[LTP] [PATCH 11/29] Hugetlb: Migrating libhugetlbfs huge_below_4GB_normal_above

Tarun Sahu tsahu@linux.ibm.com
Sun Oct 16 14:57:13 CEST 2022


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  | 204 ++++++++++++++++++
 3 files changed, 206 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..c49f13935
--- /dev/null
+++ b/testcases/kernel/mem/hugetlb/hugemmap/hugemmap14.c
@@ -0,0 +1,204 @@
+// SPDX-License-Identifier: LGPL-2.1-or-later
+/*
+ * Copyright (C) 2005-2006 David Gibson & Adam Litke, IBM Corporation.
+ *
+ * Test Name: Huge_below_4GB_normal_above
+ *
+ * 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
+ *
+ * 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.
+ *
+ * HISTORY
+ *  Written by David Gibson & Adam Litke
+ *
+ */
+
+#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)
+
+static int  fd = -1;
+static char hfile[MAXPATHLEN];
+static unsigned long hpage_size;
+static char *verbose;
+
+static void run_test(void)
+{
+	int page_size;
+	void *p, *q, *r;
+	unsigned long lowaddr, highaddr;
+	int err;
+
+	page_size = getpagesize();
+
+	fd = SAFE_OPEN(hfile, O_RDWR | O_CREAT, 0600);
+	SAFE_UNLINK(hfile);
+
+	/* We use a low address right below 4GB so we can test for
+	 * off-by-one errors
+	 */
+	lowaddr = FOURGB - hpage_size;
+	if (verbose)
+		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 */
+		unsigned long below_start = FOURGB - 256L*1024*1024;
+		unsigned long above_end = FOURGB;
+
+		if (range_is_mapped(below_start, above_end) == 1) {
+			if (verbose) {
+				tst_res(TINFO, "region (4G-256M)-4G is not free");
+				tst_res(TINFO|TERRNO, "mmap() failed");
+			}
+			tst_res(TPASS, "Successful but inconclusive");
+			SAFE_CLOSE(fd);
+			return;
+		}
+		tst_res(TFAIL|TERRNO, "mmap() huge");
+		goto fail;
+	}
+	if (p != (void *)lowaddr) {
+		tst_res(TFAIL, "Wrong address with MAP_FIXED huge");
+		goto fail;
+	}
+	if (verbose)
+		tst_res(TINFO, "done");
+	memset(p, 0, hpage_size);
+
+	err = test_addr_huge(p);
+	if (err != 1) {
+		tst_res(TFAIL, "Mapped address is not hugepage");
+		goto fail;
+	}
+
+	/* Test for off by one errors */
+	highaddr = FOURGB;
+	if (verbose)
+		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) {
+		unsigned long below_start = FOURGB;
+		unsigned long above_end = FOURGB + page_size;
+
+		if (range_is_mapped(below_start, above_end) == 1) {
+			if (verbose) {
+				tst_res(TINFO, "region 4G-(4G+page) is not free\n");
+				tst_res(TINFO|TERRNO, "mmap() failed");
+			}
+			tst_res(TPASS, "Successful but inconclusive");
+			SAFE_MUNMAP(p, hpage_size);
+			SAFE_CLOSE(fd);
+			return;
+		}
+		tst_res(TFAIL|TERRNO, "mmap() normal 1");
+		goto fail;
+	}
+	if (q != (void *)highaddr) {
+		tst_res(TFAIL, "Wrong address with MAP_FIXED normal 2");
+		goto fail;
+	}
+	if (verbose)
+		tst_res(TINFO, "done");
+
+	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;
+	if (verbose)
+		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) {
+		unsigned long below_start = highaddr;
+		unsigned long above_end = highaddr + page_size;
+
+		if (range_is_mapped(below_start, above_end) == 1) {
+			if (verbose) {
+				tst_res(TINFO, "region haddr-(haddr+page) not free");
+				tst_res(TINFO|TERRNO, "mmap() failed");
+			}
+			tst_res(TPASS, "Successful but inconclusive");
+			SAFE_MUNMAP(p, hpage_size);
+			SAFE_MUNMAP(q, page_size);
+			SAFE_CLOSE(fd);
+			return;
+		}
+		tst_res(TFAIL|TERRNO, "mmap() normal 2");
+		goto fail;
+	}
+	if (r != (void *)highaddr) {
+		tst_res(TFAIL, "Wrong address with MAP_FIXED normal 2");
+		goto fail;
+	}
+	if (verbose)
+		tst_res(TINFO, "done");
+
+	memset(r, 0, page_size);
+	tst_res(TPASS, "Successful");
+	SAFE_MUNMAP(p, hpage_size);
+	SAFE_MUNMAP(q, page_size);
+	SAFE_MUNMAP(r, page_size);
+	SAFE_CLOSE(fd);
+	return;
+fail:
+	tst_brk(TBROK, "Once failed, No point in continuing the test");
+}
+
+static void setup(void)
+{
+	if (tst_hugepages < 1)
+		tst_brk(TCONF, "Not enough hugepages for testing.");
+
+	if (!Hopt)
+		Hopt = tst_get_tmpdir();
+	SAFE_MOUNT("none", Hopt, "hugetlbfs", 0, NULL);
+
+	snprintf(hfile, sizeof(hfile), "%s/ltp_hugetlbfile%d", Hopt, getpid());
+	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");
+}
+
+static void cleanup(void)
+{
+	if (fd >= 0)
+		SAFE_CLOSE(fd);
+	umount2(Hopt, MNT_DETACH);
+}
+
+static struct tst_test test = {
+	.needs_root = 1,
+	.needs_tmpdir = 1,
+	.options = (struct tst_option[]) {
+		{"v", &verbose, "Turns on verbose mode"},
+		{"H:", &Hopt,   "Location of hugetlbfs, i.e.  -H /var/hugetlbfs"},
+		{"s:", &nr_opt, "Set the number of the been allocated hugepages"},
+		{}
+	},
+	.setup = setup,
+	.cleanup = cleanup,
+	.test_all = run_test,
+	.hugepages = {1, TST_REQUEST},
+};
-- 
2.31.1



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