Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934365Ab3JPUkt (ORCPT ); Wed, 16 Oct 2013 16:40:49 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:37259 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933857Ab3JPUkq (ORCPT ); Wed, 16 Oct 2013 16:40:46 -0400 Date: Wed, 16 Oct 2013 13:40:44 -0700 From: Andrew Morton To: "Jan Beulich" Cc: , , Subject: Re: [PATCH] fix proc_reg_get_unmapped_area() Message-Id: <20131016134044.d1bd8004f4fb94df405a541d@linux-foundation.org> In-Reply-To: <525E957802000078000FB6FE@nat28.tlf.novell.com> References: <525E957802000078000FB6FE@nat28.tlf.novell.com> X-Mailer: Sylpheed 3.2.0beta5 (GTK+ 2.24.10; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2266 Lines: 51 On Wed, 16 Oct 2013 12:32:40 +0100 "Jan Beulich" wrote: > Commit c4fe24485729fc2cbff324c111e67a1cc2f9adea ("sparc: fix PCI device > proc file mmap(2)"), while fixing one problem, introduced two new ones: > - the function truncates the return value from ->get_unmapped_area() on > 64-bit architectures, > - _all_ descendants are now required to set .get_unmapped_area to non- > NULL, which wasn't necessary before (and shouldn't be). > > Both - afaict - are a result from a too simplistic copy'n'paste from > proc_reg_mmap() done in that change. > > This likely also addresses reports like the one at > http://linux-kernel.2935.n7.nabble.com/mmap-for-proc-vmcore-broken-since-3-12-rc1-td729326.html. > > ... > > --- 3.12-rc5/fs/proc/inode.c > +++ 3.12-rc5-proc-get-unmapped-area/fs/proc/inode.c > @@ -288,12 +288,12 @@ static int proc_reg_mmap(struct file *fi > static unsigned long proc_reg_get_unmapped_area(struct file *file, unsigned long orig_addr, unsigned long len, unsigned long pgoff, unsigned long flags) > { > struct proc_dir_entry *pde = PDE(file_inode(file)); > - int rv = -EIO; > - unsigned long (*get_unmapped_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned long); > + unsigned long rv = -EIO; > + > if (use_pde(pde)) { > - get_unmapped_area = pde->proc_fops->get_unmapped_area; > - if (get_unmapped_area) > - rv = get_unmapped_area(file, orig_addr, len, pgoff, flags); > + rv = (pde->proc_fops->get_unmapped_area > + ?: current->mm->get_unmapped_area)(file, orig_addr, len, > + pgoff, flags); > unuse_pde(pde); > } > return rv; I think these two patches will address the problems: http://ozlabs.org/~akpm/mmots/broken-out/procfs-fix-unintended-truncation-of-returned-mapped-address.patch http://ozlabs.org/~akpm/mmots/broken-out/procfs-call-default-get_unmapped_area-on-mmu-present-architectures.patch I'll be sending those Linuswards today. Please check them. (I think your version would break the nommu build). -- 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/