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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 37060C38142 for ; Tue, 31 Jan 2023 18:23:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230261AbjAaSXH (ORCPT ); Tue, 31 Jan 2023 13:23:07 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50108 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229693AbjAaSXG (ORCPT ); Tue, 31 Jan 2023 13:23:06 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 61F3523C41; Tue, 31 Jan 2023 10:23:05 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id EDA176160B; Tue, 31 Jan 2023 18:23:04 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8090AC433EF; Tue, 31 Jan 2023 18:23:03 +0000 (UTC) Authentication-Results: smtp.kernel.org; dkim=pass (1024-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b="EqE57RqB" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zx2c4.com; s=20210105; t=1675189381; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=QpT46/u33S6NMwaECaUNHvlKPKaadrNKuyaF728fjXY=; b=EqE57RqBg6yn6nqrbDD80y4P2xlhLeKSyO8QWqqmnMPBmM519vHQb/nKWIimx4BHJYM9EF J9I5Hn4ZFYQ/etGHFpZOd4th2Z2/hQnXz0eZMgqSCC/XbwosLjoQvVN2spclerlvgpeZg8 1NwncALk2I8WyjLNZCZ5qyFSGyvSS1o= Received: by mail.zx2c4.com (ZX2C4 Mail Server) with ESMTPSA id 7e409f5c (TLSv1.3:TLS_AES_256_GCM_SHA384:256:NO); Tue, 31 Jan 2023 18:23:01 +0000 (UTC) Date: Tue, 31 Jan 2023 19:23:00 +0100 From: "Jason A. Donenfeld" To: Justin He Cc: Ard Biesheuvel , Huacai Chen , "linux-efi@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Alexandru Elisei Subject: Re: [PATCH 0/2] Fix boot hang issue on Ampere Emag server Message-ID: References: <20230131040355.3116-1-justin.he@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-efi@vger.kernel.org On Tue, Jan 31, 2023 at 03:21:39PM +0000, Justin He wrote: > Hi Ard, > > > -----Original Message----- > > From: Ard Biesheuvel > > Sent: Tuesday, January 31, 2023 3:19 PM > > To: Justin He ; Jason A. Donenfeld > > Cc: Huacai Chen ; linux-efi@vger.kernel.org; > > linux-kernel@vger.kernel.org; Alexandru Elisei > > Subject: Re: [PATCH 0/2] Fix boot hang issue on Ampere Emag server > > > > (cc Jason for awareness) > > > > On Tue, 31 Jan 2023 at 05:04, Jia He wrote: > > > > > > I met a hung task warning and then kernel was hung forever with latest > > > kernel on an Ampere Emag server. > > > > > > The root cause is kernel was hung when invoking an efi rts call to > > > set the RandomSeed variable during the booting stage. The > > > arch_efi_call_virt call (set_variable) was never returned and then caused the > > hung task error. > > > > > > > Given that EFI variables work on this platform (as far as I know), the problem > > may be that we are calling SetVariable() too early. > > > > Could you double check whether setting variables works as expected? > > You can use efibootmgr -t 10 as root (for example) to set the boot timeout, and > > check whether the new value is retained after a reboot (efibootmgr will print > > the current value for you) > > > > Could you also please share the kernel log up until the point where it hangs? > > > The set_variable seems to be ok in 5.19+: > root@:~# efibootmgr -t 10 > BootCurrent: 0000 > Timeout: 10 seconds I think what we want to learn is whether efibootmgr -t 10 works in the latest RC. If not, it would suggest the issue isn't with the seed setting, but with some other unrelated change. Can you run efibootmgr -t 10 (or whatever) again on a kernel where you've commented out these lines in efi.c inside of efisubsys_init(): if (efi_rt_services_supported(EFI_RT_SUPPORTED_SET_VARIABLE)) execute_with_initialized_rng(&refresh_nv_rng_seed_nb); --> // if (efi_rt_services_supported(EFI_RT_SUPPORTED_SET_VARIABLE)) // execute_with_initialized_rng(&refresh_nv_rng_seed_nb); Or something like that. Jason