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,URIBL_BLOCKED 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 A07C1C43460 for ; Thu, 6 May 2021 07:01:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7D961613BE for ; Thu, 6 May 2021 07:01:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232876AbhEFHCJ (ORCPT ); Thu, 6 May 2021 03:02:09 -0400 Received: from mail-vs1-f52.google.com ([209.85.217.52]:38498 "EHLO mail-vs1-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232873AbhEFHCJ (ORCPT ); Thu, 6 May 2021 03:02:09 -0400 Received: by mail-vs1-f52.google.com with SMTP id j128so2425040vsc.5; Thu, 06 May 2021 00:01:11 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=NoT+A0718WNsTbHBS5BGp5G+tj2RfytrZk7R7tgIl08=; b=X248YRswNzAfo6iG1kNtPokKkdBeSO8s61uJm6eTDuG4PrFnr/zB6gAcYTzegMUI4Z 7Fx2czLZ55vauWk8OQ5WrPkt42CQ5BJI5FjbLf8m1xhxBX0tHRJvP9U+vBHMeNyaxAJI AV7hCQsNQXyGuIGDFTSgGFIl9JE0CQF4goqEE3mPsHqbcjaI65xlc4l+3iL2yZG6HiyF 2AoZEQL10iJD0Q0NgwAI+s6QUMEaiSoOnHOmv4E33xUxYk6oHbbEn2yn38w+LsFYf75e zxIDlf2LrgGp6pYfceDVsbje3BNhitT06tWGt/xR9GPFrsLjM9itTWpHyqR5YibvMTgH JbLg== X-Gm-Message-State: AOAM533z2oqp/Njt2gXVBeP4JbJ/wH3mLrRaHR+z67MOlVfxdnHQAJ4j 7niDnJlGECU7b+fv8m91nNSTIAZSSNJxQ6fPIBfuqH4jwpA= X-Google-Smtp-Source: ABdhPJwtWn/D8K3Zn0jy1HK/vfeVlKteOEghQDe5DwJ1/OrY0tE/MhHEc0uYnsYlAuAKkFm96EHQ1hlHO1JAX4ayqVg= X-Received: by 2002:a67:f503:: with SMTP id u3mr1764571vsn.3.1620284470626; Thu, 06 May 2021 00:01:10 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Geert Uytterhoeven Date: Thu, 6 May 2021 09:00:59 +0200 Message-ID: Subject: Re: [PATCH v3 00/12] signal: sort out si_trapno and si_perf To: "Eric W. Biederman" 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 Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-api@vger.kernel.org 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 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. */ Thanks! Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds