arch: copy_thread: pass clone_flags as u64

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 the copy_thread
function that is called from copy_process 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-v2-3-53fcf5577d57@siemens-energy.com
Fixes: c5febea095 ("fork: Pass struct kernel_clone_args into copy_thread")
Acked-by: Guo Ren (Alibaba Damo Academy) <guoren@kernel.org>
Acked-by: Andreas Larsson <andreas@gaisler.com> # sparc
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> # m68k
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>

arch/alpha/kernel/process.c

@@ -231,7 +231,7 @@ flush_thread(void)
  */
 int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
 {
-	unsigned long clone_flags = args->flags;
+	u64 clone_flags = args->flags;
 	unsigned long usp = args->stack;
 	unsigned long tls = args->tls;
 	extern void ret_from_fork(void);

arch/arc/kernel/process.c

@@ -166,7 +166,7 @@ asmlinkage void ret_from_fork(void);
  */
 int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
 {
-	unsigned long clone_flags = args->flags;
+	u64 clone_flags = args->flags;
 	unsigned long usp = args->stack;
 	unsigned long tls = args->tls;
 	struct pt_regs *c_regs;        /* child's pt_regs */

arch/arm/kernel/process.c

@@ -234,7 +234,7 @@ asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
 
 int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
 {
-	unsigned long clone_flags = args->flags;
+	u64 clone_flags = args->flags;
 	unsigned long stack_start = args->stack;
 	unsigned long tls = args->tls;
 	struct thread_info *thread = task_thread_info(p);

arch/arm64/kernel/process.c

@@ -409,7 +409,7 @@ asmlinkage void ret_from_fork(void) asm("ret_from_fork");
 
 int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
 {
-	unsigned long clone_flags = args->flags;
+	u64 clone_flags = args->flags;
 	unsigned long stack_start = args->stack;
 	unsigned long tls = args->tls;
 	struct pt_regs *childregs = task_pt_regs(p);

arch/csky/kernel/process.c

@@ -32,7 +32,7 @@ void flush_thread(void){}
 
 int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
 {
-	unsigned long clone_flags = args->flags;
+	u64 clone_flags = args->flags;
 	unsigned long usp = args->stack;
 	unsigned long tls = args->tls;
 	struct switch_stack *childstack;

arch/hexagon/kernel/process.c

@@ -52,7 +52,7 @@ void arch_cpu_idle(void)
  */
 int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
 {
-	unsigned long clone_flags = args->flags;
+	u64 clone_flags = args->flags;
 	unsigned long usp = args->stack;
 	unsigned long tls = args->tls;
 	struct thread_info *ti = task_thread_info(p);

arch/loongarch/kernel/process.c

@@ -167,7 +167,7 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
 	unsigned long childksp;
 	unsigned long tls = args->tls;
 	unsigned long usp = args->stack;
-	unsigned long clone_flags = args->flags;
+	u64 clone_flags = args->flags;
 	struct pt_regs *childregs, *regs = current_pt_regs();
 
 	childksp = (unsigned long)task_stack_page(p) + THREAD_SIZE;

arch/m68k/kernel/process.c

@@ -141,7 +141,7 @@ asmlinkage int m68k_clone3(struct pt_regs *regs)
 
 int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
 {
-	unsigned long clone_flags = args->flags;
+	u64 clone_flags = args->flags;
 	unsigned long usp = args->stack;
 	unsigned long tls = args->tls;
 	struct fork_frame {

arch/microblaze/kernel/process.c

@@ -54,7 +54,7 @@ void flush_thread(void)
 
 int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
 {
-	unsigned long clone_flags = args->flags;
+	u64 clone_flags = args->flags;
 	unsigned long usp = args->stack;
 	unsigned long tls = args->tls;
 	struct pt_regs *childregs = task_pt_regs(p);

arch/mips/kernel/process.c

@@ -107,7 +107,7 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
  */
 int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
 {
-	unsigned long clone_flags = args->flags;
+	u64 clone_flags = args->flags;
 	unsigned long usp = args->stack;
 	unsigned long tls = args->tls;
 	struct thread_info *ti = task_thread_info(p);

arch/nios2/kernel/process.c

@@ -101,7 +101,7 @@ void flush_thread(void)
 
 int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
 {
-	unsigned long clone_flags = args->flags;
+	u64 clone_flags = args->flags;
 	unsigned long usp = args->stack;
 	unsigned long tls = args->tls;
 	struct pt_regs *childregs = task_pt_regs(p);

arch/openrisc/kernel/process.c

@@ -165,7 +165,7 @@ extern asmlinkage void ret_from_fork(void);
 int
 copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
 {
-	unsigned long clone_flags = args->flags;
+	u64 clone_flags = args->flags;
 	unsigned long usp = args->stack;
 	unsigned long tls = args->tls;
 	struct pt_regs *userregs;

arch/parisc/kernel/process.c

@@ -201,7 +201,7 @@ arch_initcall(parisc_idle_init);
 int
 copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
 {
-	unsigned long clone_flags = args->flags;
+	u64 clone_flags = args->flags;
 	unsigned long usp = args->stack;
 	unsigned long tls = args->tls;
 	struct pt_regs *cregs = &(p->thread.regs);

arch/powerpc/kernel/process.c

@@ -1805,7 +1805,7 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
 			f = ret_from_kernel_user_thread;
 		} else {
 			struct pt_regs *regs = current_pt_regs();
-			unsigned long clone_flags = args->flags;
+			u64 clone_flags = args->flags;
 			unsigned long usp = args->stack;
 
 			/* Copy registers */

arch/riscv/kernel/process.c

@@ -223,7 +223,7 @@ asmlinkage void ret_from_fork_user(struct pt_regs *regs)
 
 int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
 {
-	unsigned long clone_flags = args->flags;
+	u64 clone_flags = args->flags;
 	unsigned long usp = args->stack;
 	unsigned long tls = args->tls;
 	struct pt_regs *childregs = task_pt_regs(p);

arch/s390/kernel/process.c

@@ -106,7 +106,7 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
 
 int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
 {
-	unsigned long clone_flags = args->flags;
+	u64 clone_flags = args->flags;
 	unsigned long new_stackp = args->stack;
 	unsigned long tls = args->tls;
 	struct fake_frame

arch/sh/kernel/process_32.c

@@ -89,7 +89,7 @@ asmlinkage void ret_from_kernel_thread(void);
 
 int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
 {
-	unsigned long clone_flags = args->flags;
+	u64 clone_flags = args->flags;
 	unsigned long usp = args->stack;
 	unsigned long tls = args->tls;
 	struct thread_info *ti = task_thread_info(p);

arch/sparc/kernel/process_32.c

@@ -260,7 +260,7 @@ extern void ret_from_kernel_thread(void);
 
 int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
 {
-	unsigned long clone_flags = args->flags;
+	u64 clone_flags = args->flags;
 	unsigned long sp = args->stack;
 	unsigned long tls = args->tls;
 	struct thread_info *ti = task_thread_info(p);

arch/sparc/kernel/process_64.c

@@ -567,7 +567,7 @@ barf:
  */
 int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
 {
-	unsigned long clone_flags = args->flags;
+	u64 clone_flags = args->flags;
 	unsigned long sp = args->stack;
 	unsigned long tls = args->tls;
 	struct thread_info *t = task_thread_info(p);

arch/um/kernel/process.c

@@ -143,7 +143,7 @@ static void fork_handler(void)
 
 int copy_thread(struct task_struct * p, const struct kernel_clone_args *args)
 {
-	unsigned long clone_flags = args->flags;
+	u64 clone_flags = args->flags;
 	unsigned long sp = args->stack;
 	unsigned long tls = args->tls;
 	void (*handler)(void);