Files
LDD-LinuxDeviceDrivers/study/engine/mem/mem.c
T

126 lines
3.9 KiB
C

/*****************************************************************
文件名:mem.c
输入参数:
pid 接收待查询进程的PID
va 接收待查询的虚拟地址
*****************************************************************/
#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))) linux-3.0
if(!(pcb_tmp = find_task_by_pid(pid))) // linux-2.6
{
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&lt;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);