support vsyscall_getcpu() vsyscall. refs #385

This version simply calls getcpu() system call, so that it's not fast.
2015-02-10 15:59:23 +09:00
parent d30d8fe71c
commit a4a806bef7
5 changed files with 26 additions and 0 deletions
--- a/arch/x86/kernel/vsyscall.c
+++ b/arch/x86/kernel/vsyscall.c
@ -58,3 +58,17 @@ long vsyscall_time(void *tp)

 	return t;
 }
+
+extern int vsyscall_getcpu(unsigned *cpup, unsigned *nodep, void *tcachep)
+	__attribute__ ((section (".vsyscall.getcpu")));
+
+int vsyscall_getcpu(unsigned *cpup, unsigned *nodep, void *tcachep)
+{
+	int error;
+
+	asm ("syscall" : "=a" (error)
+			: "a" (__NR_getcpu), "D" (cpup), "S" (nodep), "d" (tcachep)
+			: "%rcx", "%r11", "memory");
+
+	return error;
+}