[PATCH] selftest/vm: Move the 128 TB mmap boundary test to the generic VM directory

[Aneesh Kumar K.V]

Architectures like PPC64 support mmap hint address based large address space
selection. This test can be run on those architectures too. Move the test from
the x86 selftests to selftest/vm so that other architectures can use it too.

We also add a few new test scenarios in this patch. We do test a few boundary
conditions before we do a high address mmap. PPC64 uses the address limit to
validate the address in the fault path. We had bugs in this area w.r.t SLB fault
handling before we updated the addess limit.

We also touch the allocated space to make sure we don't have any bugs in the
fault handling path.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
Cc: Kirill A . Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: akpm@xxxxxxxxxxxxxxxxxxxx
Cc: linux-mm@xxxxxxxxx
Link: http://lkml.kernel.org/r/20171123165226.32582-1-aneesh.kumar@xxxxxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
 tools/testing/selftests/vm/Makefile         |   1 +
 tools/testing/selftests/vm/run_vmtests      |  11 ++
 tools/testing/selftests/vm/va_128TBswitch.c | 297 ++++++++++++++++++++++++++++
 tools/testing/selftests/x86/5lvl.c          | 177 -----------------
 4 files changed, 309 insertions(+), 177 deletions(-)

diff --git a/tools/testing/selftests/vm/Makefile b/tools/testing/selftests/vm/Makefile
index 7f45806bd863..fe49b7390e13 100644
--- a/tools/testing/selftests/vm/Makefile
+++ b/tools/testing/selftests/vm/Makefile
@@ -19,6 +19,7 @@ TEST_GEN_FILES += userfaultfd
 TEST_GEN_FILES += mlock-random-test
 TEST_GEN_FILES += virtual_address_range
 TEST_GEN_FILES += gup_benchmark
+TEST_GEN_FILES += va_128TBswitch
 
 TEST_PROGS := run_vmtests
 
diff --git a/tools/testing/selftests/vm/run_vmtests b/tools/testing/selftests/vm/run_vmtests
index cc826326de87..d2561895a021 100755
--- a/tools/testing/selftests/vm/run_vmtests
+++ b/tools/testing/selftests/vm/run_vmtests
@@ -177,4 +177,15 @@ else
 	echo "[PASS]"
 fi
 
+echo "-----------------------------"
+echo "running virtual address 128TB switch test"
+echo "-----------------------------"
+./va_128TBswitch
+if [ $? -ne 0 ]; then
+    echo "[FAIL]"
+    exitcode=1
+else
+    echo "[PASS]"
+fi
+
 exit $exitcode
diff --git a/tools/testing/selftests/vm/va_128TBswitch.c b/tools/testing/selftests/vm/va_128TBswitch.c
new file mode 100644
index 000000000000..e7fe734c374f
--- /dev/null
+++ b/tools/testing/selftests/vm/va_128TBswitch.c
@@ -0,0 +1,297 @@
+/*
+ *
+ * Authors: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
+ * Authors: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+
+ * This program is distributed in the hope that it would be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ */
+
+#include <stdio.h>
+#include <sys/mman.h>
+#include <string.h>
+
+#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
+
+#ifdef __powerpc64__
+#define PAGE_SIZE	(64 << 10)
+/*
+ * This will work with 16M and 2M hugepage size
+ */
+#define HUGETLB_SIZE	(16 << 20)
+#else
+#define PAGE_SIZE	(4 << 10)
+#define HUGETLB_SIZE	(2 << 20)
+#endif
+
+/*
+ * >= 128TB is the hint addr value we used to select
+ * large address space.
+ */
+#define ADDR_SWITCH_HINT (1UL << 47)
+#define LOW_ADDR	((void *) (1UL << 30))
+#define HIGH_ADDR	((void *) (1UL << 48))
+
+struct testcase {
+	void *addr;
+	unsigned long size;
+	unsigned long flags;
+	const char *msg;
+	unsigned int low_addr_required:1;
+	unsigned int keep_mapped:1;
+};
+
+static struct testcase testcases[] = {
+	{
+		/*
+		 * If stack is moved, we could possibly allocate
+		 * this at the requested address.
+		 */
+		.addr = ((void *)(ADDR_SWITCH_HINT - PAGE_SIZE)),
+		.size = PAGE_SIZE,
+		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
+		.msg = "mmap(ADDR_SWITCH_HINT - PAGE_SIZE, PAGE_SIZE)",
+		.low_addr_required = 1,
+	},
+	{
+		/*
+		 * We should never allocate at the requested address or above it
+		 * The len cross the 128TB boundary. Without MAP_FIXED
+		 * we will always search in the lower address space.
+		 */
+		.addr = ((void *)(ADDR_SWITCH_HINT - PAGE_SIZE)),
+		.size = 2 * PAGE_SIZE,
+		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
+		.msg = "mmap(ADDR_SWITCH_HINT - PAGE_SIZE, (2 * PAGE_SIZE))",
+		.low_addr_required = 1,
+	},
+	{
+		/*
+		 * Exact mapping at 128TB, the area is free we should get that
+		 * even without MAP_FIXED.
+		 */
+		.addr = ((void *)(ADDR_SWITCH_HINT)),
+		.size = PAGE_SIZE,
+		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
+		.msg = "mmap(ADDR_SWITCH_HINT, PAGE_SIZE)",
+		.keep_mapped = 1,
+	},
+	{
+		.addr = (void *)(ADDR_SWITCH_HINT),
+		.size = 2 * PAGE_SIZE,
+		.flags = MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED,
+		.msg = "mmap(ADDR_SWITCH_HINT, 2 * PAGE_SIZE, MAP_FIXED)",
+	},
+	{
+		.addr = NULL,
+		.size = 2 * PAGE_SIZE,
+		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
+		.msg = "mmap(NULL)",
+		.low_addr_required = 1,
+	},
+	{
+		.addr = LOW_ADDR,
+		.size = 2 * PAGE_SIZE,
+		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
+		.msg = "mmap(LOW_ADDR)",
+		.low_addr_required = 1,
+	},
+	{
+		.addr = HIGH_ADDR,
+		.size = 2 * PAGE_SIZE,
+		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
+		.msg = "mmap(HIGH_ADDR)",
+		.keep_mapped = 1,
+	},
+	{
+		.addr = HIGH_ADDR,
+		.size = 2 * PAGE_SIZE,
+		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
+		.msg = "mmap(HIGH_ADDR) again",
+		.keep_mapped = 1,
+	},
+	{
+		.addr = HIGH_ADDR,
+		.size = 2 * PAGE_SIZE,
+		.flags = MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED,
+		.msg = "mmap(HIGH_ADDR, MAP_FIXED)",
+	},
+	{
+		.addr = (void *) -1,
+		.size = 2 * PAGE_SIZE,
+		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
+		.msg = "mmap(-1)",
+		.keep_mapped = 1,
+	},
+	{
+		.addr = (void *) -1,
+		.size = 2 * PAGE_SIZE,
+		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
+		.msg = "mmap(-1) again",
+	},
+	{
+		.addr = ((void *)(ADDR_SWITCH_HINT - PAGE_SIZE)),
+		.size = PAGE_SIZE,
+		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
+		.msg = "mmap(ADDR_SWITCH_HINT - PAGE_SIZE, PAGE_SIZE)",
+		.low_addr_required = 1,
+	},
+	{
+		.addr = (void *)(ADDR_SWITCH_HINT - PAGE_SIZE),
+		.size = 2 * PAGE_SIZE,
+		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
+		.msg = "mmap(ADDR_SWITCH_HINT - PAGE_SIZE, 2 * PAGE_SIZE)",
+		.low_addr_required = 1,
+		.keep_mapped = 1,
+	},
+	{
+		.addr = (void *)(ADDR_SWITCH_HINT - PAGE_SIZE / 2),
+		.size = 2 * PAGE_SIZE,
+		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
+		.msg = "mmap(ADDR_SWITCH_HINT - PAGE_SIZE/2 , 2 * PAGE_SIZE)",
+		.low_addr_required = 1,
+		.keep_mapped = 1,
+	},
+	{
+		.addr = ((void *)(ADDR_SWITCH_HINT)),
+		.size = PAGE_SIZE,
+		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
+		.msg = "mmap(ADDR_SWITCH_HINT, PAGE_SIZE)",
+	},
+	{
+		.addr = (void *)(ADDR_SWITCH_HINT),
+		.size = 2 * PAGE_SIZE,
+		.flags = MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED,
+		.msg = "mmap(ADDR_SWITCH_HINT, 2 * PAGE_SIZE, MAP_FIXED)",
+	},
+};
+
+static struct testcase hugetlb_testcases[] = {
+	{
+		.addr = NULL,
+		.size = HUGETLB_SIZE,
+		.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS,
+		.msg = "mmap(NULL, MAP_HUGETLB)",
+		.low_addr_required = 1,
+	},
+	{
+		.addr = LOW_ADDR,
+		.size = HUGETLB_SIZE,
+		.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS,
+		.msg = "mmap(LOW_ADDR, MAP_HUGETLB)",
+		.low_addr_required = 1,
+	},
+	{
+		.addr = HIGH_ADDR,
+		.size = HUGETLB_SIZE,
+		.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS,
+		.msg = "mmap(HIGH_ADDR, MAP_HUGETLB)",
+		.keep_mapped = 1,
+	},
+	{
+		.addr = HIGH_ADDR,
+		.size = HUGETLB_SIZE,
+		.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS,
+		.msg = "mmap(HIGH_ADDR, MAP_HUGETLB) again",
+		.keep_mapped = 1,
+	},
+	{
+		.addr = HIGH_ADDR,
+		.size = HUGETLB_SIZE,
+		.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED,
+		.msg = "mmap(HIGH_ADDR, MAP_FIXED | MAP_HUGETLB)",
+	},
+	{
+		.addr = (void *) -1,
+		.size = HUGETLB_SIZE,
+		.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS,
+		.msg = "mmap(-1, MAP_HUGETLB)",
+		.keep_mapped = 1,
+	},
+	{
+		.addr = (void *) -1,
+		.size = HUGETLB_SIZE,
+		.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS,
+		.msg = "mmap(-1, MAP_HUGETLB) again",
+	},
+	{
+		.addr = (void *)(ADDR_SWITCH_HINT - PAGE_SIZE),
+		.size = 2 * HUGETLB_SIZE,
+		.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS,
+		.msg = "mmap(ADDR_SWITCH_HINT - PAGE_SIZE, 2*HUGETLB_SIZE, MAP_HUGETLB)",
+		.low_addr_required = 1,
+		.keep_mapped = 1,
+	},
+	{
+		.addr = (void *)(ADDR_SWITCH_HINT),
+		.size = 2 * HUGETLB_SIZE,
+		.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED,
+		.msg = "mmap(ADDR_SWITCH_HINT , 2*HUGETLB_SIZE, MAP_FIXED | MAP_HUGETLB)",
+	},
+};
+
+static int run_test(struct testcase *test, int count)
+{
+	void *p;
+	int i, ret = 0;
+
+	for (i = 0; i < count; i++) {
+		struct testcase *t = test + i;
+
+		p = mmap(t->addr, t->size, PROT_READ | PROT_WRITE, t->flags, -1, 0);
+
+		printf("%s: %p - ", t->msg, p);
+
+		if (p == MAP_FAILED) {
+			printf("FAILED\n");
+			ret = 1;
+			continue;
+		}
+
+		if (t->low_addr_required && p >= (void *)(ADDR_SWITCH_HINT)) {
+			printf("FAILED\n");
+			ret = 1;
+		} else {
+			/*
+			 * Do a dereference of the address returned so that we catch
+			 * bugs in page fault handling
+			 */
+			memset(p, 0, t->size);
+			printf("OK\n");
+		}
+		if (!t->keep_mapped)
+			munmap(p, t->size);
+	}
+
+	return ret;
+}
+
+static int supported_arch(void)
+{
+#if defined(__powerpc64__)
+	return 1;
+#elif defined(__x86_64__)
+	return 1;
+#else
+	return 0;
+#endif
+}
+
+int main(int argc, char **argv)
+{
+	int ret;
+
+	if (!supported_arch())
+		return 0;
+
+	ret = run_test(testcases, ARRAY_SIZE(testcases));
+	if (argc == 2 && !strcmp(argv[1], "--run-hugetlb"))
+		ret = run_test(hugetlb_testcases, ARRAY_SIZE(hugetlb_testcases));
+	return ret;
+}
diff --git a/tools/testing/selftests/x86/5lvl.c b/tools/testing/selftests/x86/5lvl.c
deleted file mode 100644
index 2eafdcd4c2b3..000000000000
--- a/tools/testing/selftests/x86/5lvl.c
+++ /dev/null
@@ -1,177 +0,0 @@
-#include <stdio.h>
-#include <sys/mman.h>
-
-#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
-
-#define PAGE_SIZE	4096
-#define LOW_ADDR	((void *) (1UL << 30))
-#define HIGH_ADDR	((void *) (1UL << 50))
-
-struct testcase {
-	void *addr;
-	unsigned long size;
-	unsigned long flags;
-	const char *msg;
-	unsigned int low_addr_required:1;
-	unsigned int keep_mapped:1;
-};
-
-static struct testcase testcases[] = {
-	{
-		.addr = NULL,
-		.size = 2 * PAGE_SIZE,
-		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(NULL)",
-		.low_addr_required = 1,
-	},
-	{
-		.addr = LOW_ADDR,
-		.size = 2 * PAGE_SIZE,
-		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(LOW_ADDR)",
-		.low_addr_required = 1,
-	},
-	{
-		.addr = HIGH_ADDR,
-		.size = 2 * PAGE_SIZE,
-		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(HIGH_ADDR)",
-		.keep_mapped = 1,
-	},
-	{
-		.addr = HIGH_ADDR,
-		.size = 2 * PAGE_SIZE,
-		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(HIGH_ADDR) again",
-		.keep_mapped = 1,
-	},
-	{
-		.addr = HIGH_ADDR,
-		.size = 2 * PAGE_SIZE,
-		.flags = MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED,
-		.msg = "mmap(HIGH_ADDR, MAP_FIXED)",
-	},
-	{
-		.addr = (void*) -1,
-		.size = 2 * PAGE_SIZE,
-		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(-1)",
-		.keep_mapped = 1,
-	},
-	{
-		.addr = (void*) -1,
-		.size = 2 * PAGE_SIZE,
-		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(-1) again",
-	},
-	{
-		.addr = (void *)((1UL << 47) - PAGE_SIZE),
-		.size = 2 * PAGE_SIZE,
-		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap((1UL << 47), 2 * PAGE_SIZE)",
-		.low_addr_required = 1,
-		.keep_mapped = 1,
-	},
-	{
-		.addr = (void *)((1UL << 47) - PAGE_SIZE / 2),
-		.size = 2 * PAGE_SIZE,
-		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap((1UL << 47), 2 * PAGE_SIZE / 2)",
-		.low_addr_required = 1,
-		.keep_mapped = 1,
-	},
-	{
-		.addr = (void *)((1UL << 47) - PAGE_SIZE),
-		.size = 2 * PAGE_SIZE,
-		.flags = MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED,
-		.msg = "mmap((1UL << 47) - PAGE_SIZE, 2 * PAGE_SIZE, MAP_FIXED)",
-	},
-	{
-		.addr = NULL,
-		.size = 2UL << 20,
-		.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(NULL, MAP_HUGETLB)",
-		.low_addr_required = 1,
-	},
-	{
-		.addr = LOW_ADDR,
-		.size = 2UL << 20,
-		.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(LOW_ADDR, MAP_HUGETLB)",
-		.low_addr_required = 1,
-	},
-	{
-		.addr = HIGH_ADDR,
-		.size = 2UL << 20,
-		.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(HIGH_ADDR, MAP_HUGETLB)",
-		.keep_mapped = 1,
-	},
-	{
-		.addr = HIGH_ADDR,
-		.size = 2UL << 20,
-		.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(HIGH_ADDR, MAP_HUGETLB) again",
-		.keep_mapped = 1,
-	},
-	{
-		.addr = HIGH_ADDR,
-		.size = 2UL << 20,
-		.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED,
-		.msg = "mmap(HIGH_ADDR, MAP_FIXED | MAP_HUGETLB)",
-	},
-	{
-		.addr = (void*) -1,
-		.size = 2UL << 20,
-		.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(-1, MAP_HUGETLB)",
-		.keep_mapped = 1,
-	},
-	{
-		.addr = (void*) -1,
-		.size = 2UL << 20,
-		.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(-1, MAP_HUGETLB) again",
-	},
-	{
-		.addr = (void *)((1UL << 47) - PAGE_SIZE),
-		.size = 4UL << 20,
-		.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap((1UL << 47), 4UL << 20, MAP_HUGETLB)",
-		.low_addr_required = 1,
-		.keep_mapped = 1,
-	},
-	{
-		.addr = (void *)((1UL << 47) - (2UL << 20)),
-		.size = 4UL << 20,
-		.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED,
-		.msg = "mmap((1UL << 47) - (2UL << 20), 4UL << 20, MAP_FIXED | MAP_HUGETLB)",
-	},
-};
-
-int main(int argc, char **argv)
-{
-	int i;
-	void *p;
-
-	for (i = 0; i < ARRAY_SIZE(testcases); i++) {
-		struct testcase *t = testcases + i;
-
-		p = mmap(t->addr, t->size, PROT_NONE, t->flags, -1, 0);
-
-		printf("%s: %p - ", t->msg, p);
-
-		if (p == MAP_FAILED) {
-			printf("FAILED\n");
-			continue;
-		}
-
-		if (t->low_addr_required && p >= (void *)(1UL << 47))
-			printf("FAILED\n");
-		else
-			printf("OK\n");
-		if (!t->keep_mapped)
-			munmap(p, t->size);
-	}
-	return 0;
-}