Re: [PATCH 1/5] Split wait_noreap_copyout()

Vitaly Mayatskikh
2009-06-09T15:14:31Z

Hi, Andrew!

Can you, please, update description of
wait_task_-cleanups-split-wait_noreap_copyout.patch?

New description:
----------------------------------------------------------------------
Move getrusage() and put_user() code from wait_noreap_copyout()
to copy_wait_opts_to_user(). The same code is spreaded across all
wait_task_*() routines, it's better to reuse one copy.

User visible change: previously, waitid() was doing unconditional
put_user() in wait_noreap_copyout(), and was returning EFAULT
if infop pointer, provided by user, was NULL *and* WCONTINUED was not
set in options. Now all variants of wait() function use the same generic
copy_wait_opts_to_user(), and, thus, have the same behaviour regarding
to filling of siginfo structure. Starting from this commit waitid()
returns NULL if infop argument is NULL.
----------------------------------------------------------------------

Thanks!

>
> Move getrusage() and put_user() code from wait_noreap_copyout()
> to copy_wait_opts_to_user(). The same code is spreaded across all
> wait_task_*() routines, it's better to reuse one copy.
>
> Signed-off-by: Vitaly Mayatskikh <v.mayatskih@gmail.com>
> ---
> kernel/exit.c | 39 +++++++++++++++++++++++----------------
> 1 files changed, 23 insertions(+), 16 deletions(-)
>
> diff --git a/kernel/exit.c b/kernel/exit.c
> index 25782da..9546362 100644
> --- a/kernel/exit.c
> +++ b/kernel/exit.c
> @@ -1123,27 +1123,34 @@ static int eligible_child(struct wait_opts *wo, struct task_struct *p)
> return 1;
> }
>
> -static int wait_noreap_copyout(struct wait_opts *wo, struct task_struct *p,
> - pid_t pid, uid_t uid, int why, int status)
> +static int copy_wait_opts_to_user(struct wait_opts *wo, struct task_struct *p,
> + pid_t pid, uid_t uid, int why, int status, int signal)
> {
> - struct siginfo __user *infop;
> + struct siginfo __user *infop = wo->wo_info;
> int retval = wo->wo_rusage
> ? getrusage(p, RUSAGE_BOTH, wo->wo_rusage) : 0;
>
> + if (!retval && infop) {
> + retval = put_user(signal, &infop->si_signo);
> + if (!retval)
> + retval = put_user(0, &infop->si_errno);
> + if (!retval)
> + retval = put_user((short)why, &infop->si_code);
> + if (!retval)
> + retval = put_user(pid, &infop->si_pid);
> + if (!retval)
> + retval = put_user(uid, &infop->si_uid);
> + if (!retval)
> + retval = put_user(status, &infop->si_status);
> + }
> + return retval;
> +}
> +
> +static int wait_noreap_copyout(struct wait_opts *wo, struct task_struct *p,
> + pid_t pid, uid_t uid, int why, int status)
> +{
> + int retval = copy_wait_opts_to_user(wo, p, pid, uid, why, status, SIGCHLD);
> put_task_struct(p);
> - infop = wo->wo_info;
> - if (!retval)
> - retval = put_user(SIGCHLD, &infop->si_signo);
> - if (!retval)
> - retval = put_user(0, &infop->si_errno);
> - if (!retval)
> - retval = put_user((short)why, &infop->si_code);
> - if (!retval)
> - retval = put_user(pid, &infop->si_pid);
> - if (!retval)
> - retval = put_user(uid, &infop->si_uid);
> - if (!retval)
> - retval = put_user(status, &infop->si_status);
> if (!retval)
> retval = pid;
> return retval;
> --
> 1.6.2.2
>
>

--
wbr, Vitaly