804defea1c
Move kprobes examples from Documentation/kprobes.txt to under samples/. Patch originally by Randy Dunlap. o Updated the patch to apply on 2.6.25-rc3 o Modified examples code to build on multiple architectures. Currently, the kprobe and jprobe examples code works for x86 and powerpc o Cleaned up unneeded #includes o Cleaned up Kconfig per Sam Ravnborg's suggestions to fix build break on archs that don't have kretprobes o Implemented suggestions by Mathieu Desnoyers on CONFIG_KRETPROBES o Included Andrew Morton's cleanup based on x86-git o Modified kretprobe_example to act as a arch-agnostic module to determine routine execution times: Use 'modprobe kretprobe_example func=<func_name>' to determine execution time of func_name in nanoseconds. Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Acked-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
68 lines
1.8 KiB
C
68 lines
1.8 KiB
C
/*
|
|
* Here's a sample kernel module showing the use of jprobes to dump
|
|
* the arguments of do_fork().
|
|
*
|
|
* For more information on theory of operation of jprobes, see
|
|
* Documentation/kprobes.txt
|
|
*
|
|
* Build and insert the kernel module as done in the kprobe example.
|
|
* You will see the trace data in /var/log/messages and on the
|
|
* console whenever do_fork() is invoked to create a new process.
|
|
* (Some messages may be suppressed if syslogd is configured to
|
|
* eliminate duplicate messages.)
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/kprobes.h>
|
|
|
|
/*
|
|
* Jumper probe for do_fork.
|
|
* Mirror principle enables access to arguments of the probed routine
|
|
* from the probe handler.
|
|
*/
|
|
|
|
/* Proxy routine having the same arguments as actual do_fork() routine */
|
|
static long jdo_fork(unsigned long clone_flags, unsigned long stack_start,
|
|
struct pt_regs *regs, unsigned long stack_size,
|
|
int __user *parent_tidptr, int __user *child_tidptr)
|
|
{
|
|
printk(KERN_INFO "jprobe: clone_flags = 0x%lx, stack_size = 0x%lx,"
|
|
" regs = 0x%p\n",
|
|
clone_flags, stack_size, regs);
|
|
|
|
/* Always end with a call to jprobe_return(). */
|
|
jprobe_return();
|
|
return 0;
|
|
}
|
|
|
|
static struct jprobe my_jprobe = {
|
|
.entry = jdo_fork,
|
|
.kp = {
|
|
.symbol_name = "do_fork",
|
|
},
|
|
};
|
|
|
|
static int __init jprobe_init(void)
|
|
{
|
|
int ret;
|
|
|
|
ret = register_jprobe(&my_jprobe);
|
|
if (ret < 0) {
|
|
printk(KERN_INFO "register_jprobe failed, returned %d\n", ret);
|
|
return -1;
|
|
}
|
|
printk(KERN_INFO "Planted jprobe at %p, handler addr %p\n",
|
|
my_jprobe.kp.addr, my_jprobe.entry);
|
|
return 0;
|
|
}
|
|
|
|
static void __exit jprobe_exit(void)
|
|
{
|
|
unregister_jprobe(&my_jprobe);
|
|
printk(KERN_INFO "jprobe at %p unregistered\n", my_jprobe.kp.addr);
|
|
}
|
|
|
|
module_init(jprobe_init)
|
|
module_exit(jprobe_exit)
|
|
MODULE_LICENSE("GPL");
|