On Wed, Oct 24, 2012 at 6:41 AM, Al Viro <viro@xxxxxxxxxxxxxxxxxx> wrote:
> On Wed, Oct 24, 2012 at 05:48:37AM +0400, Max Filippov wrote:
>> Signed-off-by: Max Filippov <jcmvbkbc@xxxxxxxxx>
>> ---
>> arch/xtensa/include/asm/syscall.h | 2 +-
>> arch/xtensa/include/asm/unistd.h | 1 +
>> arch/xtensa/include/uapi/asm/unistd.h | 2 +-
>> arch/xtensa/kernel/process.c | 25 -------------------------
>> 4 files changed, 3 insertions(+), 27 deletions(-)
>
> All three applied, but there's a couple of things I'd like to have on top
> of that. Are you OK with the following incremental?
Yes. Looks like I need to send v2 to address Chris' comments,
I can put these changes there as well.
> 1) ->{set,clear}_child_tid is set by the caller; no need to set it
> in copy_thread().
> 2) for later work it would be easier if copy_thread() hadn't looked
> at regs argument at all; telling kernel_thread(9) from clone(2) can be done
> by checking p->flags & PF_KTHREAD and for clone(2) it's always going to get
> current_pt_regs().
> 3) interpretation of zero newsp is probably better off in copy_thread()
> as well. Eventually we are going to kill regs argument of do_fork() et.al.
>
> diff --git a/arch/xtensa/kernel/process.c b/arch/xtensa/kernel/process.c
> index 58e50ff..9d8f387 100644
> --- a/arch/xtensa/kernel/process.c
> +++ b/arch/xtensa/kernel/process.c
> @@ -200,7 +200,7 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
>
> int copy_thread(unsigned long clone_flags, unsigned long usp_thread_fn,
> unsigned long thread_fn_arg,
> - struct task_struct * p, struct pt_regs * regs)
> + struct task_struct * p, struct pt_regs *unused)
> {
> struct pt_regs *childregs = task_pt_regs(p);
>
> @@ -212,10 +212,10 @@ int copy_thread(unsigned long clone_flags, unsigned long usp_thread_fn,
> *((int*)childregs - 3) = (unsigned long)childregs;
> *((int*)childregs - 4) = 0;
>
> - p->set_child_tid = p->clear_child_tid = NULL;
> p->thread.sp = (unsigned long)childregs;
>
> - if (regs) {
> + if (!(p->flags & PF_KTHREAD)) {
> + struct pt_regs *regs = current_pt_regs();
> p->thread.ra = MAKE_RA_FOR_CALL(
> (unsigned long)ret_from_fork, 0x1);
>
> @@ -224,7 +224,8 @@ int copy_thread(unsigned long clone_flags, unsigned long usp_thread_fn,
> * ARs beyond a0-a15 exist past the end of the struct.
> */
> *childregs = *regs;
> - childregs->areg[1] = usp_thread_fn;
> + if (usp_thread_fn)
> + childregs->areg[1] = usp_thread_fn;
> childregs->areg[2] = 0;
>
> if (clone_flags & CLONE_VM) {
> @@ -346,7 +347,5 @@ long xtensa_clone(unsigned long clone_flags, unsigned long newsp,
> void __user *child_tid, long a5,
> struct pt_regs *regs)
> {
> - if (!newsp)
> - newsp = regs->areg[1];
> return do_fork(clone_flags, newsp, regs, 0, parent_tid, child_tid);
> }
--
Thanks.
-- Max
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