From: Ingo Molnar <mingo@elte.hu>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: "Zhang, Yanmin" <yanmin_zhang@linux.intel.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
LKML <linux-kernel@vger.kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Darren Hart <dvhltc@us.ibm.com>
Subject: Re: [GIT pull] futex fixes for 2.6.31
Date: Thu, 25 Jun 2009 12:04:13 +0200 [thread overview]
Message-ID: <20090625100413.GD29980@elte.hu> (raw)
In-Reply-To: <alpine.LFD.2.00.0906251151400.2767@localhost.localdomain>
* Thomas Gleixner <tglx@linutronix.de> wrote:
> On Thu, 25 Jun 2009, Zhang, Yanmin wrote:
> > On Wed, 2009-06-24 at 21:48 +0200, Thomas Gleixner wrote:
> > > +static int fault_in_user_writeable(u32 __user *uaddr)
> > > +{
> > > + int ret = get_user_pages(current, current->mm, (unsigned long)uaddr,
> > > + sizeof(*uaddr), 1, 0, NULL, NULL);
> > The 4th parameter of get_user_pages means page number. sizeof(*uaddr) is equal to
> > 4, so you want 4 pages?
>
> Grrr. I looked up the prototype of it in include/linux/mm.h:
>
> int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
> unsigned long start, int len, int write, int force,
> struct page **pages, struct vm_area_struct **vmas);
>
> len == number of pages ! How intutitive. :(
>
> I guess Linus tripped over it as well. See:
> http://lkml.org/lkml/2009/6/21/95
heh, and then i suggested to you to change the '4' to sizeof(u32)
;-)
Ingo
next prev parent reply other threads:[~2009-06-25 10:04 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-06-24 14:36 [PATCH V2] futex: Fix the write access fault problem for real Thomas Gleixner
2009-06-24 16:46 ` Linus Torvalds
2009-06-24 19:48 ` [GIT pull] futex fixes for 2.6.31 Thomas Gleixner
2009-06-25 2:43 ` Zhang, Yanmin
2009-06-25 9:56 ` Thomas Gleixner
2009-06-25 10:04 ` Ingo Molnar [this message]
2009-06-25 18:15 ` [GIT pull] final " Thomas Gleixner
2009-06-25 18:26 ` Linus Torvalds
2009-06-25 9:58 ` [PATCH] clarify get_user_pages() prototype Peter Zijlstra
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