From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx145.postini.com [74.125.245.145]) by kanga.kvack.org (Postfix) with SMTP id 04CA86B004F for ; Wed, 4 Jan 2012 11:52:15 -0500 (EST) Message-ID: <1325695916.2697.5.camel@twins> Subject: Re: [PATCH v8 3.2.0-rc5 1/9] uprobes: Install and remove breakpoints. From: Peter Zijlstra Date: Wed, 04 Jan 2012 17:51:56 +0100 In-Reply-To: <20111216122808.2085.76986.sendpatchset@srdronam.in.ibm.com> References: <20111216122756.2085.95791.sendpatchset@srdronam.in.ibm.com> <20111216122808.2085.76986.sendpatchset@srdronam.in.ibm.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: quoted-printable Mime-Version: 1.0 Sender: owner-linux-mm@kvack.org List-ID: To: Srikar Dronamraju Cc: Linus Torvalds , Oleg Nesterov , Ingo Molnar , Andrew Morton , LKML , Linux-mm , Andi Kleen , Christoph Hellwig , Steven Rostedt , Roland McGrath , Thomas Gleixner , Masami Hiramatsu , Arnaldo Carvalho de Melo , Anton Arapov , Ananth N Mavinakayanahalli , Jim Keniston , Stephen Rothwell On Fri, 2011-12-16 at 17:58 +0530, Srikar Dronamraju wrote: > +static int register_for_each_vma(struct uprobe *uprobe, bool is_register= ) > +{ > + struct list_head try_list; > + struct vm_area_struct *vma; > + struct address_space *mapping; > + struct vma_info *vi, *tmpvi; > + struct mm_struct *mm; > + loff_t vaddr; > + int ret =3D 0; > + > + mapping =3D uprobe->inode->i_mapping; > + INIT_LIST_HEAD(&try_list); > + while ((vi =3D find_next_vma_info(&try_list, uprobe->offset, > + mapping, is_register)) !=3D NULL)= { > + if (IS_ERR(vi)) { > + ret =3D PTR_ERR(vi); > + break; > + } > + mm =3D vi->mm; > + down_read(&mm->mmap_sem); > + vma =3D find_vma(mm, (unsigned long)vi->vaddr); > + if (!vma || !valid_vma(vma, is_register)) { > + list_del(&vi->probe_list); > + kfree(vi); > + up_read(&mm->mmap_sem); > + mmput(mm); > + continue; > + } > + vaddr =3D vma_address(vma, uprobe->offset); > + if (vma->vm_file->f_mapping->host !=3D uprobe->inode || > + vaddr !=3D vi->vaddr) { > + list_del(&vi->probe_list); > + kfree(vi); > + up_read(&mm->mmap_sem); > + mmput(mm); > + continue; > + } > + > + if (is_register) > + ret =3D install_breakpoint(mm, uprobe, vma, vi->v= addr); > + else > + remove_breakpoint(mm, uprobe, vi->vaddr); > + > + up_read(&mm->mmap_sem); > + mmput(mm); > + if (is_register) { > + if (ret && ret =3D=3D -EEXIST) > + ret =3D 0; > + if (ret) > + break; > + } Since you init ret :=3D 0 and remove_breakpoint doesn't change it, this conditional on is_register is superfluous. > + } > + list_for_each_entry_safe(vi, tmpvi, &try_list, probe_list) { > + list_del(&vi->probe_list); > + kfree(vi); > + } > + return ret; > +}=20 -- 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 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756418Ab2ADQwW (ORCPT ); Wed, 4 Jan 2012 11:52:22 -0500 Received: from casper.infradead.org ([85.118.1.10]:42094 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750745Ab2ADQwU convert rfc822-to-8bit (ORCPT ); Wed, 4 Jan 2012 11:52:20 -0500 Message-ID: <1325695916.2697.5.camel@twins> Subject: Re: [PATCH v8 3.2.0-rc5 1/9] uprobes: Install and remove breakpoints. From: Peter Zijlstra To: Srikar Dronamraju Cc: Linus Torvalds , Oleg Nesterov , Ingo Molnar , Andrew Morton , LKML , Linux-mm , Andi Kleen , Christoph Hellwig , Steven Rostedt , Roland McGrath , Thomas Gleixner , Masami Hiramatsu , Arnaldo Carvalho de Melo , Anton Arapov , Ananth N Mavinakayanahalli , Jim Keniston , Stephen Rothwell Date: Wed, 04 Jan 2012 17:51:56 +0100 In-Reply-To: <20111216122808.2085.76986.sendpatchset@srdronam.in.ibm.com> References: <20111216122756.2085.95791.sendpatchset@srdronam.in.ibm.com> <20111216122808.2085.76986.sendpatchset@srdronam.in.ibm.com> Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT X-Mailer: Evolution 3.2.1- Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2011-12-16 at 17:58 +0530, Srikar Dronamraju wrote: > +static int register_for_each_vma(struct uprobe *uprobe, bool is_register) > +{ > + struct list_head try_list; > + struct vm_area_struct *vma; > + struct address_space *mapping; > + struct vma_info *vi, *tmpvi; > + struct mm_struct *mm; > + loff_t vaddr; > + int ret = 0; > + > + mapping = uprobe->inode->i_mapping; > + INIT_LIST_HEAD(&try_list); > + while ((vi = find_next_vma_info(&try_list, uprobe->offset, > + mapping, is_register)) != NULL) { > + if (IS_ERR(vi)) { > + ret = PTR_ERR(vi); > + break; > + } > + mm = vi->mm; > + down_read(&mm->mmap_sem); > + vma = find_vma(mm, (unsigned long)vi->vaddr); > + if (!vma || !valid_vma(vma, is_register)) { > + list_del(&vi->probe_list); > + kfree(vi); > + up_read(&mm->mmap_sem); > + mmput(mm); > + continue; > + } > + vaddr = vma_address(vma, uprobe->offset); > + if (vma->vm_file->f_mapping->host != uprobe->inode || > + vaddr != vi->vaddr) { > + list_del(&vi->probe_list); > + kfree(vi); > + up_read(&mm->mmap_sem); > + mmput(mm); > + continue; > + } > + > + if (is_register) > + ret = install_breakpoint(mm, uprobe, vma, vi->vaddr); > + else > + remove_breakpoint(mm, uprobe, vi->vaddr); > + > + up_read(&mm->mmap_sem); > + mmput(mm); > + if (is_register) { > + if (ret && ret == -EEXIST) > + ret = 0; > + if (ret) > + break; > + } Since you init ret := 0 and remove_breakpoint doesn't change it, this conditional on is_register is superfluous. > + } > + list_for_each_entry_safe(vi, tmpvi, &try_list, probe_list) { > + list_del(&vi->probe_list); > + kfree(vi); > + } > + return ret; > +}