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=-15.8 required=3.0 tests=BAYES_00,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 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 96CE0C433E0 for ; Fri, 26 Feb 2021 01:22:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4F26264F45 for ; Fri, 26 Feb 2021 01:22:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229769AbhBZBWC (ORCPT ); Thu, 25 Feb 2021 20:22:02 -0500 Received: from mail.kernel.org ([198.145.29.99]:53010 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229534AbhBZBUs (ORCPT ); Thu, 25 Feb 2021 20:20:48 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 0568C64EE2; Fri, 26 Feb 2021 01:20:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1614302404; bh=pjixy04WUkPNtirbGgu3dHNZxqD9pJyObSqfb3XRUUE=; h=Date:From:To:Subject:In-Reply-To:From; b=IKrz1H9MQXHly14mBSM8iah/YzyA6WX95ZVGeazmYBv7nTJaYD03E7q6N5iB2natl VEBD8SvGys6HLHPfDz92evLasAdPiYIYC471SZIXKWFxISovLn8wev2zD+rEO5Ffw8 wSpQoFqFFy2a/+0HkAlzsldX9HYOqq5I95doT42c= Date: Thu, 25 Feb 2021 17:20:03 -0800 From: Andrew Morton To: akpm@linux-foundation.org, andreyknvl@google.com, aryabinin@virtuozzo.com, Branislav.Rankov@arm.com, catalin.marinas@arm.com, dvyukov@google.com, elver@google.com, eugenis@google.com, glider@google.com, kevin.brodsky@arm.com, linux-mm@kvack.org, mm-commits@vger.kernel.org, pcc@google.com, torvalds@linux-foundation.org, vincenzo.frascino@arm.com, will.deacon@arm.com Subject: [patch 072/118] kasan: optimize large kmalloc poisoning Message-ID: <20210226012003.btZy_td4U%akpm@linux-foundation.org> In-Reply-To: <20210225171452.713967e96554bb6a53e44a19@linux-foundation.org> User-Agent: s-nail v14.8.16 Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org From: Andrey Konovalov Subject: kasan: optimize large kmalloc poisoning Similarly to kasan_kmalloc(), kasan_kmalloc_large() doesn't need to unpoison the object as it as already unpoisoned by alloc_pages() (or by ksize() for krealloc()). This patch changes kasan_kmalloc_large() to only poison the redzone. Link: https://lkml.kernel.org/r/33dee5aac0e550ad7f8e26f590c9b02c6129b4a3.1612546384.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov Reviewed-by: Marco Elver Cc: Alexander Potapenko Cc: Andrey Ryabinin Cc: Branislav Rankov Cc: Catalin Marinas Cc: Dmitry Vyukov Cc: Evgenii Stepanov Cc: Kevin Brodsky Cc: Peter Collingbourne Cc: Vincenzo Frascino Cc: Will Deacon Signed-off-by: Andrew Morton --- mm/kasan/common.c | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-) --- a/mm/kasan/common.c~kasan-optimize-large-kmalloc-poisoning +++ a/mm/kasan/common.c @@ -494,7 +494,6 @@ EXPORT_SYMBOL(__kasan_kmalloc); void * __must_check __kasan_kmalloc_large(const void *ptr, size_t size, gfp_t flags) { - struct page *page; unsigned long redzone_start; unsigned long redzone_end; @@ -504,12 +503,23 @@ void * __must_check __kasan_kmalloc_larg if (unlikely(ptr == NULL)) return NULL; - page = virt_to_page(ptr); + /* + * The object has already been unpoisoned by kasan_alloc_pages() for + * alloc_pages() or by ksize() for krealloc(). + */ + + /* + * The redzone has byte-level precision for the generic mode. + * Partially poison the last object granule to cover the unaligned + * part of the redzone. + */ + if (IS_ENABLED(CONFIG_KASAN_GENERIC)) + kasan_poison_last_granule(ptr, size); + + /* Poison the aligned part of the redzone. */ redzone_start = round_up((unsigned long)(ptr + size), KASAN_GRANULE_SIZE); - redzone_end = (unsigned long)ptr + page_size(page); - - kasan_unpoison(ptr, size); + redzone_end = (unsigned long)ptr + page_size(virt_to_page(ptr)); kasan_poison((void *)redzone_start, redzone_end - redzone_start, KASAN_PAGE_REDZONE); _