[Devel] [PATCH vz10] Revert "ve: Replace 0 ppid with 1 (workaround for bad utils)"

[Vasileios Almpanis]

Reviewed-by: Vasileios Almpanis <vasileios.almpanis at virtuozzo.com>

On 7/27/26 7:35 PM, Konstantin Khorenko wrote:
> This reverts commit b6a803bdf66bf3da211704060a8f263706c2a364.
>
> We won't support so ancient utils which are not ready for getting 0 as a
> parent PID which actually is a normal situation and means that the
> parent process is from an outer pidns and is not visible in the
> current pidns.
>
> https://virtuozzo.atlassian.net/browse/VSTOR-139436
> Feature: procfs: virtualization and visibility configuration
> Signed-off-by: Konstantin Khorenko <khorenko at virtuozzo.com>
> ---
>   fs/proc/array.c     |  5 +++--
>   include/linux/pid.h |  1 -
>   kernel/pid.c        | 12 ------------
>   kernel/sys.c        |  2 +-
>   4 files changed, 4 insertions(+), 16 deletions(-)
>
> diff --git a/fs/proc/array.c b/fs/proc/array.c
> index 80b882fe4832..0ff32bee5c50 100644
> --- a/fs/proc/array.c
> +++ b/fs/proc/array.c
> @@ -171,7 +171,8 @@ static inline void task_state(struct seq_file *m, struct pid_namespace *ns,
>   	unsigned int max_fds = 0;
>   
>   	rcu_read_lock();
> -	ppid = pid_alive(p) ? ve_task_ppid_nr_ns(p, ns) : 0;
> +	ppid = pid_alive(p) ?
> +		task_tgid_nr_ns(rcu_dereference(p->real_parent), ns) : 0;
>   
>   	tracer = ptrace_parent(p);
>   	if (tracer)
> @@ -551,7 +552,7 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
>   		}
>   
>   		sid = task_session_nr_ns(task, ns);
> -		ppid = ve_task_ppid_nr_ns(task, ns);
> +		ppid = task_ppid_nr_ns(task, ns);
>   		pgid = task_pgrp_nr_ns(task, ns);
>   
>   		unlock_task_sighand(task, &flags);
> diff --git a/include/linux/pid.h b/include/linux/pid.h
> index 04f983d477ff..34ef8e692fee 100644
> --- a/include/linux/pid.h
> +++ b/include/linux/pid.h
> @@ -184,7 +184,6 @@ static inline pid_t pid_nr(struct pid *pid)
>   
>   pid_t pid_nr_ns(struct pid *pid, struct pid_namespace *ns);
>   pid_t pid_vnr(struct pid *pid);
> -pid_t ve_task_ppid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns);
>   
>   #define do_each_pid_task(pid, type, task)				\
>   	do {								\
> diff --git a/kernel/pid.c b/kernel/pid.c
> index c95e572efd7d..350ca2fbff5c 100644
> --- a/kernel/pid.c
> +++ b/kernel/pid.c
> @@ -517,18 +517,6 @@ pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type,
>   }
>   EXPORT_SYMBOL(__task_pid_nr_ns);
>   
> -pid_t ve_task_ppid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
> -{
> -	pid_t ppid;
> -	rcu_read_lock();
> -	ppid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns);
> -	rcu_read_unlock();
> -	/* It's dirty hack. Some old utils don't work if ppid is zero*/
> -	if (ppid == 0 && ns->child_reaper != tsk)
> -		ppid = 1;
> -	return ppid;
> -}
> -
>   struct pid_namespace *task_active_pid_ns(struct task_struct *tsk)
>   {
>   	return ns_of_pid(task_pid(tsk));
> diff --git a/kernel/sys.c b/kernel/sys.c
> index 33b05af556fa..80f8b9eb17c3 100644
> --- a/kernel/sys.c
> +++ b/kernel/sys.c
> @@ -990,7 +990,7 @@ SYSCALL_DEFINE0(getppid)
>   	int pid;
>   
>   	rcu_read_lock();
> -	pid = ve_task_ppid_nr_ns(current, task_active_pid_ns(current));
> +	pid = task_tgid_vnr(rcu_dereference(current->real_parent));
>   	rcu_read_unlock();
>   
>   	return pid;

-- 
Best regards, Vasileios Almpanis
Software Developer, Virtuozzo.