[PATCH v1] selftest mm/mseal: fix test_seal_mremap_move_dontunmap_anyaddr

[jeffxu]

From: Jeff Xu <jeffxu@xxxxxxxxxxxx>

the syscall remap accepts following:

sys_mremap(ptr, size, size, MREMAP_MAYMOVE | MREMAP_DONTUNMAP,
		(void*) 0xdead0000)

when the src is sealed, the call will fail with when error code:
EPERM

Also remove the dependency on glibc for mremap(), the previous
version of test pass on certain version of glibc and fail in another.
By calling syscall directly, we test and verify remap function
in kernel directly.

Signed-off-by: Jeff Xu <jeffxu@xxxxxxxxxxxx>
Reported-by: Pedro Falcato <pedro.falcato@xxxxxxxxx>
---
 tools/testing/selftests/mm/mseal_test.c | 44 ++++++++++++++-----------
 1 file changed, 25 insertions(+), 19 deletions(-)

diff --git a/tools/testing/selftests/mm/mseal_test.c b/tools/testing/selftests/mm/mseal_test.c
index a818f010de47..45d299fd74ed 100644
--- a/tools/testing/selftests/mm/mseal_test.c
+++ b/tools/testing/selftests/mm/mseal_test.c
@@ -110,6 +110,16 @@ static int sys_madvise(void *start, size_t len, int types)
 	return sret;
 }
 
+static void *sys_mremap(void *addr, size_t old_len, size_t new_len,
+	unsigned long flags, void *new_addr)
+{
+	void *sret;
+
+	errno = 0;
+	sret = (void *) syscall(__NR_mremap, addr, old_len, new_len, flags, new_addr);
+	return sret;
+}
+
 static int sys_pkey_alloc(unsigned long flags, unsigned long init_val)
 {
 	int ret = syscall(__NR_pkey_alloc, flags, init_val);
@@ -1115,12 +1125,12 @@ static void test_seal_mremap_shrink(bool seal)
 	}
 
 	/* shrink from 4 pages to 2 pages. */
-	ret2 = mremap(ptr, size, 2 * page_size, 0, 0);
+	ret2 = sys_mremap(ptr, size, 2 * page_size, 0, 0);
 	if (seal) {
-		FAIL_TEST_IF_FALSE(ret2 == MAP_FAILED);
+		FAIL_TEST_IF_FALSE(ret2 == (void *) MAP_FAILED);
 		FAIL_TEST_IF_FALSE(errno == EPERM);
 	} else {
-		FAIL_TEST_IF_FALSE(ret2 != MAP_FAILED);
+		FAIL_TEST_IF_FALSE(ret2 != (void *) MAP_FAILED);
 
 	}
 
@@ -1147,7 +1157,7 @@ static void test_seal_mremap_expand(bool seal)
 	}
 
 	/* expand from 2 page to 4 pages. */
-	ret2 = mremap(ptr, 2 * page_size, 4 * page_size, 0, 0);
+	ret2 = sys_mremap(ptr, 2 * page_size, 4 * page_size, 0, 0);
 	if (seal) {
 		FAIL_TEST_IF_FALSE(ret2 == MAP_FAILED);
 		FAIL_TEST_IF_FALSE(errno == EPERM);
@@ -1180,7 +1190,7 @@ static void test_seal_mremap_move(bool seal)
 	}
 
 	/* move from ptr to fixed address. */
-	ret2 = mremap(ptr, size, size, MREMAP_MAYMOVE | MREMAP_FIXED, newPtr);
+	ret2 = sys_mremap(ptr, size, size, MREMAP_MAYMOVE | MREMAP_FIXED, newPtr);
 	if (seal) {
 		FAIL_TEST_IF_FALSE(ret2 == MAP_FAILED);
 		FAIL_TEST_IF_FALSE(errno == EPERM);
@@ -1299,7 +1309,7 @@ static void test_seal_mremap_shrink_fixed(bool seal)
 	}
 
 	/* mremap to move and shrink to fixed address */
-	ret2 = mremap(ptr, size, 2 * page_size, MREMAP_MAYMOVE | MREMAP_FIXED,
+	ret2 = sys_mremap(ptr, size, 2 * page_size, MREMAP_MAYMOVE | MREMAP_FIXED,
 			newAddr);
 	if (seal) {
 		FAIL_TEST_IF_FALSE(ret2 == MAP_FAILED);
@@ -1330,7 +1340,7 @@ static void test_seal_mremap_expand_fixed(bool seal)
 	}
 
 	/* mremap to move and expand to fixed address */
-	ret2 = mremap(ptr, page_size, size, MREMAP_MAYMOVE | MREMAP_FIXED,
+	ret2 = sys_mremap(ptr, page_size, size, MREMAP_MAYMOVE | MREMAP_FIXED,
 			newAddr);
 	if (seal) {
 		FAIL_TEST_IF_FALSE(ret2 == MAP_FAILED);
@@ -1361,7 +1371,7 @@ static void test_seal_mremap_move_fixed(bool seal)
 	}
 
 	/* mremap to move to fixed address */
-	ret2 = mremap(ptr, size, size, MREMAP_MAYMOVE | MREMAP_FIXED, newAddr);
+	ret2 = sys_mremap(ptr, size, size, MREMAP_MAYMOVE | MREMAP_FIXED, newAddr);
 	if (seal) {
 		FAIL_TEST_IF_FALSE(ret2 == MAP_FAILED);
 		FAIL_TEST_IF_FALSE(errno == EPERM);
@@ -1390,14 +1400,13 @@ static void test_seal_mremap_move_fixed_zero(bool seal)
 	/*
 	 * MREMAP_FIXED can move the mapping to zero address
 	 */
-	ret2 = mremap(ptr, size, 2 * page_size, MREMAP_MAYMOVE | MREMAP_FIXED,
+	ret2 = sys_mremap(ptr, size, 2 * page_size, MREMAP_MAYMOVE | MREMAP_FIXED,
 			0);
 	if (seal) {
 		FAIL_TEST_IF_FALSE(ret2 == MAP_FAILED);
 		FAIL_TEST_IF_FALSE(errno == EPERM);
 	} else {
 		FAIL_TEST_IF_FALSE(ret2 == 0);
-
 	}
 
 	REPORT_TEST_PASS();
@@ -1420,13 +1429,12 @@ static void test_seal_mremap_move_dontunmap(bool seal)
 	}
 
 	/* mremap to move, and don't unmap src addr. */
-	ret2 = mremap(ptr, size, size, MREMAP_MAYMOVE | MREMAP_DONTUNMAP, 0);
+	ret2 = sys_mremap(ptr, size, size, MREMAP_MAYMOVE | MREMAP_DONTUNMAP, 0);
 	if (seal) {
 		FAIL_TEST_IF_FALSE(ret2 == MAP_FAILED);
 		FAIL_TEST_IF_FALSE(errno == EPERM);
 	} else {
 		FAIL_TEST_IF_FALSE(ret2 != MAP_FAILED);
-
 	}
 
 	REPORT_TEST_PASS();
@@ -1449,18 +1457,16 @@ static void test_seal_mremap_move_dontunmap_anyaddr(bool seal)
 	}
 
 	/*
-	 * The 0xdeaddead should not have effect on dest addr
+	 * The 0xdead0000 should not have effect on dest addr
 	 * when MREMAP_DONTUNMAP is set.
 	 */
-	ret2 = mremap(ptr, size, size, MREMAP_MAYMOVE | MREMAP_DONTUNMAP,
-			0xdeaddead);
+	ret2 = sys_mremap(ptr, size, size, MREMAP_MAYMOVE | MREMAP_DONTUNMAP,
+			(void *) 0xdead0000);
 	if (seal) {
-		FAIL_TEST_IF_FALSE(ret2 == MAP_FAILED);
+		FAIL_TEST_IF_FALSE(ret2 == (void *) MAP_FAILED);
 		FAIL_TEST_IF_FALSE(errno == EPERM);
 	} else {
-		FAIL_TEST_IF_FALSE(ret2 != MAP_FAILED);
-		FAIL_TEST_IF_FALSE((long)ret2 != 0xdeaddead);
-
+		FAIL_TEST_IF_FALSE(ret2 == (void *) 0xdead0000);
 	}
 
 	REPORT_TEST_PASS();
-- 
2.46.0.rc2.264.g509ed76dc8-goog