[LTP] [PATCH 3/8] Hugetlb: Migrating libhugetlbfs huge_below_4GB_normal_above

Tarun Sahu
2022-12-01T12:03:47Z

Migrating the libhugetlbfs/testcases/huge_below_4GB_normal_above.c test

Test Description: Designed to pick up a bug on ppc64 where
touches_hugepage_low_range() could give false positives because of the
peculiar (undefined) behaviour of << for large shifts

Signed-off-by: Tarun Sahu <tsahu@linux.ibm.com>
---
runtest/hugetlb | 1 +
testcases/kernel/mem/.gitignore | 1 +
.../kernel/mem/hugetlb/hugemmap/hugemmap14.c | 156 ++++++++++++++++++
3 files changed, 158 insertions(+)
create mode 100644 testcases/kernel/mem/hugetlb/hugemmap/hugemmap14.c

diff --git a/runtest/hugetlb b/runtest/hugetlb
index 2029ee4b3..796ebe7fa 100644
--- a/runtest/hugetlb
+++ b/runtest/hugetlb
@@ -15,6 +15,7 @@ hugemmap10 hugemmap10
hugemmap11 hugemmap11
hugemmap12 hugemmap12
hugemmap13 hugemmap13
+hugemmap14 hugemmap14
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 5955ed613..3106579ce 100644
--- a/testcases/kernel/mem/.gitignore
+++ b/testcases/kernel/mem/.gitignore
@@ -14,6 +14,7 @@
/hugetlb/hugemmap/hugemmap11
/hugetlb/hugemmap/hugemmap12
/hugetlb/hugemmap/hugemmap13
+/hugetlb/hugemmap/hugemmap14
/hugetlb/hugeshmat/hugeshmat01
/hugetlb/hugeshmat/hugeshmat02
/hugetlb/hugeshmat/hugeshmat03
diff --git a/testcases/kernel/mem/hugetlb/hugemmap/hugemmap14.c b/testcases/kernel/mem/hugetlb/hugemmap/hugemmap14.c
new file mode 100644
index 000000000..8ccd141f8
--- /dev/null
+++ b/testcases/kernel/mem/hugetlb/hugemmap/hugemmap14.c
@@ -0,0 +1,156 @@
+// SPDX-License-Identifier: LGPL-2.1-or-later
+/*
+ * Copyright (C) 2005-2006 David Gibson & Adam Litke, IBM Corporation.
+ * Author: David Gibson & Adam Litke
+ */
+
+/*\
+ * [Description]
+ *
+ * Designed to pick up a bug on ppc64 where touches_hugepage_low_range()
+ * could give false positives because of the peculiar (undefined)
+ * behaviour of << for large shifts
+ *
+ * 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, *r = NULL;
+ unsigned long lowaddr, highaddr;
+ unsigned long below_start;
+ unsigned long above_end;
+
+ /*
+ * We use a low address right below 4GB so we can test for
+ * off-by-one errors
+ */
+ lowaddr = FOURGB - hpage_size;
+ tst_res(TINFO, "Mapping hugepage at %lx...", lowaddr);
+ p = mmap((void *)lowaddr, hpage_size, PROT_READ|PROT_WRITE,
+ MAP_SHARED|MAP_FIXED, fd, 0);
+ if (p == MAP_FAILED) {
+ /* This is last low slice - 256M just before 4G */
+ below_start = FOURGB - 256L*1024*1024;
+ above_end = FOURGB;
+
+ if (range_is_mapped(below_start, above_end) == 1) {
+ tst_res(TINFO|TERRNO, "region (4G-256M)-4G 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 *)lowaddr) {
+ tst_res(TFAIL, "Wrong address with MAP_FIXED huge");
+ goto cleanup;
+ }
+ memset(p, 0, hpage_size);
+
+ /* Test for off by one errors */
+ highaddr = FOURGB;
+ tst_res(TINFO, "Mapping normal page at %lx...", highaddr);
+ q = mmap((void *)highaddr, page_size, PROT_READ|PROT_WRITE,
+ MAP_SHARED|MAP_FIXED|MAP_ANONYMOUS, 0, 0);
+ if (q == MAP_FAILED) {
+ below_start = FOURGB;
+ above_end = FOURGB + page_size;
+
+ if (range_is_mapped(below_start, above_end) == 1) {
+ tst_res(TINFO|TERRNO, "region 4G-(4G+page) is not free & "
+ "mmap() failed expected");
+ tst_res(TPASS, "Successful but inconclusive");
+ } else
+ tst_res(TFAIL|TERRNO, "mmap() normal 1 failed unexpected");
+ goto cleanup;
+ }
+ if (q != (void *)highaddr) {
+ tst_res(TFAIL, "Wrong address with MAP_FIXED normal 1");
+ goto cleanup;
+ }
+ memset(q, 0, page_size);
+
+ /*
+ * Why this address? Well on ppc64, we're working with 256MB
+ * segment numbers, hence >>28. In practice the shift
+ * instructions only start wrapping around with shifts 128 or
+ * greater.
+ */
+ highaddr = ((lowaddr >> 28) + 128) << 28;
+ tst_res(TINFO, "Mapping normal page at %lx...", highaddr);
+ r = mmap((void *)highaddr, page_size, PROT_READ|PROT_WRITE,
+ MAP_SHARED|MAP_FIXED|MAP_ANONYMOUS, 0, 0);
+ if (r == MAP_FAILED) {
+ below_start = highaddr;
+ above_end = highaddr + page_size;
+
+ if (range_is_mapped(below_start, above_end) == 1) {
+ tst_res(TINFO|TERRNO, "region haddr-(haddr+page) not free & "
+ "mmap() failed unexpected");
+ tst_res(TPASS, "Successful but inconclusive");
+ }
+ tst_res(TFAIL|TERRNO, "mmap() normal 2 failed unexpected");
+ goto cleanup;
+ }
+ if (r != (void *)highaddr) {
+ tst_res(TFAIL, "Wrong address with MAP_FIXED normal 2");
+ goto cleanup;
+ }
+ memset(r, 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);
+ if (r && r != MAP_FAILED)
+ SAFE_MUNMAP(r, 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 = {
+ .needs_root = 1,
+ .mntpoint = MNTPOINT,
+ .needs_hugetlbfs = 1,
+ .needs_tmpdir = 1,
+ .setup = setup,
+ .cleanup = cleanup,
+ .test_all = run_test,
+ .hugepages = {2, TST_NEEDS},