ptrace.c

ucLinux is a very good embeded sytem. Most of company use this as their development OS.

#include <errno.h>
#include <asm/ptrace.h>
#include <asm/unistd.h>

int
ptrace(int request, int pid, int addr, int data)
{
	int ret;
	int res;

	if (request > 0 && request < 4) data = (int)&ret;

	__asm__ volatile ("sub.l er0,er0\n\t"
                          "mov.b %1,r0l\n\t"
			  "mov.l %2,er1\n\t"
			  "mov.l %3,er2\n\t"
			  "mov.l %4,er3\n\t"
			  "mov.l %5,er4\n\t"
			  "trapa  #0\n\t"
			  "mov.l er0,%0"
		:"=g" (res)
		:"i" (__NR_ptrace), "g" (request), "g" (pid),
		 "g" (addr), "g" (data)
		: "er0", "er1", "er2", "er3", "er4");

	if (res >= 0) {
		if (request > 0 && request < 4) {
			__set_errno(0);
			return (ret);
		}
		return (int) res;
	}
	__set_errno(-res);
	return -1;
}