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 41DD4C43462 for ; Mon, 17 May 2021 19:58:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 22CCD60FF3 for ; Mon, 17 May 2021 19:58:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236997AbhEQT7V (ORCPT ); Mon, 17 May 2021 15:59:21 -0400 Received: from out01.mta.xmission.com ([166.70.13.231]:55158 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236924AbhEQT7S (ORCPT ); Mon, 17 May 2021 15:59:18 -0400 Received: from in01.mta.xmission.com ([166.70.13.51]) by out01.mta.xmission.com with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.93) (envelope-from ) id 1lijNH-009gqy-Gb; Mon, 17 May 2021 13:57:59 -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 1lijMX-0001ch-UG; Mon, 17 May 2021 13:57:16 -0600 From: ebiederm@xmission.com (Eric W. Biederman) To: Marco Elver Cc: 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: Mon, 17 May 2021 14:56:54 -0500 In-Reply-To: (Eric W. Biederman's message of "Tue, 04 May 2021 16:13:47 -0500") 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=1lijMX-0001ch-UG;;;mid=;;;hst=in01.mta.xmission.com;;;ip=68.227.160.95;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX19wgF5urIEeuZov1TyNkbEl+ZRf8d7DJfI= X-SA-Exim-Connect-IP: 68.227.160.95 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: [PATCH v4 0/5] siginfo: ABI fixes for TRAP_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 During the merge window an issue with si_perf and the siginfo ABI came up. The alpha and sparc siginfo structure layout had changed with the addition of SIGTRAP TRAP_PERF and the new field si_perf. The reason only alpha and sparc were affected is that they are the only architectures that use si_trapno. Looking deeper it was discovered that si_trapno is used for only a few select signals on alpha and sparc, and that none of the other _sigfault fields past si_addr are used at all. Which means technically no regression on alpha and sparc. While the alignment concerns might be dismissed the abuse of si_errno by SIGTRAP TRAP_PERF does have the potential to cause regressions in existing userspace. While we still have time before userspace starts using and depending on the new definition siginfo for SIGTRAP TRAP_PERF this set of changes cleans up siginfo_t. - The si_trapno field is demoted from magic alpha and sparc status and made an ordinary union member of the _sigfault member of siginfo_t. Without moving it of course. - si_perf is replaced with si_perf_data and si_perf_type ending the abuse of si_errno. - Unnecessary additions to signalfd_siginfo are removed. v3: https://lkml.kernel.org/r/m1tuni8ano.fsf_-_@fess.ebiederm.org v2: https://lkml.kernel.org/r/m14kfjh8et.fsf_-_@fess.ebiederm.org v1: https://lkml.kernel.org/r/m1zgxfs7zq.fsf_-_@fess.ebiederm.org This version drops the tests and fine grained handling of si_trapno on alpha and sparc (replaced assuming si_trapno is valid for all but the faults that defined different data). Eric W. Biederman (5): siginfo: Move si_trapno inside the union inside _si_fault signal: Implement SIL_FAULT_TRAPNO signal: Factor force_sig_perf out of perf_sigtrap signal: Deliver all of the siginfo perf data in _perf signalfd: Remove SIL_PERF_EVENT fields from signalfd_siginfo arch/m68k/kernel/signal.c | 3 +- arch/x86/kernel/signal_compat.c | 9 +++- fs/signalfd.c | 23 ++++----- include/linux/compat.h | 10 ++-- include/linux/sched/signal.h | 1 + include/linux/signal.h | 1 + include/uapi/asm-generic/siginfo.h | 15 +++--- include/uapi/linux/perf_event.h | 2 +- include/uapi/linux/signalfd.h | 4 +- kernel/events/core.c | 11 +--- kernel/signal.c | 59 +++++++++++++--------- .../selftests/perf_events/sigtrap_threads.c | 14 ++--- 12 files changed, 79 insertions(+), 73 deletions(-)