mirror of
https://github.com/gatieme/LDD-LinuxDeviceDrivers.git
synced 2026-08-19 19:14:17 +08:00
116 lines
3.0 KiB
C
116 lines
3.0 KiB
C
#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/kprobes.h>
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int handler_pre(struct kprobe *p, struct pt_regs *regs)
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{
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printk("current task on CPU#%d: %s (before), preempt_count = %d\n",
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smp_processor_id( ), current->comm, preempt_count( ));
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return 0;
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}
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void handler_post(struct kprobe *p, struct pt_regs *regs, unsigned long flags)
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{
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printk("current task on CPU#%d: %s (after), preempt_count = %d\n",
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smp_processor_id( ), current->comm, preempt_count( ));
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}
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int handler_fault(struct kprobe *p, struct pt_regs *regs, int trapnr)
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{
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printk("A fault happened during probing.\n");
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return 0;
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}
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/*
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* Jumper probe for do_fork.
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* Mirror principle enables access to arguments of the probed routine
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* from the probe handler.
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*/
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/* Proxy routine having the same arguments as actual do_fork() routine */
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static long jdo_fork(unsigned long clone_flags, unsigned long stack_start,
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struct pt_regs *regs, unsigned long stack_size,
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int __user *parent_tidptr, int __user *child_tidptr)
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{
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printk(KERN_INFO "jprobe: clone_flags = 0x%lx, "
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"stack_size = 0x%lx, "
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"regs = 0x%p\n",
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clone_flags, stack_size, regs);
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/* Always end with a call to jprobe_return(). */
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jprobe_return( );
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return 0;
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}
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asmlinkage __visible void __sched jschedule(void)
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{
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/* Always end with a call to jprobe_return(). */
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jprobe_return( );
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//return 0;
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}
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static struct jprobe my_jprobe = {
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.entry = jdo_fork,
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/* 注意 symbol_name与addr不能同时存在
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* 参见kprobe_addr函数--http://lxr.free-electrons.com/source/kernel/kprobes.c#L1359
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* 否则会提示参数错误ERR_PTR(-EINVAL);
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* 内核中errno的值在http://lxr.free-electrons.com/source/include/uapi/asm-generic/errno-base.h#L25
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* */
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.kp = {
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.symbol_name = "_do_fork",
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//.addr
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.pre_handler = handler_pre,
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.post_handler = handler_post,
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.fault_handler = handler_fault,
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},
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};
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static int __init jprobe_init(void)
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{
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int ret;
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//my_jprobe.kp.symbol_name = "_do_fork";
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//my_jprobe.kp.addr = kallsyms_lookup_name("_do_fork");
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#if 0
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my_jprobe.kp.pre_handler = handler_pre;
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my_jprobe.kp.post_handler = handler_post;
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my_jprobe.kp.fault_handler = handler_fault;
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#endif
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if(my_jprobe.kp.symbol_name == NULL)
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{
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my_jprobe.kp.addr = (kprobe_opcode_t *)kallsyms_lookup_name("_do_fork");
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printk("find _do_fork address at 0x%p\n", my_jprobe.kp.addr);
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}
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ret = register_jprobe(&my_jprobe);
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if (ret < 0) {
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printk(KERN_INFO "register_jprobe failed, returned %d\n", ret);
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return -1;
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}
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printk(KERN_INFO "Planted jprobe at %p, handler addr %p\n",
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my_jprobe.kp.addr, my_jprobe.entry);
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return 0;
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}
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static void __exit jprobe_exit(void)
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{
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unregister_jprobe(&my_jprobe);
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printk(KERN_INFO "jprobe at %p unregistered\n", my_jprobe.kp.addr);
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}
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module_init(jprobe_init)
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module_exit(jprobe_exit)
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MODULE_LICENSE("GPL");
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