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 X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7CC53C388F7 for ; Fri, 13 Nov 2020 13:59:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 486342222F for ; Fri, 13 Nov 2020 13:59:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="hxEERjlx" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726760AbgKMN7R (ORCPT ); Fri, 13 Nov 2020 08:59:17 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53984 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726418AbgKMN7R (ORCPT ); Fri, 13 Nov 2020 08:59:17 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1B427C0613D1; Fri, 13 Nov 2020 05:59:17 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=kLz22mCweLR//KhTGZZOStZT7C8x0TEcQ4+GK8a3nck=; b=hxEERjlxxEGjzKsTREmAdvVMX3 IS8qSDrsGEqirPWQHguhpGtopsaES8pCsNt+5gHN8a/l860hbWdnv6UVaJOHhGDnFQnRtRL9NEZwl 2fcVThumtrCipwpdqKaCwPmlfcghO0WScHCRcAU1iMyaTWAGG/jBa37pH6nsqY35UG7jilrUB+aWP Cf/AoroggY7hCjRgzQQcjmCTa0hZmV6VXmztqO0wdT3NMa5zgbf/5yIxQaBty5jexorzuyz41NXfF d6LgpX1xryRRN/FkiBND/OVPDPCEATMfBEwLPQlSYWYq21IP2C/aDonZmnwPhyokSwlrknmvJAjZ8 ZU/3bYeQ==; Received: from willy by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1kdZbE-0003f3-8l; Fri, 13 Nov 2020 13:58:48 +0000 Date: Fri, 13 Nov 2020 13:58:48 +0000 From: Matthew Wilcox To: Mike Rapoport Cc: Andrew Morton , Alexander Viro , Andy Lutomirski , Arnd Bergmann , Borislav Petkov , Catalin Marinas , Christopher Lameter , Dan Williams , Dave Hansen , David Hildenbrand , Elena Reshetova , "H. Peter Anvin" , Ingo Molnar , James Bottomley , "Kirill A. Shutemov" , Mark Rutland , Mike Rapoport , Michael Kerrisk , Palmer Dabbelt , Paul Walmsley , Peter Zijlstra , Rick Edgecombe , Shuah Khan , Thomas Gleixner , Tycho Andersen , Will Deacon , linux-api@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-nvdimm@lists.01.org, linux-riscv@lists.infradead.org, x86@kernel.org, Hagen Paul Pfeifer Subject: Re: [PATCH v8 4/9] mm: introduce memfd_secret system call to create "secret" memory areas Message-ID: <20201113135848.GF17076@casper.infradead.org> References: <20201110151444.20662-1-rppt@kernel.org> <20201110151444.20662-5-rppt@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201110151444.20662-5-rppt@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-api@vger.kernel.org On Tue, Nov 10, 2020 at 05:14:39PM +0200, Mike Rapoport wrote: > +static vm_fault_t secretmem_fault(struct vm_fault *vmf) > +{ > + struct address_space *mapping = vmf->vma->vm_file->f_mapping; > + struct inode *inode = file_inode(vmf->vma->vm_file); > + pgoff_t offset = vmf->pgoff; > + unsigned long addr; > + struct page *page; > + int ret = 0; > + > + if (((loff_t)vmf->pgoff << PAGE_SHIFT) >= i_size_read(inode)) > + return vmf_error(-EINVAL); > + > + page = find_get_entry(mapping, offset); Why did you decide to use find_get_entry() here? You don't handle swap or shadow entries. > + if (!page) { > + page = secretmem_alloc_page(vmf->gfp_mask); > + if (!page) > + return vmf_error(-EINVAL); Why is this EINVAL and not ENOMEM? > + ret = add_to_page_cache(page, mapping, offset, vmf->gfp_mask); > + if (unlikely(ret)) > + goto err_put_page; > + > + ret = set_direct_map_invalid_noflush(page, 1); > + if (ret) > + goto err_del_page_cache; > + > + addr = (unsigned long)page_address(page); > + flush_tlb_kernel_range(addr, addr + PAGE_SIZE); > + > + __SetPageUptodate(page); > + > + ret = VM_FAULT_LOCKED; > + } > + > + vmf->page = page; > + return ret; Does sparse not warn you about this abuse of vm_fault_t? Separate out 'ret' and 'err'. Andrew, please fold in this fix. I suspect Mike will want to fix the other things I mention above. diff --git a/mm/secretmem.c b/mm/secretmem.c index 3dfdbd85ba00..09ca27f21661 100644 --- a/mm/secretmem.c +++ b/mm/secretmem.c @@ -172,7 +172,7 @@ static vm_fault_t secretmem_fault(struct vm_fault *vmf) if (((loff_t)vmf->pgoff << PAGE_SHIFT) >= i_size_read(inode)) return vmf_error(-EINVAL); - page = find_get_entry(mapping, offset); + page = find_get_page(mapping, offset); if (!page) { page = secretmem_alloc_page(ctx, vmf->gfp_mask); if (!page)