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 16:15:58 +0900 Message-ID: <4C8DCFAE.4020700@hitachi.com> References: <20100812122641.fe88e846.randy.dunlap@oracle.com> <4C8D790B.8000807@hitachi.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from mail4.hitachi.co.jp ([133.145.228.5]:49080 "EHLO mail4.hitachi.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751906Ab0IMHQF (ORCPT ); Mon, 13 Sep 2010 03:16:05 -0400 In-Reply-To: <4C8D790B.8000807@hitachi.com> 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 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. Thank you, -- Masami HIRAMATSU 2nd Dept. Linux Technology Center Hitachi, Ltd., Systems Development Laboratory E-mail: masami.hiramatsu.pt@hitachi.com