Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Thomas Gleixner.

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86: Use correct byte-sized register constraint in __add()
  x86: Use correct byte-sized register constraint in __xchg_op()
  x86: vsyscall: Use NULL instead 0 for a pointer argument

arch/x86/include/asm/cmpxchg.h

@@ -43,7 +43,7 @@ extern void __add_wrong_size(void)
 		switch (sizeof(*(ptr))) {				\
 		case __X86_CASE_B:					\
 			asm volatile (lock #op "b %b0, %1\n"		\
-				      : "+r" (__ret), "+m" (*(ptr))	\
+				      : "+q" (__ret), "+m" (*(ptr))	\
 				      : : "memory", "cc");		\
 			break;						\
 		case __X86_CASE_W:					\
@@ -173,7 +173,7 @@ extern void __add_wrong_size(void)
 		switch (sizeof(*(ptr))) {				\
 		case __X86_CASE_B:					\
 			asm volatile (lock "addb %b1, %0\n"		\
-				      : "+m" (*(ptr)) : "ri" (inc)	\
+				      : "+m" (*(ptr)) : "qi" (inc)	\
 				      : "memory", "cc");		\
 			break;						\
 		case __X86_CASE_W:					\

arch/x86/kernel/vsyscall_64.c

@@ -216,9 +216,9 @@ bool emulate_vsyscall(struct pt_regs *regs, unsigned long address)
 	current_thread_info()->sig_on_uaccess_error = 1;
 
 	/*
-	 * 0 is a valid user pointer (in the access_ok sense) on 32-bit and
+	 * NULL is a valid user pointer (in the access_ok sense) on 32-bit and
 	 * 64-bit, so we don't need to special-case it here.  For all the
-	 * vsyscalls, 0 means "don't write anything" not "write it at
+	 * vsyscalls, NULL means "don't write anything" not "write it at
 	 * address 0".
 	 */
 	ret = -EFAULT;
@@ -247,7 +247,7 @@ bool emulate_vsyscall(struct pt_regs *regs, unsigned long address)
 
 		ret = sys_getcpu((unsigned __user *)regs->di,
 				 (unsigned __user *)regs->si,
-				 0);
+				 NULL);
 		break;
 	}