mirror of
https://github.com/gatieme/LDD-LinuxDeviceDrivers.git
synced 2026-08-25 00:59:39 +08:00
140 lines
4.0 KiB
C
140 lines
4.0 KiB
C
/*****************************************************************
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文件名：mem.c
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输入参数：
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pid 接收待查询进程的PID
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va 接收待查询的虚拟地址
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*****************************************************************/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/sched.h>
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#include <linux/mm.h>
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#include <asm/pgtable.h>
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#include <asm/page.h>
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MODULE_LICENSE("GPL");
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static int pid;
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static unsigned long va;
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module_param(pid,int,0644);
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module_param(va,ulong,0644);
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/*
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* find_task_by_pid maybe not supported
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* O(n) is fine :)
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*/
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struct task_struct * findTaskByPid(pid_t pid)
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{
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struct task_struct *task = NULL;
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// Traversing the process in the system to find the PID
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// add by gatieme @2016-03-20
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for_each_process(task)
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{
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if(task->pid == pid)
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{
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printk("find task by pid = %d\n", pid);
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return task;
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}
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}
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return NULL;
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}
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static int find_pgd_init(void)
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{
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unsigned long pa = 0;
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struct task_struct *pcb_tmp = NULL;
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pgd_t *pgd_tmp = NULL;
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pud_t *pud_tmp = NULL;
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pmd_t *pmd_tmp = NULL;
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pte_t *pte_tmp = NULL;
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printk(KERN_INFO"PAGE_OFFSET = 0x%lx\n",PAGE_OFFSET);
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printk(KERN_INFO"PGDIR_SHIFT = %d\n",PGDIR_SHIFT);
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printk(KERN_INFO"PUD_SHIFT = %d\n",PUD_SHIFT);
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printk(KERN_INFO"PMD_SHIFT = %d\n",PMD_SHIFT);
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printk(KERN_INFO"PAGE_SHIFT = %d\n",PAGE_SHIFT);
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printk(KERN_INFO"PTRS_PER_PGD = %d\n",PTRS_PER_PGD);
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printk(KERN_INFO"PTRS_PER_PUD = %d\n",PTRS_PER_PUD);
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printk(KERN_INFO"PTRS_PER_PMD = %d\n",PTRS_PER_PMD);
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printk(KERN_INFO"PTRS_PER_PTE = %d\n",PTRS_PER_PTE);
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printk(KERN_INFO"PAGE_MASK = 0x%lx\n",PAGE_MASK);
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//if(!(pcb_tmp = find_task_by_pid(pid)))
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if(!(pcb_tmp = findTaskByPid(pid)))
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{
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printk(KERN_INFO"Can't find the task %d .\n",pid);
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return 0;
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}
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printk(KERN_INFO"pgd = 0x%p\n",pcb_tmp->mm->pgd);
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/* 判断给出的地址va是否合法(va<vm_end)*/
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if(!find_vma(pcb_tmp->mm,va))
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{
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printk(KERN_INFO"virt_addr 0x%lx not available.\n",va);
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return 0;
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}
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pgd_tmp = pgd_offset(pcb_tmp->mm,va);
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printk(KERN_INFO"pgd_tmp = 0x%p\n",pgd_tmp);
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printk(KERN_INFO"pgd_val(*pgd_tmp) = 0x%lx\n",pgd_val(*pgd_tmp));
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if(pgd_none(*pgd_tmp))
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{
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printk(KERN_INFO"Not mapped in pgd.\n");
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return 0;
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}
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pud_tmp = pud_offset(pgd_tmp,va);
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printk(KERN_INFO"pud_tmp = 0x%p\n",pud_tmp);
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printk(KERN_INFO"pud_val(*pud_tmp) = 0x%lx\n",pud_val(*pud_tmp));
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if(pud_none(*pud_tmp))
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{
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printk(KERN_INFO"Not mapped in pud.\n");
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return 0;
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}
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pmd_tmp = pmd_offset(pud_tmp,va);
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printk(KERN_INFO"pmd_tmp = 0x%p\n",pmd_tmp);
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printk(KERN_INFO"pmd_val(*pmd_tmp) = 0x%lx\n",pmd_val(*pmd_tmp));
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if(pmd_none(*pmd_tmp))
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{
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printk(KERN_INFO"Not mapped in pmd.\n");
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return 0;
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}
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/*在这里，把原来的pte_offset_map()改成了pte_offset_kernel*/
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pte_tmp = pte_offset_kernel(pmd_tmp,va);
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printk(KERN_INFO"pte_tmp = 0x%p\n",pte_tmp);
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printk(KERN_INFO"pte_val(*pte_tmp) = 0x%lx\n",pte_val(*pte_tmp));
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if(pte_none(*pte_tmp))
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{
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printk(KERN_INFO"Not mapped in pte.\n");
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return 0;
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}
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if(!pte_present(*pte_tmp)){
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printk(KERN_INFO"pte not in RAM.\n");
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return 0;
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}
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pa = (pte_val(*pte_tmp) & PAGE_MASK) | (va & ~PAGE_MASK);
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printk(KERN_INFO"virt_addr 0x%lx in RAM is 0x%lx t .\n",va,pa);
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printk(KERN_INFO"contect in 0x%lx is 0x%lx\n", pa, *(unsigned long *)((char *)pa + PAGE_OFFSET));
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return 0;
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}
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static void find_pgd_exit(void)
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{
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printk(KERN_INFO"Goodbye!\n");
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}
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module_init(find_pgd_init);
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module_exit(find_pgd_exit);
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