[PATCH v9 7/7] selftest: test system mappings are sealed.

From: jeffxu
Date: Tue Mar 04 2025 - 21:19:17 EST


From: Jeff Xu <jeffxu@xxxxxxxxxxxx>

Add sysmap_is_sealed.c to test system mappings are sealed.

Note: CONFIG_MSEAL_SYSTEM_MAPPINGS must be set, as indicated in
config file.

Signed-off-by: Jeff Xu <jeffxu@xxxxxxxxxxxx>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx>
---
tools/testing/selftests/Makefile | 1 +
.../mseal_system_mappings/.gitignore | 2 +
.../selftests/mseal_system_mappings/Makefile | 6 +
.../selftests/mseal_system_mappings/config | 1 +
.../mseal_system_mappings/sysmap_is_sealed.c | 119 ++++++++++++++++++
5 files changed, 129 insertions(+)
create mode 100644 tools/testing/selftests/mseal_system_mappings/.gitignore
create mode 100644 tools/testing/selftests/mseal_system_mappings/Makefile
create mode 100644 tools/testing/selftests/mseal_system_mappings/config
create mode 100644 tools/testing/selftests/mseal_system_mappings/sysmap_is_sealed.c

diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index 8daac70c2f9d..be836be8f03f 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -61,6 +61,7 @@ TARGETS += mount
TARGETS += mount_setattr
TARGETS += move_mount_set_group
TARGETS += mqueue
+TARGETS += mseal_system_mappings
TARGETS += nci
TARGETS += net
TARGETS += net/af_unix
diff --git a/tools/testing/selftests/mseal_system_mappings/.gitignore b/tools/testing/selftests/mseal_system_mappings/.gitignore
new file mode 100644
index 000000000000..319c497a595e
--- /dev/null
+++ b/tools/testing/selftests/mseal_system_mappings/.gitignore
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+sysmap_is_sealed
diff --git a/tools/testing/selftests/mseal_system_mappings/Makefile b/tools/testing/selftests/mseal_system_mappings/Makefile
new file mode 100644
index 000000000000..2b4504e2f52f
--- /dev/null
+++ b/tools/testing/selftests/mseal_system_mappings/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0-only
+CFLAGS += -std=c99 -pthread -Wall $(KHDR_INCLUDES)
+
+TEST_GEN_PROGS := sysmap_is_sealed
+
+include ../lib.mk
diff --git a/tools/testing/selftests/mseal_system_mappings/config b/tools/testing/selftests/mseal_system_mappings/config
new file mode 100644
index 000000000000..675cb9f37b86
--- /dev/null
+++ b/tools/testing/selftests/mseal_system_mappings/config
@@ -0,0 +1 @@
+CONFIG_MSEAL_SYSTEM_MAPPINGS=y
diff --git a/tools/testing/selftests/mseal_system_mappings/sysmap_is_sealed.c b/tools/testing/selftests/mseal_system_mappings/sysmap_is_sealed.c
new file mode 100644
index 000000000000..0d2af30c3bf5
--- /dev/null
+++ b/tools/testing/selftests/mseal_system_mappings/sysmap_is_sealed.c
@@ -0,0 +1,119 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * test system mappings are sealed when
+ * KCONFIG_MSEAL_SYSTEM_MAPPINGS=y
+ */
+
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <errno.h>
+#include <unistd.h>
+#include <string.h>
+#include <stdbool.h>
+
+#include "../kselftest.h"
+#include "../kselftest_harness.h"
+
+#define VMFLAGS "VmFlags:"
+#define MSEAL_FLAGS "sl"
+#define MAX_LINE_LEN 512
+
+bool has_mapping(char *name, FILE *maps)
+{
+ char line[MAX_LINE_LEN];
+
+ while (fgets(line, sizeof(line), maps)) {
+ if (strstr(line, name))
+ return true;
+ }
+
+ return false;
+}
+
+bool mapping_is_sealed(char *name, FILE *maps)
+{
+ char line[MAX_LINE_LEN];
+
+ while (fgets(line, sizeof(line), maps)) {
+ if (!strncmp(line, VMFLAGS, strlen(VMFLAGS))) {
+ if (strstr(line, MSEAL_FLAGS))
+ return true;
+
+ return false;
+ }
+ }
+
+ return false;
+}
+
+FIXTURE(basic) {
+ FILE *maps;
+};
+
+FIXTURE_SETUP(basic)
+{
+ self->maps = fopen("/proc/self/smaps", "r");
+ if (!self->maps)
+ SKIP(return, "Could not open /proc/self/smap, errno=%d",
+ errno);
+};
+
+FIXTURE_TEARDOWN(basic)
+{
+ if (self->maps)
+ fclose(self->maps);
+};
+
+FIXTURE_VARIANT(basic)
+{
+ char *name;
+ bool sealed;
+};
+
+FIXTURE_VARIANT_ADD(basic, vdso) {
+ .name = "[vdso]",
+ .sealed = true,
+};
+
+FIXTURE_VARIANT_ADD(basic, vvar) {
+ .name = "[vvar]",
+ .sealed = true,
+};
+
+FIXTURE_VARIANT_ADD(basic, vvar_vclock) {
+ .name = "[vvar_vclock]",
+ .sealed = true,
+};
+
+FIXTURE_VARIANT_ADD(basic, sigpage) {
+ .name = "[sigpage]",
+ .sealed = true,
+};
+
+FIXTURE_VARIANT_ADD(basic, vectors) {
+ .name = "[vectors]",
+ .sealed = true,
+};
+
+FIXTURE_VARIANT_ADD(basic, uprobes) {
+ .name = "[uprobes]",
+ .sealed = true,
+};
+
+FIXTURE_VARIANT_ADD(basic, stack) {
+ .name = "[stack]",
+ .sealed = false,
+};
+
+TEST_F(basic, check_sealed)
+{
+ if (!has_mapping(variant->name, self->maps)) {
+ SKIP(return, "could not find the mapping, %s",
+ variant->name);
+ }
+
+ EXPECT_EQ(variant->sealed,
+ mapping_is_sealed(variant->name, self->maps));
+};
+
+TEST_HARNESS_MAIN
--
2.48.1.711.g2feabab25a-goog