fix some issues in x32 syscall_cp_fixup

- the nanosleep fixup "fixed" the second timespec* argument erroneusly.
- the futex fixup was missing the check for FUTEX_WAIT.
- general cleanup using a macro.

arch/x32/src/syscall_cp_fixup.c

@@ -5,28 +5,25 @@ long __syscall_cp_internal(volatile void*, long long, long long, long long, long
 struct __timespec { long long tv_sec; long tv_nsec; };
 struct __timespec_kernel { long long tv_sec; long long tv_nsec; };
 #define __tsc(X) ((struct __timespec*)(unsigned long)(X))
+#define __fixup(X) do { if(X) X = (unsigned long) (&(struct __timespec_kernel) \
+                   { .tv_sec = __tsc(X)->tv_sec, .tv_nsec = __tsc(X)->tv_nsec}); } while(0)
 
 long __syscall_cp_asm (volatile void * foo, long long n, long long a1, long long a2, long long a3,
 	                     long long a4, long long a5, long long a6) {
 	switch (n) {
 	case SYS_mq_timedsend: case SYS_mq_timedreceive: case SYS_pselect6:
-		if(a5) a5 = (unsigned long) (&(struct __timespec_kernel) {
-		.tv_sec = __tsc(a5)->tv_sec, .tv_nsec = __tsc(a5)->tv_nsec});
+		__fixup(a5);
 		break;
 	case SYS_futex:
-		if(a4) a4 = (unsigned long) (&(struct __timespec_kernel) {
-		.tv_sec = __tsc(a4)->tv_sec, .tv_nsec = __tsc(a4)->tv_nsec});
-		if(n == SYS_futex) break;
+		if((a2 & (~128 /* FUTEX_PRIVATE_FLAG */)) == 0 /* FUTEX_WAIT */)
+			__fixup(a4);
+		break;
 	case SYS_clock_nanosleep:
 	case SYS_rt_sigtimedwait: case SYS_ppoll:
-		if(a3) a3 = (unsigned long) (&(struct __timespec_kernel) {
-		.tv_sec = __tsc(a3)->tv_sec, .tv_nsec = __tsc(a3)->tv_nsec});
+		__fixup(a3);
 		break;
 	case SYS_nanosleep:
-		if(a1) a1 = (unsigned long) (&(struct __timespec_kernel) {
-		.tv_sec = __tsc(a1)->tv_sec, .tv_nsec = __tsc(a1)->tv_nsec});
-		if(a2) a2 = (unsigned long) (&(struct __timespec_kernel) {
-		.tv_sec = __tsc(a2)->tv_sec, .tv_nsec = __tsc(a2)->tv_nsec});
+		__fixup(a1);
 		break;
 	}
 	return __syscall_cp_internal(foo, n, a1, a2, a3, a4, a5, a6);