Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BDB19C433F5 for ; Fri, 3 Dec 2021 10:42:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1351753AbhLCKqL (ORCPT ); Fri, 3 Dec 2021 05:46:11 -0500 Received: from foss.arm.com ([217.140.110.172]:46902 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1351699AbhLCKqK (ORCPT ); Fri, 3 Dec 2021 05:46:10 -0500 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 5F20D1435; Fri, 3 Dec 2021 02:42:46 -0800 (PST) Received: from a077416.arm.com (unknown [10.163.33.180]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 9934B3F5A1; Fri, 3 Dec 2021 02:42:43 -0800 (PST) From: Amit Daniel Kachhap To: linux-kernel@vger.kernel.org Cc: Christoph Hellwig , Vincenzo Frascino , Kevin Brodsky , linux-fsdevel , kexec , Amit Daniel Kachhap Subject: [RFC PATCH 00/14] fs/proc/vmcore: Remove unnecessary user pointer conversions Date: Fri, 3 Dec 2021 16:12:17 +0530 Message-Id: <20211203104231.17597-1-amit.kachhap@arm.com> X-Mailer: git-send-email 2.17.1 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, This series aims to restructure the external interfaces as well internal code used in fs/proc/vmcore.c by removing the interchangeable use of user and kernel pointers. This unnecessary conversion may obstruct the tools such as sparse in generating meaningful results. This also simplifies the things by keeping the user and kernel pointers separate during propagation. The external interfaces such as copy_oldmem_page, copy_oldmem_page_encrypted and read_from_oldmem are used across different architectures. The goal here is to update one architecture at a time and hence there is an extra cleanup done in the end to remove the intermediaries. In this series, an extra user pointer is added as a parameter to all the above functions instead of an union as there were disagreement in earlier ideas of using universal pointer [1,2]. This series is posted as RFC so as to find out an acceptable way of handling this use case. This series is based on v5.16-rc3 and is compile tested for modified architectures and boot tested in qemu for all architectures except ia64. Note: This patch series breaks the crash dump functionality after patch 3 and is restored after each arch implements its own copy_oldmem_page_buf() interface. Thanks, Amit Daniel [1]: https://lore.kernel.org/lkml/20200624162901.1814136-2-hch@lst.de/ [2]: https://lore.kernel.org/lkml/CAHk-=wit9enePELG=-HnLsr0nY5bucFNjqAqWoFTuYDGR1P4KA@mail.gmail.com/ Amit Daniel Kachhap (14): fs/proc/vmcore: Update read_from_oldmem() for user pointer fs/proc/vmcore: Update copy_oldmem_page_encrypted() for user buffer fs/proc/vmcore: Update copy_oldmem_page() for user buffer x86/crash_dump_64: Use the new interface copy_oldmem_page_buf x86/crash_dump_32: Use the new interface copy_oldmem_page_buf arm64/crash_dump: Use the new interface copy_oldmem_page_buf arm/crash_dump: Use the new interface copy_oldmem_page_buf mips/crash_dump: Use the new interface copy_oldmem_page_buf sh/crash_dump: Use the new interface copy_oldmem_page_buf riscv/crash_dump: Use the new interface copy_oldmem_page_buf powerpc/crash_dump: Use the new interface copy_oldmem_page_buf ia64/crash_dump: Use the new interface copy_oldmem_page_buf s390/crash_dump: Use the new interface copy_oldmem_page_buf fs/proc/vmcore: Remove the unused old interface copy_oldmem_page arch/arm/kernel/crash_dump.c | 21 ++++---- arch/arm64/kernel/crash_dump.c | 21 ++++---- arch/ia64/kernel/crash_dump.c | 25 +++++----- arch/mips/kernel/crash_dump.c | 24 ++++----- arch/powerpc/kernel/crash_dump.c | 33 +++++++------ arch/riscv/kernel/crash_dump.c | 25 +++++----- arch/s390/kernel/crash_dump.c | 12 ++--- arch/sh/kernel/crash_dump.c | 25 +++++----- arch/x86/kernel/crash_dump_32.c | 24 ++++----- arch/x86/kernel/crash_dump_64.c | 48 +++++++++--------- fs/proc/vmcore.c | 85 +++++++++++++++++--------------- include/linux/crash_dump.h | 23 +++++---- 12 files changed, 189 insertions(+), 177 deletions(-) -- 2.17.1