copy_process: pass clone_flags as u64 across calltree

With the introduction of clone3 in commit 7f192e3cd3 ("fork: add
clone3") the effective bit width of clone_flags on all architectures was
increased from 32-bit to 64-bit, with a new type of u64 for the flags.
However, for most consumers of clone_flags the interface was not
changed from the previous type of unsigned long.

While this works fine as long as none of the new 64-bit flag bits
(CLONE_CLEAR_SIGHAND and CLONE_INTO_CGROUP) are evaluated, this is still
undesirable in terms of the principle of least surprise.

Thus, this commit fixes all relevant interfaces of callees to
sys_clone3/copy_process (excluding the architecture-specific
copy_thread) to consistently pass clone_flags as u64, so that
no truncation to 32-bit integers occurs on 32-bit architectures.

Signed-off-by: Simon Schuster <schuster.simon@siemens-energy.com>
Link: https://lore.kernel.org/20250901-nios2-implement-clone3-v2-2-53fcf5577d57@siemens-energy.com
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>

kernel/cgroup/namespace.c

@@ -47,7 +47,7 @@ void free_cgroup_ns(struct cgroup_namespace *ns)
 }
 EXPORT_SYMBOL(free_cgroup_ns);
 
-struct cgroup_namespace *copy_cgroup_ns(unsigned long flags,
+struct cgroup_namespace *copy_cgroup_ns(u64 flags,
 					struct user_namespace *user_ns,
 					struct cgroup_namespace *old_ns)
 {

kernel/cred.c

@@ -287,7 +287,7 @@ struct cred *prepare_exec_creds(void)
  * The new process gets the current process's subjective credentials as its
  * objective and subjective credentials
  */
-int copy_creds(struct task_struct *p, unsigned long clone_flags)
+int copy_creds(struct task_struct *p, u64 clone_flags)
 {
 	struct cred *new;
 	int ret;

kernel/events/uprobes.c

@@ -2160,7 +2160,7 @@ static void dup_xol_work(struct callback_head *work)
 /*
  * Called in context of a new clone/fork from copy_process.
  */
-void uprobe_copy_process(struct task_struct *t, unsigned long flags)
+void uprobe_copy_process(struct task_struct *t, u64 flags)
 {
 	struct uprobe_task *utask = current->utask;
 	struct mm_struct *mm = current->mm;

kernel/fork.c

@@ -1507,7 +1507,7 @@ static struct mm_struct *dup_mm(struct task_struct *tsk,
 	return NULL;
 }
 
-static int copy_mm(unsigned long clone_flags, struct task_struct *tsk)
+static int copy_mm(u64 clone_flags, struct task_struct *tsk)
 {
 	struct mm_struct *mm, *oldmm;
 
@@ -1545,7 +1545,7 @@ static int copy_mm(unsigned long clone_flags, struct task_struct *tsk)
 	return 0;
 }
 
-static int copy_fs(unsigned long clone_flags, struct task_struct *tsk)
+static int copy_fs(u64 clone_flags, struct task_struct *tsk)
 {
 	struct fs_struct *fs = current->fs;
 	if (clone_flags & CLONE_FS) {
@@ -1566,7 +1566,7 @@ static int copy_fs(unsigned long clone_flags, struct task_struct *tsk)
 	return 0;
 }
 
-static int copy_files(unsigned long clone_flags, struct task_struct *tsk,
+static int copy_files(u64 clone_flags, struct task_struct *tsk,
 		      int no_files)
 {
 	struct files_struct *oldf, *newf;
@@ -1645,7 +1645,7 @@ static void posix_cpu_timers_init_group(struct signal_struct *sig)
 	posix_cputimers_group_init(pct, cpu_limit);
 }
 
-static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
+static int copy_signal(u64 clone_flags, struct task_struct *tsk)
 {
 	struct signal_struct *sig;
 

kernel/nsproxy.c

@@ -64,7 +64,7 @@ static inline struct nsproxy *create_nsproxy(void)
  * Return the newly created nsproxy.  Do not attach this to the task,
  * leave it to the caller to do proper locking and attach it to task.
  */
-static struct nsproxy *create_new_namespaces(unsigned long flags,
+static struct nsproxy *create_new_namespaces(u64 flags,
 	struct task_struct *tsk, struct user_namespace *user_ns,
 	struct fs_struct *new_fs)
 {
@@ -144,7 +144,7 @@ static struct nsproxy *create_new_namespaces(unsigned long flags,
  * called from clone.  This now handles copy for nsproxy and all
  * namespaces therein.
  */
-int copy_namespaces(unsigned long flags, struct task_struct *tsk)
+int copy_namespaces(u64 flags, struct task_struct *tsk)
 {
 	struct nsproxy *old_ns = tsk->nsproxy;
 	struct user_namespace *user_ns = task_cred_xxx(tsk, user_ns);

kernel/pid_namespace.c

@@ -171,7 +171,7 @@ static void destroy_pid_namespace_work(struct work_struct *work)
 	} while (ns != &init_pid_ns && refcount_dec_and_test(&ns->ns.count));
 }
 
-struct pid_namespace *copy_pid_ns(unsigned long flags,
+struct pid_namespace *copy_pid_ns(u64 flags,
 	struct user_namespace *user_ns, struct pid_namespace *old_ns)
 {
 	if (!(flags & CLONE_NEWPID))

kernel/sched/core.c

@@ -4472,7 +4472,7 @@ int wake_up_state(struct task_struct *p, unsigned int state)
  * __sched_fork() is basic setup which is also used by sched_init() to
  * initialize the boot CPU's idle task.
  */
-static void __sched_fork(unsigned long clone_flags, struct task_struct *p)
+static void __sched_fork(u64 clone_flags, struct task_struct *p)
 {
 	p->on_rq			= 0;
 
@@ -4707,7 +4707,7 @@ late_initcall(sched_core_sysctl_init);
 /*
  * fork()/clone()-time setup:
  */
-int sched_fork(unsigned long clone_flags, struct task_struct *p)
+int sched_fork(u64 clone_flags, struct task_struct *p)
 {
 	__sched_fork(clone_flags, p);
 	/*

kernel/sched/fair.c

@@ -3542,7 +3542,7 @@ static void task_numa_work(struct callback_head *work)
 	}
 }
 
-void init_numa_balancing(unsigned long clone_flags, struct task_struct *p)
+void init_numa_balancing(u64 clone_flags, struct task_struct *p)
 {
 	int mm_users = 0;
 	struct mm_struct *mm = p->mm;

kernel/sched/sched.h

@@ -1935,12 +1935,12 @@ extern void sched_setnuma(struct task_struct *p, int node);
 extern int migrate_task_to(struct task_struct *p, int cpu);
 extern int migrate_swap(struct task_struct *p, struct task_struct *t,
 			int cpu, int scpu);
-extern void init_numa_balancing(unsigned long clone_flags, struct task_struct *p);
+extern void init_numa_balancing(u64 clone_flags, struct task_struct *p);
 
 #else /* !CONFIG_NUMA_BALANCING: */
 
 static inline void
-init_numa_balancing(unsigned long clone_flags, struct task_struct *p)
+init_numa_balancing(u64 clone_flags, struct task_struct *p)
 {
 }
 

kernel/time/namespace.c

@@ -130,7 +130,7 @@ static struct time_namespace *clone_time_ns(struct user_namespace *user_ns,
  *
  * Return: timens_for_children namespace or ERR_PTR.
  */
-struct time_namespace *copy_time_ns(unsigned long flags,
+struct time_namespace *copy_time_ns(u64 flags,
 	struct user_namespace *user_ns, struct time_namespace *old_ns)
 {
 	if (!(flags & CLONE_NEWTIME))

kernel/utsname.c

@@ -86,7 +86,7 @@ static struct uts_namespace *clone_uts_ns(struct user_namespace *user_ns,
  * utsname of this process won't be seen by parent, and vice
  * versa.
  */
-struct uts_namespace *copy_utsname(unsigned long flags,
+struct uts_namespace *copy_utsname(u64 flags,
 	struct user_namespace *user_ns, struct uts_namespace *old_ns)
 {
 	struct uts_namespace *new_ns;