From patchwork Thu Mar 22 05:23:36 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joel Stanley X-Patchwork-Id: 132249 Delivered-To: patch@linaro.org Received: by 10.46.84.29 with SMTP id i29csp406510ljb; Wed, 21 Mar 2018 22:23:54 -0700 (PDT) X-Google-Smtp-Source: AG47ELsTIyLtKsp7I8Ir9+9JcJ9WdhyBrgteAph4c4LexeJnspwwUdOZ1APLCiLstopD7+OvJ/Pk X-Received: by 2002:a17:902:7502:: with SMTP id i2-v6mr6541866pll.220.1521696234081; Wed, 21 Mar 2018 22:23:54 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1521696234; cv=none; d=google.com; s=arc-20160816; b=LJQxz75jFWJQyMRAQ3BveIt7cqKXLdrFYnVeJ+sfPg+ahSAe3Q8CJrS/h1zrsKbRzm /1JwXf3u86/DS8+rX9NNJ50Otm5Gpw8cKsS322pSFtnmO58B4LD6BG5LcZZiRSiHobi9 10NNbE0gJEY7OjBAV3v7OJdhDbno2p5epswcmKxofmi7HP5gRKfDWsEC8svh4QQ0u394 7EKltG3VZXftF1VAlvrOjocEld7dQ8DAbjsmwJo6GTynJTDcfQzGsp0ElWMoxp+fgJK8 NAsBtrTrVfNQr9B0mq1EebddBRDHZZcJkrVaDFxceY4A7OIVK6VP9pnXQn8iSw6e+dH9 c6ww== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:message-id:date:subject:cc:to:from :dkim-signature:arc-authentication-results; bh=slte1YSMmLpG3tDvoGF8P74n1GTvzOYOZyhLRd5vJYk=; b=Y2Wd38zTDJzEBwrmFteRre1PclVigUXuN2EIe0miuhJSk+9J+XzxxGsmWBcq4O5xEk 1GouvdzUPgoiISrnbWCWXN0ABBQarJdp+vvyBN5RvYEaev14Gs2BgII40c2brNMMVAjv I+jE2O8OZzfuFEz4oUfK7u/9PongLJ8+m5RmFZFgS6RgEgHkMjwGnnkh/HxiaDkmwZwt pHkGyjaiDGKyyA2U7gDX0+v286jJuXOdBNqRMPjESAHjD/ZhOX0XQvTFNB5F/lRDX763 GfsXu2B8dWCFzV7P8Og7eTSdqANPEkqfoFf14X4HRUItKkPAJysoLW6AxiQMDI6otOJv oJaA== ARC-Authentication-Results: i=1; mx.google.com; dkim=fail header.i=@gmail.com header.s=20161025 header.b=QpljvzuE; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id x7si3809731pgr.301.2018.03.21.22.23.53; Wed, 21 Mar 2018 22:23:54 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=fail header.i=@gmail.com header.s=20161025 header.b=QpljvzuE; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752333AbeCVFXu (ORCPT + 28 others); Thu, 22 Mar 2018 01:23:50 -0400 Received: from mail-pl0-f66.google.com ([209.85.160.66]:34761 "EHLO mail-pl0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752042AbeCVFXr (ORCPT ); Thu, 22 Mar 2018 01:23:47 -0400 Received: by mail-pl0-f66.google.com with SMTP id u11-v6so4645665plq.1; Wed, 21 Mar 2018 22:23:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:to:cc:subject:date:message-id; bh=slte1YSMmLpG3tDvoGF8P74n1GTvzOYOZyhLRd5vJYk=; b=QpljvzuETu56yBlSG7MSwvsYwzTFa7SJfpw36sEfl1XbuCzI0TB0sRtNXzhIWXpyF+ YVpziyYunQAqR8i9o2obsVJdeeIqC7H3JT/QHww8gzX3ZPXnsSbTa05dNtt33+wQ4GJ+ eRek+IvlvXseqsysN8CPH88IbUzNBzbtl6Bt0kRu2TEvVeg4T3SASB8NivmGqZ29SwNd JXJd7AC9C7v6ABB9rjw1OFtRHSV+dYhcrn2gp15rSIrGD1g//MEkbDB+aHsPJwLVgK2+ X2BAtst+7fjTtR4GZEN0WhPTM5NkZ1VJtCWIT35lnIYU+2uyiSWlt92Aks9/u+QvcC9C 1xrA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id; bh=slte1YSMmLpG3tDvoGF8P74n1GTvzOYOZyhLRd5vJYk=; b=F1NP4x0ADGhHWzedklqac2cc4O5p5egVll+pLoLJQnodnXdRluIIVUthzsqyW9NTz+ LOnr4CkwARPsK2yXQU0v3iHDMoMPgvzZJ0oUZPM4KQ+XC/em8Xx3zElT9KXaL74PGlrT a+jH7HMEQasrA7n4J3oK2D5d4fkrYgi51El0urAbg/3ffw7e8K3GrqCg9PBZsxa9HFS6 cTcY2NWw9BG5GYfUPTJ29N5Og1kXvnkxiSRkCojQX6kjyTuX5lTELcKsaUJJZViZWpID 51/63R4xrGJC6MG+arRoOxPQsdFTfb7jM5sS4BHLv/2x24ZO/o6R50/4T9MwSuofqCTg KujA== X-Gm-Message-State: AElRT7H9xb8NhB3rXVOLRsRe7KC+jWlgpdLI/HNj4mLv09uU3z00Zcuz xhDdJ5SORKCbBRBgmh8R7hZ7IScB X-Received: by 2002:a17:902:7081:: with SMTP id z1-v6mr18249336plk.333.1521696226822; Wed, 21 Mar 2018 22:23:46 -0700 (PDT) Received: from aurora.jms.id.au ([203.0.153.9]) by smtp.gmail.com with ESMTPSA id q9sm926168pgs.89.2018.03.21.22.23.43 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 21 Mar 2018 22:23:46 -0700 (PDT) Received: by aurora.jms.id.au (sSMTP sendmail emulation); Thu, 22 Mar 2018 15:53:39 +1030 From: Joel Stanley To: Jonathan Corbet , "Tobin C . Harding" Cc: Michael Ellerman , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] Documentation: Mention why %p prints ptrval Date: Thu, 22 Mar 2018 15:53:36 +1030 Message-Id: <20180322052336.1001-1-joel@jms.id.au> X-Mailer: git-send-email 2.15.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When debugging recent kernels, people will see '(ptrval)' but there isn't much information as to what that means. Briefly describe why it's there. Signed-off-by: Joel Stanley --- Documentation/core-api/printk-formats.rst | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) -- 2.15.1 Acked-by: Tobin C. Harding diff --git a/Documentation/core-api/printk-formats.rst b/Documentation/core-api/printk-formats.rst index 934559b3c130..eb30efdd2e78 100644 --- a/Documentation/core-api/printk-formats.rst +++ b/Documentation/core-api/printk-formats.rst @@ -60,8 +60,8 @@ Plain Pointers Pointers printed without a specifier extension (i.e unadorned %p) are hashed to prevent leaking information about the kernel memory layout. This has the added benefit of providing a unique identifier. On 64-bit machines -the first 32 bits are zeroed. If you *really* want the address see %px -below. +the first 32 bits are zeroed. The kernel will print ``(ptrval)`` until it +gathers enough entropy. If you *really* want the address see %px below. Symbols/Function Pointers -------------------------