From: Mike Frysinger <vapier@gentoo.org>
To: linux-ia64@vger.kernel.org
Subject: Re: getcpu() returns EFAULT when called via the vdso
Date: Tue, 15 May 2012 05:41:11 +0000 [thread overview]
Message-ID: <201205150141.12655.vapier@gentoo.org> (raw)
In-Reply-To: <201205061645.24398.vapier@gentoo.org>
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On Tuesday 08 May 2012 17:13:28 Tony Luck wrote:
> On Mon, May 7, 2012 at 4:53 PM, Mike Frysinger <vapier@gentoo.org> wrote:
> > i guess that needs to load some p reg with a NULL pointer test and then
> > do the loads/stores based on that. calling getcpu(NULL, NULL, NULL)
> > from userspace shouldn't trigger EFAULT.
>
> We could do that (see attached, untested, patch). But it wouldn't help
> the sched_getcpu() code much ... it would stop getting -EFAULT, but
> it still wouldn't have the right return value.
seems to work for me
Tested-by: Mike Frysinger <vapier@gentoo.org>
also, strace shows the successful syscall via the vdso, but not the failing
ones. not sure where things are going wrong with that though.
-mike
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next prev parent reply other threads:[~2012-05-15 5:41 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-05-06 20:45 getcpu() returns EFAULT when called via the vdso Mike Frysinger
2012-05-07 17:58 ` Luck, Tony
2012-05-07 23:12 ` Mike Frysinger
2012-05-07 23:53 ` Mike Frysinger
2012-05-08 21:13 ` Tony Luck
2012-05-08 22:31 ` Mike Frysinger
2012-05-15 5:41 ` Mike Frysinger [this message]
2012-11-29 23:34 ` Mike Frysinger
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