From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 CD8631F0E3F; Sat, 21 Dec 2024 13:27:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734787636; cv=none; b=e3Afjwxzi4w6aDdTl68zlo5U8QJLYiZXqEHPeLIBIF61bWfNAE/Qxi1OTkkgSShrLB8hPsrF+jnJgp4wC0dvAH2LZz+ZqtfTW7cEBbHeZNtNcGDe7hrRVrQ4ODCZzw3tae9u1ivqabB4qZOtjzPafFgJWVh7TQ+MO+YJaZTOgk4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734787636; c=relaxed/simple; bh=IrQfaWG0S34gcasdLD+2ibOyBB7hqqsBOKwtZ+kfCs8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=VhUgyM6FUZX+s3aMq4pjfDi1n6PcW0H7cFvbczzPlUA4LxwvP5LPBAm7tt4kOJ45C51G4dmEhV7PUaZZ58kRiC3t/GdF743CiKKlKeKEgygnywZASJHJ/8ZXpgugrnlt2EaCuRCHthp6XDfyPsrn8ffBCQMiuoWc9hbAkUYXi+Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=yr8zFJfZ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="yr8zFJfZ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id ED831C4CECE; Sat, 21 Dec 2024 13:27:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1734787635; bh=IrQfaWG0S34gcasdLD+2ibOyBB7hqqsBOKwtZ+kfCs8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=yr8zFJfZjEmZZook/3jPtNQfYRcxXtLDJO/X4x8LDORU0crcb6tnEHE0BlvdAxVqh m0M94gEHk94RTy9UWDyIdMP1nZgsPPI7J44yqvsOqqqqotxUB0tkCtqfNRNq5XCCSp W95UGOwfamKPYPTlHQJVURVoOmumBXQxoiKoANFU= Date: Sat, 21 Dec 2024 14:27:11 +0100 From: Greg KH To: Nihar Chaithanya Cc: dpenkler@gmail.com, dan.carpenter@linaro.org, roheetchavan@gmail.com, arnd@arndb.de, linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org, skhan@linuxfoundation.org Subject: Re: [PATCH v2] staging: gpib: cb7210: Add error handling Message-ID: <2024122150-overarch-cough-a86b@gregkh> References: <20241221091121.35476-1-niharchaithanya@gmail.com> <2024122119-unclamped-affecting-0e0a@gregkh> <2024122133-outskirts-causing-099a@gregkh> Precedence: bulk X-Mailing-List: linux-staging@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Sat, Dec 21, 2024 at 04:59:31PM +0530, Nihar Chaithanya wrote: > > On 21/12/24 15:13, Greg KH wrote: > > On Sat, Dec 21, 2024 at 10:25:41AM +0100, Greg KH wrote: > > > On Sat, Dec 21, 2024 at 02:41:25PM +0530, Nihar Chaithanya wrote: > > > > The if condition in cb7210_init_module() would always fail as > > > > the value of err is constantly 0. The function > > > > cb_pcmcia_init_module() can be refactored into a single line, > > > > and can be replaced entirely with pcmcia_register_driver(). > > > > > > > > Replace redundant cb_pcmcia_init_module() with > > > > pcmcia_register_driver() which returns appropriate error code if > > > > it fails. Handle the error if it fails and print the debug message. > > > > > > > > This issue was reported by Coverity Scan. > > > > Report: > > > > CID 1635894: (#1 of 1): 'Constant' variable guards dead code (DEADCODE) > > > > dead_error_line: Execution cannot reach this statement: return -1;. > > > > > > > > Signed-off-by: Nihar Chaithanya > > > > --- > > > > v1 --> v2: Replaced the redundant cb_pcmcia_init_module() with > > > > pcmcia_register_driver(). > > > > > > > > drivers/staging/gpib/cb7210/cb7210.c | 13 ++++--------- > > > > 1 file changed, 4 insertions(+), 9 deletions(-) > > > > > > > > diff --git a/drivers/staging/gpib/cb7210/cb7210.c b/drivers/staging/gpib/cb7210/cb7210.c > > > > index 63df7f3eb3f3..abd6632d8448 100644 > > > > --- a/drivers/staging/gpib/cb7210/cb7210.c > > > > +++ b/drivers/staging/gpib/cb7210/cb7210.c > > > > @@ -1351,12 +1351,6 @@ static struct pcmcia_driver cb_gpib_cs_driver = { > > > > .resume = cb_gpib_resume, > > > > }; > > > > -int cb_pcmcia_init_module(void) > > > > -{ > > > > - pcmcia_register_driver(&cb_gpib_cs_driver); > > > > - return 0; > > > > -} > > > > - > > > > void cb_pcmcia_cleanup_module(void) > > > > { > > > > DEBUG(0, "cb_gpib_cs: unloading\n"); > > > > @@ -1526,11 +1520,12 @@ static int __init cb7210_init_module(void) > > > > gpib_register_driver(&cb_pcmcia_interface, THIS_MODULE); > > > > gpib_register_driver(&cb_pcmcia_accel_interface, THIS_MODULE); > > > > gpib_register_driver(&cb_pcmcia_unaccel_interface, THIS_MODULE); > > > > - err += cb_pcmcia_init_module(); > > > > + err = pcmcia_register_driver(&cb_gpib_cs_driver); > > > > #endif > > > > - if (err) > > > > + if (err) { > > > > + pr_err("cb7210: registering PCMCIA driver with the bus core failed\n"); > > > > return -1; > > > Not your issue, but "-1" is not a valid error number, shouldn't this be > > > returning a real error (i.e. the one that was returned?) > > > > > > And err += is crazy, thanks for removing that, BUT you forgot to unwind > > > the previous functions so now if pcmcia_register_driver() fails, you > > > have a semi-registered system and then the module will unload (as init > > > fails) and bad things will happen :( > So I need be unregistering the driver if the pcmcia_register_driver() fails > right? Yes, all of them. thanks, greg k-h