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=-5.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 E82FAC433FE for ; Mon, 7 Dec 2020 23:28:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A60D123A21 for ; Mon, 7 Dec 2020 23:28:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728199AbgLGX1l (ORCPT ); Mon, 7 Dec 2020 18:27:41 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39544 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728082AbgLGX1l (ORCPT ); Mon, 7 Dec 2020 18:27:41 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B3949C061749; Mon, 7 Dec 2020 15:27:00 -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=efNDHUK0kIQReg6gaBBlG6h4xr6jASmtw1EOBKXAyLk=; b=oGXIksxSLHfNq7Nd/dxPiETxai mZtQiABwOFbH8NXwaWami88IxDL1hfJ4dv7e7Q+LbAUNozIpP5+zIxMLJwyTb95LgXSFNQFFKv07t qOM246LaVu4VWp64BOg1lBAfdF3iOr7e+nxZtJBoKT+vet7S2MgLxSgzHHmJIXaBEvBk6Hl4YuexJ oPAdoLlJEm2lmEP9Q72FEaFRqf6ECFzVqauCUiH6nFIYWy76i0T/fi+i5xymYslOjPd+ye72PRyrC MIAcklDxsQADXt6YHuzm3eLs7DKjwNYcU8Ae0/ouGCc2dY8JAbRd3Vh0ZUPiTLt7hnxE5rIm1mKaV 5CNKN6/A==; Received: from willy by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1kmPu5-0001ze-EJ; Mon, 07 Dec 2020 23:26:49 +0000 Date: Mon, 7 Dec 2020 23:26:49 +0000 From: Matthew Wilcox To: ira.weiny@intel.com Cc: Thomas Gleixner , Andrew Morton , Dave Hansen , Christoph Hellwig , Dan Williams , Al Viro , Eric Biggers , Joonas Lahtinen , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH V2 2/2] mm/highmem: Lift memcpy_[to|from]_page to core Message-ID: <20201207232649.GD7338@casper.infradead.org> References: <20201207225703.2033611-1-ira.weiny@intel.com> <20201207225703.2033611-3-ira.weiny@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201207225703.2033611-3-ira.weiny@intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Dec 07, 2020 at 02:57:03PM -0800, ira.weiny@intel.com wrote: > +static inline void memcpy_page(struct page *dst_page, size_t dst_off, > + struct page *src_page, size_t src_off, > + size_t len) > +{ > + char *dst = kmap_local_page(dst_page); > + char *src = kmap_local_page(src_page); I appreciate you've only moved these, but please add: BUG_ON(dst_off + len > PAGE_SIZE || src_off + len > PAGE_SIZE); > + memcpy(dst + dst_off, src + src_off, len); > + kunmap_local(src); > + kunmap_local(dst); > +} > + > +static inline void memmove_page(struct page *dst_page, size_t dst_off, > + struct page *src_page, size_t src_off, > + size_t len) > +{ > + char *dst = kmap_local_page(dst_page); > + char *src = kmap_local_page(src_page); BUG_ON(dst_off + len > PAGE_SIZE || src_off + len > PAGE_SIZE); > + memmove(dst + dst_off, src + src_off, len); > + kunmap_local(src); > + kunmap_local(dst); > +} > + > +static inline void memcpy_from_page(char *to, struct page *page, size_t offset, size_t len) > +{ > + char *from = kmap_local_page(page); BUG_ON(offset + len > PAGE_SIZE); > + memcpy(to, from + offset, len); > + kunmap_local(from); > +} > + > +static inline void memcpy_to_page(struct page *page, size_t offset, const char *from, size_t len) > +{ > + char *to = kmap_local_page(page); BUG_ON(offset + len > PAGE_SIZE); > + memcpy(to + offset, from, len); > + kunmap_local(to); > +} > + > +static inline void memset_page(struct page *page, size_t offset, int val, size_t len) > +{ > + char *addr = kmap_local_page(page); BUG_ON(offset + len > PAGE_SIZE); > + memset(addr + offset, val, len); > + kunmap_local(addr); > +} > + > #endif /* _LINUX_PAGEMAP_H */