From patchwork Fri Jan 8 17:11:50 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Willem de Bruijn X-Patchwork-Id: 12007071 X-Patchwork-Delegate: kuba@kernel.org 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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 76236C433E6 for ; Fri, 8 Jan 2021 17:12:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 48AC923A00 for ; Fri, 8 Jan 2021 17:12:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728310AbhAHRMi (ORCPT ); Fri, 8 Jan 2021 12:12:38 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52008 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727714AbhAHRMh (ORCPT ); Fri, 8 Jan 2021 12:12:37 -0500 Received: from mail-qt1-x82d.google.com (mail-qt1-x82d.google.com [IPv6:2607:f8b0:4864:20::82d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A3248C061381 for ; Fri, 8 Jan 2021 09:11:57 -0800 (PST) Received: by mail-qt1-x82d.google.com with SMTP id h19so6956696qtq.13 for ; Fri, 08 Jan 2021 09:11:57 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=zX1KVOpyBappsSnNg0k+iRQDKdP/WgwvzGOnOf5giSM=; b=Gns2tIgzxbMxLmQ+hdSG92lrKSG/hYJQU0qqJMpNzRJHfIL2ig4zjnsZp43bS3ICzF oDsOAat1aB9Qf7DHMRrjtHN374clGzzlWGjD30rZ88hFz94t5WvFk6drTWe/o/lauv/3 kJ5ZU71117ofgazcQwMFUwsCn7cAKgtDXykYpbypgDp/frdsXXO6Gar5GKVWrOB5xwjH xRW58E/oV/9pRPgkcP0/tNeORR/sY66zrbsz7h4S0deEE6qngN3reG1Hiq8JIuAlmIDr PksFSe9pSy0IV+h1mIXHmlr0PBmicOE8f6CyUi2sEQGOdUVwwY7yOXUSGXEFkgrLg9Sx cPLA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=zX1KVOpyBappsSnNg0k+iRQDKdP/WgwvzGOnOf5giSM=; b=WckpWdLoNzimXXnBDIA5TEkuI8TYqXJSiTZ3bv7MCiDXpcAriA2aWxXB+8m1c+cXSH YS7NJBKNn9zEMo7XyXJ4S9XIDJ2d5jZm6jazIV0Ivt8uX7GLkrRTDSsWpzhCAtWBGkbF lZPP4DI39KfnzpONyn7fBZ85KVVvBsuhN9gUyxS6xutW9t/P1pMpkOwiIwMw5ZdqyIAj lLpxdvuOeKsMx9CR3P5wgAYEsp6a2JWAKlQ8M+eQ94n2vraDTFmLxAc14D2gbGy1SDzo /2NeksioRUNeVNkkc3zkJbqlzICeFkqWF/BA7KPYDvAhSNGZuWTFBsHBUhQRgEOEZPNA fmTQ== X-Gm-Message-State: AOAM530mCRIIH6p/ukj9pZ8vyWGFtqero3txIUZxidPZzf+mrnTrPJJC 478s+7lDThIZ2tyvSWu6+eQf02J4+ko= X-Google-Smtp-Source: ABdhPJzgjMxHdL206Nwy03LxFc5ollQ6smzj160B+5ezhnZ3D6f6R9DAFo0XteTWbb9kLr1NH32H5w== X-Received: by 2002:ac8:6f77:: with SMTP id u23mr4486363qtv.118.1610125916643; Fri, 08 Jan 2021 09:11:56 -0800 (PST) Received: from willemb.nyc.corp.google.com ([2620:0:1003:312:f693:9fff:fef4:3e8a]) by smtp.gmail.com with ESMTPSA id c2sm5081600qke.109.2021.01.08.09.11.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 08 Jan 2021 09:11:55 -0800 (PST) From: Willem de Bruijn To: netdev@vger.kernel.org Cc: davem@davemloft.net, kuba@kernel.org, Willem de Bruijn , Steven Rostedt , Linus Torvalds Subject: [PATCH net 1/3] net: support kmap_local forced debugging in skb_frag_foreach Date: Fri, 8 Jan 2021 12:11:50 -0500 Message-Id: <20210108171152.2961251-2-willemdebruijn.kernel@gmail.com> X-Mailer: git-send-email 2.30.0.284.gd98b1dd5eaa7-goog In-Reply-To: <20210108171152.2961251-1-willemdebruijn.kernel@gmail.com> References: <20210108171152.2961251-1-willemdebruijn.kernel@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org From: Willem de Bruijn Skb frags may be backed by highmem and/or compound pages. Highmem pages need kmap_atomic mappings to access. But kmap_atomic maps a single page, not the entire compound page. skb_foreach_page iterates over an skb frag, in one step in the common case, page by page only if kmap_atomic must be called for each page. The decision logic is captured in skb_frag_must_loop. CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP extends kmap from highmem to all pages, to increase code coverage. Extend skb_frag_must_loop to this new condition. Link: https://lore.kernel.org/linux-mm/20210106180132.41dc249d@gandalf.local.home/ Fixes: 0e91a0c6984c ("mm/highmem: Provide CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP") Reported-by: Steven Rostedt (VMware) Signed-off-by: Linus Torvalds Signed-off-by: Willem de Bruijn Tested-by: Steven Rostedt (VMware) --- include/linux/skbuff.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 333bcdc39635..c858adfb5a82 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -366,7 +366,7 @@ static inline void skb_frag_size_sub(skb_frag_t *frag, int delta) static inline bool skb_frag_must_loop(struct page *p) { #if defined(CONFIG_HIGHMEM) - if (PageHighMem(p)) + if (IS_ENABLED(CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP) || PageHighMem(p)) return true; #endif return false;