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=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 978B3C433DF for ; Wed, 27 May 2020 21:18:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8091620835 for ; Wed, 27 May 2020 21:18:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728124AbgE0VS2 (ORCPT ); Wed, 27 May 2020 17:18:28 -0400 Received: from foss.arm.com ([217.140.110.172]:44764 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726114AbgE0VS1 (ORCPT ); Wed, 27 May 2020 17:18:27 -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 6A2E01042; Wed, 27 May 2020 14:18:27 -0700 (PDT) Received: from e103592.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 6A16F3F52E; Wed, 27 May 2020 14:18:26 -0700 (PDT) From: Dave Martin To: Michael Kerrisk Cc: linux-man@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Tim Chen , Thomas Gleixner Subject: [PATCH v2 2/6] prctl.2: Add PR_SPEC_INDIRECT_BRANCH for SPECULATION_CTRL prctls Date: Wed, 27 May 2020 22:17:34 +0100 Message-Id: <1590614258-24728-3-git-send-email-Dave.Martin@arm.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1590614258-24728-1-git-send-email-Dave.Martin@arm.com> References: <1590614258-24728-1-git-send-email-Dave.Martin@arm.com> Sender: linux-man-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-man@vger.kernel.org Add the PR_SPEC_INDIRECT_BRANCH "misfeature" added in Linux 4.20 for PR_SET_SPECULATION_CTRL and PR_GET_SPECULATION_CTRL. Signed-off-by: Dave Martin Cc: Tim Chen Cc: Thomas Gleixner --- man2/prctl.2 | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-) diff --git a/man2/prctl.2 b/man2/prctl.2 index dc99218..b6fb51c 100644 --- a/man2/prctl.2 +++ b/man2/prctl.2 @@ -1213,11 +1213,20 @@ arguments must be specified as 0; otherwise the call fails with the error .\" commit 356e4bfff2c5489e016fdb925adbf12a1e3950ee Sets the state of the speculation misfeature specified in .IR arg2 . -Currently, the only permitted value for this argument is +Currently, this argument must be one of: +.RS +.TP .B PR_SPEC_STORE_BYPASS -(otherwise the call fails with the error +speculative store bypass control, or +.\" commit 9137bb27e60e554dab694eafa4cca241fa3a694f +.TP +.BR PR_SPEC_INDIRECT_BRANCH " (since Linux 4.20)" +indirect branch speculation control. +.RE +.IP +(Otherwise the call fails with the error .BR ENODEV ). -This setting is a per-thread attribute. +These settings are per-thread attributes. The .IR arg3 argument is used to hand in the control value, @@ -1235,13 +1244,16 @@ Same as .BR PR_SPEC_DISABLE , but cannot be undone. A subsequent -.B -prctl(..., PR_SPEC_ENABLE) +.BR prctl (\c +.IR arg2 , +.BR PR_SPEC_ENABLE ) +with the same value for +.I arg2 will fail with the error .BR EPERM . .RE .IP -Any other value in +Any unsupported value in .IR arg3 will result in the call failing with the error .BR ERANGE . -- 2.1.4