Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751742AbYKLGxn (ORCPT ); Wed, 12 Nov 2008 01:53:43 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750845AbYKLGxe (ORCPT ); Wed, 12 Nov 2008 01:53:34 -0500 Received: from e31.co.us.ibm.com ([32.97.110.149]:36015 "EHLO e31.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750798AbYKLGxd (ORCPT ); Wed, 12 Nov 2008 01:53:33 -0500 Date: Wed, 12 Nov 2008 12:22:38 +0530 From: Ananth N Mavinakayanahalli To: Masami Hiramatsu Cc: Andrew Morton , Jim Keniston , David Miller , Rusty Russell , LKML , systemtap-ml Subject: Re: [PATCH 5/7] kprobes: Remove called_from argument Message-ID: <20081112065238.GB3081@in.ibm.com> Reply-To: ananth@in.ibm.com References: <4919F1A9.5070601@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4919F1A9.5070601@redhat.com> User-Agent: Mutt/1.5.16 (2007-06-09) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2588 Lines: 65 On Tue, Nov 11, 2008 at 03:57:13PM -0500, Masami Hiramatsu wrote: > Remove called_from argument from kprobes which had been used for preventing > self-refering of kernel module. However, since we don't keep module's refcount > after registering kprobe any more, there is no reason to check that. > > This patch also simplifies registering/unregistering functions because we don't > need to use __builtin_return_address(0) which was passed to called_from. > > Signed-off-by: Masami Hiramatsu > --- > kernel/kprobes.c | 70 +++++++++++-------------------------------------------- > 1 file changed, 14 insertions(+), 56 deletions(-) > > Index: 2.6.28-rc4/kernel/kprobes.c > =================================================================== > --- 2.6.28-rc4.orig/kernel/kprobes.c > +++ 2.6.28-rc4/kernel/kprobes.c > @@ -641,8 +641,7 @@ static kprobe_opcode_t __kprobes *kprobe > return (kprobe_opcode_t *)(((char *)addr) + p->offset); > } > > -static int __kprobes __register_kprobe(struct kprobe *p, > - unsigned long called_from) > +int __kprobes register_kprobe(struct kprobe *p) > { > int ret = 0; > struct kprobe *old_p; > @@ -673,13 +672,10 @@ static int __kprobes __register_kprobe(s > * We must hold a refcount of the probed module while updating > * its code to prohibit unexpected unloading. > */ > - if (calling_mod != probed_mod) { > - if (unlikely(!try_module_get(probed_mod))) { > - preempt_enable(); > - return -EINVAL; > - } > - } else > - probed_mod = NULL; > + if (unlikely(!try_module_get(probed_mod))) { > + preempt_enable(); > + return -EINVAL; > + } You also need the following to get this to compile, don't you? Signed-off-by: Ananth N Mavinakayanahalli Index: linux-2.6.28-rc4/kernel/kprobes.c =================================================================== --- linux-2.6.28-rc4.orig/kernel/kprobes.c 2008-11-12 11:13:30.000000000 +0530 +++ linux-2.6.28-rc4/kernel/kprobes.c 2008-11-12 12:18:44.000000000 +0530 @@ -666,8 +666,6 @@ */ probed_mod = __module_text_address((unsigned long) p->addr); if (probed_mod) { - struct module *calling_mod; - calling_mod = __module_text_address(called_from); /* * We must hold a refcount of the probed module while updating * its code to prohibit unexpected unloading. -- 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/