進程地址空間地址轉換為物理地址

kernel代碼

/* * To test kernel's scheduler * Date:2011/8/8 13:04 * ### wait queue ### */#include <linux/init.h>#include <linux/list.h>#include <linux/module.h>#include <linux/kmod.h>#include <linux/kernel.h>#include <linux/slab.h>#include <linux/interrupt.h>#include <linux/delay.h>#include <linux/kthread.h>#include <linux/sched.h>#include <linux/wait.h>#include <linux/kallsyms.h>#include <linux/uaccess.h>#include <linux/miscdevice.h>#include <linux/fs.h>#include <mach/hardware.h>#include <asm/io.h>#include <asm/irq.h>#include <asm/page.h>#include <asm/mman.h>#include <asm/pgtable.h>#include <asm/uaccess.h>#include <asm/cacheflush.h>#include <mach/bitfield.h>//#define SYNC_DEBUG/*<1> no define SYNC_DEBUG[ 2160.339202] [bloop, 68]i = 0[ 2160.445648] [bloop, 68]i = 0[ 2160.554992] [bloop, 68]i = 0[ 2160.664337] [bloop, 68]i = 0[ 2160.773712] [bloop, 68]i = 0[ 2160.883087] [bloop, 68]i = 0[ 2160.992462] [bloop, 68]i = 0[ 2161.100952] [bloop, 68]i = 0[ 2161.210357] [bloop, 68]i = 0[ 2161.319702] [bloop, 68]i = 0[ 2161.429962] [bloop, 68]i = 1[ 2161.539337] [bloop, 68]i = 1[ 2161.648773] [bloop, 68]i = 1<2> define SYNC_DEBUG[ 2160.339202] [bloop, 68]i = 0[ 2161.648773] [bloop, 68]i = 1[ 2161.648773] [bloop, 68]i = 2*//*### Get data from user space(not copy_from_user api) #### insmod /data/thread_test.ko[ 7366.976959] [thread_init, 201]# # # # # /data/vm_test[ 7385.550354] VM test open[ 7385.553436] VM_TEST_GET_VADDR:  0x0007eb78vaddress: 0x0007eb78 str: yugui.hu@gmail.com[ 7385.557708] str:yugui.hu@gmail.com[ 7385.565307] paddr: 0xc5f62b78[ 7385.568267] [ 7385.568267] =======Data========[ 7385.572998] yugui.hu@gmail.com[ 7385.576049] =======Data=======qByte!! */struct task_struct *kthreadA;struct task_struct *kthreadB;static int i = 0;#ifdef SYNC_DEBUGstatic wait_queue_head_t wait;#endif// IOCTL#define VM_TEST_GET_VADDR 0#define KSYM_NAME_LEN 128#define KSYM_SYMBOL_LEN (sizeof("%s+%#lx/%#lx [%s]") + (KSYM_NAME_LEN - 1) + \ 2*(BITS_PER_LONG*3/10) + (MODULE_NAME_LEN - 1) + 1)/*#define SCHED_NORMAL0#define SCHED_FIFO1#define SCHED_RR2#define SCHED_BATCH3#define SCHED_IDLE5*/static int aloop(void *x){struct sched_param param = { .sched_priority = 0 };sched_setscheduler(current, SCHED_NORMAL, ¶m);while (!kthread_should_stop()) {msleep(1000);i++;#ifdef SYNC_DEBUGwake_up_interruptible(&wait);#endif}return 0;}static int bloop(void *x){struct sched_param param = { .sched_priority = 2 };sched_setscheduler(current, SCHED_FIFO, ¶m);while (!kthread_should_stop()) {#ifdef SYNC_DEBUGinterruptible_sleep_on(&wait);#endifprintk("[%s, %d]i = %d\n", __func__, __LINE__, i);msleep(100);}return 0;}static unsigned long uva_to_pa(struct mm_struct *mm, unsigned long addr){unsigned long ret = 0UL;pgd_t *pgd;pud_t *pud;pmd_t *pmd;pte_t *pte;pgd = pgd_offset(mm, addr);if (!pgd_none(*pgd)) {pud = pud_offset(pgd, addr);if (!pud_none(*pud)) {pmd = pmd_offset(pud, addr);if (!pmd_none(*pmd)) {pte = pte_offset_map(pmd, addr);if (!pte_none(*pte) && pte_present(*pte)) {/* Use hard PTE */pte = (pte_t *)((u32)pte - 2048);if(pte)ret = (*pte & 0xfffff000) | (addr & 0xfff);}}}}return ret;}static intvm_test_open( struct inode * inode, struct file * file ){printk("VM test open\n");return 0;}static intvm_test_ioctl( struct inode * inode, struct file * file,unsigned int cmd, unsigned long arg ){void __user *argp = (void __user *)arg;unsigned long vaddr;unsigned long paddr;unsigned char str[20] = {0};switch (cmd){case VM_TEST_GET_VADDR:printk("VM_TEST_GET_VADDR:  0x%08x\n", (unsigned long)argp);/* output data from user space */ copy_from_user(str, argp, 18);   /* ！！！刪除這個函數後，uva_to_pa不能得到物理地址，還在研究中（缺頁異常） */printk("str:%s\n", str);/* Get physical address */struct mm_struct *mm = current->mm;paddr = uva_to_pa(mm, vaddr);if (paddr == 0)printk("Can't find physical address!\n");elseprintk("paddr: 0x%08x\n", paddr);printk("\n=======Data========\n");unsigned long vpp = ioremap_nocache(paddr, 18);int i = 0;for (i = 0; i < 18; i++) {printk("%c", *(volatile unsigned char *)(vpp + i));}printk("\n=======Data=======\n");return 0;default:return -EINVAL;}}static struct file_operations vm_test_fops = {.owner    = THIS_MODULE,.open  = vm_test_open,.ioctl  = vm_test_ioctl,};static struct miscdevice vm_test_misc_device = {.minor    = MISC_DYNAMIC_MINOR,.name     = "VM-TEST",.fops     = &vm_test_fops,};static int thread_init(void){int err = 0;printk("[%s, %d]\n", __func__, __LINE__);#ifdef SYNC_DEBUGinit_waitqueue_head(&wait);#endif//kthreadA = kthread_run(aloop, NULL, "thread-A");//kthreadB = kthread_run(bloop, NULL, "thread-B");err = misc_register(&vm_test_misc_device);if (err != 0)printk("misc register device failed!\n");return 0;}static void thread_exit(void){#ifdef SYNC_DEBUGwait_queue_t *curr, *next;char str[KSYM_SYMBOL_LEN] = {0};#endifmisc_deregister(&vm_test_misc_device);printk("[%s, %d]\n", __func__, __LINE__);//kthread_stop(kthreadA);mdelay(200);#ifdef SYNC_DEBUGlist_for_each_entry_safe(curr, next, &(wait.task_list), task_list) {memset(str, 0 , KSYM_SYMBOL_LEN);kallsyms_lookup((unsigned long)curr->private, NULL, NULL, NULL, str);printk("waiting thread name: %s\n", str);}wake_up_interruptible(&wait);#endif//kthread_stop(kthreadB);}module_init(thread_init);module_exit(thread_exit);MODULE_LICENSE("GPL");

Makefile

# Makefile exampleARCH ?= armCROSS_COMPILE ?= arm-none-linux-gnueabi-KERNELDIR ?= /KERNEL_OUTifneq ($(KERNELRELEASE),)obj-m := thread_test.o# Otherwise we were called directly from the command line; invoke the kernel build system.elsedefault:$(MAKE) -C $(KERNELDIR) M=$(PWD) ARCH=$(ARCH) CROSS_COMPILE=$(CROSS_COMPILE) modulesendif

user space代碼

/* * file  : vm_test.c *  * How to use it: * ./vm_test */#include <stdio.h>#include <stdlib.h>#include <string.h>#include <unistd.h>#include <sys/fcntl.h>#include <sys/ioctl.h>#include <sys/mman.h>#include <sys/time.h>#include <string.h>#define DEVICE "/dev/VM-TEST"#define VM_TEST_GET_VADDR 0char str[20]= "yugui.hu@gmail.com";int main(int argc, char *argv[]){int fd = 0;char chr = 0;fd = open(DEVICE, O_RDWR);if (fd < 0) {printf("Can't open the %s\n", DEVICE);return -1;}printf("vaddress: 0x%08x str: %s\n", (unsigned long)str, str);ioctl(fd, VM_TEST_GET_VADDR, str);while (1) {chr = getchar();if (chr == 'q') {printf("Byte!!\n");return 0;}}return 0;}