src/linux/wait4.c

   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 }