From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Authentication-Results: smtp.codeaurora.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="ueOLRjFh" DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 823756070B Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752123AbeFFNNn (ORCPT + 25 others); Wed, 6 Jun 2018 09:13:43 -0400 Received: from merlin.infradead.org ([205.233.59.134]:59650 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751864AbeFFNNh (ORCPT ); Wed, 6 Jun 2018 09:13:37 -0400 Date: Wed, 6 Jun 2018 15:13:02 +0200 From: Peter Zijlstra To: Adrian Hunter Cc: Thomas Gleixner , Arnaldo Carvalho de Melo , Ingo Molnar , Andy Lutomirski , "H. Peter Anvin" , Andi Kleen , Alexander Shishkin , Dave Hansen , Joerg Roedel , Jiri Olsa , linux-kernel@vger.kernel.org, x86@kernel.org, rostedt@goodmis.org, daniel@iogearbox.net Subject: Re: [PATCH V4 1/3] kallsyms: Simplify update_iter_mod() Message-ID: <20180606131302.GB12180@hirez.programming.kicks-ass.net> References: <1528289651-4113-1-git-send-email-adrian.hunter@intel.com> <1528289651-4113-2-git-send-email-adrian.hunter@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1528289651-4113-2-git-send-email-adrian.hunter@intel.com> User-Agent: Mutt/1.9.5 (2018-04-13) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jun 06, 2018 at 03:54:09PM +0300, Adrian Hunter wrote: > The logic in update_iter_mod() is overcomplicated and gets worse every time > another get_ksymbol_* function is added. > > In preparation for adding another get_ksymbol_* function, simplify logic in > update_iter_mod(). > > Signed-off-by: Adrian Hunter > Acked-by: Andi Kleen Both Daniel and Steven touched this function last year, let's also Cc them. Acked-by: Peter Zijlstra (Intel) > --- > kernel/kallsyms.c | 25 +++++++++++-------------- > 1 file changed, 11 insertions(+), 14 deletions(-) > > diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c > index a23e21ada81b..aa31aa07f2ef 100644 > --- a/kernel/kallsyms.c > +++ b/kernel/kallsyms.c > @@ -506,27 +506,24 @@ static void reset_iter(struct kallsym_iter *iter, loff_t new_pos) > } > } > > +/* > + * The end position (last + 1) of each additional kallsyms section is recorded > + * in iter->pos_..._end as each section is added, and so can be used to > + * determine which get_ksymbol_...() function to call next. > + */ > static int update_iter_mod(struct kallsym_iter *iter, loff_t pos) > { > iter->pos = pos; > > - if (iter->pos_ftrace_mod_end > 0 && > - iter->pos_ftrace_mod_end < iter->pos) > - return get_ksymbol_bpf(iter); > - > - if (iter->pos_mod_end > 0 && > - iter->pos_mod_end < iter->pos) { > - if (!get_ksymbol_ftrace_mod(iter)) > - return get_ksymbol_bpf(iter); > + if ((!iter->pos_mod_end || iter->pos_mod_end > pos) && > + get_ksymbol_mod(iter)) > return 1; > - } > > - if (!get_ksymbol_mod(iter)) { > - if (!get_ksymbol_ftrace_mod(iter)) > - return get_ksymbol_bpf(iter); > - } > + if ((!iter->pos_ftrace_mod_end || iter->pos_ftrace_mod_end > pos) && > + get_ksymbol_ftrace_mod(iter)) > + return 1; > > - return 1; > + return get_ksymbol_bpf(iter); > } > > /* Returns false if pos at or past end of file. */ > -- > 1.9.1 >