Am Mi., 18. Juni 2025 um 22:54 Uhr schrieb Christian Brauner
<brauner@xxxxxxxxxx>:
>
> The validation is now completely handled in path_from_stashed().
>
> Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx>
Reviewed-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@xxxxxxxxxxxxx>
> ---
> fs/pidfs.c | 53 -----------------------------------------------------
> 1 file changed, 53 deletions(-)
>
> diff --git a/fs/pidfs.c b/fs/pidfs.c
> index bc2342cf4492..ec375692a710 100644
> --- a/fs/pidfs.c
> +++ b/fs/pidfs.c
> @@ -804,58 +804,8 @@ static int pidfs_export_permission(struct handle_to_path_ctx *ctx,
> return 0;
> }
>
> -static inline bool pidfs_pid_valid(struct pid *pid, const struct path *path,
> - unsigned int flags)
> -{
> - enum pid_type type;
> -
> - if (flags & PIDFD_STALE)
> - return true;
> -
> - /*
> - * Make sure that if a pidfd is created PIDFD_INFO_EXIT
> - * information will be available. So after an inode for the
> - * pidfd has been allocated perform another check that the pid
> - * is still alive. If it is exit information is available even
> - * if the task gets reaped before the pidfd is returned to
> - * userspace. The only exception are indicated by PIDFD_STALE:
> - *
> - * (1) The kernel is in the middle of task creation and thus no
> - * task linkage has been established yet.
> - * (2) The caller knows @pid has been registered in pidfs at a
> - * time when the task was still alive.
> - *
> - * In both cases exit information will have been reported.
> - */
> - if (flags & PIDFD_THREAD)
> - type = PIDTYPE_PID;
> - else
> - type = PIDTYPE_TGID;
> -
> - /*
> - * Since pidfs_exit() is called before struct pid's task linkage
> - * is removed the case where the task got reaped but a dentry
> - * was already attached to struct pid and exit information was
> - * recorded and published can be handled correctly.
> - */
> - if (unlikely(!pid_has_task(pid, type))) {
> - struct pidfs_attr *attr;
> -
> - attr = READ_ONCE(pid->attr);
> - if (!attr)
> - return false;
> - if (!READ_ONCE(attr->exit_info))
> - return false;
> - }
> -
> - return true;
> -}
> -
> static struct file *pidfs_export_open(struct path *path, unsigned int oflags)
> {
> - if (!pidfs_pid_valid(d_inode(path->dentry)->i_private, path, oflags))
> - return ERR_PTR(-ESRCH);
> -
> /*
> * Clear O_LARGEFILE as open_by_handle_at() forces it and raise
> * O_RDWR as pidfds always are.
> @@ -993,9 +943,6 @@ struct file *pidfs_alloc_file(struct pid *pid, unsigned int flags)
> if (ret < 0)
> return ERR_PTR(ret);
>
> - if (!pidfs_pid_valid(pid, &path, flags))
> - return ERR_PTR(-ESRCH);
> -
> flags &= ~PIDFD_STALE;
> flags |= O_RDWR;
> pidfd_file = dentry_open(&path, flags, current_cred());
>
> --
> 2.47.2
>
