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=-4.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=no 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 BC6ECC54E4B for ; Mon, 11 May 2020 20:42:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9E18920882 for ; Mon, 11 May 2020 20:42:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589229757; bh=qgN70zVmcGfRw/D2t3Nj/SkzDqrrL4QsN2ZVTKK73gY=; h=From:To:Cc:Subject:Date:List-ID:From; b=TtySuM/LET5/tBh3/dv6bfbqwuzchHdXhPdMexSd+s8zOaKT/PdN8pMhGzCj0mpyZ zGw7A0ICW5pFPExsgzdypAZ0klEpfp4o0oW7QwjXZ6ofcX/hUn97ZFjQdGOvspqYpI 0dyDhUK0lhTVLnKpclaX+/FFUbPygFonOrwiN7pg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731757AbgEKUme (ORCPT ); Mon, 11 May 2020 16:42:34 -0400 Received: from mail.kernel.org ([198.145.29.99]:53950 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729842AbgEKUmc (ORCPT ); Mon, 11 May 2020 16:42:32 -0400 Received: from localhost.localdomain (236.31.169.217.in-addr.arpa [217.169.31.236]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B3B4E20661; Mon, 11 May 2020 20:42:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589229752; bh=qgN70zVmcGfRw/D2t3Nj/SkzDqrrL4QsN2ZVTKK73gY=; h=From:To:Cc:Subject:Date:From; b=N7KUSjM3xKHtF+AGgrDQ460HMdYLs/8nqJ2Cwy7wJJQISA1YiedoQ+VtoWy40T1hU jW/OXAF4N3Up3dwu0VO0Helui/+tfEENMR+bmxVbXUnaXllJn2/uaIJL29GJx3dcok AguCdtZesS/WIdgX23kp1goGy3DNnSaBp6q67l8w= From: Will Deacon To: linux-kernel@vger.kernel.org Cc: elver@google.com, tglx@linutronix.de, paulmck@kernel.org, mingo@kernel.org, peterz@infradead.org, will@kernel.org Subject: [PATCH v5 00/18] Rework READ_ONCE() to improve codegen Date: Mon, 11 May 2020 21:41:32 +0100 Message-Id: <20200511204150.27858-1-will@kernel.org> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi folks, (trimmed CC list since v4 since this is largely just a rebase) This is version five of the READ_ONCE() codegen improvement series that I've previously posted here: RFC: https://lore.kernel.org/lkml/20200110165636.28035-1-will@kernel.org v2: https://lore.kernel.org/lkml/20200123153341.19947-1-will@kernel.org v3: https://lore.kernel.org/lkml/20200415165218.20251-1-will@kernel.org v4: https://lore.kernel.org/lkml/20200421151537.19241-1-will@kernel.org The main change since v4 is that this is now based on top of the KCSAN changes queued in -tip (locking/kcsan) and therefore contains the patches necessary to avoid breaking sparc32 as well as some cleanups to consolidate {READ,WRITE}_ONCE() and data_race(). Other changes include: * Treat 'char' as distinct from 'signed char' and 'unsigned char' for __builtin_types_compatible_p() * Add a compile-time assertion that the argument to READ_ONCE_NOCHECK() points at something the same size as 'unsigned long' I'm happy for all of this to go via -tip, or I can take it via arm64. Please let me know. Cheers, Will Cc: Marco Elver Cc: Thomas Gleixner Cc: Paul E. McKenney Cc: Ingo Molnar Cc: Peter Zijlstra --->8 Will Deacon (18): sparc32: mm: Fix argument checking in __srmmu_get_nocache() sparc32: mm: Restructure sparc32 MMU page-table layout sparc32: mm: Change pgtable_t type to pte_t * instead of struct page * sparc32: mm: Reduce allocation size for PMD and PTE tables compiler/gcc: Raise minimum GCC version for kernel builds to 4.8 netfilter: Avoid assigning 'const' pointer to non-const pointer net: tls: Avoid assigning 'const' pointer to non-const pointer fault_inject: Don't rely on "return value" from WRITE_ONCE() arm64: csum: Disable KASAN for do_csum() READ_ONCE: Simplify implementations of {READ,WRITE}_ONCE() READ_ONCE: Enforce atomicity for {READ,WRITE}_ONCE() memory accesses READ_ONCE: Drop pointer qualifiers when reading from scalar types locking/barriers: Use '__unqual_scalar_typeof' for load-acquire macros arm64: barrier: Use '__unqual_scalar_typeof' for acquire/release macros gcov: Remove old GCC 3.4 support kcsan: Rework data_race() so that it can be used by READ_ONCE() READ_ONCE: Use data_race() to avoid KCSAN instrumentation linux/compiler.h: Remove redundant '#else' Documentation/process/changes.rst | 2 +- arch/arm/crypto/Kconfig | 12 +- arch/arm64/include/asm/barrier.h | 16 +- arch/arm64/lib/csum.c | 20 +- arch/sparc/include/asm/page_32.h | 12 +- arch/sparc/include/asm/pgalloc_32.h | 11 +- arch/sparc/include/asm/pgtable_32.h | 40 +- arch/sparc/include/asm/pgtsrmmu.h | 36 +- arch/sparc/include/asm/viking.h | 5 +- arch/sparc/kernel/head_32.S | 8 +- arch/sparc/mm/hypersparc.S | 3 +- arch/sparc/mm/srmmu.c | 95 ++--- arch/sparc/mm/viking.S | 5 +- crypto/Kconfig | 1 - drivers/xen/time.c | 2 +- include/asm-generic/barrier.h | 16 +- include/linux/compiler-gcc.h | 5 +- include/linux/compiler.h | 207 +++++----- include/linux/compiler_types.h | 26 ++ init/Kconfig | 1 - kernel/gcov/Kconfig | 24 -- kernel/gcov/Makefile | 3 +- kernel/gcov/gcc_3_4.c | 573 ---------------------------- lib/fault-inject.c | 4 +- net/netfilter/core.c | 2 +- net/tls/tls_main.c | 2 +- scripts/gcc-plugins/Kconfig | 2 +- 27 files changed, 257 insertions(+), 876 deletions(-) delete mode 100644 kernel/gcov/gcc_3_4.c -- 2.26.2.645.ge9eca65c58-goog