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| Path | csiph.com!goblin3!goblin2!goblin.stu.neva.ru!aioe.org!bofh.it!news.nic.it!robomod |
|---|---|
| From | Peter Zijlstra <peterz@infradead.org> |
| Newsgroups | linux.kernel |
| Subject | Re: [RFC]: Possible race condition in kernel futex code |
| Date | Fri, 09 Oct 2015 13:40:03 +0200 |
| Message-ID | <qhEbN-R9-25@gated-at.bofh.it> (permalink) |
| References | <qgfSa-2Pr-33@gated-at.bofh.it> <qhBQC-63L-23@gated-at.bofh.it> <qhCCZ-6Yo-3@gated-at.bofh.it> <qhD61-7Lm-5@gated-at.bofh.it> |
| X-Original-To | Thomas Gleixner <tglx@linutronix.de> |
| MIME-Version | 1.0 |
| Content-Type | text/plain; charset=us-ascii |
| Content-Disposition | inline |
| User-Agent | Mutt/1.5.21 (2012-12-30) |
| Sender | robomod@news.nic.it |
| List-ID | <linux-kernel.vger.kernel.org> |
| X-Mailing-List | linux-kernel@vger.kernel.org |
| Approved | robomod@news.nic.it |
| Lines | 22 |
| Organization | linux.* mail to news gateway |
| X-Original-Cc | Hans Zuidam <h.zuidam@computer.org>, Jaccon Bastiaansen <jaccon.bastiaansen@gmail.com>, x86@kernel.org, mingo@redhat.com, "H. Peter Anvin" <hpa@zytor.com>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, stable@vger.kernel.org, Linus Torvalds <torvalds@linux-foundation.org> |
| X-Original-Date | Fri, 9 Oct 2015 13:35:52 +0200 |
| X-Original-Message-ID | <20151009113552.GC3816@twins.programming.kicks-ass.net> |
| X-Original-References | <CAGzjT4ez+gWr3BFQsEr-wma+vs6UZNJ+mRARx_BWoAKEJSsN=w@mail.gmail.com> <alpine.DEB.2.11.1510090946200.6097@nanos> <4387EFE3-55AB-433B-83E1-2AFC413C7B9A@online.nl> <alpine.DEB.2.11.1510091054230.6097@nanos> |
| X-Original-Sender | linux-kernel-owner@vger.kernel.org |
| Xref | csiph.com linux.kernel:1243281 |
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On Fri, Oct 09, 2015 at 11:25:09AM +0100, Thomas Gleixner wrote: > Hans, > > On Fri, 9 Oct 2015, Hans Zuidam wrote: > > On 9 okt. 2015, at 11:06, Thomas Gleixner <tglx@linutronix.de> wrote: > > > You cannot use an explicit 32bit read. We need an access which > > > handles the fault gracefully. > > > > The reason for the explicit read suggestion is to avoid the > > _builtin_constant_p() in __copy_from_user_nocheck(). The GCC manual > > says that there may be situations where it returns 0 even though the > > argument is a constant. > > That's insane at best. Right, but I bet that is for cases where constant propagation completely fails, and this is a trivial case, I have no problem relying on it. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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Re: [RFC]: Possible race condition in kernel futex code Thomas Gleixner <tglx@linutronix.de> - 2015-10-09 11:10 +0200
Re: [RFC]: Possible race condition in kernel futex code Hans Zuidam <h.zuidam@online.nl> - 2015-10-09 12:00 +0200
Re: [RFC]: Possible race condition in kernel futex code Thomas Gleixner <tglx@linutronix.de> - 2015-10-09 12:30 +0200
Re: [RFC]: Possible race condition in kernel futex code Peter Zijlstra <peterz@infradead.org> - 2015-10-09 13:40 +0200
Re: [RFC]: Possible race condition in kernel futex code Greg KH <greg@kroah.com> - 2015-10-18 02:30 +0200
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