From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael Kerrisk (man-pages)" Subject: Re: [PATCH 1/3] sched: Make sched_setattr() correctly return -EFBIG Date: Wed, 14 May 2014 05:23:50 +0200 Message-ID: <5372E1C6.5070109@gmail.com> References: <536CEAEE.4010609@gmail.com> <536CEC17.9070903@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <536CEC17.9070903-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> Sender: linux-man-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Peter Zijlstra Cc: mtk.manpages-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, lkml , Juri Lelli , Dario Faggioli , Ingo Molnar , "linux-man-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" List-Id: linux-man@vger.kernel.org Peter, In the title of this patch, EFBIG should have been E2BIG. Shall I resubmit a corrected version? Cheers, Michael On 05/09/2014 04:54 PM, Michael Kerrisk (man-pages) wrote: > From: Michael Kerrisk > > The documented[1] behavior of sched_attr() in your proposed man page text is: > > sched_attr::size must be set to the size of the structure, as in > sizeof(struct sched_attr), if the provided structure is smaller > than the kernel structure, any additional fields are assumed > '0'. If the provided structure is larger than the kernel structure, > the kernel verifies all additional fields are '0' if not the > syscall will fail with -E2BIG. > > As currently implemented, sched_copy_attr() returns -EFBIG for > for this case, but the logic in sys_sched_setattr() converts that > error to -EFAULT. This patch fixes the behavior. > > [1] http://thread.gmane.org/gmane.linux.kernel/1615615/focus=1697760 > > Signed-off-by: Michael Kerrisk > --- > kernel/sched/core.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/kernel/sched/core.c b/kernel/sched/core.c > index 268a45e..6c9ce28 100644 > --- a/kernel/sched/core.c > +++ b/kernel/sched/core.c > @@ -3650,8 +3650,9 @@ SYSCALL_DEFINE3(sched_setattr, pid_t, pid, struct sched_attr __user *, uattr, > if (!uattr || pid < 0 || flags) > return -EINVAL; > > - if (sched_copy_attr(uattr, &attr)) > - return -EFAULT; > + retval = sched_copy_attr(uattr, &attr); > + if (retval) > + return retval; > > rcu_read_lock(); > retval = -ESRCH; > -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/ -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html