Commit bbc46b23 authored by Simon Schuster's avatar Simon Schuster Committed by Christian Brauner
Browse files

arch: copy_thread: pass clone_flags as u64 



With the introduction of clone3 in commit 7f192e3c ("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: default avatarSimon Schuster <schuster.simon@siemens-energy.com>
Link: https://lore.kernel.org/20250901-nios2-implement-clone3-v2-3-53fcf5577d57@siemens-energy.com


Fixes: c5febea0 ("fork: Pass struct kernel_clone_args into copy_thread")
Acked-by: default avatarGuo Ren (Alibaba Damo Academy) <guoren@kernel.org>
Acked-by: Andreas Larsson <andreas@gaisler.com> # sparc
Acked-by: default avatarDavid Hildenbrand <david@redhat.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> # m68k
Reviewed-by: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent edd3cb05

arch/alpha/kernel/process.c

+1 −1
Original line number Diff line number Diff line
@@ -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

+1 −1
Original line number Diff line number Diff line
@@ -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

+1 −1
Original line number Diff line number Diff line
@@ -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

+1 −1
Original line number Diff line number Diff line
@@ -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

+1 −1
Original line number Diff line number Diff line
@@ -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;