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=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 E3547C47076 for ; Tue, 12 May 2020 16:37:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C975A20720 for ; Tue, 12 May 2020 16:37:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727853AbgELQht (ORCPT ); Tue, 12 May 2020 12:37:49 -0400 Received: from foss.arm.com ([217.140.110.172]:58164 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725851AbgELQhs (ORCPT ); Tue, 12 May 2020 12:37:48 -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 7C404D6E; Tue, 12 May 2020 09:37:47 -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 CA7123F305; Tue, 12 May 2020 09:37:46 -0700 (PDT) From: Dave Martin To: mtk.manpages@gmail.com Cc: linux-man@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH 02/14] prctl.2: Add health warning Date: Tue, 12 May 2020 17:36:47 +0100 Message-Id: <1589301419-24459-3-git-send-email-Dave.Martin@arm.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1589301419-24459-1-git-send-email-Dave.Martin@arm.com> References: <1589301419-24459-1-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 In reality, almost every prctl interferes with assumptions that the compiler and C library / runtime rely on. prctl() can therefore make userspace explode in a variety ways that are likely to be hard to debug. This is not obvious to the uninitiated, so add a warning. Signed-off-by: Dave Martin --- man2/prctl.2 | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/man2/prctl.2 b/man2/prctl.2 index 7932ada..a35b748 100644 --- a/man2/prctl.2 +++ b/man2/prctl.2 @@ -66,6 +66,11 @@ prctl \- operations on a process or thread manipulates various aspects of the behavior of the calling thread or process. .PP +Note that careless use of +.BR prctl () +can confuse the userspace run-time environment, +so these operations should be used with care (if at all). +.PP .BR prctl () is called with a first argument describing what to do (with values defined in \fI\fP), and further -- 2.1.4