From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail172.messagelabs.com (mail172.messagelabs.com [216.82.254.3]) by kanga.kvack.org (Postfix) with ESMTP id 5556D6B004F for ; Mon, 12 Jan 2009 18:00:33 -0500 (EST) Date: Mon, 12 Jan 2009 14:59:39 -0800 From: Andrew Morton Subject: Re: [PATCH]Fix: 32bit binary has 64bit address of stack vma Message-Id: <20090112145939.5ae28ada.akpm@linux-foundation.org> In-Reply-To: <604427e00901051539x52ab85bcua94cd8036e5b619a@mail.gmail.com> References: <604427e00901051539x52ab85bcua94cd8036e5b619a@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Ying Han Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, mikew@google.com, rohitseth@google.com List-ID: On Mon, 5 Jan 2009 15:39:07 -0800 Ying Han wrote: > From: Ying Han > > Fix 32bit binary get 64bit stack vma offset. > > 32bit binary running on 64bit system, the /proc/pid/maps shows for the > vma represents stack get a 64bit adress: > ff96c000-ff981000 rwxp 7ffffffea000 00:00 0 [stack] > > Signed-off-by: Ying Han > > fs/exec.c | 5 +- > > diff --git a/fs/exec.c b/fs/exec.c > index 4e834f1..8c3eff4 100644 > --- a/fs/exec.c > +++ b/fs/exec.c > @@ -517,6 +517,7 @@ static int shift_arg_pages(struct vm_area_struct *vma, uns > unsigned long length = old_end - old_start; > unsigned long new_start = old_start - shift; > unsigned long new_end = old_end - shift; > + unsigned long new_pgoff = new_start >> PAGE_SHIFT; > struct mmu_gather *tlb; > > BUG_ON(new_start > new_end); > @@ -531,7 +532,7 @@ static int shift_arg_pages(struct vm_area_struct *vma, uns > /* > * cover the whole range: [new_start, old_end) > */ > - vma_adjust(vma, new_start, old_end, vma->vm_pgoff, NULL); > + vma_adjust(vma, new_start, old_end, new_pgoff, NULL); > > /* > * move the page tables downwards, on failure we rely on > @@ -564,7 +565,7 @@ static int shift_arg_pages(struct vm_area_struct *vma, uns > /* > * shrink the vma to just the new range. > */ > - vma_adjust(vma, new_start, new_end, vma->vm_pgoff, NULL); > + vma_adjust(vma, new_start, new_end, new_pgoff, NULL); > > return 0; I rewrote the chagnelog as below. Please confirm that it makes sense? Subject: fs/exec.c: fix value of vma->vm_pgoff for the stack VMA of 32-bit processes From: Ying Han With a 32 bit binary running on a 64 bit system, the /proc/pid/maps for the [stack] VMA displays a 64-bit address: ff96c000-ff981000 rwxp 7ffffffea000 00:00 0 [stack] This is because vma->vm_pgoff for that VMA is incorrectly being stored in units of offset-in-bytes. It should be stored in units of offset-in-pages. Signed-off-by: Ying Han Cc: Mike Waychison Cc: Hugh Dickins Signed-off-by: Andrew Morton --- fs/exec.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff -puN fs/exec.c~fs-execc-fix-value-of-vma-vm_pgoff-for-the-stack-vma-of-32-bit-processes fs/exec.c --- a/fs/exec.c~fs-execc-fix-value-of-vma-vm_pgoff-for-the-stack-vma-of-32-bit-processes +++ a/fs/exec.c @@ -509,6 +509,7 @@ static int shift_arg_pages(struct vm_are unsigned long length = old_end - old_start; unsigned long new_start = old_start - shift; unsigned long new_end = old_end - shift; + unsigned long new_pgoff = new_start >> PAGE_SHIFT; struct mmu_gather *tlb; BUG_ON(new_start > new_end); @@ -523,7 +524,7 @@ static int shift_arg_pages(struct vm_are /* * cover the whole range: [new_start, old_end) */ - vma_adjust(vma, new_start, old_end, vma->vm_pgoff, NULL); + vma_adjust(vma, new_start, old_end, new_pgoff, NULL); /* * move the page tables downwards, on failure we rely on @@ -556,7 +557,7 @@ static int shift_arg_pages(struct vm_are /* * shrink the vma to just the new range. */ - vma_adjust(vma, new_start, new_end, vma->vm_pgoff, NULL); + vma_adjust(vma, new_start, new_end, new_pgoff, NULL); return 0; } _ -- 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/ . Don't email: email@kvack.org