From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 57B83C43462 for ; Thu, 6 May 2021 15:14:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1C89061176 for ; Thu, 6 May 2021 15:14:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235098AbhEFPPc (ORCPT ); Thu, 6 May 2021 11:15:32 -0400 Received: from out02.mta.xmission.com ([166.70.13.232]:45168 "EHLO out02.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234977AbhEFPP3 (ORCPT ); Thu, 6 May 2021 11:15:29 -0400 Received: from in01.mta.xmission.com ([166.70.13.51]) by out02.mta.xmission.com with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.93) (envelope-from ) id 1lefhp-005MIv-LY; Thu, 06 May 2021 09:14:25 -0600 Received: from ip68-227-160-95.om.om.cox.net ([68.227.160.95] helo=fess.xmission.com) by in01.mta.xmission.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.87) (envelope-from ) id 1lefhl-0000RC-E9; Thu, 06 May 2021 09:14:22 -0600 From: ebiederm@xmission.com (Eric W. Biederman) To: Geert Uytterhoeven Cc: Marco Elver , Arnd Bergmann , Florian Weimer , "David S. Miller" , Peter Zijlstra , Ingo Molnar , Thomas Gleixner , Peter Collingbourne , Dmitry Vyukov , Alexander Potapenko , sparclinux , linux-arch , Linux Kernel Mailing List , Linux API , kasan-dev References: Date: Thu, 06 May 2021 10:14:17 -0500 In-Reply-To: (Geert Uytterhoeven's message of "Thu, 6 May 2021 09:00:59 +0200") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-XM-SPF: eid=1lefhl-0000RC-E9;;;mid=;;;hst=in01.mta.xmission.com;;;ip=68.227.160.95;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX19LyVyCtQprDRirlYQLwegi4JFnnMVJ0N8= X-SA-Exim-Connect-IP: 68.227.160.95 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: Re: [PATCH v3 00/12] signal: sort out si_trapno and si_perf X-SA-Exim-Version: 4.2.1 (built Thu, 05 May 2016 13:38:54 -0600) X-SA-Exim-Scanned: Yes (on in01.mta.xmission.com) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Geert Uytterhoeven writes: > Hi Eric, > > On Tue, May 4, 2021 at 11:14 PM Eric W. Biederman wrote: >> This set of changes sorts out the ABI issues with SIGTRAP TRAP_PERF, and >> hopefully will can get merged before any userspace code starts using the >> new ABI. >> >> The big ideas are: >> - Placing the asserts first to prevent unexpected ABI changes >> - si_trapno becomming ordinary fault subfield. >> - struct signalfd_siginfo is almost full >> >> This set of changes starts out with Marco's static_assert changes and >> additional one of my own that enforces the fact that the alignment of >> siginfo_t is also part of the ABI. Together these build time >> checks verify there are no unexpected ABI changes in the changes >> that follow. >> >> The field si_trapno is changed to become an ordinary extension of the >> _sigfault member of siginfo. >> >> The code is refactored a bit and then si_perf_type is added along side >> si_perf_data in the _perf subfield of _sigfault of siginfo_t. >> >> Finally the signalfd_siginfo fields are removed as they appear to be >> filling up the structure without userspace actually being able to use >> them. > > Thanks for your series, which is now in next-20210506. > >> arch/alpha/include/uapi/asm/siginfo.h | 2 - >> arch/alpha/kernel/osf_sys.c | 2 +- >> arch/alpha/kernel/signal.c | 4 +- >> arch/alpha/kernel/traps.c | 24 ++--- >> arch/alpha/mm/fault.c | 4 +- >> arch/arm/kernel/signal.c | 39 +++++++ >> arch/arm64/kernel/signal.c | 39 +++++++ >> arch/arm64/kernel/signal32.c | 39 +++++++ >> arch/mips/include/uapi/asm/siginfo.h | 2 - >> arch/sparc/include/uapi/asm/siginfo.h | 3 - >> arch/sparc/kernel/process_64.c | 2 +- >> arch/sparc/kernel/signal32.c | 37 +++++++ >> arch/sparc/kernel/signal_64.c | 36 +++++++ >> arch/sparc/kernel/sys_sparc_32.c | 2 +- >> arch/sparc/kernel/sys_sparc_64.c | 2 +- >> arch/sparc/kernel/traps_32.c | 22 ++-- >> arch/sparc/kernel/traps_64.c | 44 ++++---- >> arch/sparc/kernel/unaligned_32.c | 2 +- >> arch/sparc/mm/fault_32.c | 2 +- >> arch/sparc/mm/fault_64.c | 2 +- >> arch/x86/kernel/signal_compat.c | 15 ++- > > No changes needed for other architectures? > All m68k configs are broken with Thanks. I hadn't realized that si_perf asserts existed on m68k. Thankfully linux-next caught this these. Looking a little more deeply, it is strange that this is tested on m68k. The architecture does not implement HAVE_PERF_EVENTS so it is impossible for this signal to be generated. On the off chance this these new signals will appear on m68k someday I will update the assertion. > arch/m68k/kernel/signal.c:626:35: error: 'siginfo_t' {aka 'struct > siginfo'} has no member named 'si_perf'; did you mean 'si_errno'? > > See e.g. http://kisskb.ellerman.id.au/kisskb/buildresult/14537820/ > > There are still a few more references left to si_perf: > > $ git grep -n -w si_perf > Next/merge.log:2902:Merging userns/for-next (4cf4e48fff05 signal: sort > out si_trapno and si_perf) > arch/m68k/kernel/signal.c:626: BUILD_BUG_ON(offsetof(siginfo_t, > si_perf) != 0x10); > include/uapi/linux/perf_event.h:467: * siginfo_t::si_perf, e.g. to > permit user to identify the event. > tools/testing/selftests/perf_events/sigtrap_threads.c:46:/* Unique > value to check si_perf is correctly set from > perf_event_attr::sig_data. */ I will sweep them up as well. Eric