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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT 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 AB95BC433E0 for ; Fri, 15 May 2020 21:34:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8C6C020709 for ; Fri, 15 May 2020 21:34:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727799AbgEOVen (ORCPT ); Fri, 15 May 2020 17:34:43 -0400 Received: from 16.mo7.mail-out.ovh.net ([46.105.72.216]:53444 "EHLO 16.mo7.mail-out.ovh.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726301AbgEOVen (ORCPT ); Fri, 15 May 2020 17:34:43 -0400 Received: from player738.ha.ovh.net (unknown [10.108.42.82]) by mo7.mail-out.ovh.net (Postfix) with ESMTP id D540D164512 for ; Fri, 15 May 2020 23:26:40 +0200 (CEST) Received: from sk2.org (82-65-25-201.subs.proxad.net [82.65.25.201]) (Authenticated sender: steve@sk2.org) by player738.ha.ovh.net (Postfix) with ESMTPSA id 923521286A113; Fri, 15 May 2020 21:26:35 +0000 (UTC) From: Stephen Kitt To: Jonathan Corbet , Mauro Carvalho Chehab , linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Stephen Kitt Subject: [PATCH v2] docs: sysctl/kernel: document unaligned controls Date: Fri, 15 May 2020 23:24:44 +0200 Message-Id: <20200515212443.5012-1-steve@sk2.org> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Ovh-Tracer-Id: 653021949153856901 X-VR-SPAMSTATE: OK X-VR-SPAMSCORE: -100 X-VR-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrgeduhedrleekgdduheelucetufdoteggodetrfdotffvucfrrhhofhhilhgvmecuqfggjfdpvefjgfevmfevgfenuceurghilhhouhhtmecuhedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmnecujfgurhephffvufffkffogggtgfesthekredtredtjeenucfhrhhomhepufhtvghphhgvnhcumfhithhtuceoshhtvghvvgesshhkvddrohhrgheqnecuggftrfgrthhtvghrnhepieektefhtdffgfefveehudejvdeileefffdvtdefgeffffehudekudeuhedvledunecukfhppedtrddtrddtrddtpdekvddrieehrddvhedrvddtudenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepmhhouggvpehsmhhtphdqohhuthdphhgvlhhopehplhgrhigvrhejfeekrdhhrgdrohhvhhdrnhgvthdpihhnvghtpedtrddtrddtrddtpdhmrghilhhfrhhomhepshhtvghvvgesshhkvddrohhrghdprhgtphhtthhopehlihhnuhigqdhkvghrnhgvlhesvhhgvghrrdhkvghrnhgvlhdrohhrgh Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This documents ignore-unaligned-usertrap, unaligned-dump-stack, and unaligned-trap, based on arch/arc/kernel/unaligned.c, arch/ia64/kernel/unaligned.c, and arch/parisc/kernel/unaligned.c. While we're at it, integrate unaligned-memory-access.txt into the docs tree. Signed-off-by: Stephen Kitt --- Changes since v1: - move unaligned-memory-access.txt to process/ - removed UTF-8 apostrophe from the commit message Documentation/admin-guide/sysctl/kernel.rst | 51 +++++++++++++++++++ Documentation/process/index.rst | 1 + .../unaligned-memory-access.rst} | 0 3 files changed, 52 insertions(+) rename Documentation/{unaligned-memory-access.txt => process/unaligned-memory-access.rst} (100%) diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst index eb6bc9cc0318..4bb4d55f20ff 100644 --- a/Documentation/admin-guide/sysctl/kernel.rst +++ b/Documentation/admin-guide/sysctl/kernel.rst @@ -402,6 +402,25 @@ Controls whether the panic kmsg data should be reported to Hyper-V. = ========================================================= +ignore-unaligned-usertrap +========================= + +On architectures where unaligned accesses cause traps, and where this +feature is supported (``CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN``; +currently, ``arc`` and ``ia64``), controls whether all unaligned traps +are logged. + += ============================================================= +0 Log all unaligned accesses. +1 Only warn the first time a process traps. This is the default + setting. += ============================================================= + +See also `unaligned-trap`_ and `unaligned-dump-stack`_. On ``ia64``, +this allows system administrators to override the +``IA64_THREAD_UAC_NOPRINT`` ``prctl`` and avoid logs being flooded. + + kexec_load_disabled =================== @@ -1252,6 +1271,38 @@ See :doc:`/admin-guide/kernel-parameters` and :doc:`/trace/boottime-trace`. +.. _unaligned-dump-stack: + +unaligned-dump-stack (ia64) +=========================== + +When logging unaligned accesses, controls whether the stack is +dumped. + += =================================================== +0 Do not dump the stack. This is the default setting. +1 Dump the stack. += =================================================== + +See also `ignore-unaligned-usertrap`_. + + +unaligned-trap +============== + +On architectures where unaligned accesses cause traps, and where this +feature is supported (``CONFIG_SYSCTL_ARCH_UNALIGN_ALLOW``; currently, +``arc`` and ``parisc``), controls whether unaligned traps are caught +and emulated (instead of failing). + += ======================================================== +0 Do not emulate unaligned accesses. +1 Emulate unaligned accesses. This is the default setting. += ======================================================== + +See also `ignore-unaligned-usertrap`_. + + unknown_nmi_panic ================= diff --git a/Documentation/process/index.rst b/Documentation/process/index.rst index 6399d92f0b21..f07c9250c3ac 100644 --- a/Documentation/process/index.rst +++ b/Documentation/process/index.rst @@ -61,6 +61,7 @@ lack of a better place. botching-up-ioctls clang-format ../riscv/patch-acceptance + unaligned-memory-access .. only:: subproject and html diff --git a/Documentation/unaligned-memory-access.txt b/Documentation/process/unaligned-memory-access.rst similarity index 100% rename from Documentation/unaligned-memory-access.txt rename to Documentation/process/unaligned-memory-access.rst base-commit: 56b62540782bfde459acc8eb15b949eaf151c881 -- 2.20.1