From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753145AbYIVBNY (ORCPT ); Sun, 21 Sep 2008 21:13:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752894AbYIVBNO (ORCPT ); Sun, 21 Sep 2008 21:13:14 -0400 Received: from fgwmail6.fujitsu.co.jp ([192.51.44.36]:48337 "EHLO fgwmail6.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752936AbYIVBNN (ORCPT ); Sun, 21 Sep 2008 21:13:13 -0400 Date: Mon, 22 Sep 2008 10:12:18 +0900 From: KOSAKI Motohiro To: Paul Mundt , linux-kernel@vger.kernel.org, Linus Torvalds , Mathieu Desnoyers , "Frank Ch. Eigler" , Roland McGrath Subject: Re: [PATCH] [RFC] tracehook: Hook in syscall tracing markers. Cc: kosaki.motohiro@jp.fujitsu.com In-Reply-To: <20080921021630.GA6443@linux-sh.org> References: <20080921021630.GA6443@linux-sh.org> Message-Id: <20080922010408.F53D.KOSAKI.MOTOHIRO@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Mailer: Becky! ver. 2.42 [ja] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Paul, > At kernel summit, the idea that syscall tracing was generally desirable > for tracing was mentioned several times, as was the argument that kernel > developers aren't placing markers in meaningful locations. This is a > simple patch to try and do that for the syscall case. > > Presently LTTng attempts to litter these trace markers all over the > architecture code, primarily to get around the fact that there was no > generic way to get at this information before. Now that platforms are > starting to do their syscall entry/exit notifiers through tracehook and > we have the asm/syscall.h interface, all of this information can be > generically abstracted. > > Signed-off-by: Paul Mundt > I think marriage between tracehook and generic marker is very good idea. at least, instruction pointer and return value are definitly useful. but... Have you seen Mathieu's tracepoint patch? I recommend to use tracepoint insted use marker directly. > --- > > include/linux/tracehook.h | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/include/linux/tracehook.h b/include/linux/tracehook.h > index 6186a78..481ff45 100644 > --- a/include/linux/tracehook.h > +++ b/include/linux/tracehook.h > @@ -49,6 +49,9 @@ > #include > #include > #include > +#include > +#include > + > struct linux_binprm; > > /** > @@ -112,6 +115,8 @@ static inline __must_check int tracehook_report_syscall_entry( > struct pt_regs *regs) > { > ptrace_report_syscall(regs); > + trace_mark(kernel_arch_syscall_entry, "syscall_id %ld ip #p%ld", > + syscall_get_nr(NULL, regs), instruction_pointer(regs)); > return 0; > } > > @@ -135,6 +140,8 @@ static inline __must_check int tracehook_report_syscall_entry( > static inline void tracehook_report_syscall_exit(struct pt_regs *regs, int step) > { > ptrace_report_syscall(regs); > + trace_mark(kernel_arch_syscall_exit, "ret %ld", > + syscall_get_return_value(NULL, regs)); > }