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=-26.4 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=unavailable 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 A30BDC11F65 for ; Wed, 30 Jun 2021 15:02:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8E061611CC for ; Wed, 30 Jun 2021 15:02:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235835AbhF3PFO (ORCPT ); Wed, 30 Jun 2021 11:05:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34354 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235817AbhF3PFL (ORCPT ); Wed, 30 Jun 2021 11:05:11 -0400 Received: from mail-qv1-xf49.google.com (mail-qv1-xf49.google.com [IPv6:2607:f8b0:4864:20::f49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 41152C061756 for ; Wed, 30 Jun 2021 08:02:41 -0700 (PDT) Received: by mail-qv1-xf49.google.com with SMTP id eb2-20020ad44e420000b029025a58adfc6bso1582768qvb.9 for ; Wed, 30 Jun 2021 08:02:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=NsJPxv+Yi9Y0Cxl+/SZ8/0DfgNfKjUrGLSr4GOlizVE=; b=ZSFYc1N7Bh9wv2errbcoilHdQgrtZa4Egl/x1q8DWx087ZrALCwjG7d45PprJ7nOV+ 8ybg4z8OgnOrqDzpnDFp+d256wUotxawgE/vD2sBzRB+i9B08DGeCdhjXrw3GFVws+AS syJ+SBqSs9SGklX7ualr3e0kyhIbqSZqAXs5MsS0ReBBnE3YswrsTgZ4xk6ur3Q3qwkh mlkpUkSm1Y3v1Fgz/jYzX7caVUQz7AWqahH08YA04wZxzv4uDmF8A7Zo8QN3KPPw2DYy wtL6FSIyBrpaFv5c37rI/H2FcsggCqbNJLo/kQWTBPugSIKS0T8xVMd4H67528gI2oDi 6H2Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=NsJPxv+Yi9Y0Cxl+/SZ8/0DfgNfKjUrGLSr4GOlizVE=; b=swduT26uVAXMG5H9wJOnSskRuYNJ2MLZ40er+XCqANRjrWGqZTAlx0vDzQ0CQCsomZ J4YFdBLQ/nl7b9pyiyk6ndfihgzo8DtmNdovRgUxwp7WEKBylEfg710opLfpaK8nbTo3 y0W5axNlbQxoh2UQYC+XIaJ2AWRENBkqU18q6RPM9gm+W5HyIqEsuYCBno8tzS0Df/zv RbObG19dtTHOV/F+DR5JRnLwHMBiYKhMt39qctKCU0kgBMn0KseHYICUBMRoZprJ5SNb /5a/sn+iAlL141KwoCe9Udw8Q8reo+FbkzqIQoETsZHHQ8U8xQuaDxhlkfqfGkq9J1XB iLHQ== X-Gm-Message-State: AOAM530O2Ogrud+LCy68bwB53cQzEtEsIgodqL+t4MG9aGH70Weuo3Ph J0Z1iUuagezbkTpY7kmi+ooNoN/7NNo= X-Google-Smtp-Source: ABdhPJy7krc3G3WIMTiQX8NdRFoM6NqtuGwGFCDI6oCddBMt9ABKJsibDaVZoTeNgXV5FaqCkdk5iSEw/Sg= X-Received: from glider.muc.corp.google.com ([2a00:79e0:15:13:a3fc:e8:8089:1013]) (user=glider job=sendgmr) by 2002:a05:6214:966:: with SMTP id do6mr37584817qvb.57.1625065360398; Wed, 30 Jun 2021 08:02:40 -0700 (PDT) Date: Wed, 30 Jun 2021 17:02:34 +0200 In-Reply-To: <20210630150234.1109496-1-glider@google.com> Message-Id: <20210630150234.1109496-2-glider@google.com> Mime-Version: 1.0 References: <20210630150234.1109496-1-glider@google.com> X-Mailer: git-send-email 2.32.0.93.g670b81a890-goog Subject: [PATCH v4 2/2] kfence: skip all GFP_ZONEMASK allocations From: Alexander Potapenko To: akpm@linux-foundation.org Cc: dvyukov@google.com, elver@google.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, stable@vger.kernel.org, gregkh@linuxfoundation.org, jrdr.linux@gmail.com, Alexander Potapenko Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Allocation requests outside ZONE_NORMAL (MOVABLE, HIGHMEM or DMA) cannot be fulfilled by KFENCE, because KFENCE memory pool is located in a zone different from the requested one. Because callers of kmem_cache_alloc() may actually rely on the allocation to reside in the requested zone (e.g. memory allocations done with __GFP_DMA must be DMAable), skip all allocations done with GFP_ZONEMASK and/or respective SLAB flags (SLAB_CACHE_DMA and SLAB_CACHE_DMA32). Fixes: 0ce20dd84089 ("mm: add Kernel Electric-Fence infrastructure") Cc: Andrew Morton Cc: Dmitry Vyukov Cc: Marco Elver Cc: Greg Kroah-Hartman Cc: Souptick Joarder Cc: stable@vger.kernel.org # 5.12+ Signed-off-by: Alexander Potapenko Reviewed-by: Marco Elver --- v2: - added parentheses around the GFP clause, as requested by Marco v3: - ignore GFP_ZONEMASK, which also covers __GFP_HIGHMEM and __GFP_MOVABLE - move the flag check at the beginning of the function, as requested by Souptick Joarder v4: - minor fixes to description and comment formatting --- mm/kfence/core.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/mm/kfence/core.c b/mm/kfence/core.c index 33bb20d91bf6a..1cbdb62e6d0fb 100644 --- a/mm/kfence/core.c +++ b/mm/kfence/core.c @@ -740,6 +740,15 @@ void *__kfence_alloc(struct kmem_cache *s, size_t size, gfp_t flags) if (size > PAGE_SIZE) return NULL; + /* + * Skip allocations from non-default zones, including DMA. We cannot + * guarantee that pages in the KFENCE pool will have the requested + * properties (e.g. reside in DMAable memory). + */ + if ((flags & GFP_ZONEMASK) || + (s->flags & (SLAB_CACHE_DMA | SLAB_CACHE_DMA32))) + return NULL; + /* * allocation_gate only needs to become non-zero, so it doesn't make * sense to continue writing to it and pay the associated contention -- 2.32.0.93.g670b81a890-goog