4 files changed, 57 insertions, 0 deletions
diff --git a/lib/libc/internal/util/Kbuild b/lib/libc/internal/util/Kbuild
new file mode 100644
index 00000000..9c8d0fc7
--- /dev/null
+++ b/lib/libc/internal/util/Kbuild
@@ -0,0 +1,3 @@
+obj-y += futex.o
+obj-y += panic.o
+obj-y += syscall.o
diff --git a/lib/libc/internal/util/futex.c b/lib/libc/internal/util/futex.c
new file mode 100644
index 00000000..2f9872a0
--- /dev/null
+++ b/lib/libc/internal/util/futex.c
@@ -0,0 +1,13 @@
+#include <linux/futex.h>
+#include <syscall.h>
+
+int __futex_wait(volatile int *uaddr, int val)
+{
+	return syscall(futex, uaddr, FUTEX_WAIT | FUTEX_PRIVATE_FLAG, val, 0, 0, 0);
+}
+
+int __futex_wake(volatile int *uaddr, int n)
+{
+	/* futex(uaddr, FUTEX_WAKE, val=n, ...) */
+	return syscall(futex, uaddr, FUTEX_WAKE | FUTEX_PRIVATE_FLAG, n, 0, 0, 0);
+}
diff --git a/lib/libc/internal/util/panic.c b/lib/libc/internal/util/panic.c
new file mode 100644
index 00000000..1af6d6cf
--- /dev/null
+++ b/lib/libc/internal/util/panic.c
@@ -0,0 +1,29 @@
+#include <string.h>
+#include <sys/cdefs.h>
+#include <sys/uio.h>
+#include <unistd.h>
+
+__dead void __libc_panic(const char *prefix, const char *f, const char *errmsg)
+{
+	struct iovec iovec[5];
+	const char *e = "libc panic: ";
+
+	iovec[0].iov_base = (char *)e;
+	iovec[0].iov_len = sizeof("libc panic: ") - 1;
+
+	iovec[1].iov_base = (char *)prefix;
+	iovec[1].iov_len = strlen(prefix);
+
+	iovec[2].iov_base = (char *)f;
+	iovec[2].iov_len = strlen(f);
+
+	iovec[3].iov_base = (char *)errmsg;
+	iovec[3].iov_len = strlen(errmsg);
+
+	iovec[4].iov_base = "\n";
+	iovec[4].iov_len = 1;
+
+	writev(STDERR_FILENO, iovec, 5);
+
+	__builtin_trap();
+}
diff --git a/lib/libc/internal/util/syscall.c b/lib/libc/internal/util/syscall.c
new file mode 100644
index 00000000..f7fd3c4b
--- /dev/null
+++ b/lib/libc/internal/util/syscall.c
@@ -0,0 +1,12 @@
+#include <errno.h>
+#include <sys/cdefs.h>
+
+long __syscall_ret(long ret)
+{
+	if (__predict_false(ret > -4096 && ret < 0)) {
+		errno = (int)-ret;
+		ret = -1;
+	}
+
+	return ret;
+}