add prlimit syscall wrapper

arch/i386/bits/syscall.h

@@ -470,6 +470,7 @@ static inline long __syscall6(long __n, long __a1, long __a2, long __a3, long __
 #define __NR_inotify_init1	332
 #define __NR_preadv		333
 #define __NR_pwritev		334
+#define __NR_prlimit64		340
 
 /* fixup legacy 16-bit junk */
 #undef __NR_lchown
@@ -881,6 +882,7 @@ static inline long __syscall6(long __n, long __a1, long __a2, long __a3, long __
 #define SYS_inotify_init1	332
 #define SYS_preadv		333
 #define SYS_pwritev		334
+#define SYS_prlimit64		340
 
 /* fixup legacy 16-bit junk */
 #undef SYS_lchown

include/sys/resource.h

@@ -9,6 +9,10 @@ extern "C" {
 #define __NEED_time_t
 #define __NEED_struct_timeval
 
+#ifdef _GNU_SOURCE
+#define __NEED_pid_t
+#endif
+
 #include <bits/alltypes.h>
 
 typedef unsigned long long rlim_t;
@@ -49,6 +53,10 @@ int getrusage (int, struct rusage *);
 int getpriority (int, id_t);
 int setpriority (int, id_t, int);
 
+#ifdef _GNU_SOURCE
+int prlimit(pid_t, int, const struct rlimit *, struct rlimit *);
+#endif
+
 #define PRIO_PROCESS 0
 #define PRIO_PGRP    1
 #define PRIO_USER    2

src/misc/prlimit.c

@@ -0,0 +1,8 @@
+#include <unistd.h>
+#include <sys/resource.h>
+#include "syscall.h"
+
+int prlimit(pid_t pid, int resource, const struct rlimit *new_limit, struct rlimit *old_limit)
+{
+	return syscall(SYS_prlimit64, pid, resource, new_limit, old_limit);
+}