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 C1F26C02194 for ; Thu, 6 Feb 2025 16:59:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc: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=n3Hy+POSduc71X+W8hWlAuSJjnlkGON1R9mAu4I/VXM=; b=XQuoGtAaoXI4bFtmGo7rWxGauL 33jfcqm+151W5g/L9UyvD1LxHN5zlDV/TaOugew6EjpnjhymW0Y7JIHBAJOTx0nBmLN7liB/xUSdv kjCXBVG5IwtpGDiFme85GkyZ13Zf0NYMr6+bwYPy/dYovr7xlToiCDFL6aaLkdrU1e8bggvc7t9vu +7dunAuNVPqUK3rbTgW45wM19dI9oZHAofXwqmNurhtLtYah6nvRXvwIRrp1LJ0GwbUv9Fmt426cl oMUHltcjW/rzRJwcuxKOgdFgtRkNkhHR4OMfI7QHMmRPzKfAtYMqi8jQkvUJX4BYvNDnDjZbDzyQK g1hDwQDQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tg5Di-00000006vGD-3qt5; Thu, 06 Feb 2025 16:59:18 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tg5CK-00000006v51-3br7 for linux-arm-kernel@lists.infradead.org; Thu, 06 Feb 2025 16:57:54 +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 656A312FC; Thu, 6 Feb 2025 08:58:13 -0800 (PST) Received: from NH27D9T0LF (unknown [10.57.10.111]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 409213F63F; Thu, 6 Feb 2025 08:57:49 -0800 (PST) Date: Thu, 6 Feb 2025 17:57:41 +0100 From: Emanuele Rocca To: Will Deacon Cc: Mark Rutland , linux-arm-kernel@lists.infradead.org Subject: Re: [BUG] ARM64 regression: NULL pointer dereference in arm_smccc_version_init+0x90/0x1ac Message-ID: References: <20250131124103.GA29766@willie-the-truck> <20250204100014.GA777@willie-the-truck> <20250206131154.GD3204@willie-the-truck> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250206131154.GD3204@willie-the-truck> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250206_085752_938564_3BA85C67 X-CRM114-Status: UNSURE ( 6.66 ) X-CRM114-Notice: Please train this message. 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 2025-02-06 01:11, Will Deacon wrote: > In your screenshot, x6 looks like it's retained its poison value, but > that was the register being corrupted in the initial report. Maybe you > could share the diff you made? Sure, please see [1]. A kernel built with that patch crashes and all registers retain their poison values. I now also tried moving the poisoning before the smccc_version / smccc_conduit assignments, and the resulting kernel does *not* crash. See [2]. [1] https://people.debian.org/~ema/w1-w17-crash.diff [2] https://people.debian.org/~ema/w1-w17-nocrash.diff