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 8E439C433FE for ; Thu, 13 Oct 2022 05:17:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229655AbiJMFR5 (ORCPT ); Thu, 13 Oct 2022 01:17:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38136 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229563AbiJMFRw (ORCPT ); Thu, 13 Oct 2022 01:17:52 -0400 Received: from mail-pj1-x1035.google.com (mail-pj1-x1035.google.com [IPv6:2607:f8b0:4864:20::1035]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B4986DFB4F for ; Wed, 12 Oct 2022 22:17:51 -0700 (PDT) Received: by mail-pj1-x1035.google.com with SMTP id l1-20020a17090a72c100b0020a6949a66aso991774pjk.1 for ; Wed, 12 Oct 2022 22:17:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=in-reply-to:references:from:subject:cc:to:message-id:date :content-transfer-encoding:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=mgmqesKftHWSE00KVINL+qar8kr975tlk3Np4LjyX8Q=; b=Ap67t8eBPka2yMd7er9LDEs53x9v8JVEDtBdMR14a5SlrrytCuZCiyXjVhUVmZeCOE Y+P8ejPt2qamBIN0SlFvfbWOfI1+7X/fsyDYM++cnobTCDK3e5M142w4mRYlA8lCSSd1 NxAAsJbOaZ+NHaii/y2O2oK7LdXxvmrjDHGwVROe+OklbH7ywWZyDesmK8fsFT2ZJeN2 rUdJwKU4hY32fcKMCix/GVwYKw6z6Ge30bLaKQkYjUc/aTKiCN2b9ZtFbtzONnx8TMmj jGppR2hoMipONWwNwyacr2pI07px6dIozZPD+zawdGUpwc9raHrn4jVntGsgkhllI6wp 7jMw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:references:from:subject:cc:to:message-id:date :content-transfer-encoding:mime-version:x-gm-message-state:from:to :cc:subject:date:message-id:reply-to; bh=mgmqesKftHWSE00KVINL+qar8kr975tlk3Np4LjyX8Q=; b=zoyChMHcw9XRI7nF4kgsvHcDZ7f1mcbFQmPgVxAz4t9v75hq6e7o97hc/w0Fq3mOlt TSMgbVtR0hPHaEEOrivl6viPGnI2XjtjMg26E2WskdsRjNqHvALoxD9UgJK5WXx14GZE NEa13o3IUpONXQ+hPo3NK6S48fwUKKvjz0rEo+VqSzmmLUK9TjlC6InDCOqEJoKPzk0G KQV0N67L5eXyiA7JZAyaulovY8pEXq60XAEgIXdnxUEg/9q+aqBWlL4tMKfxis3yfv8A qREfsnv0qCND7wgHnWEPEZRSoKH6ACDfbSB+vMAPHQGBRDVPuFp8HFpGK+wjcm9e7Tio pyCA== X-Gm-Message-State: ACrzQf3uA3T8XV/IZPp5Gx9OdM1d6RtSVutbPdmCOzCPsbEG2EYpnwIH X6o+S0PP2QF/TTzu7xVIGuQ= X-Google-Smtp-Source: AMsMyM7jUL85MKl03w4acrGr8UP5tMKsHerd1QVIEu6aZ/7f6V3fHuV49DgjCHZWgFyNZtXTFja00w== X-Received: by 2002:a17:902:e552:b0:179:e795:71c5 with SMTP id n18-20020a170902e55200b00179e79571c5mr32627906plf.57.1665638271270; Wed, 12 Oct 2022 22:17:51 -0700 (PDT) Received: from localhost ([202.173.165.98]) by smtp.gmail.com with ESMTPSA id e17-20020a17090301d100b00172e19c2fa9sm11720893plh.9.2022.10.12.22.17.40 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 12 Oct 2022 22:17:50 -0700 (PDT) Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=UTF-8 Date: Thu, 13 Oct 2022 15:17:37 +1000 Message-Id: To: "Jason A. Donenfeld" , "Guenter Roeck" Cc: "Michael Ellerman" , "Linus Torvalds" , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: Re: [GIT PULL] Please pull powerpc/linux.git powerpc-6.1-1 tag From: "Nicholas Piggin" X-Mailer: aerc 0.11.0 References: <87edvhntv0.fsf@mpe.ellerman.id.au> <20221012141827.GA2405914@roeck-us.net> <20221012164452.GA2990467@roeck-us.net> <20221012174826.GB2995920@roeck-us.net> In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu Oct 13, 2022 at 4:37 AM AEST, Jason A. Donenfeld wrote: > On Wed, Oct 12, 2022 at 10:48:26AM -0700, Guenter Roeck wrote: > > > I've also managed to not hit this bug a few times. When it triggers, > > > after "kprobes: kprobe jump-optimization is enabled. All kprobes are > > > optimized if possible.", there's a long hang - tens seconds before it > > > continues. When it doesn't trigger, there's no hang at that point in = the > > > boot process. > > >=20 > >=20 > > That probably explains why my attempts to bisect the problem were > > unsuccessful. > > So I just did this: > > diff --git a/drivers/char/random.c b/drivers/char/random.c > index 2fe28eeb2f38..2d70bc09db7e 100644 > --- a/drivers/char/random.c > +++ b/drivers/char/random.c > @@ -1212,6 +1212,7 @@ static void __cold try_to_generate_entropy(void) > struct entropy_timer_state stack; > unsigned int i, num_different =3D 0; > unsigned long last =3D random_get_entropy(); > + return; > > for (i =3D 0; i < NUM_TRIAL_SAMPLES - 1; ++i) { > stack.entropy =3D random_get_entropy(); > > And then ran it, and now we get the lockup from the idle process: Yep that rules out the random code. And really if it was calling schedule() it shouldn't be getting a softlockup anyway. Thanks, Nick