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 454C6C433F5 for ; Wed, 12 Jan 2022 18:35:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1356327AbiALSfc (ORCPT ); Wed, 12 Jan 2022 13:35:32 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48342 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1356295AbiALSf2 (ORCPT ); Wed, 12 Jan 2022 13:35:28 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B5DFFC06173F; Wed, 12 Jan 2022 10:35:27 -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 D4839619FF; Wed, 12 Jan 2022 18:35:26 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id ADB3BC36AE5; Wed, 12 Jan 2022 18:35:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1642012526; bh=tR5cYmecoyO98RJuj0F+0SYvT7MUWJ1IrdeUSbPm5c8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=tVXkyMo44DPuThg3+etMdPiKtsHEgk5EW6REFoIazT6KtZjfaTMsYYHZGV2LLp5J0 PiAT8tOvCkp/Fhu2AfAzo3j5B2dPdFcWyZ47jQfXSrlS5DmDhPJd850uAPfUz0MaOB f2ICKV9/TM/PXXTy26JULoMRlCD361wcNnmDSS/aGAJpj6tNaqR+bNLhYiDGcXzOQB tyJfgFO6nyQenDbj92eww8zvFLjrBSo1DaPvVYPXD5imjt0fAniW3EX98r1RFfvKXL KxD4GlWlCGepG3nSKK0VLVMSLQCqK9IiiPQ+hZSmjQGmYhzXsibhjdsZfhyr2t2tJC JS8jm05kNnF2A== Date: Wed, 12 Jan 2022 20:35:15 +0200 From: Jarkko Sakkinen To: Tadeusz Struk Cc: Jason Gunthorpe , linux-integrity@vger.kernel.org, stable@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 1/2] tpm: Fix error handling in async work Message-ID: References: <20220111055228.1830-1-tstruk@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220111055228.1830-1-tstruk@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jan 10, 2022 at 09:52:27PM -0800, Tadeusz Struk wrote: > When an invalid (non existing) handle is used in a TPM command, > that uses the resource manager interface (/dev/tpmrm0) the resource > manager tries to load it from its internal cache, but fails and > the tpm_dev_transmit returns an -EINVAL error to the caller. > The existing async handler doesn't handle these error cases > currently and the condition in the poll handler never returns > mask with EPOLLIN set. > The result is that the poll call blocks and the application gets stuck > until the user_read_timer wakes it up after 120 sec. > Change the tpm_dev_async_work function to handle error conditions > returned from tpm_dev_transmit they are also reflected in the poll mask > and a correct error code could passed back to the caller. > > Cc: Jarkko Sakkinen > Cc: Jason Gunthorpe > Cc: > Cc: > Cc: > Fixes: 9e1b74a63f77 ("tpm: add support for nonblocking operation") > Signed-off-by: Tadeusz Struk > --- > Changed in v2: > - Updated commit message with better problem description > - Fixed typeos. > Changed in v3: > - Added a comment to tpm_dev_async_work. > - Updated commit message. > --- > drivers/char/tpm/tpm-dev-common.c | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/drivers/char/tpm/tpm-dev-common.c b/drivers/char/tpm/tpm-dev-common.c > index c08cbb306636..50df8f09ff79 100644 > --- a/drivers/char/tpm/tpm-dev-common.c > +++ b/drivers/char/tpm/tpm-dev-common.c > @@ -69,7 +69,13 @@ static void tpm_dev_async_work(struct work_struct *work) > ret = tpm_dev_transmit(priv->chip, priv->space, priv->data_buffer, > sizeof(priv->data_buffer)); > tpm_put_ops(priv->chip); > - if (ret > 0) { > + > + /* > + * If ret is > 0 then tpm_dev_transmit returned the size of the > + * response. If ret is < 0 then tpm_dev_transmit failed and > + * returned a return code. > + */ > + if (ret != 0) { > priv->response_length = ret; > mod_timer(&priv->user_read_timer, jiffies + (120 * HZ)); > } > -- > 2.30.2 > These look good to me! Thank you. I'm in process of compiling a test kernel. /Jarkko