Re: [PATCH] signalfd: fill in ssi_int for posix timers and messagequeues

From: Davide Libenzi
Date: Sat Jul 03 2010 - 15:17:35 EST


On Fri, 2 Jul 2010, Nathan Lynch wrote:

> If signalfd is used to consume a signal generated by a POSIX interval
> timer or POSIX message queue, the ssi_int field does not reflect the
> data (sigevent->sigev_value) supplied to timer_create(2) or
> mq_notify(3). (The ssi_ptr field, however, is filled in.)
>
> This behavior differs from signalfd's treatment of sigqueue-generated
> signals -- see the default case in signalfd_copyinfo. It also gives
> results that differ from the case when a signal is handled
> conventionally via a sigaction-registered handler.
>
> So, set signalfd_siginfo->ssi_int in the remaining cases (__SI_TIMER,
> __SI_MESGQ) where ssi_ptr is set.
>
> Signed-off-by: Nathan Lynch <ntl@xxxxxxxxx>
> ---
> fs/signalfd.c | 2 ++
> 1 files changed, 2 insertions(+), 0 deletions(-)
>
> diff --git a/fs/signalfd.c b/fs/signalfd.c
> index f329849..1c5a6ad 100644
> --- a/fs/signalfd.c
> +++ b/fs/signalfd.c
> @@ -88,6 +88,7 @@ static int signalfd_copyinfo(struct signalfd_siginfo __user *uinfo,
> err |= __put_user(kinfo->si_tid, &uinfo->ssi_tid);
> err |= __put_user(kinfo->si_overrun, &uinfo->ssi_overrun);
> err |= __put_user((long) kinfo->si_ptr, &uinfo->ssi_ptr);
> + err |= __put_user(kinfo->si_int, &uinfo->ssi_int);
> break;
> case __SI_POLL:
> err |= __put_user(kinfo->si_band, &uinfo->ssi_band);
> @@ -111,6 +112,7 @@ static int signalfd_copyinfo(struct signalfd_siginfo __user *uinfo,
> err |= __put_user(kinfo->si_pid, &uinfo->ssi_pid);
> err |= __put_user(kinfo->si_uid, &uinfo->ssi_uid);
> err |= __put_user((long) kinfo->si_ptr, &uinfo->ssi_ptr);
> + err |= __put_user(kinfo->si_int, &uinfo->ssi_int);
> break;
> default:

I am fine with it, but I now noticed that signalfd_copyinfo() got out of
sync from copy_siginfo_to_user(), which should match.
Do you mind aligning that too, as part of your patch?
An adding a comment on the lines of the one in copy_siginfo_to_user() to
signalfd_copyinfo() too?
If you do not want to, let me know and I'll do it.


- Davide


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