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>

security/apparmor/lsm.c

@@ -112,7 +112,7 @@ static void apparmor_task_free(struct task_struct *task)
 }
 
 static int apparmor_task_alloc(struct task_struct *task,
-			       unsigned long clone_flags)
+			       u64 clone_flags)
 {
 	struct aa_task_ctx *new = task_ctx(task);
 

security/security.c

@@ -3185,7 +3185,7 @@ int security_file_truncate(struct file *file)
  *
  * Return: Returns a zero on success, negative values on failure.
  */
-int security_task_alloc(struct task_struct *task, unsigned long clone_flags)
+int security_task_alloc(struct task_struct *task, u64 clone_flags)
 {
 	int rc = lsm_task_alloc(task);
 

security/selinux/hooks.c

@@ -4144,7 +4144,7 @@ static int selinux_file_open(struct file *file)
 /* task security operations */
 
 static int selinux_task_alloc(struct task_struct *task,
-			      unsigned long clone_flags)
+			      u64 clone_flags)
 {
 	u32 sid = current_sid();
 

security/tomoyo/tomoyo.c

@@ -514,7 +514,7 @@ struct lsm_blob_sizes tomoyo_blob_sizes __ro_after_init = {
  * Returns 0.
  */
 static int tomoyo_task_alloc(struct task_struct *task,
-			     unsigned long clone_flags)
+			     u64 clone_flags)
 {
 	struct tomoyo_task *old = tomoyo_task(current);
 	struct tomoyo_task *new = tomoyo_task(task);