From mboxrd@z Thu Jan 1 00:00:00 1970 From: Masami Hiramatsu Subject: Re: [PATCH -next] optprobes: fix kconfig depends/selects Date: Mon, 13 Sep 2010 19:14:13 +0900 Message-ID: <4C8DF975.4040502@hitachi.com> References: <20100812122641.fe88e846.randy.dunlap@oracle.com> <4C8D790B.8000807@hitachi.com> <4C8DCFAE.4020700@hitachi.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from mail9.hitachi.co.jp ([133.145.228.44]:59287 "EHLO mail9.hitachi.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751867Ab0IMKOU (ORCPT ); Mon, 13 Sep 2010 06:14:20 -0400 In-Reply-To: Sender: linux-next-owner@vger.kernel.org List-ID: To: Felipe Contreras Cc: Randy Dunlap , lkml , linux-next@vger.kernel.org, Ananth N Mavinakayanahalli , Anil S Keshavamurthy , "David S. Miller" , akpm , 2nddept-manager@sdl.hitachi.co.jp (2010/09/13 18:41), Felipe Contreras wrote: > On Mon, Sep 13, 2010 at 10:15 AM, Masami Hiramatsu > wrote: >> (2010/09/13 10:06), Masami Hiramatsu wrote: >>> (2010/09/12 19:49), Felipe Contreras wrote: >>>> On Thu, Aug 12, 2010 at 10:26 PM, Randy Dunlap wrote: >>>>> From: Randy Dunlap >>>>> >>>>> KALLSYMS and KALLSYMS_ALL depend on DEBUG_KERNEL, so add that dependency. >>>>> KALLSYMS_ALL depends on KALLSYMS, so select both of them, not just KALLSYMS_ALL. >>>>> >>>>> warning: (OPTPROBES && KPROBES && HAVE_OPTPROBES && !PREEMPT || MTD_UBI_DEBUG && MTD && SYSFS && MTD_UBI || UBIFS_FS_DEBUG && MISC_FILESYSTEMS && UBIFS_FS || LOCKDEP && DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT || LATENCYTOP && HAVE_LATENCYTOP_SUPPORT) selects KALLSYMS_ALL which has unmet direct dependencies (DEBUG_KERNEL && KALLSYMS) >>>>> >>>>> Signed-off-by: Randy Dunlap >>>>> Cc: Ananth N Mavinakayanahalli >>>>> Cc: Anil S Keshavamurthy >>>>> Cc: "David S. Miller" >>>>> Cc: Masami Hiramatsu >>>>> --- >>>>> arch/Kconfig | 2 ++ >>>>> 1 file changed, 2 insertions(+) >>>>> >>>>> --- linux-next-20100810.orig/arch/Kconfig >>>>> +++ linux-next-20100810/arch/Kconfig >>>>> @@ -45,6 +45,8 @@ config OPTPROBES >>>>> def_bool y >>>>> depends on KPROBES && HAVE_OPTPROBES >>>>> depends on !PREEMPT >>>>> + depends on DEBUG_KERNEL >>>>> + select KALLSYMS >>>>> select KALLSYMS_ALL >>>>> >>>>> config HAVE_EFFICIENT_UNALIGNED_ACCESS >>>>> -- >>>> >>>> This causes another problem: >>>> >>>> arch/Kconfig:33:error: recursive dependency detected! >>>> arch/Kconfig:33: symbol KPROBES depends on KALLSYMS >>>> init/Kconfig:825: symbol KALLSYMS is selected by OPTPROBES >>>> arch/Kconfig:44: symbol OPTPROBES depends on KPROBES >>>> >>>> The 'select KALLSYMS' is redundant. >>>> >>>> Otherwise: Signed-off-by: Felipe Contreras >>>> >>> >>> Thanks, let me clear the dependency; >>> Kprobes uses kallsyms_lookup for finding target function and checking >>> instruction boundary, thus CONFIG_KPROBES should select CONFIG_KALLSYMS >>> and CONFIG_KALLSYMS_ALL. >>> Optprobe is a optional feature which is supported on x86 arch, and >>> it also uses kallsyms_lookup for checking instructions in the target >>> function. Anyway, since optprobe itself is depends on kprobes, it doesn't >>> need to select both of KALLSYMS/KALLSYMS_ALL. >> >> Hmm, wait, I might misunderstand something here. I thought >> KALLSYMS_ALL added symbols of static functions. >> But, does KALLSYMS_ALL just add symbols of variables? >> If so, both of KPROBES and OPTPROBES require only KALLSYMS. >> It means that they don't need to care about CONFIG_DEBUG_KERNEL. > > So: > - select KALLSYMS_ALL > + depends on KALLSYMS_ALL > > Because KALLSYMS_ALL depends on DEBUG_KERNEL && KALLSYMS. No, what I meant is; - select KALLSYMS_ALL :-) -- Masami HIRAMATSU 2nd Dept. Linux Technology Center Hitachi, Ltd., Systems Development Laboratory E-mail: masami.hiramatsu.pt@hitachi.com