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=-14.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, NICE_REPLY_A,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 13A72C433E0 for ; Wed, 3 Mar 2021 20:07:30 +0000 (UTC) Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 09C2964EDC for ; Wed, 3 Mar 2021 20:07:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 09C2964EDC Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=desiato.20200630; h=Sender:Content-Transfer-Encoding :Content-Type:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:Mime-Version:References:In-Reply-To:Message-Id: Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=69AaNYs4ljPA7Zjoc85a0y4+GAtbcFA8qDXTMHywQkw=; b=L3tvbN1OmX7CVrl2WZXkAOLo1 BnpZ7EyE2RLdW0ff2w5+apJ3qhQUvlDx8QgBYrhxDMDxzpV/ZUW1Bn3+pind59uc/W6A9qRrTSb2g MAfGTLx1lJ+jzowUAVjlfU5ASE8zv3TAExJYtoQ9W2ptK9ENyRCBCKbisUOheSnHM3g/e1o/QQ9BD O2w8aMCRk5BwVaxfqWj0p7026YdQj1wF47f/xIU5aujDtL9Q+pwavRWbbHsBy26zB2YPv44PTBzhl s2I26FOWNh2vEll8UU4PGM4oRPLp0N+w/mkSgnG0WLXB0RMCdH1p03bnao2dxz7wF86fUAJFW/mFH x+K7o1LdQ==; Received: from localhost ([::1] helo=desiato.infradead.org) by desiato.infradead.org with esmtp (Exim 4.94 #2 (Red Hat Linux)) id 1lHXiA-006LNG-UI; Wed, 03 Mar 2021 20:03:11 +0000 Received: from casper.infradead.org ([2001:8b0:10b:1236::1]) by desiato.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lHT4i-005IU8-3H for linux-arm-kernel@desiato.infradead.org; Wed, 03 Mar 2021 15:06:08 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:Content-Type: Mime-Version:References:In-Reply-To:Message-Id:Subject:Cc:To:From:Date:Sender :Reply-To:Content-ID:Content-Description; bh=O1SgMHZZVkUbwgYV8dnXWfQmUUU3EKiDodGFDtHPfCE=; b=XjqabxPkzLItnumgqPaW4gNAWa xA6qZu5bow6ux/j8njRUAu/HfByomgC+EMpAKAwjM/Nrw5Xt3dKureG5p8b/xLxaOnMRAzCjoNHmy 76brEwPzKI0U4xjG8eoFeFz173C8DCfxsIW3K9pdzDfP5lkKNNbYaoc5UVZLcuTioUzCHGM39JrHg OuskQq2k1loHqlg+mqUgLP+QVGfms8oMm+Xp1gphLdW072PcYKbty4Udl5bZijMJ5eR8HkeObfyGq SisUI2DHFFF1nWEoXza5VHA3F7gImKhZZywgNHph2IJUFcUfifCLcS4oV3jnGfMxsE+u+v3ctbflx ljhgskrg==; Received: from mail.kernel.org ([198.145.29.99]) by casper.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lHQSd-002VWG-QG for linux-arm-kernel@lists.infradead.org; Wed, 03 Mar 2021 12:18:41 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id 0834A60C3E; Wed, 3 Mar 2021 12:18:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1614773912; bh=v3CqCbTv0mkQkZ9Ih1RedXVPZV9P2fo8wFRseCGcHv8=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=blDw8YeZouCbRsfc7ZOUXPRTlU59K/tmWQLE8EanPyntbPVhlqDdyM3ZtTCq0d4OG qrod534Ed4NAeIkg6ogDPq5pMCoJR5J3LrAlD8BJmZEugEGc94+PzpbMq5GV+CMQAR MnpIku34NR5dTqmIv6TNWUEC0k1fM3UY4dslGpQ1bg5NZjw0j2VG5a2Bt3Rk9Hs3Vw PvkcyVKZy0KJMX5BwbK4WzsHN8TmKXWDgWdHWg4qZrkvd4UazhLOctL2VCDZNw/Qxs EZoviPLUTogdPA6j3raB605qmkGjGyv1HjuDnmjupQVgvIrnAi3DGuWd+4ZFdH4kUN 83uw+wxaX/AeQ== Date: Wed, 3 Mar 2021 21:18:27 +0900 From: Masami Hiramatsu To: ShaoBo Huang Cc: , , , , , , , , , , , Subject: Re: [PATCH 4.9.y] arm: kprobes: Allow to handle reentered kprobe on single-stepping Message-Id: <20210303211827.eeb89c8a9b140152fbcd997c@kernel.org> In-Reply-To: <20210303071052.33740-1-huangshaobo6@huawei.com> References: <20210303071052.33740-1-huangshaobo6@huawei.com> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.32; x86_64-pc-linux-gnu) Mime-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210303_121841_957666_59139453 X-CRM114-Status: GOOD ( 17.70 ) 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-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi ShaoBo, Thanks for backporting and real bug report! On Wed, 3 Mar 2021 15:10:52 +0800 ShaoBo Huang wrote: > From: Masami Hiramatsu > > commit f3fbd7ec62dec1528fb8044034e2885f2b257941 upstream > > This is arm port of commit 6a5022a56ac3 ("kprobes/x86: Allow to > handle reentered kprobe on single-stepping") > > Since the FIQ handlers can interrupt in the single stepping > (or preparing the single stepping, do_debug etc.), we should > consider a kprobe is hit in the NMI handler. Even in that > case, the kprobe is allowed to be reentered as same as the > kprobes hit in kprobe handlers > (KPROBE_HIT_ACTIVE or KPROBE_HIT_SSDONE). > > The real issue will happen when a kprobe hit while another > reentered kprobe is processing (KPROBE_REENTER), because > we already consumed a saved-area for the previous kprobe. > > Signed-off-by: Masami Hiramatsu > Signed-off-by: Jon Medhurst > Fixes: 24ba613c9d6c ("ARM kprobes: core code") > Cc: stable@vger.kernel.org #v2.6.25~v4.11 > Signed-off-by: huangshaobo > --- > arch/arm/probes/kprobes/core.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/arch/arm/probes/kprobes/core.c b/arch/arm/probes/kprobes/core.c > index 3eb018fa1a1f..c3362ddd6c4c 100644 > --- a/arch/arm/probes/kprobes/core.c > +++ b/arch/arm/probes/kprobes/core.c > @@ -270,6 +270,7 @@ void __kprobes kprobe_handler(struct pt_regs *regs) > switch (kcb->kprobe_status) { > case KPROBE_HIT_ACTIVE: > case KPROBE_HIT_SSDONE: > + case KPROBE_HIT_SS: > /* A pre- or post-handler probe got us here. */ > kprobes_inc_nmissed_count(p); > save_previous_kprobe(kcb); > @@ -278,6 +279,11 @@ void __kprobes kprobe_handler(struct pt_regs *regs) > singlestep(p, regs, kcb); > restore_previous_kprobe(kcb); > break; > + case KPROBE_REENTER: > + /* A nested probe was hit in FIQ, it is a BUG */ > + pr_warn("Unrecoverable kprobe detected at %p.\n", > + p->addr); > + /* fall through */ > default: > /* impossible cases */ > BUG(); > -- > 2.12.3 > -- Masami Hiramatsu _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel