[LTP] [PATCH v2 2/8] Hugetlb: Migrating libhugetlbfs huge_at_4GB_normal_below

[Tarun Sahu]

Migrating the libhugetlbfs/testcases/huge_at_4GB_normal_below.c test

Test Description: On some old ppc64 kernel, when hpage is mmaped on 32 bit
boundary and normal page below it, it triggers the bug caused by
off-by-one error.

Signed-off-by: Tarun Sahu <tsahu@linux.ibm.com>
---
 runtest/hugetlb                               |   1 +
 testcases/kernel/mem/.gitignore               |   1 +
 .../kernel/mem/hugetlb/hugemmap/hugemmap13.c  | 126 ++++++++++++++++++
 3 files changed, 128 insertions(+)
 create mode 100644 testcases/kernel/mem/hugetlb/hugemmap/hugemmap13.c

diff --git a/runtest/hugetlb b/runtest/hugetlb
index 4c16e1e7c..2029ee4b3 100644
--- a/runtest/hugetlb
+++ b/runtest/hugetlb
@@ -14,6 +14,7 @@ hugemmap09 hugemmap09
 hugemmap10 hugemmap10
 hugemmap11 hugemmap11
 hugemmap12 hugemmap12
+hugemmap13 hugemmap13
 hugemmap05_1 hugemmap05 -m
 hugemmap05_2 hugemmap05 -s
 hugemmap05_3 hugemmap05 -s -m
diff --git a/testcases/kernel/mem/.gitignore b/testcases/kernel/mem/.gitignore
index adea760c7..5955ed613 100644
--- a/testcases/kernel/mem/.gitignore
+++ b/testcases/kernel/mem/.gitignore
@@ -13,6 +13,7 @@
 /hugetlb/hugemmap/hugemmap10
 /hugetlb/hugemmap/hugemmap11
 /hugetlb/hugemmap/hugemmap12
+/hugetlb/hugemmap/hugemmap13
 /hugetlb/hugeshmat/hugeshmat01
 /hugetlb/hugeshmat/hugeshmat02
 /hugetlb/hugeshmat/hugeshmat03
diff --git a/testcases/kernel/mem/hugetlb/hugemmap/hugemmap13.c b/testcases/kernel/mem/hugetlb/hugemmap/hugemmap13.c
new file mode 100644
index 000000000..7235c55ac
--- /dev/null
+++ b/testcases/kernel/mem/hugetlb/hugemmap/hugemmap13.c
@@ -0,0 +1,126 @@
+// SPDX-License-Identifier: LGPL-2.1-or-later
+/*
+ * Copyright (C) 2005-2006 David Gibson & Adam Litke, IBM Corporation.
+ * Author: David Gibson & Adam Litke
+ */
+
+/*\
+ * [Description]
+ *
+ * On some old ppc64 kernel, when hpage is mmaped on 32 bit boundary and
+ * normal page below it, it triggers the bug caused by off-by-one error.
+ *
+ * WARNING: The offsets and addresses used within are specifically
+ * calculated to trigger the bug as it existed. Don't mess with them
+ * unless you *really* know what you're doing.
+ */
+
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <sys/mount.h>
+#include <limits.h>
+#include <sys/param.h>
+#include <sys/types.h>
+
+#include "hugetlb.h"
+
+#define FOURGB (1UL << 32)
+#define MNTPOINT "hugetlbfs/"
+static int  fd = -1;
+static unsigned long hpage_size;
+static int page_size;
+
+static void run_test(void)
+{
+	void *p, *q = NULL;
+	unsigned long lowaddr;
+	unsigned long below_start;
+	unsigned long above_end;
+
+	p = mmap((void *)FOURGB, hpage_size, PROT_READ|PROT_WRITE,
+		 MAP_SHARED | MAP_FIXED, fd, 0);
+	if (p == MAP_FAILED) {
+		/* slice 0 (high) spans from 4G-1T */
+		below_start = FOURGB;
+		above_end = 1024L*1024*1024*1024;
+
+		if (range_is_mapped(below_start, above_end) == 1) {
+			tst_res(TINFO|TERRNO, "region 4G-IT is not free & "
+					"mmap() failed expected");
+			tst_res(TPASS, "Successful but inconclusive");
+		} else
+			tst_res(TFAIL|TERRNO, "mmap() huge failed unexpected");
+		goto cleanup;
+	}
+	if (p != (void *)FOURGB) {
+		tst_res(TFAIL, "Wrong address with MAP_FIXED huge");
+		goto cleanup;
+	}
+
+	tst_res(TINFO, "Mapped hugetlb at %p", p);
+
+	memset(p, 0, hpage_size);
+
+	/* Test just below 4GB to check for off-by-one errors */
+	lowaddr = FOURGB - page_size;
+	q = mmap((void *)lowaddr, page_size, PROT_READ|PROT_WRITE,
+		 MAP_SHARED|MAP_FIXED|MAP_ANONYMOUS, 0, 0);
+	if (q == MAP_FAILED) {
+		below_start = FOURGB - page_size;
+		above_end = FOURGB;
+
+		if (range_is_mapped(below_start, above_end) == 1) {
+			tst_res(TINFO|TERRNO, "region (4G-page)-4G is not free & "
+					"mmap() failed expected");
+			tst_res(TPASS, "Successful but inconclusive");
+		} else
+			tst_res(TFAIL|TERRNO, "mmap() normal failed unexpected");
+		goto cleanup;
+	}
+	if (q != (void *)lowaddr) {
+		tst_res(TFAIL, "Wrong address with MAP_FIXED normal");
+		goto cleanup;
+	}
+
+	memset(q, 0, page_size);
+	tst_res(TPASS, "Successful");
+
+cleanup:
+	if (p && p != MAP_FAILED)
+		SAFE_MUNMAP(p, hpage_size);
+	if (q && q != MAP_FAILED)
+		SAFE_MUNMAP(q, page_size);
+}
+
+static void setup(void)
+{
+	page_size = getpagesize();
+	hpage_size = SAFE_READ_MEMINFO("Hugepagesize:")*1024;
+
+	if (sizeof(void *) <= 4)
+		tst_brk(TCONF, "Machine must be >32 bit");
+	if (hpage_size > FOURGB)
+		tst_brk(TCONF, "Huge page size is too large");
+	fd = tst_creat_unlinked(MNTPOINT, 0);
+}
+
+static void cleanup(void)
+{
+	if (fd > 0)
+		SAFE_CLOSE(fd);
+}
+
+static struct tst_test test = {
+	.tags = (struct tst_tag[]) {
+		{"linux-git", "9a94c5793a7b"},
+		{}
+	},
+	.needs_root = 1,
+	.mntpoint = MNTPOINT,
+	.needs_hugetlbfs = 1,
+	.needs_tmpdir = 1,
+	.setup = setup,
+	.cleanup = cleanup,
+	.test_all = run_test,
+	.hugepages = {2, TST_NEEDS},
+};
-- 
2.31.1