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 8164AC77B7F for ; Fri, 27 Jun 2025 19:04:54 +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: Content-Transfer-Encoding:Content-Type:In-Reply-To:From:References:To:Subject :MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=cFffsWSP9wE6BDzyHbT0IRZNUmIrPtpRMCeF7m6L65I=; b=nwmHviisXlxjJk eYHtHvRYtCu0oSV8On9FfyriU8K3ERdpm7SG7ffQFVenNKOX63eq2vQFKgJ5TRIuZUi/8vRY1L2Qe e28yodp/MOtTmoBzhzgTTWTG0Qd5JAGsQtXXayhmMfZdh+evD6AOGPpvXHo8GJPXWXAUauxHzk89r IMVfprbeqpXdC3Xs/LlNGUX2LAZxjwrBGgFgr8LBRjwd/5ggc/iFEyKHQv12OJZcw78gnpxFiKSVI Q36CIxhdLat3fA7lfnjeN9xOh8Wl+celgcjSP+PDfUVQfxvdXys3dGhbwDX4GKki7Cd9odSVcKp5y cG8Aj3CyjG7/AEDZahyg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uVENT-0000000FYuC-2tEG; Fri, 27 Jun 2025 19:04:47 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uVCrJ-0000000FPVz-2x0t for linux-arm-kernel@lists.infradead.org; Fri, 27 Jun 2025 17:27:30 +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 BA0761A00; Fri, 27 Jun 2025 10:27:11 -0700 (PDT) Received: from [10.57.30.218] (unknown [10.57.30.218]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 3498F3F66E; Fri, 27 Jun 2025 10:27:27 -0700 (PDT) Message-ID: Date: Fri, 27 Jun 2025 18:27:21 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 00/13] arm64: debug: remove hook registration, split exception entry To: Will Deacon References: <20250620211207.773980-1-ada.coupriediaz@arm.com> From: Ada Couprie Diaz Content-Language: en-US Organization: Arm Ltd. In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250627_102729_784411_46887EBA X-CRM114-Status: GOOD ( 16.98 ) 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: Mark Rutland , Anshuman Khandual , "Luis Claudio R . Goncalves" , Catalin Marinas , linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Will, On 27/06/2025 16:48, Will Deacon wrote: > Hi Ada, > > On Fri, Jun 20, 2025 at 10:11:54PM +0100, Ada Couprie Diaz wrote: >> This series simplifies the debug exception entry path by removing handler >> registration mechanisms for the debug exception handlers, a holdover from >> the arm kernel, as well as the break and stepping handlers. >> This moves much of the code related to debug exceptions outside of >> `mm/fault.c` where it didn't make much sense. >> This allows us to split the debug exception entries: going from one common >> path per EL for all debug exceptions to a unique one per exception and EL. >> >> The result is a much simpler and fully static exception entry path, which >> we tailor to the different exceptions and their constraints. > I think this looks great, thanks. I've left Reviewed-bys on everything > and a minor nit on the last patch. Thanks ! Added your tag and applied the nit, I raised the possibility earlier so absolutely fine with it. > However, the linker is less > enthusiastic than me because it fails with this series and 'allnoconfig': > > ld.lld: error: undefined symbol: do_breakpoint > >>> referenced by entry-common.c > >>> arch/arm64/kernel/entry-common.o:(el1_breakpt) in archive vmlinux.a > >>> referenced by entry-common.c > >>> arch/arm64/kernel/entry-common.o:(el0_breakpt) in archive vmlinux.a > > ld.lld: error: undefined symbol: do_watchpoint > >>> referenced by entry-common.c > >>> arch/arm64/kernel/entry-common.o:(el1_watchpt) in archive vmlinux.a > >>> referenced by entry-common.c > >>> arch/arm64/kernel/entry-common.o:(el0_watchpt) in archive vmlinux.a > make[2]: *** [scripts/Makefile.vmlinux:91: vmlinux] Error 1 > > Please can you take a look? Apologies, I knew exactly what that was : hardware breakpoints being behind a config, which I failed to consider when exposing the handlers in `include/asm/exception.h`. I added a static inline stub for this case for both and built successfully with `allnoconfig`. > Will I sent a v5 with the changes mentioned here and the fix for `allnoconfig`. Thanks, Ada