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 6E452C4450A for ; Thu, 16 Jul 2026 13:24:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To: Content-Type:MIME-Version:References:Message-ID:Subject:To:From:Date:Reply-To :Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=pviMfnX/HUaOmx/ovGW50P9j3K4uudlc7YTeokSyPvE=; b=FnrObdTOieiAvB9uuVh8LjLAsR HGf+aSyjRNzkJIULaev0gtCLovjlhZDQPL93rc2O6PpI1vHU2qDbUiJMM21w8o3zOcc2mExmV8FiP v+xI8wjpyAp9WZypxOrPsQD7WV5w88Slruc6CuZepEhudUe1N9B5XaP9AUIUK0U8p7rtVs2qfDOiX W36jqVgPUKRyfXHrAe3ZF2vqrSZEab6CsM0M+5CQSH550mwOGyJicRpjs/PqLum6k7RjxV//AUwGB ZwLaiXqmY1HACcxzRkhAypIKZJ8YOd4mxhRRuyvlWayT1i1T77vJPk1GKQZ96Fh/LRU/xJuYCzqR+ yE8aA+Ew==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wkM4c-0000000HNjl-0wwl; Thu, 16 Jul 2026 13:24:22 +0000 Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wkM4b-0000000HNjY-1Fhr for linux-arm-kernel@lists.infradead.org; Thu, 16 Jul 2026 13:24:21 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 12285434E3; Thu, 16 Jul 2026 13:24:21 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B1AE41F00A3E; Thu, 16 Jul 2026 13:24:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784208261; bh=pviMfnX/HUaOmx/ovGW50P9j3K4uudlc7YTeokSyPvE=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=H76DTIwwU8Z72uPRHja7ie2zD8snRxH7/gCNKaWMv6sk/6GsfZoYKdczqoJhsLPGt pwV03mBycS61lRZn9ovWs8wXMGJs55CECUzKcSeRqdPaALEVbn7LLXluCitQeQcNPb zywiB/k0km18wCd1EW6LUYZpjOo26guc22ctDzakcYhztOQr6BjaHmch6x4bc7/aad 7Qvtdyewx4crUQqOHjjgqCw6DMYPJLC8jcxFpw8knR20bh+fsHunXCBvLANptTrLuS M5bn65A8Jm1JHboMxIKZo3r37oAxYXi4WpnsnDHmVCdcRQL2gCNwmlS4xdcjBo35eY tz8YLt8kD4U3A== Date: Thu, 16 Jul 2026 14:24:15 +0100 From: Will Deacon To: Pu Hu Subject: Re: [RFC v3 2/2] arm64: kprobes: Allow reentering kprobes while single-stepping Message-ID: References: <20260710063242.228714-1-hupu@transsion.com> <20260710063242.228714-3-hupu@transsion.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260710063242.228714-3-hupu@transsion.com> 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: , Cc: Hongyan Xia , Jiazi Li , "catalin.marinas@arm.com" , "linux-kernel@vger.kernel.org" , "naveen@kernel.org" , "mhiramat@kernel.org" , "yang@os.amperecomputing.com" , "davem@davemloft.net" , "linux-arm-kernel@lists.infradead.org" , "linux-trace-kernel@vger.kernel.org" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, Jul 10, 2026 at 06:32:55AM +0000, Pu Hu wrote: > From: Pu Hu > > A kprobe can be hit while another kprobe is in KPROBE_HIT_SS state. This > can happen when tracing or perf code runs from the debug exception path > while the first kprobe is preparing or executing its out-of-line > single-step instruction. I don't understand this part. The single-step runs with debug exceptions disabled (kprobes_save_local_irqflag() sets PSTATE.D) so how do we end up taking one? Will