Aarch64 unit test fixes.

On Aarch64, zero bytes are illegal instructions, this is added to
the icache-hygiene test.

In mremap-expand-slice-collision, if __LP64__ is defined then
mappings are attempted at 1TB boundaries which are outside the
allowable mmap region for Aarch64. For __aarch64__ we change this
mapping back to 256MB slices.

Signed-off-by: Steve Capper <steve.capper@linaro.org>
Signed-off-by: Eric B Munson <emunson@mgebm.net>

tests/icache-hygiene.c

@@ -54,7 +54,7 @@ static void cacheflush(void *p)
 {
 #if defined(__powerpc__)
 	asm volatile("dcbst 0,%0; sync; icbi 0,%0; isync" : : "r"(p));
-#elif defined(__arm__)
+#elif defined(__arm__) || defined(__aarch64__)
 	__clear_cache(p, p + COPY_SIZE);
 #endif
 }
@@ -87,8 +87,9 @@ static void *sig_expected;
 static void sig_handler(int signum, siginfo_t *si, void *uc)
 {
 #if defined(__powerpc__) || defined(__powerpc64__) || defined(__ia64__) || \
-    defined(__s390__) || defined(__s390x__) || defined(__sparc__)
-	/* On powerpc and ia64 and s390, 0 bytes are an illegal
+    defined(__s390__) || defined(__s390x__) || defined(__sparc__) || \
+    defined(__aarch64__)
+	/* On powerpc, ia64, s390 and Aarch64, 0 bytes are an illegal
 	 * instruction, so, if the icache is cleared properly, we SIGILL
 	 * as soon as we jump into the cleared page */
 	if (signum == SIGILL) {

tests/mremap-expand-slice-collision.c

@@ -38,7 +38,7 @@ void init_slice_boundary(int fd)
 	unsigned long slice_size;
 	void *p1, *p2, *heap;
 	int slices_ok, i, rc;
-#ifdef __LP64__
+#if defined(__LP64__) && !defined(__aarch64__)
 	/* powerpc: 1TB slices starting at 1 TB */
 	slice_boundary = 0x10000000000;
 	slice_size = 0x10000000000;