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 E0934C25B08 for ; Sun, 21 Aug 2022 01:00:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235939AbiHUBAw (ORCPT ); Sat, 20 Aug 2022 21:00:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33912 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232315AbiHUBAu (ORCPT ); Sat, 20 Aug 2022 21:00:50 -0400 Received: from mail-wr1-x42e.google.com (mail-wr1-x42e.google.com [IPv6:2a00:1450:4864:20::42e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 60A101E3EA; Sat, 20 Aug 2022 18:00:49 -0700 (PDT) Received: by mail-wr1-x42e.google.com with SMTP id b5so4901910wrr.5; Sat, 20 Aug 2022 18:00:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc; bh=a4jNHFHiClDdq/v49nsMbA8I7HwKAy8R6hrK4YLcETg=; b=AXPnI89Txz85BoWVYAFCMtMPbQcGFSRW9UnKTu6iScu4HS0WqlGWSD9JtoSlTj70EP mZiagAyiMBkanQ7JZ7mBCJueCAvdX0+/UkZ5D5VPGYEnOaqT1tXH7H/xw0T3hQwXlC4b vl3orITND69HNkgeXNp56lMh5QVGVWA5jAYDKERihJAGkVIx2trU73w2i7dh/BNDJG82 Ep9cwajpDz7iBIOmLCm7ODT7JtrbCTr+rduE9jiQ8cfpX/PEGHjP6Aai1P6VFTImcO66 kcYtnqjcC7Pzq/JWMdynbGRSoowQgEZszBEltfRK6NHhRu5PdcmWfqmcUQpXi9TGhooV Wu4A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc; bh=a4jNHFHiClDdq/v49nsMbA8I7HwKAy8R6hrK4YLcETg=; b=ahZsxp3B0FV/o0aUGOymNfH7V5PhlR7ak6f75t8mZAfbO012oLJnzkeV664RoxE2XI idku2LYObldQH2RFAzhI+WE19VHFwWR00OG5ZLpB9XRp2UZS4zAj4rKdEWeYbyOMxb9p SKFCXQlMQj7cwyWodCkin1WkjXxEwF6qr/7hSP6LXZ7s8vriZS29Vn0rg7b5nsS2F/I7 zpYY2mJ2fHjo2eod7Ne19qTWT0Fktv381/maGB3CtotIV0ni1HVINyk8vTkx8FHkzL1d mOL/Bi1sknhsiQkczioFFeB3aSL0If36EUK9wjTsvVR99f4ohBI6HKQ/u979BSIEzPhK cNOg== X-Gm-Message-State: ACgBeo1hWGogJeLIqGxF1VzYBPIDxzeJJu7ZmzFimkdMO9ztuTpOSNaq 1LqCtM5LQu2NKMkgwGA6DbJ8AeASKFc= X-Google-Smtp-Source: AA6agR5zLE9kQ65fXHG6rjjR2ZpdPg7mUbxbgX8Wf/KmxTkJHk+7GWOjEPvnFelVMh/hMofl4rxKbg== X-Received: by 2002:adf:f208:0:b0:225:25e6:c964 with SMTP id p8-20020adff208000000b0022525e6c964mr7555213wro.531.1661043647749; Sat, 20 Aug 2022 18:00:47 -0700 (PDT) Received: from localhost.localdomain ([185.192.68.223]) by smtp.gmail.com with ESMTPSA id r38-20020a05600c322600b003a2e92edeccsm12148515wmp.46.2022.08.20.18.00.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 20 Aug 2022 18:00:44 -0700 (PDT) From: Zhouyi Zhou To: mpe@ellerman.id.au, npiggin@gmail.com, christophe.leroy@csgroup.eu, atrajeev@linux.vnet.ibm.com, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, lance@osuosl.org, paulmck@kernel.org, rcu@vger.kernel.org Cc: Zhouyi Zhou Subject: [PATCH linux-next] powerpc: disable sanitizer in irq_soft_mask_set Date: Sun, 21 Aug 2022 09:00:30 +0800 Message-Id: <20220821010030.97539-1-zhouzhouyi@gmail.com> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In ppc, compiler based sanitizer will generate instrument instructions around statement WRITE_ONCE(local_paca->irq_soft_mask, mask): 0xc000000000295cb0 <+0>: addis r2,r12,774 0xc000000000295cb4 <+4>: addi r2,r2,16464 0xc000000000295cb8 <+8>: mflr r0 0xc000000000295cbc <+12>: bl 0xc00000000008bb4c 0xc000000000295cc0 <+16>: mflr r0 0xc000000000295cc4 <+20>: std r31,-8(r1) 0xc000000000295cc8 <+24>: addi r3,r13,2354 0xc000000000295ccc <+28>: mr r31,r13 0xc000000000295cd0 <+32>: std r0,16(r1) 0xc000000000295cd4 <+36>: stdu r1,-48(r1) 0xc000000000295cd8 <+40>: bl 0xc000000000609b98 <__asan_store1+8> 0xc000000000295cdc <+44>: nop 0xc000000000295ce0 <+48>: li r9,1 0xc000000000295ce4 <+52>: stb r9,2354(r31) 0xc000000000295ce8 <+56>: addi r1,r1,48 0xc000000000295cec <+60>: ld r0,16(r1) 0xc000000000295cf0 <+64>: ld r31,-8(r1) 0xc000000000295cf4 <+68>: mtlr r0 If there is a context switch before "stb r9,2354(r31)", r31 may not equal to r13, in such case, irq soft mask will not work. This patch disable sanitizer in irq_soft_mask_set. Signed-off-by: Zhouyi Zhou --- Dear PPC developers I found this bug when trying to do rcutorture tests in ppc VM of Open Source Lab of Oregon State University following Paul E. McKenny's guidance. console.log report following bug: [ 346.527467][ T100] BUG: using smp_processor_id() in preemptible [00000000] code: rcu_torture_rea/100^M [ 346.529416][ T100] caller is rcu_preempt_deferred_qs_irqrestore+0x74/0xed0^M [ 346.531157][ T100] CPU: 4 PID: 100 Comm: rcu_torture_rea Tainted: G W 5.19.0-rc5-next-20220708-dirty #253^M [ 346.533620][ T100] Call Trace:^M [ 346.534449][ T100] [c0000000094876c0] [c000000000ce2b68] dump_stack_lvl+0xbc/0x108 (unreliable)^M [ 346.536632][ T100] [c000000009487710] [c000000001712954] check_preemption_disabled+0x154/0x160^M [ 346.538665][ T100] [c0000000094877a0] [c0000000002ce2d4] rcu_preempt_deferred_qs_irqrestore+0x74/0xed0^M [ 346.540830][ T100] [c0000000094878b0] [c0000000002cf3c0] __rcu_read_unlock+0x290/0x3b0^M [ 346.542746][ T100] [c000000009487910] [c0000000002bb330] rcu_torture_read_unlock+0x30/0xb0^M [ 346.544779][ T100] [c000000009487930] [c0000000002b7ff8] rcutorture_one_extend+0x198/0x810^M [ 346.546851][ T100] [c000000009487a10] [c0000000002b8bfc] rcu_torture_one_read+0x58c/0xc90^M [ 346.548844][ T100] [c000000009487ca0] [c0000000002b942c] rcu_torture_reader+0x12c/0x360^M [ 346.550784][ T100] [c000000009487db0] [c0000000001de978] kthread+0x1e8/0x220^M [ 346.552555][ T100] [c000000009487e10] [c00000000000cd54] ret_from_kernel_thread+0x5c/0x64^M After 12 days debugging, I finally narrow the problem to irq_soft_mask_set. I am a beginner, hope I can be of some beneficial to the community ;-) Thanks Zhouyi -- arch/powerpc/include/asm/hw_irq.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/powerpc/include/asm/hw_irq.h b/arch/powerpc/include/asm/hw_irq.h index 26ede09c521d..a5ae8d82cc9d 100644 --- a/arch/powerpc/include/asm/hw_irq.h +++ b/arch/powerpc/include/asm/hw_irq.h @@ -121,7 +121,7 @@ static inline notrace unsigned long irq_soft_mask_return(void) * for the critical section and as a clobber because * we changed paca->irq_soft_mask */ -static inline notrace void irq_soft_mask_set(unsigned long mask) +static inline notrace __no_kcsan __no_sanitize_address void irq_soft_mask_set(unsigned long mask) { /* * The irq mask must always include the STD bit if any are set. -- 2.34.1