[LTP] [PATCH 2/2] hugemmap35: add regression test for 49ccf2c3cafb

[Andrea Cervesato]

From: Andrea Cervesato <andrea.cervesato@suse.com>

Add a regression test verifying that a hugetlbfs file can be mapped
with PROT_MTE even when MAP_HUGETLB is not set in the mmap() flags.

Before the referenced commit, VM_MTE_ALLOWED was not set early enough
for hugetlbfs file mappings, so such an mmap() was wrongly rejected.

Signed-off-by: Andrea Cervesato <andrea.cervesato@suse.com>
---
 runtest/hugetlb                                    |   1 +
 testcases/kernel/mem/.gitignore                    |   1 +
 testcases/kernel/mem/hugetlb/hugemmap/hugemmap35.c | 105 +++++++++++++++++++++
 3 files changed, 107 insertions(+)

diff --git a/runtest/hugetlb b/runtest/hugetlb
index 0896d3c941f068628f53c31197b293906c4ecba6..8ee0e6f828cb1954e03d67d40fe691d6521361bf 100644
--- a/runtest/hugetlb
+++ b/runtest/hugetlb
@@ -36,6 +36,7 @@ hugemmap30 hugemmap30
 hugemmap31 hugemmap31
 hugemmap32 hugemmap32
 hugemmap34 hugemmap34
+hugemmap35 hugemmap35
 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 b4455de51d6d6a9cc3d8b7ff392fc3ea9e95890a..0e59035dfdcf759aa16c069575bb1f4eb58f321c 100644
--- a/testcases/kernel/mem/.gitignore
+++ b/testcases/kernel/mem/.gitignore
@@ -36,6 +36,7 @@
 /hugetlb/hugemmap/hugemmap31
 /hugetlb/hugemmap/hugemmap32
 /hugetlb/hugemmap/hugemmap34
+/hugetlb/hugemmap/hugemmap35
 /hugetlb/hugeshmat/hugeshmat01
 /hugetlb/hugeshmat/hugeshmat02
 /hugetlb/hugeshmat/hugeshmat03
diff --git a/testcases/kernel/mem/hugetlb/hugemmap/hugemmap35.c b/testcases/kernel/mem/hugetlb/hugemmap/hugemmap35.c
new file mode 100644
index 0000000000000000000000000000000000000000..1c11013e0de6b6dd870e3ffc48562912a44cf7f7
--- /dev/null
+++ b/testcases/kernel/mem/hugetlb/hugemmap/hugemmap35.c
@@ -0,0 +1,105 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2026 SUSE LLC Andrea Cervesato <andrea.cervesato@suse.com>
+ */
+
+/*\
+ * Test that :manpage:`mmap(2)` accepts ``PROT_MTE`` for hugetlbfs file
+ * mappings that do not specify ``MAP_HUGETLB``.
+ *
+ * On arm64, hugetlbfs file mappings must get ``VM_MTE_ALLOWED`` before mmap
+ * flag validation. This is needed because mapping a hugetlbfs file does not
+ * have to use ``MAP_HUGETLB``. The test needs root to reserve huge pages and
+ * mount hugetlbfs.
+ */
+
+#define _GNU_SOURCE
+
+#include "tst_test.h"
+#include "hugetlb.h"
+#include "lapi/mman.h"
+#include "lapi/mmap.h"
+
+#define MNTPOINT "hugetlbfs/"
+
+static int fd = -1;
+static long hpage_size;
+
+#define TC(x) {x, #x}
+
+static struct tcase {
+	int flags;
+	const char *desc;
+} tcases[] = {
+	TC(MAP_SHARED),
+	TC(MAP_PRIVATE),
+};
+
+static void run(unsigned int n)
+{
+	struct tcase *tc = &tcases[n];
+	volatile char *ptr;
+
+	TESTPTR(mmap(NULL, hpage_size, PROT_READ | PROT_WRITE | PROT_MTE,
+		     tc->flags, fd, 0));
+
+	if (TST_RET_PTR == MAP_FAILED) {
+		if (TST_ERR == ENOMEM)
+			tst_brk(TCONF, "Not enough huge pages");
+
+		tst_res(TFAIL | TTERRNO, "mmap(PROT_MTE, %s) without MAP_HUGETLB failed",
+			tc->desc);
+		return;
+	}
+
+	ptr = TST_RET_PTR;
+	*ptr = 1;
+
+	SAFE_MUNMAP(TST_RET_PTR, hpage_size);
+
+	tst_res(TPASS, "mmap(PROT_MTE, %s) without MAP_HUGETLB passed", tc->desc);
+}
+
+static void setup(void)
+{
+	hpage_size = tst_get_hugepage_size();
+	if (!hpage_size)
+		tst_brk(TCONF, "Huge pages are not supported");
+
+	TESTPTR(mmap(NULL, hpage_size, PROT_READ | PROT_MTE,
+		     MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB, -1, 0));
+
+	if (TST_RET_PTR == MAP_FAILED)
+		tst_brk(TCONF | TTERRNO, "PROT_MTE is not supported with MAP_HUGETLB");
+
+	SAFE_MUNMAP(TST_RET_PTR, hpage_size);
+
+	fd = tst_creat_unlinked(MNTPOINT, 0, 0600);
+	SAFE_FTRUNCATE(fd, hpage_size);
+}
+
+static void cleanup(void)
+{
+	if (fd != -1)
+		SAFE_CLOSE(fd);
+}
+
+static struct tst_test test = {
+	.test = run,
+	.setup = setup,
+	.cleanup = cleanup,
+	.tcnt = ARRAY_SIZE(tcases),
+	.needs_root = 1,
+	.needs_tmpdir = 1,
+	.mntpoint = MNTPOINT,
+	.needs_hugetlbfs = 1,
+	.hugepages = { 2, TST_NEEDS },
+	.supported_archs = (const char *const []) {
+		"aarch64",
+		NULL
+	},
+	.tags = (const struct tst_tag[]) {
+		{"linux-git", "49ccf2c3cafb"},
+		{}
+	},
+};

-- 
2.51.0