Kprobes support for IA64

[Ananth N Mavinakayanahalli]

On Mon, May 23, 2005 at 12:47:07PM -0700, Lynch, Rusty wrote:
> 
....

> >
> >I worked with Prarit Bhargava (SGI) today to show the usage of
> >kprobes/jprobes on ia64. Everything worked fine, except for a
> consistent:
> >
> >-bash: child setpgid (xxx to xxx): No such process
> >                       ^^^    ^^^ pids of bash
> >message during rmmod of a jprobe module. Not sure why this message
> comes
> >up though. The machine we were testing on was a 16-way Altix box I
> think.
> >
> >Ananth
> 
> I haven't seen this message before.  Do you have a simple testcase that
> exposes this?

I normally use the attached (barebones) jprobe test module (originally by 
Prasanna). We modified just the jp.kp.addr and .entry values for IA64 in 
this file to test.

Thanks,
Ananth
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/*jprobes-sample.c */

#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/kallsyms.h>
#include <linux/module.h>
#include <linux/kprobes.h>
#include <asm/types.h>

/* 
 * Jumper probe for blockdev_direct_IO
 * Mirror principle enables access to arguments of the probed routine 
 * from the probe handler.
 */

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("In handler? \n");
	printk("jprobe: clone_flags=0x%x, stack_start=0x%x, stack_size=0x%x\n", clone_flags, stack_start, stack_size);
	jprobe_return(); 
	return 0;
}

static struct jprobe my_jprobe = {
	{.addr = (kprobe_opcode_t *)0xc011eb20}, 
	.entry = JPROBE_ENTRY(jdo_fork)
	//.entry = (kprobe_opcode_t *)jdo_fork
};

int init_module(void)
{
	int ret;

	/* first time invokation to initialize probe handler */
	printk("plant jprobe at %p, handler addr %p\n", 
		my_jprobe.kp.addr, my_jprobe.entry);
	/* now we are all set to register the probe */
	ret = register_jprobe(&my_jprobe);
	if (ret) {
		printk("Unable to register jprobe\n");
		return ret;
	}
		
	printk("registered jprobe\n");
	return 0;
}

void cleanup_module(void)
{
	unregister_jprobe(&my_jprobe);
	printk("jprobe unregistered\n");
}
MODULE_LICENSE("GPL");