lib/libc/posix/_ptrace.c

   1 #include <lib.h>
   2 #define ptrace  _ptrace
   3 #include <unistd.h>
   4
   5 PUBLIC long ptrace(int req, pid_t pid, long addr, long data)
   6 {
   7   message m;
   8
   9   m.m2_i1 = pid;
  10   m.m2_i2 = req;
  11   m.PMTRACE_ADDR = addr;
  12   m.m2_l2 = data;
  13   if (_syscall(MM, PTRACE, &m) < 0) return(-1);
  14
  15   /* There was no error, but -1 is a legal return value.  Clear errno if
  16    * necessary to distinguish this case.  _syscall has set errno to nonzero
  17    * for the error case.
  18    */
  19   if (m.m2_l2 == -1) errno = 0;
  20   return(m.m2_l2);
  21 }