From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wr1-f41.google.com (mail-wr1-f41.google.com [209.85.221.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3857A190076 for ; Wed, 5 Jun 2024 10:15:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.41 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717582510; cv=none; b=nNgAgqrrXoPWnLIfRR2a4+FeZy+KQyeznQh1ihCN1xBz8S9jaIkHnE1fITDVf+G4zhBc2jjS90lVYMtNiGZJWKmPJF3GpVhciEaDY2cLbyRmmYlePVgfaGohBCb+ZcGbnfAmJfoLfuMptgbeqQpOscQArZ2R1ssBjV4WbcVJXr0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717582510; c=relaxed/simple; bh=HtGAESEB5A4ifQnCilFXSr6+jFmp7L7fR5ovmv6VOLM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ai4hAGUsdcMN8XyzGn5hhptmvYjOTe0bxKZxllCU3w07fWodAc+DOnu8ts9RRww1QcNuGYMhEGx0k4+f8khFJBPPRxEy3QvewDZeENY1gE/dTakxwHayZi+3CzVi4TntXLSxMDyDmEwT+qoLbu0fmzIWwadMc5s7g1hWRchukPQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=suse.com; spf=pass smtp.mailfrom=suse.com; dkim=pass (2048-bit key) header.d=suse.com header.i=@suse.com header.b=P+S9AzXT; arc=none smtp.client-ip=209.85.221.41 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=suse.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=suse.com header.i=@suse.com header.b="P+S9AzXT" Received: by mail-wr1-f41.google.com with SMTP id ffacd0b85a97d-35dceef429bso404905f8f.1 for ; Wed, 05 Jun 2024 03:15:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=google; t=1717582506; x=1718187306; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=KxyCUVpRxT9r4WcxUsE/s7yKzpPU3+jmGl5p/EECmd8=; b=P+S9AzXT4qUzdg3Q8sFz20HLKR3Y48m0Cjf4GiZLRdtHEAB1cSed60Wcm0N83kSpMR snoi6SRAc18AOnjuBZBdxS46x1Q3KYD7ZRr9wZQY/ipa/4WaXjWYJ4Z2tRnrTqkYIhTd PbT5uIASqHG3c0+xpX12vLEVfzoF0jubg1I2opMfsNu6TJ/+XAtLjFONE10t7eM7eZtt 5364hpudXMjzX+v3KGI9fcNcJHIe3nxhH5HUcFQLmh9Y4lnHCr52MdEgQYNhZJ1uwe6t sprBOlsxX7RXWOIj/yZ9IBEG0QqpYpb0UpRp2YHvKCFG3egK+8VC/AqMIl037TvgF2Cb duvQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1717582506; x=1718187306; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=KxyCUVpRxT9r4WcxUsE/s7yKzpPU3+jmGl5p/EECmd8=; b=B7bVb/46/C+oPTarLKvLQGsVzS/b3r/3rDEus3e2O23dhE7+VuSgU3GBiegWo1B7e6 j1EgmlxQ3v6OeDkunRZNbG+q6dFgQtO66mPVwX3uvqQuYqIp5dFkNIsp34EsqpYx3jvg KpadYEOmUxkcTp5joc4WK1jz/No72glLG3yitwo0z6Ipfkag/iSwHZnva0oAexlJN2h2 vOwODBIqnSSC6nptwnG+0NCltfTzJVuFhh5Rrqcnlb4ANyd3RJXU71+KzRvWUusUZUKJ tnbSje59kqqVZOAz4ZSG3o40YtjWD1guGiYmCGFSP7a7lxQpitftpbQNIgwhHrjEjwZZ dToQ== X-Forwarded-Encrypted: i=1; AJvYcCVgS7r9ut02ZTeY4zFakQuLJhjy31ABy1cZPZJWTnQ/jFzzuIzR6+0FkzEpKugeTU88cZWd9WUxINwuDCMxJCJIwlQPqIDocETrjVme X-Gm-Message-State: AOJu0YzCh9TrFrqZi9fPCTi3hNRjo9GinrR0BlNKLSnDuC7mvulXHeJj XWtLQH++WIVUkquFTFnWO/6R4uAaM4mpx/F74qn0O+8YkSYlpVlVEI0RAEr0KsnwYLOXhj9+tAG W X-Google-Smtp-Source: AGHT+IHlsyaSK+z56mrklM5jykYlSjK8tWb2sNaVuZk0ryedcd43/wbhrOlsz6C5ljOByT6CxIWoQQ== X-Received: by 2002:adf:fcca:0:b0:35a:e093:7682 with SMTP id ffacd0b85a97d-35e7c591326mr4996354f8f.30.1717582506511; Wed, 05 Jun 2024 03:15:06 -0700 (PDT) Received: from pathway.suse.cz ([176.114.240.50]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-703599758b6sm1426482b3a.173.2024.06.05.03.15.02 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 05 Jun 2024 03:15:06 -0700 (PDT) Date: Wed, 5 Jun 2024 12:14:56 +0200 From: Petr Mladek To: Juri Lelli Cc: Sergey Senozhatsky , Steven Rostedt , linux-kernel@vger.kernel.org, John Ogness Subject: Re: [PATCH linux-next] printk: nbcon: Fix nbcon_cpu_emergency_flush() when preemptible Message-ID: References: <87zfrzvhsp.fsf@jogness.linutronix.de> 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: On Wed 2024-06-05 12:10:50, Petr Mladek wrote: > On Wed 2024-06-05 11:57:34, John Ogness wrote: > > nbcon_cpu_emergency_flush() can be called in a preemptible > > context. In that case the CPU is not in an emergency state. > > However, in order to see that the CPU is not in an emergency > > state (accessing the per-cpu variable), preemption must be > > disabled. > > > > Disable preemption when checking the CPU state. > > > > Reported-by: Juri Lelli > > Closes: https://lore.kernel.org/aqkcpca4vgadxc3yzcu74xwq3grslj5m43f3eb5fcs23yo2gy4@gcsnqcts5tos > > Fixes: 46a1379208b7 ("printk: nbcon: Implement emergency sections") > > Signed-off-by: John Ogness > > Great catch! > > Reviewed-by: Petr Mladek > > I am going to push it... Juri, should/could I add your Tested-by ? Best Regards, Petr