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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 5D396C43334 for ; Tue, 14 Jun 2022 03:21:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Content-Type: Content-Transfer-Encoding:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:From:References:CC:To:Subject: MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=GK5Y34urZ0QdimtV9wGyscix/Dw8zqQqGwLuj/qWFWY=; b=iHC7SBv9nlpoCf xvFwgtDg+qOL4iHrf5NBefSLfbUHSOZ+WjdYyepBSB0v9lCvnGbfHeUcpNBzf+yolBSm8SqEQtDgZ 7KPN8hLIMlJyHe4NZlgpi7Vdd8EzvNixYSPf9z6afujNsqRXxrJsFyYjQcmNMJR9B0v5piFjAl8Tk mLqZ6lv6bPK6gy/o/ljrgF91U0Inf9RTdCjqk0F3Rz5G6d8pBLo0SiYH6oiG8t8/hpKXWLXW1BJ5e islbagIKGMH1I9q9aq0AYs4mlV2icxKtx0kIC09POw8JsvS6+RzfRypx1pyJCJ9+ZwvTto2jLiV1x /8Ax9GCzw1wBrl45IoSA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1o0x6J-006ssd-CE; Tue, 14 Jun 2022 03:20:19 +0000 Received: from szxga03-in.huawei.com ([45.249.212.189]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1o0x6F-006spf-28 for linux-arm-kernel@lists.infradead.org; Tue, 14 Jun 2022 03:20:17 +0000 Received: from dggpemm500024.china.huawei.com (unknown [172.30.72.55]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4LMYZm4jndzDrD4; Tue, 14 Jun 2022 11:19:44 +0800 (CST) Received: from dggpemm500001.china.huawei.com (7.185.36.107) by dggpemm500024.china.huawei.com (7.185.36.203) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Tue, 14 Jun 2022 11:20:09 +0800 Received: from [10.174.177.243] (10.174.177.243) by dggpemm500001.china.huawei.com (7.185.36.107) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Tue, 14 Jun 2022 11:20:08 +0800 Message-ID: <2737609c-78d9-b679-f2d6-a681614f68b5@huawei.com> Date: Tue, 14 Jun 2022 11:20:07 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.9.1 Subject: Re: [PATCH v4 2/2] arm64: kcsan: Support detecting more missing memory barriers Content-Language: en-US To: Mark Rutland CC: , , , , , Jonathan Corbet , , References: <20220523113126.171714-1-wangkefeng.wang@huawei.com> <20220523113126.171714-3-wangkefeng.wang@huawei.com> From: Kefeng Wang In-Reply-To: X-Originating-IP: [10.174.177.243] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To dggpemm500001.china.huawei.com (7.185.36.107) X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220613_202015_500341_2BC75072 X-CRM114-Status: GOOD ( 16.90 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Will and Catalin, kindly ping... On 2022/5/23 22:16, Mark Rutland wrote: > On Mon, May 23, 2022 at 07:31:26PM +0800, Kefeng Wang wrote: >> As "kcsan: Support detecting a subset of missing memory barriers"[1] >> introduced KCSAN_STRICT/KCSAN_WEAK_MEMORY which make kcsan detects >> more missing memory barrier, but arm64 don't have KCSAN instrumentation >> for barriers, so the new selftest test_barrier() and test cases for >> memory barrier instrumentation in kcsan_test module will fail, even >> panic on selftest. >> >> Let's prefix all barriers with __ on arm64, as asm-generic/barriers.h >> defined the final instrumented version of these barriers, which will >> fix the above issues. >> >> Note, barrier instrumentation that can be disabled via __no_kcsan with >> appropriate compiler-support (and not just with objtool help), see >> commit bd3d5bd1a0ad ("kcsan: Support WEAK_MEMORY with Clang where no >> objtool support exists"), it adds disable_sanitizer_instrumentation to >> __no_kcsan attribute which will remove all sanitizer instrumentation fully >> (with Clang 14.0). Meanwhile, GCC does the same thing with no_sanitize. >> >> [1] https://lore.kernel.org/linux-mm/20211130114433.2580590-1-elver@google.com/ >> >> Acked-by: Marco Elver >> Signed-off-by: Kefeng Wang > Having built this with GCC 12.1.0 and LLVM 14.0.0, I think this patch itself > doesn't introduce any new problems, and logically makes sense. With that in > mind: > > Acked-by: Mark Rutland > > As an aside, having scanned the resulting vmlinux with objdump, there are > plenty of latent issues where we get KCSAN instrumentation where we don't want > it (e.g. early/late in arm64's entry-common.o). The bulk of those are due to > missing `nonistr` or `__always_inline`, which we'll need to fix up. > > Thanks, > Mark. > >> --- >> arch/arm64/include/asm/barrier.h | 12 ++++++------ >> 1 file changed, 6 insertions(+), 6 deletions(-) >> >> diff --git a/arch/arm64/include/asm/barrier.h b/arch/arm64/include/asm/barrier.h >> index 9f3e2c3d2ca0..2cfc4245d2e2 100644 >> --- a/arch/arm64/include/asm/barrier.h >> +++ b/arch/arm64/include/asm/barrier.h >> @@ -50,13 +50,13 @@ >> #define pmr_sync() do {} while (0) >> #endif >> >> -#define mb() dsb(sy) >> -#define rmb() dsb(ld) >> -#define wmb() dsb(st) >> +#define __mb() dsb(sy) >> +#define __rmb() dsb(ld) >> +#define __wmb() dsb(st) >> >> -#define dma_mb() dmb(osh) >> -#define dma_rmb() dmb(oshld) >> -#define dma_wmb() dmb(oshst) >> +#define __dma_mb() dmb(osh) >> +#define __dma_rmb() dmb(oshld) >> +#define __dma_wmb() dmb(oshst) >> >> #define io_stop_wc() dgh() >> >> -- >> 2.35.3 >> > . _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel