1 files changed, 342 insertions, 0 deletions
diff --git a/tools/testing/selftests/clone3/clone3.c b/tools/testing/selftests/clone3/clone3.c
new file mode 100644
index 000000000000..289e0c7c1f09
--- /dev/null
+++ b/tools/testing/selftests/clone3/clone3.c
@@ -0,0 +1,342 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/* Based on Christian Brauner's clone3() example */
+
+#define _GNU_SOURCE
+#include <errno.h>
+#include <inttypes.h>
+#include <linux/types.h>
+#include <linux/sched.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/syscall.h>
+#include <sys/types.h>
+#include <sys/un.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <sched.h>
+
+#include "kselftest.h"
+#include "clone3_selftests.h"
+
+enum test_mode {
+	CLONE3_ARGS_NO_TEST,
+	CLONE3_ARGS_ALL_0,
+	CLONE3_ARGS_INVAL_EXIT_SIGNAL_BIG,
+	CLONE3_ARGS_INVAL_EXIT_SIGNAL_NEG,
+	CLONE3_ARGS_INVAL_EXIT_SIGNAL_CSIG,
+	CLONE3_ARGS_INVAL_EXIT_SIGNAL_NSIG,
+};
+
+static int call_clone3(uint64_t flags, size_t size, enum test_mode test_mode)
+{
+	struct __clone_args args = {
+		.flags = flags,
+		.exit_signal = SIGCHLD,
+	};
+
+	struct clone_args_extended {
+		struct __clone_args args;
+		__aligned_u64 excess_space[2];
+	} args_ext;
+
+	pid_t pid = -1;
+	int status;
+
+	memset(&args_ext, 0, sizeof(args_ext));
+	if (size > sizeof(struct __clone_args))
+		args_ext.excess_space[1] = 1;
+
+	if (size == 0)
+		size = sizeof(struct __clone_args);
+
+	switch (test_mode) {
+	case CLONE3_ARGS_NO_TEST:
+		/*
+		 * Uses default 'flags' and 'SIGCHLD'
+		 * assignment.
+		 */
+		break;
+	case CLONE3_ARGS_ALL_0:
+		args.flags = 0;
+		args.exit_signal = 0;
+		break;
+	case CLONE3_ARGS_INVAL_EXIT_SIGNAL_BIG:
+		args.exit_signal = 0xbadc0ded00000000ULL;
+		break;
+	case CLONE3_ARGS_INVAL_EXIT_SIGNAL_NEG:
+		args.exit_signal = 0x0000000080000000ULL;
+		break;
+	case CLONE3_ARGS_INVAL_EXIT_SIGNAL_CSIG:
+		args.exit_signal = 0x0000000000000100ULL;
+		break;
+	case CLONE3_ARGS_INVAL_EXIT_SIGNAL_NSIG:
+		args.exit_signal = 0x00000000000000f0ULL;
+		break;
+	}
+
+	memcpy(&args_ext.args, &args, sizeof(struct __clone_args));
+
+	pid = sys_clone3((struct __clone_args *)&args_ext, size);
+	if (pid < 0) {
+		ksft_print_msg("%s - Failed to create new process\n",
+				strerror(errno));
+		return -errno;
+	}
+
+	if (pid == 0) {
+		ksft_print_msg("I am the child, my PID is %d\n", getpid());
+		_exit(EXIT_SUCCESS);
+	}
+
+	ksft_print_msg("I am the parent (%d). My child's pid is %d\n",
+			getpid(), pid);
+
+	if (waitpid(-1, &status, __WALL) < 0) {
+		ksft_print_msg("waitpid() returned %s\n", strerror(errno));
+		return -errno;
+	}
+	if (!WIFEXITED(status)) {
+		ksft_print_msg("Child did not exit normally, status 0x%x\n",
+			       status);
+		return EXIT_FAILURE;
+	}
+	if (WEXITSTATUS(status))
+		return WEXITSTATUS(status);
+
+	return 0;
+}
+
+static bool test_clone3(uint64_t flags, size_t size, int expected,
+			enum test_mode test_mode)
+{
+	int ret;
+
+	ksft_print_msg(
+		"[%d] Trying clone3() with flags %#" PRIx64 " (size %zu)\n",
+		getpid(), flags, size);
+	ret = call_clone3(flags, size, test_mode);
+	ksft_print_msg("[%d] clone3() with flags says: %d expected %d\n",
+			getpid(), ret, expected);
+	if (ret != expected) {
+		ksft_print_msg(
+			"[%d] Result (%d) is different than expected (%d)\n",
+			getpid(), ret, expected);
+		return false;
+	}
+
+	return true;
+}
+
+typedef bool (*filter_function)(void);
+typedef size_t (*size_function)(void);
+
+static bool not_root(void)
+{
+	if (getuid() != 0) {
+		ksft_print_msg("Not running as root\n");
+		return true;
+	}
+
+	return false;
+}
+
+static bool no_timenamespace(void)
+{
+	if (not_root())
+		return true;
+
+	if (!access("/proc/self/ns/time", F_OK))
+		return false;
+
+	ksft_print_msg("Time namespaces are not supported\n");
+	return true;
+}
+
+static size_t page_size_plus_8(void)
+{
+	return getpagesize() + 8;
+}
+
+struct test {
+	const char *name;
+	uint64_t flags;
+	size_t size;
+	size_function size_function;
+	int expected;
+	enum test_mode test_mode;
+	filter_function filter;
+};
+
+static const struct test tests[] = {
+	{
+		.name = "simple clone3()",
+		.flags = 0,
+		.size = 0,
+		.expected = 0,
+		.test_mode = CLONE3_ARGS_NO_TEST,
+	},
+	{
+		.name = "clone3() in a new PID_NS",
+		.flags = CLONE_NEWPID,
+		.size = 0,
+		.expected = 0,
+		.test_mode = CLONE3_ARGS_NO_TEST,
+		.filter = not_root,
+	},
+	{
+		.name = "CLONE_ARGS_SIZE_VER0",
+		.flags = 0,
+		.size = CLONE_ARGS_SIZE_VER0,
+		.expected = 0,
+		.test_mode = CLONE3_ARGS_NO_TEST,
+	},
+	{
+		.name = "CLONE_ARGS_SIZE_VER0 - 8",
+		.flags = 0,
+		.size = CLONE_ARGS_SIZE_VER0 - 8,
+		.expected = -EINVAL,
+		.test_mode = CLONE3_ARGS_NO_TEST,
+	},
+	{
+		.name = "sizeof(struct clone_args) + 8",
+		.flags = 0,
+		.size = sizeof(struct __clone_args) + 8,
+		.expected = 0,
+		.test_mode = CLONE3_ARGS_NO_TEST,
+	},
+	{
+		.name = "exit_signal with highest 32 bits non-zero",
+		.flags = 0,
+		.size = 0,
+		.expected = -EINVAL,
+		.test_mode = CLONE3_ARGS_INVAL_EXIT_SIGNAL_BIG,
+	},
+	{
+		.name = "negative 32-bit exit_signal",
+		.flags = 0,
+		.size = 0,
+		.expected = -EINVAL,
+		.test_mode = CLONE3_ARGS_INVAL_EXIT_SIGNAL_NEG,
+	},
+	{
+		.name = "exit_signal not fitting into CSIGNAL mask",
+		.flags = 0,
+		.size = 0,
+		.expected = -EINVAL,
+		.test_mode = CLONE3_ARGS_INVAL_EXIT_SIGNAL_CSIG,
+	},
+	{
+		.name = "NSIG < exit_signal < CSIG",
+		.flags = 0,
+		.size = 0,
+		.expected = -EINVAL,
+		.test_mode = CLONE3_ARGS_INVAL_EXIT_SIGNAL_NSIG,
+	},
+	{
+		.name = "Arguments sizeof(struct clone_args) + 8",
+		.flags = 0,
+		.size = sizeof(struct __clone_args) + 8,
+		.expected = 0,
+		.test_mode = CLONE3_ARGS_ALL_0,
+	},
+	{
+		.name = "Arguments sizeof(struct clone_args) + 16",
+		.flags = 0,
+		.size = sizeof(struct __clone_args) + 16,
+		.expected = -E2BIG,
+		.test_mode = CLONE3_ARGS_ALL_0,
+	},
+	{
+		.name = "Arguments sizeof(struct clone_arg) * 2",
+		.flags = 0,
+		.size = sizeof(struct __clone_args) + 16,
+		.expected = -E2BIG,
+		.test_mode = CLONE3_ARGS_ALL_0,
+	},
+	{
+		.name = "Arguments > page size",
+		.flags = 0,
+		.size_function = page_size_plus_8,
+		.expected = -E2BIG,
+		.test_mode = CLONE3_ARGS_NO_TEST,
+	},
+	{
+		.name = "CLONE_ARGS_SIZE_VER0 in a new PID NS",
+		.flags = CLONE_NEWPID,
+		.size = CLONE_ARGS_SIZE_VER0,
+		.expected = 0,
+		.test_mode = CLONE3_ARGS_NO_TEST,
+		.filter = not_root,
+	},
+	{
+		.name = "CLONE_ARGS_SIZE_VER0 - 8 in a new PID NS",
+		.flags = CLONE_NEWPID,
+		.size = CLONE_ARGS_SIZE_VER0 - 8,
+		.expected = -EINVAL,
+		.test_mode = CLONE3_ARGS_NO_TEST,
+	},
+	{
+		.name = "sizeof(struct clone_args) + 8 in a new PID NS",
+		.flags = CLONE_NEWPID,
+		.size = sizeof(struct __clone_args) + 8,
+		.expected = 0,
+		.test_mode = CLONE3_ARGS_NO_TEST,
+		.filter = not_root,
+	},
+	{
+		.name = "Arguments > page size in a new PID NS",
+		.flags = CLONE_NEWPID,
+		.size_function = page_size_plus_8,
+		.expected = -E2BIG,
+		.test_mode = CLONE3_ARGS_NO_TEST,
+	},
+	{
+		.name = "New time NS",
+		.flags = CLONE_NEWTIME,
+		.size = 0,
+		.expected = 0,
+		.test_mode = CLONE3_ARGS_NO_TEST,
+		.filter = no_timenamespace,
+	},
+	{
+		.name = "exit signal (SIGCHLD) in flags",
+		.flags = SIGCHLD,
+		.size = 0,
+		.expected = -EINVAL,
+		.test_mode = CLONE3_ARGS_NO_TEST,
+	},
+};
+
+int main(int argc, char *argv[])
+{
+	size_t size;
+	int i;
+
+	ksft_print_header();
+	ksft_set_plan(ARRAY_SIZE(tests));
+	test_clone3_supported();
+
+	for (i = 0; i < ARRAY_SIZE(tests); i++) {
+		if (tests[i].filter && tests[i].filter()) {
+			ksft_test_result_skip("%s\n", tests[i].name);
+			continue;
+		}
+
+		if (tests[i].size_function)
+			size = tests[i].size_function();
+		else
+			size = tests[i].size;
+
+		ksft_print_msg("Running test '%s'\n", tests[i].name);
+
+		ksft_test_result(test_clone3(tests[i].flags, size,
+					     tests[i].expected,
+					     tests[i].test_mode),
+				 "%s\n", tests[i].name);
+	}
+
+	ksft_finished();
+}