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=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,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 B81E1C433E2 for ; Wed, 9 Sep 2020 14:10:28 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 5EF5421D7D for ; Wed, 9 Sep 2020 14:10:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="kOQtI+Jk" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5EF5421D7D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com 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=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:MIME-Version:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:References:In-Reply-To:Message-Id:Date:Subject:To: From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=Dmwv1Ty6rCjUtUYsdxcJTRtR9IunkDhYjpOCEI1fWqM=; b=kOQtI+Jkdsd2zyuj6dOuN5kyXr v3pm4dqX88JZbM25fP6P2yNGh5FwZysrRgVI+ACfy9oK21m3GgHTfEDEguDj/krcVFEMasivxTVjj jjidxzRmaJ6ipWRRz2ZbP7nQ21WrhhNCnYhjFq/F/UgOILSXYQcvuWHcIKah+7fnvukAXSY7n5roU FXc59oqOgH6A+QPVta2xE8QzFATidM8ecn4/2pZ9ssu2qA0HUGpfnfSAOEi0WHohRRRQbIMoVfpJ6 PHWOkUUY/Le6qI0VsX13iLBlRtG8jbIwCBxaHlfwaY8byT7PmSVSgXLxxyvBKCrHFdjT5kickkUYd AgkHZG3A==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kG0mU-0000HM-VC; Wed, 09 Sep 2020 14:09:03 +0000 Received: from foss.arm.com ([217.140.110.172]) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kG0mR-0000Fi-1Q for linux-arm-kernel@lists.infradead.org; Wed, 09 Sep 2020 14:09:00 +0000 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 3219731B; Wed, 9 Sep 2020 07:08:58 -0700 (PDT) Received: from a077416.arm.com (unknown [10.57.14.111]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 2D43A3F66E; Wed, 9 Sep 2020 07:08:51 -0700 (PDT) From: Amit Daniel Kachhap To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v7 6/6] arm64: kprobe: clarify the comment of steppable hint instructions Date: Wed, 9 Sep 2020 19:37:59 +0530 Message-Id: <20200909140759.4170-7-amit.kachhap@arm.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200909140759.4170-1-amit.kachhap@arm.com> References: <20200909140759.4170-1-amit.kachhap@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200909_100859_195186_16222404 X-CRM114-Status: GOOD ( 12.46 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Suzuki K Poulose , Catalin Marinas , Mark Brown , James Morse , Amit Daniel Kachhap , Vincenzo Frascino , Will Deacon , Dave Martin MIME-Version: 1.0 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 The existing comment about steppable hint instruction is not complete and only describes NOP instructions as steppable. As the function aarch64_insn_is_steppable_hint allows all white-listed instruction to be probed so the comment is updated to reflect this. Signed-off-by: Amit Daniel Kachhap Reviewed-by: Dave Martin --- arch/arm64/kernel/probes/decode-insn.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kernel/probes/decode-insn.c b/arch/arm64/kernel/probes/decode-insn.c index c541fb48886e..104101f633b1 100644 --- a/arch/arm64/kernel/probes/decode-insn.c +++ b/arch/arm64/kernel/probes/decode-insn.c @@ -43,8 +43,10 @@ static bool __kprobes aarch64_insn_is_steppable(u32 insn) != AARCH64_INSN_SPCLREG_DAIF; /* - * The HINT instruction is is problematic when single-stepping, - * except for the NOP case. + * The HINT instruction is steppable only if it is in whitelist + * and the rest of other such instructions are blocked for + * single stepping as they may cause exception or other + * unintended behaviour. */ if (aarch64_insn_is_hint(insn)) return aarch64_insn_is_steppable_hint(insn); -- 2.17.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel