wait4.c raw

   1  #define _GNU_SOURCE
   2  #include <sys/wait.h>
   3  #include <sys/resource.h>
   4  #include <string.h>
   5  #include <errno.h>
   6  #include "syscall.h"
   7  
   8  pid_t wait4(pid_t pid, int *status, int options, struct rusage *ru)
   9  {
  10  	int r;
  11  #ifdef SYS_wait4_time64
  12  	if (ru) {
  13  		long long kru64[18];
  14  		r = __syscall(SYS_wait4_time64, pid, status, options, kru64);
  15  		if (!r) {
  16  			ru->ru_utime = (struct timeval)
  17  				{ .tv_sec = kru64[0], .tv_usec = kru64[1] };
  18  			ru->ru_stime = (struct timeval)
  19  				{ .tv_sec = kru64[2], .tv_usec = kru64[3] };
  20  			char *slots = (char *)&ru->ru_maxrss;
  21  			for (int i=0; i<14; i++)
  22  				*(long *)(slots + i*sizeof(long)) = kru64[4+i];
  23  		}
  24  		if (SYS_wait4_time64 == SYS_wait4 || r != -ENOSYS)
  25  			return __syscall_ret(r);
  26  	}
  27  #endif
  28  	char *dest = ru ? (char *)&ru->ru_maxrss - 4*sizeof(long) : 0;
  29  	r = __syscall(SYS_wait4, pid, status, options, dest);
  30  	if (r>0 && ru && sizeof(time_t) > sizeof(long)) {
  31  		long kru[4];
  32  		memcpy(kru, dest, 4*sizeof(long));
  33  		ru->ru_utime = (struct timeval)
  34  			{ .tv_sec = kru[0], .tv_usec = kru[1] };
  35  		ru->ru_stime = (struct timeval)
  36  			{ .tv_sec = kru[2], .tv_usec = kru[3] };
  37  	}
  38  	return __syscall_ret(r);
  39  }
  40