1 files changed, 71 insertions, 0 deletions
diff --git a/arch/x86/um/vdso/um_vdso.c b/arch/x86/um/vdso/um_vdso.c
new file mode 100644
index 00000000..7c441b59
--- /dev/null
+++ b/arch/x86/um/vdso/um_vdso.c
@@ -0,0 +1,71 @@
+/*
+ * Copyright (C) 2011 Richard Weinberger <richrd@nod.at>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This vDSO turns all calls into a syscall so that UML can trap them.
+ */
+
+
+/* Disable profiling for userspace code */
+#define DISABLE_BRANCH_PROFILING
+
+#include <linux/time.h>
+#include <linux/getcpu.h>
+#include <asm/unistd.h>
+
+int __vdso_clock_gettime(clockid_t clock, struct timespec *ts)
+{
+	long ret;
+
+	asm("syscall" : "=a" (ret) :
+		"0" (__NR_clock_gettime), "D" (clock), "S" (ts) : "memory");
+
+	return ret;
+}
+int clock_gettime(clockid_t, struct timespec *)
+	__attribute__((weak, alias("__vdso_clock_gettime")));
+
+int __vdso_gettimeofday(struct timeval *tv, struct timezone *tz)
+{
+	long ret;
+
+	asm("syscall" : "=a" (ret) :
+		"0" (__NR_gettimeofday), "D" (tv), "S" (tz) : "memory");
+
+	return ret;
+}
+int gettimeofday(struct timeval *, struct timezone *)
+	__attribute__((weak, alias("__vdso_gettimeofday")));
+
+time_t __vdso_time(time_t *t)
+{
+	long secs;
+
+	asm volatile("syscall"
+		: "=a" (secs)
+		: "0" (__NR_time), "D" (t) : "cc", "r11", "cx", "memory");
+
+	return secs;
+}
+int time(time_t *t) __attribute__((weak, alias("__vdso_time")));
+
+long
+__vdso_getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *unused)
+{
+	/*
+	 * UML does not support SMP, we can cheat here. :)
+	 */
+
+	if (cpu)
+		*cpu = 0;
+	if (node)
+		*node = 0;
+
+	return 0;
+}
+
+long getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *tcache)
+	__attribute__((weak, alias("__vdso_getcpu")));