From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail6.bemta8.messagelabs.com (mail6.bemta8.messagelabs.com [216.82.243.55]) by kanga.kvack.org (Postfix) with ESMTP id D78416B016A for ; Fri, 26 Aug 2011 17:23:33 -0400 (EDT) Date: Fri, 26 Aug 2011 14:23:28 -0700 From: Andrew Morton Subject: Re: [PATCH] mm/mempolicy.c: fix pgoff in mbind vma merge Message-Id: <20110826142328.ab4726cb.akpm@linux-foundation.org> In-Reply-To: <14efb4b829a69f8c13d65de60a4508c0bbb0a5f5.1312212325.git.caspar@casparzhang.com> References: <14efb4b829a69f8c13d65de60a4508c0bbb0a5f5.1312212325.git.caspar@casparzhang.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Caspar Zhang Cc: linux-mm , KOSAKI Motohiro , LKML On Mon, 1 Aug 2011 23:28:55 +0800 Caspar Zhang wrote: > commit 9d8cebd4bcd7c3878462fdfda34bbcdeb4df7ef4 didn't real fix the > mbind vma merge problem due to wrong pgoff value passing to vma_merge(), > which made vma_merge() always return NULL. > > Re-tested the patched kernel with the reproducer provided in commit > 9d8cebd, got correct result like below: > > addr = 0x7ffa5aaa2000 > [snip] > 7ffa5aaa2000-7ffa5aaa6000 rw-p 00000000 00:00 0 > 7fffd556f000-7fffd5584000 rw-p 00000000 00:00 0 [stack] > Please also describe the output before the patch is applied, and tell us what you believe is wrong with it? > --- a/mm/mempolicy.c > +++ b/mm/mempolicy.c > @@ -636,7 +636,6 @@ static int mbind_range(struct mm_struct *mm, unsigned long start, > struct vm_area_struct *prev; > struct vm_area_struct *vma; > int err = 0; > - pgoff_t pgoff; > unsigned long vmstart; > unsigned long vmend; > > @@ -649,9 +648,9 @@ static int mbind_range(struct mm_struct *mm, unsigned long start, > vmstart = max(start, vma->vm_start); > vmend = min(end, vma->vm_end); > > - pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT); > prev = vma_merge(mm, prev, vmstart, vmend, vma->vm_flags, > - vma->anon_vma, vma->vm_file, pgoff, new_pol); > + vma->anon_vma, vma->vm_file, vma->vm_pgoff, > + new_pol); > if (prev) { > vma = prev; > next = vma->vm_next; > -- > 1.7.6 -- 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