From patchwork Fri Dec 3 10:42:19 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Amit Daniel Kachhap X-Patchwork-Id: 12654763 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 CCB78C433EF for ; Fri, 3 Dec 2021 10:42:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1351827AbhLCKqW (ORCPT ); Fri, 3 Dec 2021 05:46:22 -0500 Received: from foss.arm.com ([217.140.110.172]:46934 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1351858AbhLCKqV (ORCPT ); Fri, 3 Dec 2021 05:46:21 -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 8B7B81477; Fri, 3 Dec 2021 02:42:57 -0800 (PST) Received: from a077416.arm.com (unknown [10.163.33.180]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 9C1773F5A1; Fri, 3 Dec 2021 02:42:52 -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 , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Young , Baoquan He , Vivek Goyal , x86 Subject: [RFC PATCH 02/14] fs/proc/vmcore: Update copy_oldmem_page_encrypted() for user buffer Date: Fri, 3 Dec 2021 16:12:19 +0530 Message-Id: <20211203104231.17597-3-amit.kachhap@arm.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20211203104231.17597-1-amit.kachhap@arm.com> References: <20211203104231.17597-1-amit.kachhap@arm.com> Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org The exported interface copy_oldmem_page_encrypted() passes user pointer without __user annotation and does unnecessary user/kernel pointer conversions during the pointer propagation. Hence it is modified to have a new parameter for user pointer. The other similar interface copy_oldmem_page() will be updated in the subsequent patches. x86_64 crash dump is also modified to use this modified interface. No functionality change intended. Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: Dave Young Cc: Baoquan He Cc: Vivek Goyal Cc: x86 Cc: kexec Cc: linux-fsdevel Signed-off-by: Amit Daniel Kachhap --- arch/x86/kernel/crash_dump_64.c | 12 +++++++++--- fs/proc/vmcore.c | 24 +++++++++++------------- include/linux/crash_dump.h | 6 +++--- 3 files changed, 23 insertions(+), 19 deletions(-) diff --git a/arch/x86/kernel/crash_dump_64.c b/arch/x86/kernel/crash_dump_64.c index 6433513ef43a..99cd505628fa 100644 --- a/arch/x86/kernel/crash_dump_64.c +++ b/arch/x86/kernel/crash_dump_64.c @@ -66,10 +66,16 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize, * memory with the encryption mask set to accommodate kdump on SME-enabled * machines. */ -ssize_t copy_oldmem_page_encrypted(unsigned long pfn, char *buf, size_t csize, - unsigned long offset, int userbuf) +ssize_t copy_oldmem_page_encrypted(unsigned long pfn, char __user *ubuf, + char *kbuf, size_t csize, + unsigned long offset) { - return __copy_oldmem_page(pfn, buf, csize, offset, userbuf, true); + if (ubuf) + return __copy_oldmem_page(pfn, (__force char *)ubuf, csize, + offset, 1, true); + else + return __copy_oldmem_page(pfn, kbuf, csize, + offset, 0, true); } ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos) diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c index 39b4353bd37c..fa4492ef6124 100644 --- a/fs/proc/vmcore.c +++ b/fs/proc/vmcore.c @@ -168,16 +168,10 @@ ssize_t read_from_oldmem(char __user *ubuf, char *kbuf, size_t count, else if (clear_user(ubuf, nr_bytes)) tmp = -EFAULT; } else { - if (encrypted && ubuf) - tmp = copy_oldmem_page_encrypted(pfn, - (__force char *)ubuf, - nr_bytes, - offset, 1); - else if (encrypted && kbuf) - tmp = copy_oldmem_page_encrypted(pfn, - kbuf, - nr_bytes, - offset, 0); + if (encrypted) + tmp = copy_oldmem_page_encrypted(pfn, ubuf, + kbuf, nr_bytes, + offset); else if (ubuf) tmp = copy_oldmem_page(pfn, (__force char *)ubuf, nr_bytes, offset, 1); @@ -247,10 +241,14 @@ int __weak remap_oldmem_pfn_range(struct vm_area_struct *vma, * Architectures which support memory encryption override this. */ ssize_t __weak -copy_oldmem_page_encrypted(unsigned long pfn, char *buf, size_t csize, - unsigned long offset, int userbuf) +copy_oldmem_page_encrypted(unsigned long pfn, char __user *ubuf, char *kbuf, + size_t csize, unsigned long offset) { - return copy_oldmem_page(pfn, buf, csize, offset, userbuf); + if (ubuf) + return copy_oldmem_page(pfn, (__force char *)ubuf, csize, + offset, 1); + else + return copy_oldmem_page(pfn, kbuf, csize, offset, 0); } /* diff --git a/include/linux/crash_dump.h b/include/linux/crash_dump.h index eb0ed423ccc8..36a7f08f4ad2 100644 --- a/include/linux/crash_dump.h +++ b/include/linux/crash_dump.h @@ -26,9 +26,9 @@ extern int remap_oldmem_pfn_range(struct vm_area_struct *vma, extern ssize_t copy_oldmem_page(unsigned long, char *, size_t, unsigned long, int); -extern ssize_t copy_oldmem_page_encrypted(unsigned long pfn, char *buf, - size_t csize, unsigned long offset, - int userbuf); +extern ssize_t copy_oldmem_page_encrypted(unsigned long pfn, + char __user *ubuf, char *kbuf, + size_t csize, unsigned long offset); void vmcore_cleanup(void);