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 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 9F2ECC433F5 for ; Fri, 3 Dec 2021 10:44:02 +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=NtQPXYAByRsWOglrrr7PUcr9eLvAVNOyeChkyxyfDmM=; b=yyE5RWSTciisVd Gt+a56iQW87H4AW0pNXM1BW9ZgzO6u8Z8kQ72KYmQV/PZ1jZxZzQATq2OFRDnWamp0TS/2QG3ozcW knnDy/8l6JRo5qqR+T5AU8XuasuMJ/Y8l6xNgbgTkiMDaHTDtF5iT0gwhI2e2Wt89KRRI4sAlCGqT iHGQMPA+UcPbDjfwdrWivW1l+Gmivk0ZMlyCdczn1KNGHt/OXX8L1HKUmyrUkfnYt6aLV/oWjyyzF 06q+G3fflTRbXcryfyLUkXihehggUek6QysuW91Qk9xipQt8WSTYQqipZnzwO0ucfKu2oTJM6qF6m bFo9cZ0nTQGL5fNhAdvg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mt62k-00FCph-IL; Fri, 03 Dec 2021 10:43:54 +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 1mt62P-00FCZh-2k; Fri, 03 Dec 2021 10:43:34 +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 77EF415A1; Fri, 3 Dec 2021 02:43:32 -0800 (PST) Received: from a077416.arm.com (unknown [10.163.33.180]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 89AF53F5A1; Fri, 3 Dec 2021 02:43:28 -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 , Paul Walmsley , Palmer Dabbelt , Albert Ou , linux-riscv Subject: [RFC PATCH 10/14] riscv/crash_dump: Use the new interface copy_oldmem_page_buf Date: Fri, 3 Dec 2021 16:12:27 +0530 Message-Id: <20211203104231.17597-11-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_024333_203867_7F0245F1 X-CRM114-Status: GOOD ( 11.92 ) X-BeenThere: linux-riscv@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 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=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. Use the interface copy_oldmem_page_buf() to avoid this issue. Cc: Paul Walmsley Cc: Palmer Dabbelt Cc: Albert Ou Cc: linux-riscv Signed-off-by: Amit Daniel Kachhap --- arch/riscv/kernel/crash_dump.c | 25 +++++++++++++------------ 1 file changed, 13 insertions(+), 12 deletions(-) diff --git a/arch/riscv/kernel/crash_dump.c b/arch/riscv/kernel/crash_dump.c index 86cc0ada5752..3a8fadcd1278 100644 --- a/arch/riscv/kernel/crash_dump.c +++ b/arch/riscv/kernel/crash_dump.c @@ -9,20 +9,21 @@ #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; use copy_to_user() if + * this pointer is not NULL + * @kbuf: kernel buffer where the copied page is placed; use memcpy() if this + * pointer is not NULL * @csize: number of bytes to copy * @offset: offset in bytes into the page - * @userbuf: if set, @buf is in a 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. + * This function copies one page from old kernel memory into the buffer pointed + * by 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; @@ -33,13 +34,13 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf, if (!vaddr) return -ENOMEM; - if (userbuf) { - if (copy_to_user((char __user *)buf, vaddr + offset, csize)) { + if (ubuf) { + if (copy_to_user(ubuf, vaddr + offset, csize)) { memunmap(vaddr); return -EFAULT; } } else - memcpy(buf, vaddr + offset, csize); + memcpy(kbuf, vaddr + offset, csize); memunmap(vaddr); return csize; -- 2.17.1 _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv