On 12/08, Christian König wrote:
>
> On 12/7/25 13:39, Oleg Nesterov wrote:
> > Nowaday task->group_leader->mm != task->mm is only possible if
> > a) task is not a group leader and b) task->group_leader->mm == NULL
> > because task->group_leader has already exited using sys_exit().
>
> Just for my understanding: That is because CLONE_THREAD can only be
> specified together with CLONE_SIGHAND and CLONE_VM, correct?
Yes, copy copy_process() does
if ((clone_flags & CLONE_THREAD) && !(clone_flags & CLONE_SIGHAND))
return ERR_PTR(-EINVAL);
if ((clone_flags & CLONE_SIGHAND) && !(clone_flags & CLONE_VM))
return ERR_PTR(-EINVAL);
...
if (clone_flags & CLONE_THREAD) {
p->group_leader = current->group_leader;
p->tgid = current->tgid;
} else {
p->group_leader = p;
p->tgid = p->pid;
}
> Reviewed-by: Christian König <[email protected]>
Thanks!
> Should we pick that one up or do you want to merge it upstream somehow?
If you don't object, I would like to route this series via -mm tree.
See 0/7, I am going to send more (simple) tree-wide changes which depend
on this series.
Oleg.
> Regards,
> Christian.
>
> > ---
> > drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 3 ---
> > drivers/gpu/drm/amd/amdkfd/kfd_process.c | 10 ----------
> > 2 files changed, 13 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> > b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> > index a0f8ba382b9e..e44f158a11f0 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> > @@ -2551,9 +2551,6 @@ void amdgpu_vm_set_task_info(struct amdgpu_vm *vm)
> > vm->task_info->task.pid = current->pid;
> > get_task_comm(vm->task_info->task.comm, current);
> >
> > - if (current->group_leader->mm != current->mm)
> > - return;
> > -
> > vm->task_info->tgid = current->tgid;
> > get_task_comm(vm->task_info->process_name, current->group_leader);
> > }
> > diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_process.c
> > b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
> > index a085faac9fe1..f8ef18a3aa71 100644
> > --- a/drivers/gpu/drm/amd/amdkfd/kfd_process.c
> > +++ b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
> > @@ -833,12 +833,6 @@ struct kfd_process *kfd_create_process(struct
> > task_struct *thread)
> > if (!(thread->mm && mmget_not_zero(thread->mm)))
> > return ERR_PTR(-EINVAL);
> >
> > - /* Only the pthreads threading model is supported. */
> > - if (thread->group_leader->mm != thread->mm) {
> > - mmput(thread->mm);
> > - return ERR_PTR(-EINVAL);
> > - }
> > -
> > /* If the process just called exec(3), it is possible that the
> > * cleanup of the kfd_process (following the release of the mm
> > * of the old process image) is still in the cleanup work queue.
> > @@ -918,10 +912,6 @@ struct kfd_process *kfd_get_process(const struct
> > task_struct *thread)
> > if (!thread->mm)
> > return ERR_PTR(-EINVAL);
> >
> > - /* Only the pthreads threading model is supported. */
> > - if (thread->group_leader->mm != thread->mm)
> > - return ERR_PTR(-EINVAL);
> > -
> > process = find_process(thread, false);
> > if (!process)
> > return ERR_PTR(-EINVAL);
>
