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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 C777DC4338F for ; Wed, 4 Aug 2021 14:36:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AC2D260F94 for ; Wed, 4 Aug 2021 14:36:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237776AbhHDOg3 (ORCPT ); Wed, 4 Aug 2021 10:36:29 -0400 Received: from szxga02-in.huawei.com ([45.249.212.188]:7925 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237361AbhHDOg2 (ORCPT ); Wed, 4 Aug 2021 10:36:28 -0400 Received: from dggemv711-chm.china.huawei.com (unknown [172.30.72.57]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4GfvMn3qJJz83dT; Wed, 4 Aug 2021 22:32:21 +0800 (CST) Received: from dggpemm500019.china.huawei.com (7.185.36.180) by dggemv711-chm.china.huawei.com (10.1.198.66) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Wed, 4 Aug 2021 22:36:12 +0800 Received: from ubuntu1804.huawei.com (10.67.174.98) by dggpemm500019.china.huawei.com (7.185.36.180) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Wed, 4 Aug 2021 22:36:12 +0800 From: Pu Lehui To: , , , , , , , , , CC: , , , , Subject: [PATCH] powerpc/kprobes: Fix kprobe Oops happens in booke Date: Wed, 4 Aug 2021 22:37:35 +0800 Message-ID: <20210804143735.148547-1-pulehui@huawei.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.67.174.98] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To dggpemm500019.china.huawei.com (7.185.36.180) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When using kprobe on powerpc booke series processor, Oops happens as show bellow: [ 35.861352] Oops: Exception in kernel mode, sig: 5 [#1] [ 35.861676] BE PAGE_SIZE=4K SMP NR_CPUS=24 QEMU e500 [ 35.861905] Modules linked in: [ 35.862144] CPU: 0 PID: 76 Comm: sh Not tainted 5.14.0-rc3-00060-g7e96bf476270 #18 [ 35.862610] NIP: c0b96470 LR: c00107b4 CTR: c0161c80 [ 35.862805] REGS: c387fe70 TRAP: 0700 Not tainted (5.14.0-rc3-00060-g7e96bf476270) [ 35.863198] MSR: 00029002 CR: 24022824 XER: 20000000 [ 35.863577] [ 35.863577] GPR00: c0015218 c387ff20 c313e300 c387ff50 00000004 40000002 40000000 0a1a2cce [ 35.863577] GPR08: 00000000 00000004 00000000 59764000 24022422 102490c2 00000000 00000000 [ 35.863577] GPR16: 00000000 00000000 00000040 10240000 10240000 10240000 10240000 10220000 [ 35.863577] GPR24: ffffffff 10240000 00000000 00000000 bfc655e8 00000800 c387ff50 00000000 [ 35.865367] NIP [c0b96470] schedule+0x0/0x130 [ 35.865606] LR [c00107b4] interrupt_exit_user_prepare_main+0xf4/0x100 [ 35.865974] Call Trace: [ 35.866142] [c387ff20] [c0053224] irq_exit+0x114/0x120 (unreliable) [ 35.866472] [c387ff40] [c0015218] interrupt_return+0x14/0x13c [ 35.866728] --- interrupt: 900 at 0x100af3dc [ 35.866963] NIP: 100af3dc LR: 100de020 CTR: 00000000 [ 35.867177] REGS: c387ff50 TRAP: 0900 Not tainted (5.14.0-rc3-00060-g7e96bf476270) [ 35.867488] MSR: 0002f902 CR: 20022422 XER: 20000000 [ 35.867808] [ 35.867808] GPR00: c001509c bfc65570 1024b4d0 00000000 100de020 20022422 bfc655a8 100af3dc [ 35.867808] GPR08: 0002f902 00000000 00000000 00000000 72656773 102490c2 00000000 00000000 [ 35.867808] GPR16: 00000000 00000000 00000040 10240000 10240000 10240000 10240000 10220000 [ 35.867808] GPR24: ffffffff 10240000 00000000 00000000 bfc655e8 10245910 ffffffff 00000001 [ 35.869406] NIP [100af3dc] 0x100af3dc [ 35.869578] LR [100de020] 0x100de020 [ 35.869751] --- interrupt: 900 [ 35.870001] Instruction dump: [ 35.870283] 40c20010 815e0518 714a0100 41e2fd04 39200000 913e00c0 3b1e0450 4bfffd80 [ 35.870666] 0fe00000 92a10024 4bfff1a9 60000000 <7fe00008> 7c0802a6 93e1001c 7c5f1378 [ 35.871339] ---[ end trace 23ff848139efa9b9 ]--- There is no real mode for booke arch and the MMU translation is always on. The corresponding MSR_IS/MSR_DS bit in booke is used to switch the address space, but not for real mode judgment. Fixes: 21f8b2fa3ca5 ("powerpc/kprobes: Ignore traps that happened in real mode") Signed-off-by: Pu Lehui --- arch/powerpc/include/asm/ptrace.h | 6 ++++++ arch/powerpc/kernel/kprobes.c | 5 +---- 2 files changed, 7 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h index 3e5d470a6155..4aec1a97024b 100644 --- a/arch/powerpc/include/asm/ptrace.h +++ b/arch/powerpc/include/asm/ptrace.h @@ -187,6 +187,12 @@ static inline unsigned long frame_pointer(struct pt_regs *regs) #define user_mode(regs) (((regs)->msr & MSR_PR) != 0) #endif +#ifdef CONFIG_BOOKE +#define real_mode(regs) 0 +#else +#define real_mode(regs) (!((regs)->msr & MSR_IR) || !((regs)->msr & MSR_DR)) +#endif + #define force_successful_syscall_return() \ do { \ set_thread_flag(TIF_NOERROR); \ diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c index cbc28d1a2e1b..fac9a5974718 100644 --- a/arch/powerpc/kernel/kprobes.c +++ b/arch/powerpc/kernel/kprobes.c @@ -289,10 +289,7 @@ int kprobe_handler(struct pt_regs *regs) unsigned int *addr = (unsigned int *)regs->nip; struct kprobe_ctlblk *kcb; - if (user_mode(regs)) - return 0; - - if (!(regs->msr & MSR_IR) || !(regs->msr & MSR_DR)) + if (user_mode(regs) || real_mode(regs)) return 0; /* -- 2.17.1