From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail137.messagelabs.com (mail137.messagelabs.com [216.82.249.19]) by kanga.kvack.org (Postfix) with SMTP id 968616B006C for ; Fri, 11 Nov 2011 12:25:02 -0500 (EST) Date: Fri, 11 Nov 2011 18:24:58 +0100 From: Andrea Arcangeli Subject: Re: [PATCH] mmap: fix loop when adjusting vma Message-ID: <20111111172458.GC4479@redhat.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Hillf Danton Cc: Andrew Morton , Hugh Dickins , Johannes Weiner , LKML , linux-mm@kvack.org On Fri, Nov 11, 2011 at 08:53:23PM +0800, Hillf Danton wrote: > --- a/mm/mmap.c Fri Nov 11 20:35:46 2011 > +++ b/mm/mmap.c Fri Nov 11 20:41:32 2011 > @@ -490,6 +490,7 @@ __vma_unlink(struct mm_struct *mm, struc > int vma_adjust(struct vm_area_struct *vma, unsigned long start, > unsigned long end, pgoff_t pgoff, struct vm_area_struct *insert) > { > + unsigned long saved_end = end; > struct mm_struct *mm = vma->vm_mm; > struct vm_area_struct *next = vma->vm_next; > struct vm_area_struct *importer = NULL; > @@ -634,7 +635,14 @@ again: remove_next = 1 + (end > next-> > */ > if (remove_next == 2) { > next = vma->vm_next; > - goto again; > + if (next) { > + /* > + * we have more work, reload @end in case > + * it is clobbered. > + */ > + end = saved_end; > + goto again; > + } > } Doesn't matter if it's clobbered, remove_next will be set to 1 and that's all we care about. Caller should use vma->vm_next->vm_end as "end" anyway for case 6 so it wouldn't be set to 2. Also next can't be NULL if remove_next == 2. So I don't think this is necessary. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org