n",pgd_val(*pgd_tmp));
if(pgd_none(*pgd_tmp)){
printk(KERN_INFO"Not mapped in pgd.\n");
return 0;
}
pud_tmp = pud_offset(pgd_tmp,va);
printk(KERN_INFO"pud_tmp = 0x%p\n",pud_tmp);
printk(KERN_INFO"pud_val(*pud_tmp) = 0x%lx\n",pud_val(*pud_tmp));
if(pud_none(*pud_tmp)){
printk(KERN_INFO"Not mapped in pud.\n");
return 0;
}
pmd_tmp = pmd_offset(pud_tmp,va);
printk(KERN_INFO"pmd_tmp = 0x%p\n",pmd_tmp);
printk(KERN_INFO"pmd_val(*pmd_tmp) = 0x%lx\n",pmd_val(*pmd_tmp));
if(pmd_none(*pmd_tmp)){
printk(KERN_INFO"Not mapped in pmd.\n");
return 0;
}
/*在这里，把原来的pte_offset_map()改成了pte_offset_kernel*/
pte_tmp = pte_offset_kernel(pmd_tmp,va);


printk(KERN_INFO"pte_tmp = 0x%p\n",pte_tmp);
printk(KERN_INFO"pte_val(*pte_tmp) = 0x%lx\n",pte_val(*pte_tmp));
if(pte_none(*pte_tmp)){
printk(KERN_INFO"Not mapped in pte.\n");
return 0;
}
if(!pte_present(*pte_tmp)){
printk(KERN_INFO"pte not in RAM.\n");
return 0;
}
pa = (pte_val(*pte_tmp) & PAGE_MASK) |(va & ~PAGE_MASK);
printk(KERN_INFO"virt_addr 0x%lx in RAM is 0x%lx .\n",va,pa);
printk(KERN_INFO"contect in 0x%lx is 0x%lx\n",pa,
*(unsigned long *)((char *)pa + PAGE_OFFSET));

return 0;


}


static void find_pgd_exit(void)
{
printk(KERN_INFO"Goodbye!\n");


}


module_init(find_pgd_init);
module_exit(find_pgd_exit);