mirror of
https://github.com/cirosantilli/linux-kernel-module-cheat.git
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2b0a5724a7
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67 lines
1.6 KiB
C
67 lines
1.6 KiB
C
/* https://cirosantilli.com/linux-kernel-module-cheat#virt-to-phys */
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#include <asm/io.h> /* virt_to_phys */
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#include <linux/debugfs.h>
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#include <linux/delay.h> /* usleep_range */
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#include <linux/kernel.h>
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#include <linux/kthread.h>
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#include <linux/module.h>
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#include <linux/seq_file.h> /* single_open, single_release */
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#include <linux/slab.h> /* kmalloc, kfree */
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static volatile u32 *kmalloc_ptr;
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static volatile u32 static_var;
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static struct dentry *debugfs_file;
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static int show(struct seq_file *m, void *v)
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{
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seq_printf(m,
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"*kmalloc_ptr = 0x%llx\n"
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"kmalloc_ptr = %px\n"
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"virt_to_phys(kmalloc_ptr) = 0x%llx\n"
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"static_var = 0x%llx\n"
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"&static_var = %px\n"
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"virt_to_phys(&static_var) = 0x%llx\n",
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(unsigned long long)*kmalloc_ptr,
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kmalloc_ptr,
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(unsigned long long)virt_to_phys((void *)kmalloc_ptr),
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(unsigned long long)static_var,
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&static_var,
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(unsigned long long)virt_to_phys((void *)&static_var)
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);
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return 0;
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}
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static int open(struct inode *inode, struct file *file)
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{
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return single_open(file, show, NULL);
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}
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static const struct file_operations fops = {
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.llseek = seq_lseek,
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.open = open,
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.owner = THIS_MODULE,
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.read = seq_read,
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.release = single_release,
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};
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static int myinit(void)
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{
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kmalloc_ptr = kmalloc(sizeof(kmalloc_ptr), GFP_KERNEL);
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*kmalloc_ptr = 0x12345678;
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static_var = 0x12345678;
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debugfs_file = debugfs_create_file("lkmc_virt_to_phys", S_IRUSR, NULL, NULL, &fops);
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return 0;
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}
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static void myexit(void)
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{
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debugfs_remove(debugfs_file);
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kfree((void *)kmalloc_ptr);
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}
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module_init(myinit)
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module_exit(myexit)
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MODULE_LICENSE("GPL");
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