x86: map vsyscalls early enough

map vsyscalls early enough. This is important if a __vsyscall_fn
function is used by other kernel code too.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/x86/kernel/setup_64.c

@@ -45,6 +45,7 @@
 #include <asm/mtrr.h>
 #include <asm/uaccess.h>
 #include <asm/system.h>
+#include <asm/vsyscall.h>
 #include <asm/io.h>
 #include <asm/smp.h>
 #include <asm/msr.h>
@@ -453,6 +454,7 @@ void __init setup_arch(char **cmdline_p)
 #endif
 	reserve_crashkernel();
 	paging_init();
+	map_vsyscall();
 
 	early_quirks();
 

arch/x86/kernel/vsyscall_64.c

@@ -319,7 +319,7 @@ cpu_vsyscall_notifier(struct notifier_block *n, unsigned long action, void *arg)
 	return NOTIFY_DONE;
 }
 
-static void __init map_vsyscall(void)
+void __init map_vsyscall(void)
 {
 	extern char __vsyscall_0;
 	unsigned long physaddr_page0 = __pa_symbol(&__vsyscall_0);
@@ -335,7 +335,6 @@ static int __init vsyscall_init(void)
 	BUG_ON((unsigned long) &vtime != VSYSCALL_ADDR(__NR_vtime));
 	BUG_ON((VSYSCALL_ADDR(0) != __fix_to_virt(VSYSCALL_FIRST_PAGE)));
 	BUG_ON((unsigned long) &vgetcpu != VSYSCALL_ADDR(__NR_vgetcpu));
-	map_vsyscall();
 #ifdef CONFIG_SYSCTL
 	register_sysctl_table(kernel_root_table2);
 #endif

include/asm-x86/vsyscall.h

@@ -36,6 +36,8 @@ extern volatile unsigned long __jiffies;
 extern int vgetcpu_mode;
 extern struct timezone sys_tz;
 
+extern void map_vsyscall(void);
+
 #endif /* __KERNEL__ */
 
 #endif /* _ASM_X86_64_VSYSCALL_H_ */