From patchwork Tue May 19 22:12:31 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Williams X-Patchwork-Id: 225524 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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS 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 EF2D2C433E0 for ; Tue, 19 May 2020 22:28:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C13FE206C3 for ; Tue, 19 May 2020 22:28:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726536AbgESW2o (ORCPT ); Tue, 19 May 2020 18:28:44 -0400 Received: from mga12.intel.com ([192.55.52.136]:14393 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726432AbgESW2o (ORCPT ); Tue, 19 May 2020 18:28:44 -0400 IronPort-SDR: tM64yaY0VVmOTrgLbsyZPHkwBBfokNq25XixByctoKhCrmsrRN9cYFmxrWySPt5NGS8sKZn5IB Y7yA+o2ocXMA== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 May 2020 15:28:43 -0700 IronPort-SDR: K4gouk3kgt6TlmETPZvcuoH4GKDKD8iWteFL3OMV34DttzTKYx2Vm86O3xgzK00SdxVPRNm6aX xlKyDYPFpfmg== X-IronPort-AV: E=Sophos;i="5.73,411,1583222400"; d="scan'208";a="253395613" Received: from dwillia2-desk3.jf.intel.com (HELO dwillia2-desk3.amr.corp.intel.com) ([10.54.39.16]) by orsmga007-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 May 2020 15:28:43 -0700 Subject: [PATCH v3 0/2] Renovate memcpy_mcsafe with copy_mc_to_{user, kernel} From: Dan Williams To: tglx@linutronix.de, mingo@redhat.com Cc: Tony Luck , Vivek Goyal , Peter Zijlstra , Linus Torvalds , Alexander Viro , Borislav Petkov , stable@vger.kernel.org, x86@kernel.org, "H. Peter Anvin" , Andy Lutomirski , Paul Mackerras , Benjamin Herrenschmidt , Erwin Tsaur , Michael Ellerman , Mikulas Patocka , Arnaldo Carvalho de Melo , linux-kernel@vger.kernel.org, linux-nvdimm@lists.01.org Date: Tue, 19 May 2020 15:12:31 -0700 Message-ID: <158992635164.403910.2616621400995359522.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: StGit/0.18-3-g996c MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org Changes since v2 [1]: - Replace the non-descriptive copy_safe() with copy_mc_to_user() and copy_mc_to_kernel() several code organization cleanups resulted from this rename, which further proves the point that the name deeply matters for maintainability in this case. (Linus) - Do not use copy_user_generic() as the generic x86 backend for copy_mc_to_user() since the #MC handler explicitly wants the exception to be trapped by a _ASM_EXTABLE_FAULT handler. (Vivek). - Rename copy_safe_slow() to copy_mc_fragile() to better indicate what the implementation is handling. copy_safe_fast() is replaced with copy_mc_generic(). --- The primary motivation to go touch memcpy_mcsafe() is that the existing benefit of doing slow "handle with care" copies is obviated on newer CPUs. With that concern lifted it also obviates the need to continue to update the MCA-recovery capability detection code currently gated by "mcsafe_key". Now the old "mcsafe_key" opt-in to perform the copy with concerns for recovery fragility can instead be made an opt-out from the default fast copy implementation (enable_copy_mc_fragile()). The discussion with Linus on the first iteration of this patch identified that memcpy_mcsafe() was misnamed relative to its usage. The new names copy_mc_to_user() and copy_mc_to_kernel() clearly indicate the intended use case and lets the architecture organize the implementation accordingly. For both powerpc and x86 a copy_mc_generic() implementation is added as the backend for these interfaces. Patches are relative to tip/master. --- Dan Williams (2): x86, powerpc: Rename memcpy_mcsafe() to copy_mc_to_{user,kernel}() x86/copy_mc: Introduce copy_mc_generic() arch/powerpc/Kconfig | 2 arch/powerpc/include/asm/string.h | 2 arch/powerpc/include/asm/uaccess.h | 40 +++-- arch/powerpc/lib/Makefile | 2 arch/powerpc/lib/copy_mc_64.S | 4 arch/x86/Kconfig | 2 arch/x86/Kconfig.debug | 2 arch/x86/include/asm/copy_mc_test.h | 75 +++++++++ arch/x86/include/asm/mcsafe_test.h | 75 --------- arch/x86/include/asm/string_64.h | 32 ---- arch/x86/include/asm/uaccess_64.h | 35 ++-- arch/x86/kernel/cpu/mce/core.c | 8 - arch/x86/kernel/quirks.c | 9 - arch/x86/lib/Makefile | 1 arch/x86/lib/copy_mc.c | 64 ++++++++ arch/x86/lib/copy_mc_64.S | 165 ++++++++++++++++++++ arch/x86/lib/memcpy_64.S | 115 -------------- arch/x86/lib/usercopy_64.c | 21 --- drivers/md/dm-writecache.c | 15 +- drivers/nvdimm/claim.c | 2 drivers/nvdimm/pmem.c | 6 - include/linux/string.h | 9 - include/linux/uaccess.h | 9 + include/linux/uio.h | 10 + lib/Kconfig | 7 + lib/iov_iter.c | 43 +++-- tools/arch/x86/include/asm/copy_safe_test.h | 13 ++ tools/arch/x86/include/asm/mcsafe_test.h | 13 -- tools/arch/x86/lib/memcpy_64.S | 115 -------------- tools/objtool/check.c | 5 - tools/perf/bench/Build | 1 tools/perf/bench/mem-memcpy-x86-64-lib.c | 24 --- tools/testing/nvdimm/test/nfit.c | 48 +++--- .../testing/selftests/powerpc/copyloops/.gitignore | 2 tools/testing/selftests/powerpc/copyloops/Makefile | 6 - .../testing/selftests/powerpc/copyloops/copy_mc.S | 0 36 files changed, 460 insertions(+), 522 deletions(-) rename arch/powerpc/lib/{memcpy_mcsafe_64.S => copy_mc_64.S} (98%) create mode 100644 arch/x86/include/asm/copy_mc_test.h delete mode 100644 arch/x86/include/asm/mcsafe_test.h create mode 100644 arch/x86/lib/copy_mc.c create mode 100644 arch/x86/lib/copy_mc_64.S create mode 100644 tools/arch/x86/include/asm/copy_safe_test.h delete mode 100644 tools/arch/x86/include/asm/mcsafe_test.h delete mode 100644 tools/perf/bench/mem-memcpy-x86-64-lib.c rename tools/testing/selftests/powerpc/copyloops/{memcpy_mcsafe_64.S => copy_mc.S} (100%) base-commit: bba413deb1065f1291cb1f366247513f11215520