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Diffstat (limited to 'tools/testing/selftests/mm/mdwe_test.c')
-rw-r--r--tools/testing/selftests/mm/mdwe_test.c303
1 files changed, 303 insertions, 0 deletions
diff --git a/tools/testing/selftests/mm/mdwe_test.c b/tools/testing/selftests/mm/mdwe_test.c
new file mode 100644
index 000000000000..200bedcdc32e
--- /dev/null
+++ b/tools/testing/selftests/mm/mdwe_test.c
@@ -0,0 +1,303 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#ifdef __aarch64__
+#include <asm/hwcap.h>
+#endif
+
+#include <linux/mman.h>
+#include <linux/prctl.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/auxv.h>
+#include <sys/prctl.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#include "../kselftest_harness.h"
+
+#ifndef __aarch64__
+# define PROT_BTI 0
+#endif
+
+TEST(prctl_flags)
+{
+ EXPECT_LT(prctl(PR_SET_MDWE, PR_MDWE_NO_INHERIT, 0L, 0L, 7L), 0);
+ EXPECT_EQ(errno, EINVAL);
+
+ EXPECT_LT(prctl(PR_SET_MDWE, 7L, 0L, 0L, 0L), 0);
+ EXPECT_EQ(errno, EINVAL);
+ EXPECT_LT(prctl(PR_SET_MDWE, 0L, 7L, 0L, 0L), 0);
+ EXPECT_EQ(errno, EINVAL);
+ EXPECT_LT(prctl(PR_SET_MDWE, 0L, 0L, 7L, 0L), 0);
+ EXPECT_EQ(errno, EINVAL);
+ EXPECT_LT(prctl(PR_SET_MDWE, 0L, 0L, 0L, 7L), 0);
+ EXPECT_EQ(errno, EINVAL);
+
+ EXPECT_LT(prctl(PR_GET_MDWE, 7L, 0L, 0L, 0L), 0);
+ EXPECT_EQ(errno, EINVAL);
+ EXPECT_LT(prctl(PR_GET_MDWE, 0L, 7L, 0L, 0L), 0);
+ EXPECT_EQ(errno, EINVAL);
+ EXPECT_LT(prctl(PR_GET_MDWE, 0L, 0L, 7L, 0L), 0);
+ EXPECT_EQ(errno, EINVAL);
+ EXPECT_LT(prctl(PR_GET_MDWE, 0L, 0L, 0L, 7L), 0);
+ EXPECT_EQ(errno, EINVAL);
+}
+
+FIXTURE(consecutive_prctl_flags) {};
+FIXTURE_SETUP(consecutive_prctl_flags) {}
+FIXTURE_TEARDOWN(consecutive_prctl_flags) {}
+
+FIXTURE_VARIANT(consecutive_prctl_flags)
+{
+ unsigned long first_flags;
+ unsigned long second_flags;
+ bool should_work;
+};
+
+FIXTURE_VARIANT_ADD(consecutive_prctl_flags, can_keep_no_flags)
+{
+ .first_flags = 0,
+ .second_flags = 0,
+ .should_work = true,
+};
+
+FIXTURE_VARIANT_ADD(consecutive_prctl_flags, can_keep_exec_gain)
+{
+ .first_flags = PR_MDWE_REFUSE_EXEC_GAIN,
+ .second_flags = PR_MDWE_REFUSE_EXEC_GAIN,
+ .should_work = true,
+};
+
+FIXTURE_VARIANT_ADD(consecutive_prctl_flags, can_keep_both_flags)
+{
+ .first_flags = PR_MDWE_REFUSE_EXEC_GAIN | PR_MDWE_NO_INHERIT,
+ .second_flags = PR_MDWE_REFUSE_EXEC_GAIN | PR_MDWE_NO_INHERIT,
+ .should_work = true,
+};
+
+FIXTURE_VARIANT_ADD(consecutive_prctl_flags, cant_disable_mdwe)
+{
+ .first_flags = PR_MDWE_REFUSE_EXEC_GAIN,
+ .second_flags = 0,
+ .should_work = false,
+};
+
+FIXTURE_VARIANT_ADD(consecutive_prctl_flags, cant_disable_mdwe_no_inherit)
+{
+ .first_flags = PR_MDWE_REFUSE_EXEC_GAIN | PR_MDWE_NO_INHERIT,
+ .second_flags = 0,
+ .should_work = false,
+};
+
+FIXTURE_VARIANT_ADD(consecutive_prctl_flags, cant_disable_no_inherit)
+{
+ .first_flags = PR_MDWE_REFUSE_EXEC_GAIN | PR_MDWE_NO_INHERIT,
+ .second_flags = PR_MDWE_REFUSE_EXEC_GAIN,
+ .should_work = false,
+};
+
+FIXTURE_VARIANT_ADD(consecutive_prctl_flags, cant_enable_no_inherit)
+{
+ .first_flags = PR_MDWE_REFUSE_EXEC_GAIN,
+ .second_flags = PR_MDWE_REFUSE_EXEC_GAIN | PR_MDWE_NO_INHERIT,
+ .should_work = false,
+};
+
+TEST_F(consecutive_prctl_flags, two_prctls)
+{
+ int ret;
+
+ EXPECT_EQ(prctl(PR_SET_MDWE, variant->first_flags, 0L, 0L, 0L), 0);
+
+ ret = prctl(PR_SET_MDWE, variant->second_flags, 0L, 0L, 0L);
+ if (variant->should_work) {
+ EXPECT_EQ(ret, 0);
+
+ ret = prctl(PR_GET_MDWE, 0L, 0L, 0L, 0L);
+ ASSERT_EQ(ret, variant->second_flags);
+ } else {
+ EXPECT_NE(ret, 0);
+ ASSERT_EQ(errno, EPERM);
+ }
+}
+
+FIXTURE(mdwe)
+{
+ void *p;
+ int flags;
+ size_t size;
+ pid_t pid;
+};
+
+FIXTURE_VARIANT(mdwe)
+{
+ bool enabled;
+ bool forked;
+ bool inherit;
+};
+
+FIXTURE_VARIANT_ADD(mdwe, stock)
+{
+ .enabled = false,
+ .forked = false,
+ .inherit = false,
+};
+
+FIXTURE_VARIANT_ADD(mdwe, enabled)
+{
+ .enabled = true,
+ .forked = false,
+ .inherit = true,
+};
+
+FIXTURE_VARIANT_ADD(mdwe, inherited)
+{
+ .enabled = true,
+ .forked = true,
+ .inherit = true,
+};
+
+FIXTURE_VARIANT_ADD(mdwe, not_inherited)
+{
+ .enabled = true,
+ .forked = true,
+ .inherit = false,
+};
+
+static bool executable_map_should_fail(const FIXTURE_VARIANT(mdwe) *variant)
+{
+ return variant->enabled && (!variant->forked || variant->inherit);
+}
+
+FIXTURE_SETUP(mdwe)
+{
+ unsigned long mdwe_flags;
+ int ret, status;
+
+ self->p = NULL;
+ self->flags = MAP_SHARED | MAP_ANONYMOUS;
+ self->size = getpagesize();
+
+ if (!variant->enabled)
+ return;
+
+ mdwe_flags = PR_MDWE_REFUSE_EXEC_GAIN;
+ if (!variant->inherit)
+ mdwe_flags |= PR_MDWE_NO_INHERIT;
+
+ ret = prctl(PR_SET_MDWE, mdwe_flags, 0L, 0L, 0L);
+ ASSERT_EQ(ret, 0) {
+ TH_LOG("PR_SET_MDWE failed or unsupported");
+ }
+
+ ret = prctl(PR_GET_MDWE, 0L, 0L, 0L, 0L);
+ ASSERT_EQ(ret, mdwe_flags);
+
+ if (variant->forked) {
+ self->pid = fork();
+ ASSERT_GE(self->pid, 0) {
+ TH_LOG("fork failed\n");
+ }
+
+ if (self->pid > 0) {
+ ret = waitpid(self->pid, &status, 0);
+ ASSERT_TRUE(WIFEXITED(status));
+ exit(WEXITSTATUS(status));
+ }
+ }
+}
+
+FIXTURE_TEARDOWN(mdwe)
+{
+ if (self->p && self->p != MAP_FAILED)
+ munmap(self->p, self->size);
+}
+
+TEST_F(mdwe, mmap_READ_EXEC)
+{
+ self->p = mmap(NULL, self->size, PROT_READ | PROT_EXEC, self->flags, 0, 0);
+ EXPECT_NE(self->p, MAP_FAILED);
+}
+
+TEST_F(mdwe, mmap_WRITE_EXEC)
+{
+ self->p = mmap(NULL, self->size, PROT_WRITE | PROT_EXEC, self->flags, 0, 0);
+ if (executable_map_should_fail(variant)) {
+ EXPECT_EQ(self->p, MAP_FAILED);
+ } else {
+ EXPECT_NE(self->p, MAP_FAILED);
+ }
+}
+
+TEST_F(mdwe, mprotect_stay_EXEC)
+{
+ int ret;
+
+ self->p = mmap(NULL, self->size, PROT_READ | PROT_EXEC, self->flags, 0, 0);
+ ASSERT_NE(self->p, MAP_FAILED);
+
+ ret = mprotect(self->p, self->size, PROT_READ | PROT_EXEC);
+ EXPECT_EQ(ret, 0);
+}
+
+TEST_F(mdwe, mprotect_add_EXEC)
+{
+ int ret;
+
+ self->p = mmap(NULL, self->size, PROT_READ, self->flags, 0, 0);
+ ASSERT_NE(self->p, MAP_FAILED);
+
+ ret = mprotect(self->p, self->size, PROT_READ | PROT_EXEC);
+ if (executable_map_should_fail(variant)) {
+ EXPECT_LT(ret, 0);
+ } else {
+ EXPECT_EQ(ret, 0);
+ }
+}
+
+TEST_F(mdwe, mprotect_WRITE_EXEC)
+{
+ int ret;
+
+ self->p = mmap(NULL, self->size, PROT_WRITE, self->flags, 0, 0);
+ ASSERT_NE(self->p, MAP_FAILED);
+
+ ret = mprotect(self->p, self->size, PROT_WRITE | PROT_EXEC);
+ if (executable_map_should_fail(variant)) {
+ EXPECT_LT(ret, 0);
+ } else {
+ EXPECT_EQ(ret, 0);
+ }
+}
+
+TEST_F(mdwe, mmap_FIXED)
+{
+ void *p;
+
+ self->p = mmap(NULL, self->size, PROT_READ, self->flags, 0, 0);
+ ASSERT_NE(self->p, MAP_FAILED);
+
+ /* MAP_FIXED unmaps the existing page before mapping which is allowed */
+ p = mmap(self->p, self->size, PROT_READ | PROT_EXEC,
+ self->flags | MAP_FIXED, 0, 0);
+ EXPECT_EQ(p, self->p);
+}
+
+TEST_F(mdwe, arm64_BTI)
+{
+ int ret;
+
+#ifdef __aarch64__
+ if (!(getauxval(AT_HWCAP2) & HWCAP2_BTI))
+#endif
+ SKIP(return, "HWCAP2_BTI not supported");
+
+ self->p = mmap(NULL, self->size, PROT_EXEC, self->flags, 0, 0);
+ ASSERT_NE(self->p, MAP_FAILED);
+
+ ret = mprotect(self->p, self->size, PROT_EXEC | PROT_BTI);
+ EXPECT_EQ(ret, 0);
+}
+
+TEST_HARNESS_MAIN
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.