From patchwork Fri Dec 3 10:42:24 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: 12694646 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id F26A5C433EF for ; Fri, 3 Dec 2021 10:44:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:List-Subscribe:List-Help: List-Post:List-Archive:List-Unsubscribe:List-Id:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=K5jrzkc/ogeyPhFOzVfKgjA7G0qgTcimwysdDj1t4S0=; b=nVFgIRI0aifGUg taN7djeZdKbE8rgu22WN/OBfj0kUc5XUe+TqDy/EtwYyl78oPFA032Ie+4vLjrHUxhPbEvnJeGgWk xCswCvax5+C+ARiokna7UBDwl08i30PuExRe3WfRpLNuxUtSzmvmsm0bT6xadPc+kAxwhyicNW4Kn 3x4Ga8B859Dcaqm9CIHQaa4PsF9GSjOBXFw8VYdgIlViEW8uptNj6xMLlWKeuA1E65pLZ+MFl4Ka8 e6AQk6Z14vnj6i34V+TQxuTe2kAyIOzOGcczYm7frDkahX9/8JtDvRJFnO8W15FhS9P/fl6xxoFcw +jTSEDooMnKM2ryg5Vlg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mt62T-00FCcN-To; Fri, 03 Dec 2021 10:43:38 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mt62C-00FCQl-Bx; Fri, 03 Dec 2021 10:43:21 +0000 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 DA0901595; Fri, 3 Dec 2021 02:43:19 -0800 (PST) Received: from a077416.arm.com (unknown [10.163.33.180]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 849863F5A1; Fri, 3 Dec 2021 02:43:16 -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 , Russell King , linux-arm-kernel Subject: [RFC PATCH 07/14] arm/crash_dump: Use the new interface copy_oldmem_page_buf Date: Fri, 3 Dec 2021 16:12:24 +0530 Message-Id: <20211203104231.17597-8-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> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211203_024320_509908_8B56F14A X-CRM114-Status: GOOD ( 12.23 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org The current interface copy_oldmem_page() passes user pointer without __user annotation and hence does unnecessary user/kernel pointer conversions during its implementation. Implement the interface copy_oldmem_page_buf() to avoid this issue. Cc: Russell King Cc: linux-arm-kernel Signed-off-by: Amit Daniel Kachhap --- arch/arm/kernel/crash_dump.c | 21 ++++++++++----------- 1 file changed, 10 insertions(+), 11 deletions(-) diff --git a/arch/arm/kernel/crash_dump.c b/arch/arm/kernel/crash_dump.c index 53cb92435392..bb0395ab9f98 100644 --- a/arch/arm/kernel/crash_dump.c +++ b/arch/arm/kernel/crash_dump.c @@ -16,20 +16,19 @@ #include /** - * copy_oldmem_page() - copy one page from old kernel memory + * copy_oldmem_page_buf() - copy one page from old kernel memory * @pfn: page frame number to be copied - * @buf: buffer where the copied page is placed + * @ubuf: user buffer where the copied page is placed + * @kbuf: kernel buffer where the copied page is placed * @csize: number of bytes to copy * @offset: offset in bytes into the page - * @userbuf: if set, @buf is int he user address space * * This function copies one page from old kernel memory into buffer pointed by - * @buf. If @buf is in userspace, set @userbuf to %1. Returns number of bytes - * copied or negative error in case of failure. + * either @ubuf or @kbuf. Returns number of bytes copied or negative error in + * case of failure. */ -ssize_t copy_oldmem_page(unsigned long pfn, char *buf, - size_t csize, unsigned long offset, - int userbuf) +ssize_t copy_oldmem_page_buf(unsigned long pfn, char __user *ubuf, char *kbuf, + size_t csize, unsigned long offset) { void *vaddr; @@ -40,13 +39,13 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf, if (!vaddr) return -ENOMEM; - if (userbuf) { - if (copy_to_user(buf, vaddr + offset, csize)) { + if (ubuf) { + if (copy_to_user(ubuf, vaddr + offset, csize)) { iounmap(vaddr); return -EFAULT; } } else { - memcpy(buf, vaddr + offset, csize); + memcpy(kbuf, vaddr + offset, csize); } iounmap(vaddr);