3 files changed, 134 insertions, 0 deletions
diff --git a/tools/testing/selftests/vm/Makefile b/tools/testing/selftests/vm/Makefile
index dba889004ea1..cbb29e41ef2b 100644
--- a/tools/testing/selftests/vm/Makefile
+++ b/tools/testing/selftests/vm/Makefile
@@ -16,6 +16,7 @@ TEST_GEN_FILES += thuge-gen
 TEST_GEN_FILES += transhuge-stress
 TEST_GEN_FILES += userfaultfd
 TEST_GEN_FILES += mlock-random-test
+TEST_GEN_FILES += virtual_address_range
 
 TEST_PROGS := run_vmtests
 
diff --git a/tools/testing/selftests/vm/run_vmtests b/tools/testing/selftests/vm/run_vmtests
index 3214a6456d13..0640923ded7e 100755
--- a/tools/testing/selftests/vm/run_vmtests
+++ b/tools/testing/selftests/vm/run_vmtests
@@ -165,4 +165,15 @@ else
 	echo "[PASS]"
 fi
 
+echo "-----------------------------"
+echo "running virtual_address_range"
+echo "-----------------------------"
+./virtual_address_range
+if [ $? -ne 0 ]; then
+	echo "[FAIL]"
+	exitcode=1
+else
+	echo "[PASS]"
+fi
+
 exit $exitcode
diff --git a/tools/testing/selftests/vm/virtual_address_range.c b/tools/testing/selftests/vm/virtual_address_range.c
new file mode 100644
index 000000000000..3b02aa6eb9da
--- /dev/null
+++ b/tools/testing/selftests/vm/virtual_address_range.c
@@ -0,0 +1,122 @@
+/*
+ * Copyright 2017, Anshuman Khandual, IBM Corp.
+ * Licensed under GPLv2.
+ *
+ * Works on architectures which support 128TB virtual
+ * address range and beyond.
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+#include <numaif.h>
+#include <sys/mman.h>
+#include <sys/time.h>
+
+/*
+ * Maximum address range mapped with a single mmap()
+ * call is little bit more than 16GB. Hence 16GB is
+ * chosen as the single chunk size for address space
+ * mapping.
+ */
+#define MAP_CHUNK_SIZE   17179869184UL /* 16GB */
+
+/*
+ * Address space till 128TB is mapped without any hint
+ * and is enabled by default. Address space beyond 128TB
+ * till 512TB is obtained by passing hint address as the
+ * first argument into mmap() system call.
+ *
+ * The process heap address space is divided into two
+ * different areas one below 128TB and one above 128TB
+ * till it reaches 512TB. One with size 128TB and the
+ * other being 384TB.
+ */
+#define NR_CHUNKS_128TB   8192UL /* Number of 16GB chunks for 128TB */
+#define NR_CHUNKS_384TB  24576UL /* Number of 16GB chunks for 384TB */
+
+#define ADDR_MARK_128TB  (1UL << 47) /* First address beyond 128TB */
+
+static char *hind_addr(void)
+{
+	int bits = 48 + rand() % 15;
+
+	return (char *) (1UL << bits);
+}
+
+static int validate_addr(char *ptr, int high_addr)
+{
+	unsigned long addr = (unsigned long) ptr;
+
+	if (high_addr) {
+		if (addr < ADDR_MARK_128TB) {
+			printf("Bad address %lx\n", addr);
+			return 1;
+		}
+		return 0;
+	}
+
+	if (addr > ADDR_MARK_128TB) {
+		printf("Bad address %lx\n", addr);
+		return 1;
+	}
+	return 0;
+}
+
+static int validate_lower_address_hint(void)
+{
+	char *ptr;
+
+	ptr = mmap((void *) (1UL << 45), MAP_CHUNK_SIZE, PROT_READ |
+			PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+
+	if (ptr == MAP_FAILED)
+		return 0;
+
+	return 1;
+}
+
+int main(int argc, char *argv[])
+{
+	char *ptr[NR_CHUNKS_128TB];
+	char *hptr[NR_CHUNKS_384TB];
+	char *hint;
+	unsigned long i, lchunks, hchunks;
+
+	for (i = 0; i < NR_CHUNKS_128TB; i++) {
+		ptr[i] = mmap(NULL, MAP_CHUNK_SIZE, PROT_READ | PROT_WRITE,
+					MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+
+		if (ptr[i] == MAP_FAILED) {
+			if (validate_lower_address_hint())
+				return 1;
+			break;
+		}
+
+		if (validate_addr(ptr[i], 0))
+			return 1;
+	}
+	lchunks = i;
+
+	for (i = 0; i < NR_CHUNKS_384TB; i++) {
+		hint = hind_addr();
+		hptr[i] = mmap(hint, MAP_CHUNK_SIZE, PROT_READ | PROT_WRITE,
+					MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+
+		if (hptr[i] == MAP_FAILED)
+			break;
+
+		if (validate_addr(hptr[i], 1))
+			return 1;
+	}
+	hchunks = i;
+
+	for (i = 0; i < lchunks; i++)
+		munmap(ptr[i], MAP_CHUNK_SIZE);
+
+	for (i = 0; i < hchunks; i++)
+		munmap(hptr[i], MAP_CHUNK_SIZE);
+
+	return 0;
+}