signalfd: fill in ssi_int for posix timers and message queues

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.

akpm: a non-back-compatible change.  Merge into -stable to minimise the
number of kernels which are in the field and which miss this feature.

Signed-off-by: Nathan Lynch <ntl@pobox.com>
Acked-by: Davide Libenzi <davidel@xmailserver.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/fs/signalfd.c b/fs/signalfd.c
index f329849ce3c0..1c5a6add779d 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:
                 /*