selftests: add tests for clone3() with *set_tid

This tests clone3() with *set_tid to see if all desired PIDs are working
as expected. The tests are trying multiple invalid input parameters as
well as creating processes while specifying a certain PID in multiple
PID namespaces at the same time.

Additionally this moves common clone3() test code into clone3_selftests.h.

Signed-off-by: Adrian Reber <areber@redhat.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Link: https://lore.kernel.org/r/20191115123621.142252-2-areber@redhat.com
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

Author: adrianreber

tools/testing/selftests/clone3/.gitignore

@@ -1,2 +1,3 @@
 clone3
 clone3_clear_sighand
+clone3_set_tid

tools/testing/selftests/clone3/Makefile

@@ -1,6 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0
 CFLAGS += -g -I../../../../usr/include/
 
-TEST_GEN_PROGS := clone3 clone3_clear_sighand
+TEST_GEN_PROGS := clone3 clone3_clear_sighand clone3_set_tid
 
 include ../lib.mk

tools/testing/selftests/clone3/clone3.c

@@ -18,6 +18,7 @@
 #include <sched.h>
 
 #include "../kselftest.h"
+#include "clone3_selftests.h"
 
 /*
  * Different sizes of struct clone_args
@@ -35,11 +36,6 @@ enum test_mode {
 	CLONE3_ARGS_INVAL_EXIT_SIGNAL_NSIG,
 };
 
-static pid_t raw_clone(struct clone_args *args, size_t size)
-{
-	return syscall(__NR_clone3, args, size);
-}
-
 static int call_clone3(uint64_t flags, size_t size, enum test_mode test_mode)
 {
 	struct clone_args args = {
@@ -83,7 +79,7 @@ static int call_clone3(uint64_t flags, size_t size, enum test_mode test_mode)
 
 	memcpy(&args_ext.args, &args, sizeof(struct clone_args));
 
-	pid = raw_clone((struct clone_args *)&args_ext, size);
+	pid = sys_clone3((struct clone_args *)&args_ext, size);
 	if (pid < 0) {
 		ksft_print_msg("%s - Failed to create new process\n",
 				strerror(errno));

tools/testing/selftests/clone3/clone3_clear_sighand.c

@@ -14,30 +14,12 @@
 #include <sys/wait.h>
 
 #include "../kselftest.h"
+#include "clone3_selftests.h"
 
 #ifndef CLONE_CLEAR_SIGHAND
 #define CLONE_CLEAR_SIGHAND 0x100000000ULL
 #endif
 
-#ifndef __NR_clone3
-#define __NR_clone3 -1
-struct clone_args {
-	__aligned_u64 flags;
-	__aligned_u64 pidfd;
-	__aligned_u64 child_tid;
-	__aligned_u64 parent_tid;
-	__aligned_u64 exit_signal;
-	__aligned_u64 stack;
-	__aligned_u64 stack_size;
-	__aligned_u64 tls;
-};
-#endif
-
-static pid_t sys_clone3(struct clone_args *args, size_t size)
-{
-	return syscall(__NR_clone3, args, size);
-}
-
 static void test_clone3_supported(void)
 {
 	pid_t pid;

tools/testing/selftests/clone3/clone3_selftests.h

@@ -0,0 +1,35 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef _CLONE3_SELFTESTS_H
+#define _CLONE3_SELFTESTS_H
+
+#define _GNU_SOURCE
+#include <sched.h>
+#include <stdint.h>
+#include <syscall.h>
+#include <linux/types.h>
+
+#define ptr_to_u64(ptr) ((__u64)((uintptr_t)(ptr)))
+
+#ifndef __NR_clone3
+#define __NR_clone3 -1
+struct clone_args {
+	__aligned_u64 flags;
+	__aligned_u64 pidfd;
+	__aligned_u64 child_tid;
+	__aligned_u64 parent_tid;
+	__aligned_u64 exit_signal;
+	__aligned_u64 stack;
+	__aligned_u64 stack_size;
+	__aligned_u64 tls;
+	__aligned_u64 set_tid;
+	__aligned_u64 set_tid_size;
+};
+#endif
+
+static pid_t sys_clone3(struct clone_args *args, size_t size)
+{
+	return syscall(__NR_clone3, args, size);
+}
+
+#endif /* _CLONE3_SELFTESTS_H */