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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 982E0C433EF for ; Fri, 22 Oct 2021 13:56:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7FADE611F2 for ; Fri, 22 Oct 2021 13:56:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232276AbhJVN7M (ORCPT ); Fri, 22 Oct 2021 09:59:12 -0400 Received: from foss.arm.com ([217.140.110.172]:54264 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230355AbhJVN7L (ORCPT ); Fri, 22 Oct 2021 09:59:11 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id CC2951FB; Fri, 22 Oct 2021 06:56:53 -0700 (PDT) Received: from lakrids.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id B86B93F694; Fri, 22 Oct 2021 06:56:50 -0700 (PDT) From: Mark Rutland To: linux-kernel@vger.kernel.org, tglx@linutronix.de, mingo@redhat.com, peterz@infradead.org Cc: benh@kernel.crashing.org, boqun.feng@gmail.com, bp@alien8.de, catalin.marinas@arm.com, dvyukov@google.com, elver@google.com, ink@jurassic.park.msu.ru, jonas@southpole.se, juri.lelli@redhat.com, linux@armlinux.org.uk, luto@kernel.org, mark.rutland@arm.com, mattst88@gmail.com, michal.simek@xilinx.com, mpe@ellerman.id.au, paulmck@kernel.org, paulus@samba.org, rth@twiddle.net, shorne@gmail.com, stefan.kristiansson@saunalahti.fi, vincent.guittot@linaro.org, will@kernel.org Subject: [PATCH v6 00/10] thread_info: use helpers to snapshot thread flags Date: Fri, 22 Oct 2021 14:56:33 +0100 Message-Id: <20211022135643.7442-1-mark.rutland@arm.com> X-Mailer: git-send-email 2.11.0 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org TIP folk, I've been assuming this would go via the TIP tree. Are you happy to pick this up nowish, or as a fixup after the next -rc1? There have been no significant changes since v3, and the series applies cleanly from v5.15-rc1 all the way to next-20211022, so I'm not expecting any conflict. Usual blurb below... As thread_info::flags scan be manipulated by remote threads, it is necessary to use atomics or READ_ONCE() to ensure that code manipulates a consistent snapshot, but we open-code plain accesses to thread_info::flags across the kernel tree. Generally we get away with this, but tools like KCSAN legitimately warn that there is a data-race, and this is potentially fragile with compiler optimizations, LTO, etc. These patches introduce new helpers to snahpshot the thread flags, with the intent being that these should replace all plain accesses. Since v1 [1]: * Drop RFC * Make read_ti_thread_flags() __always_inline * Clarify commit messages * Fix typo in arm64 patch * Accumulate Reviewed-by / Acked-by tags * Drop powerpc patch to avoid potential conflicts (per [2]) Since v2 [3]: * Rebase to v5.14-rc1 * Reinstate powerpc patch Since v3 [4]: * Rebase to v5.14-rc4 Since v4 [5]: * Rebase to v5.15-rc1 * Apply Acked-by / Tested-by tags Since v5 [6]: * Fix trivial whitespace bug in x86 patch [1] https://lore.kernel.org/r/20210609122001.18277-1-mark.rutland@arm.com [2] https://lore.kernel.org/r/87k0mvtgeb.fsf@mpe.ellerman.id.au [3] https://lore.kernel.org/r/20210621090602.16883-1-mark.rutland@arm.com [4] https://lore.kernel.org/r/20210713113842.2106-1-mark.rutland@arm.com [5] https://lore.kernel.org/r/20210803095428.17009-1-mark.rutland@arm.com [6] https://lore.kernel.org/r/20210914103027.53565-1-mark.rutland@arm.com Thanks, Mark. Mark Rutland (10): thread_info: add helpers to snapshot thread flags entry: snapshot thread flags sched: snapshot thread flags alpha: snapshot thread flags arm: snapshot thread flags arm64: snapshot thread flags microblaze: snapshot thread flags openrisc: snapshot thread flags powerpc: snapshot thread flags x86: snapshot thread flags arch/alpha/kernel/signal.c | 2 +- arch/arm/kernel/signal.c | 2 +- arch/arm/mm/alignment.c | 2 +- arch/arm64/kernel/entry-common.c | 2 +- arch/arm64/kernel/ptrace.c | 4 ++-- arch/arm64/kernel/signal.c | 2 +- arch/arm64/kernel/syscall.c | 4 ++-- arch/microblaze/kernel/signal.c | 2 +- arch/openrisc/kernel/signal.c | 2 +- arch/powerpc/kernel/interrupt.c | 13 ++++++------- arch/powerpc/kernel/ptrace/ptrace.c | 3 +-- arch/x86/kernel/process.c | 8 ++++---- arch/x86/kernel/process.h | 4 ++-- arch/x86/mm/tlb.c | 2 +- include/linux/entry-kvm.h | 2 +- include/linux/thread_info.h | 14 ++++++++++++++ kernel/entry/common.c | 4 ++-- kernel/entry/kvm.c | 4 ++-- kernel/sched/core.c | 2 +- 19 files changed, 45 insertions(+), 33 deletions(-) -- 2.11.0