From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from vps0.lunn.ch (vps0.lunn.ch [156.67.10.101]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4C4123D75CE for ; Wed, 18 Mar 2026 13:30:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=156.67.10.101 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773840620; cv=none; b=XyEl3YHB6NQxD8Jmi67cOIZKkXvW56EyU0TBWomg8Zw+Sum9jwhuAm3CDEdxAvGhaVkAmKS7EvWoX27b1l7NPCfPZW2PnvVjE+UYdBlFEKJlkI1/aV+/gVT21+9sGRQq3nFyEKH3W0iKQwaQ9OX7JU5hGv1HIGY1S8VYULGC8hY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773840620; c=relaxed/simple; bh=+GdmIIfxET69rH3HGTHk0fTZrI5BtOY2DAdMjXbYXzk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=F06t5CBX49VvhTPmwW+6xfsjxykVsCK9l0e7l9mP4YVlUJvzNND1eDnZORchEyZE/8xTHGXo4tzF/dwT6lPNqktxUGccAbdxcPkyaQ0dHoHd2xB06CJDOMB5mHfyMKi9QCZ0tFRE5YXJi0HzbEfTLBEiJ58ccSeTeCz9+zT0qb4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lunn.ch; spf=pass smtp.mailfrom=lunn.ch; dkim=pass (1024-bit key) header.d=lunn.ch header.i=@lunn.ch header.b=Zj5gM0Tj; arc=none smtp.client-ip=156.67.10.101 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lunn.ch Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=lunn.ch Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=lunn.ch header.i=@lunn.ch header.b="Zj5gM0Tj" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lunn.ch; s=20171124; h=In-Reply-To:Content-Disposition:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:From:Sender:Reply-To:Subject: Date:Message-ID:To:Cc:MIME-Version:Content-Type:Content-Transfer-Encoding: Content-ID:Content-Description:Content-Disposition:In-Reply-To:References; bh=q16INdj5Bbx7Rja1/wsZxQcnDm7VEmJ4xMzfrpXcfTA=; b=Zj5gM0TjUHWgkWrn0VgshTJyG6 VsSLwYUNIQvtrEPzfdfJSdnfInL7t6WY+dgsGdIY26w2L3Y8iuq0ANSedXTEtPeAC+ouQnvXKZ+AN T2FYKGsqzriKN6YwAFOsc83XhgWmRpQvIvAH0/cBt2LNLejps5AuB4GlSwqL5V8ct0eA=; Received: from andrew by vps0.lunn.ch with local (Exim 4.94.2) (envelope-from ) id 1w2qyD-00CCig-G7; Wed, 18 Mar 2026 14:29:57 +0100 Date: Wed, 18 Mar 2026 14:29:57 +0100 From: Andrew Lunn To: Li Jun Cc: gregory.clement@bootlin.com, sebastian.hesselbarth@gmail.com, linux@armlinux.org.uk, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] arm: mvebu: fix null pointer when access Message-ID: References: <20260318075324.2477118-1-lijun01@kylinos.cn> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260318075324.2477118-1-lijun01@kylinos.cn> On Wed, Mar 18, 2026 at 03:53:24PM +0800, Li Jun wrote: > the kzalloc may return null pointer, will cause kernel panic. The kernel is a dead man walking if the memory allocation fails, so that coherency cannot be configured correctly. A panic at least gives a stack trace, rather than a nearly undebuggable deadlock later on. Not all kernel panics are bad. You need to look at the context, the comments in the code. Andrew