From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932080AbbC0MRN (ORCPT ); Fri, 27 Mar 2015 08:17:13 -0400 Received: from mail.skyhub.de ([78.46.96.112]:57762 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752600AbbC0MRL (ORCPT ); Fri, 27 Mar 2015 08:17:11 -0400 Date: Fri, 27 Mar 2015 13:15:21 +0100 From: Borislav Petkov To: Ingo Molnar Cc: ast@plumgrid.com, dvlasenk@redhat.com, luto@amacapital.net, fweisbec@gmail.com, linux-kernel@vger.kernel.org, wad@chromium.org, rostedt@goodmis.org, oleg@redhat.com, mingo@kernel.org, torvalds@linux-foundation.org, hpa@zytor.com, keescook@chromium.org, tglx@linutronix.de, linux-tip-commits@vger.kernel.org Subject: Re: [tip:x86/asm] x86/asm/entry/64: Use better label name, fix comments Message-ID: <20150327121521.GC18927@pd.tnic> References: <1427303896-24023-1-git-send-email-dvlasenk@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Mar 27, 2015 at 04:46:44AM -0700, tip-bot for Denys Vlasenko wrote: > Commit-ID: 146b2b097d7a322b64b88a927fc5d870fc79a60b > Gitweb: http://git.kernel.org/tip/146b2b097d7a322b64b88a927fc5d870fc79a60b > Author: Denys Vlasenko > AuthorDate: Wed, 25 Mar 2015 18:18:13 +0100 > Committer: Ingo Molnar > CommitDate: Fri, 27 Mar 2015 09:57:05 +0100 > > x86/asm/entry/64: Use better label name, fix comments > > A named label "ret_from_sys_call" implies that there are jumps > to this location from elsewhere, as happens with many other > labels in this file. > > But this label is used only by the JMP a few insns above. > To make that obvious, use local numeric label instead. > > Improve comments: > > "and return regs->ax" isn't too informative. We always return > regs->ax. > > The comment suggesting that it'd be cool to use rip relative > addressing for CALL is deleted. It's unclear why that would be > an improvement - we aren't striving to use position-independent > code here. PIC code here would require something like LEA > sys_call_table(%rip),reg + CALL *(reg,%rax*8)... > > "iret frame is also incomplete" is no longer true, fix that too. > > Also fix typo in comment. > > Signed-off-by: Denys Vlasenko > Cc: Alexei Starovoitov > Cc: Andy Lutomirski > Cc: Borislav Petkov > Cc: Frederic Weisbecker > Cc: H. Peter Anvin > Cc: Kees Cook > Cc: Linus Torvalds > Cc: Oleg Nesterov > Cc: Steven Rostedt > Cc: Will Drewry > Link: http://lkml.kernel.org/r/1427303896-24023-1-git-send-email-dvlasenk@redhat.com > Signed-off-by: Ingo Molnar > --- > arch/x86/kernel/entry_64.S | 13 ++++++------- > 1 file changed, 6 insertions(+), 7 deletions(-) Shouldn't you take v2 of that one? https://lkml.kernel.org/r/1427307629-10024-1-git-send-email-dvlasenk@redhat.com v2 is missing this hunk though: --- @@ -1407,7 +1406,7 @@ ENTRY(nmi) * NMI. */ - /* Use %rdx as out temp variable throughout */ + /* Use %rdx as our temp variable throughout */ pushq_cfi %rdx CFI_REL_OFFSET rdx, 0 -- I blame Denys for sending too many patches! :) -- Regards/Gruss, Boris. ECO tip #101: Trim your mails when you reply. --