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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1AA36C43217 for ; Fri, 25 Mar 2022 01:10:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1357174AbiCYBMa (ORCPT ); Thu, 24 Mar 2022 21:12:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41640 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1354193AbiCYBMT (ORCPT ); Thu, 24 Mar 2022 21:12:19 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D2481BD2D2 for ; Thu, 24 Mar 2022 18:10:46 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 8DC35B82708 for ; Fri, 25 Mar 2022 01:10:45 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 30642C340EE; Fri, 25 Mar 2022 01:10:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1648170644; bh=F3/yFJ7raynTdLtU41lsWpEJSkEvMmD97MF6IDu3z9I=; h=Date:To:From:In-Reply-To:Subject:From; b=vQcJIH3R5fOxiAnDvc0RYX60GJrHHoY/rRvtC02x1Td6zGqsGrvKPsmC9cUvGXcEq uxLVBv3f8CSIUhcqa73GU82XkBS7OoQBojj8H+fu2vVqpnAWpHNXqVMjmIFUJ06amK eu2rHCmzLqkZHNYUK1e8yJpDHOn9q8l45Yf1qeEY= Date: Thu, 24 Mar 2022 18:10:43 -0700 To: will@kernel.org, vincenzo.frascino@arm.com, ryabinin.a.a@gmail.com, pcc@google.com, mark.rutland@arm.com, glider@google.com, eugenis@google.com, elver@google.com, dvyukov@google.com, catalin.marinas@arm.com, andreyknvl@google.com, akpm@linux-foundation.org, patches@lists.linux.dev, linux-mm@kvack.org, mm-commits@vger.kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org From: Andrew Morton In-Reply-To: <20220324180758.96b1ac7e17675d6bc474485e@linux-foundation.org> Subject: [patch 043/114] kasan, page_alloc: rework kasan_unpoison_pages call site Message-Id: <20220325011044.30642C340EE@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org From: Andrey Konovalov Subject: kasan, page_alloc: rework kasan_unpoison_pages call site Rework the checks around kasan_unpoison_pages() call in post_alloc_hook(). The logical condition for calling this function is: - If a software KASAN mode is enabled, we need to mark shadow memory. - Otherwise, HW_TAGS KASAN is enabled, and it only makes sense to set tags if they haven't already been cleared by tag_clear_highpage(), which is indicated by init_tags. This patch concludes the changes for post_alloc_hook(). Link: https://lkml.kernel.org/r/0ecebd0d7ccd79150e3620ea4185a32d3dfe912f.1643047180.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov Acked-by: Marco Elver Cc: Alexander Potapenko Cc: Andrey Ryabinin Cc: Catalin Marinas Cc: Dmitry Vyukov Cc: Evgenii Stepanov Cc: Mark Rutland Cc: Peter Collingbourne Cc: Vincenzo Frascino Cc: Will Deacon Signed-off-by: Andrew Morton --- mm/page_alloc.c | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) --- a/mm/page_alloc.c~kasan-page_alloc-rework-kasan_unpoison_pages-call-site +++ a/mm/page_alloc.c @@ -2382,15 +2382,20 @@ inline void post_alloc_hook(struct page /* Note that memory is already initialized by the loop above. */ init = false; } - if (kasan_has_integrated_init()) { - if (!init_tags) { - kasan_unpoison_pages(page, order, init); + /* + * If either a software KASAN mode is enabled, or, + * in the case of hardware tag-based KASAN, + * if memory tags have not been cleared via tag_clear_highpage(). + */ + if (IS_ENABLED(CONFIG_KASAN_GENERIC) || + IS_ENABLED(CONFIG_KASAN_SW_TAGS) || + kasan_hw_tags_enabled() && !init_tags) { + /* Mark shadow memory or set memory tags. */ + kasan_unpoison_pages(page, order, init); - /* Note that memory is already initialized by KASAN. */ + /* Note that memory is already initialized by KASAN. */ + if (kasan_has_integrated_init()) init = false; - } - } else { - kasan_unpoison_pages(page, order, init); } /* If memory is still not initialized, do it now. */ if (init) _