fusl/src/linux/prlimit.c

#define _GNU_SOURCE
#include <sys/resource.h>
#include "syscall.h"
#include "libc.h"

#define FIX(x)                        \
  do {                                \
    if ((x) >= SYSCALL_RLIM_INFINITY) \
      (x) = RLIM_INFINITY;            \
  } while (0)

int prlimit(pid_t pid,
            int resource,
            const struct rlimit* new_limit,
            struct rlimit* old_limit) {
  struct rlimit tmp;
  int r;
  if (new_limit && SYSCALL_RLIM_INFINITY != RLIM_INFINITY) {
    tmp = *new_limit;
    FIX(tmp.rlim_cur);
    FIX(tmp.rlim_max);
    new_limit = &tmp;
  }
  r = syscall(SYS_prlimit64, pid, resource, new_limit, old_limit);
  if (!r && old_limit && SYSCALL_RLIM_INFINITY != RLIM_INFINITY) {
    FIX(old_limit->rlim_cur);
    FIX(old_limit->rlim_max);
  }
  return r;
}