Add a "fork" of musl as //fusl.

fusl/src/misc/setrlimit.c

Index: fusl/src/misc/setrlimit.c
diff --git a/fusl/src/misc/setrlimit.c b/fusl/src/misc/setrlimit.c
new file mode 100644
index 0000000000000000000000000000000000000000..7130d719e6fec053ca848590f0ea15712adee9f4
--- /dev/null
+++ b/fusl/src/misc/setrlimit.c
@@ -0,0 +1,50 @@
+#include <sys/resource.h>
+#include <errno.h>
+#include "syscall.h"
+#include "libc.h"
+
+#define MIN(a, b) ((a)<(b) ? (a) : (b))
+#define FIX(x) do{ if ((x)>=SYSCALL_RLIM_INFINITY) (x)=RLIM_INFINITY; }while(0)
+
+int __setrlimit(int resource, const struct rlimit *rlim)
+{
+	unsigned long k_rlim[2];
+	struct rlimit tmp;
+	if (SYSCALL_RLIM_INFINITY != RLIM_INFINITY) {
+		tmp = *rlim;
+		FIX(tmp.rlim_cur);
+		FIX(tmp.rlim_max);
+		rlim = &tmp;
+	}
+	int ret = __syscall(SYS_prlimit64, 0, resource, rlim, 0);
+	if (ret != -ENOSYS) return ret;
+	k_rlim[0] = MIN(rlim->rlim_cur, MIN(-1UL, SYSCALL_RLIM_INFINITY));
+	k_rlim[1] = MIN(rlim->rlim_max, MIN(-1UL, SYSCALL_RLIM_INFINITY));
+	return __syscall(SYS_setrlimit, resource, k_rlim);
+}
+
+struct ctx {
+	const struct rlimit *rlim;
+	int res;
+	int err;
+};
+
+static void do_setrlimit(void *p)
+{
+	struct ctx *c = p;
+	if (c->err>0) return;
+	c->err = -__setrlimit(c->res, c->rlim);
+}
+
+int setrlimit(int resource, const struct rlimit *rlim)
+{
+	struct ctx c = { .res = resource, .rlim = rlim, .err = -1 };
+	__synccall(do_setrlimit, &c);
+	if (c.err) {
+		if (c.err>0) errno = c.err;
+		return -1;
+	}
+	return 0;
+}
+
+LFS64(setrlimit);