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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 46BABC433E0 for ; Tue, 19 Jan 2021 22:59:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2491723104 for ; Tue, 19 Jan 2021 22:59:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726709AbhASW7L (ORCPT ); Tue, 19 Jan 2021 17:59:11 -0500 Received: from foss.arm.com ([217.140.110.172]:33160 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404202AbhASOUB (ORCPT ); Tue, 19 Jan 2021 09:20:01 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 0DACDD6E; Tue, 19 Jan 2021 06:19:16 -0800 (PST) Received: from [10.37.8.29] (unknown [10.37.8.29]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 1A0743F719; Tue, 19 Jan 2021 06:19:13 -0800 (PST) Subject: Re: [PATCH v4 3/5] kasan: Add report for async mode To: Catalin Marinas , Andrey Konovalov Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, Will Deacon , Dmitry Vyukov , Andrey Ryabinin , Alexander Potapenko , Marco Elver , Evgenii Stepanov , Branislav Rankov References: <20210118183033.41764-1-vincenzo.frascino@arm.com> <20210118183033.41764-4-vincenzo.frascino@arm.com> <20210119130440.GC17369@gaia> From: Vincenzo Frascino Message-ID: <813f907f-0de8-6b96-c67a-af9aecf31a70@arm.com> Date: Tue, 19 Jan 2021 14:23:03 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20210119130440.GC17369@gaia> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 1/19/21 1:04 PM, Catalin Marinas wrote: > On Mon, Jan 18, 2021 at 06:30:31PM +0000, Vincenzo Frascino wrote: >> KASAN provides an asynchronous mode of execution. >> >> Add reporting functionality for this mode. >> >> Cc: Dmitry Vyukov >> Cc: Andrey Ryabinin >> Cc: Alexander Potapenko >> Cc: Andrey Konovalov >> Signed-off-by: Vincenzo Frascino >> --- >> include/linux/kasan.h | 3 +++ >> mm/kasan/report.c | 16 ++++++++++++++-- >> 2 files changed, 17 insertions(+), 2 deletions(-) >> >> diff --git a/include/linux/kasan.h b/include/linux/kasan.h >> index fe1ae73ff8b5..8f43836ccdac 100644 >> --- a/include/linux/kasan.h >> +++ b/include/linux/kasan.h >> @@ -336,6 +336,9 @@ static inline void *kasan_reset_tag(const void *addr) >> bool kasan_report(unsigned long addr, size_t size, >> bool is_write, unsigned long ip); >> >> +bool kasan_report_async(unsigned long addr, size_t size, >> + bool is_write, unsigned long ip); > > We have no address, no size and no is_write information. Do we have a > reason to pass all these arguments here? Not sure what SPARC ADI does > but they may not have all this information either. We can pass ip as the > point where we checked the TFSR reg but that's about it. > I kept the interface generic for future development and mainly to start a discussion. I do not have a strong opinion either way. If Andrey agrees as well I am happy to change it to what you are suggesting in v5. >> + >> #else /* CONFIG_KASAN_SW_TAGS || CONFIG_KASAN_HW_TAGS */ >> >> static inline void *kasan_reset_tag(const void *addr) >> diff --git a/mm/kasan/report.c b/mm/kasan/report.c >> index c0fb21797550..946016ead6a9 100644 >> --- a/mm/kasan/report.c >> +++ b/mm/kasan/report.c >> @@ -388,11 +388,11 @@ static void __kasan_report(unsigned long addr, size_t size, bool is_write, >> start_report(&flags); >> >> print_error_description(&info); >> - if (addr_has_metadata(untagged_addr)) >> + if (addr_has_metadata(untagged_addr) && (untagged_addr != 0)) >> print_tags(get_tag(tagged_addr), info.first_bad_addr); >> pr_err("\n"); >> >> - if (addr_has_metadata(untagged_addr)) { >> + if (addr_has_metadata(untagged_addr) && (untagged_addr != 0)) { >> print_address_description(untagged_addr, get_tag(tagged_addr)); >> pr_err("\n"); >> print_memory_metadata(info.first_bad_addr); >> @@ -419,6 +419,18 @@ bool kasan_report(unsigned long addr, size_t size, bool is_write, >> return ret; >> } >> >> +bool kasan_report_async(unsigned long addr, size_t size, >> + bool is_write, unsigned long ip) >> +{ >> + pr_info("==================================================================\n"); >> + pr_info("KASAN: set in asynchronous mode\n"); >> + pr_info("KASAN: some information might not be accurate\n"); >> + pr_info("KASAN: fault address is ignored\n"); >> + pr_info("KASAN: write/read distinction is ignored\n"); >> + >> + return kasan_report(addr, size, is_write, ip); > > So just call kasan_report (0, 0, 0, ip) here. > Fine by me. -- Regards, Vincenzo