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 C68B0226186; Wed, 11 Dec 2024 13:15:15 +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=1733922916; cv=none; b=df6xqetgaZx71kFzd1DL8E8cYF+OLAmRA62NT6pfaxxripQ+BIOmaXcbxw4umRk3BT6R9XGILENCV3bvdkCUWa5I16eibhPK6YSy12GWsQs3uswMh8kOrXuX2kd5Sc3ZjLVl2Nygn+u2wrf185YPonQLD7sK+st3KzsixiTOsNY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733922916; c=relaxed/simple; bh=IfWJJWrkHUieFv0YCu1Ku2mdZQjH8pVYpe8Efo+32Cc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=I0NSpk7hJqqeA4rC/f+ktL6X8XmSeJCqXMgvAWTBoIt/6Vp/DQjMEUHCOluS/N2SwjZ7HgRgzwSpnJX7bnAv7t5pS5dZfR0/+qTo4ZCm+kVFNFMOc37r0qPTLscCkxDGfTPhgoSR23MEgpGFKbqKqZXoKrHU8JenGpkBYya1BGo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=LwSrtw23; 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="LwSrtw23" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D5D81C4CED2; Wed, 11 Dec 2024 13:15:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1733922915; bh=IfWJJWrkHUieFv0YCu1Ku2mdZQjH8pVYpe8Efo+32Cc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=LwSrtw23YolMvTdE8Y20anTQx0v0u2ZZVMVUMW6MCzdH2cRY5E2U+LZ9V3S80TwY+ BeSGRCaVgSxe25dqPoNRM6DKefmewOuXyc3nB4ggnmP1087dizfF3uKHtcQ6FLaXTZ KvIkQNwfUz4FLjOknrRadzJop9pV/l0neRgeFjfM= Date: Wed, 11 Dec 2024 14:14:37 +0100 From: Greg KH To: Danilo Krummrich Cc: rafael@kernel.org, bhelgaas@google.com, ojeda@kernel.org, alex.gaynor@gmail.com, boqun.feng@gmail.com, gary@garyguo.net, bjorn3_gh@protonmail.com, benno.lossin@proton.me, tmgross@umich.edu, a.hindborg@samsung.com, aliceryhl@google.com, airlied@gmail.com, fujita.tomonori@gmail.com, lina@asahilina.net, pstanner@redhat.com, ajanulgu@redhat.com, lyude@redhat.com, robh@kernel.org, daniel.almeida@collabora.com, saravanak@google.com, dirk.behme@de.bosch.com, j@jannau.net, fabien.parent@linaro.org, chrisi.schrefl@gmail.com, rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, devicetree@vger.kernel.org Subject: Re: [PATCH v5 01/16] rust: pass module name to `Module::init` Message-ID: <2024121109-ample-retrain-bde0@gregkh> References: <20241210224947.23804-1-dakr@kernel.org> <20241210224947.23804-2-dakr@kernel.org> <2024121112-gala-skincare-c85e@gregkh> <2024121111-acquire-jarring-71af@gregkh> <2024121128-mutt-twice-acda@gregkh> <2024121131-carnival-cash-8c5f@gregkh> Precedence: bulk X-Mailing-List: devicetree@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, Dec 11, 2024 at 01:34:31PM +0100, Danilo Krummrich wrote: > On Wed, Dec 11, 2024 at 01:22:33PM +0100, Danilo Krummrich wrote: > > On Wed, Dec 11, 2024 at 12:05:10PM +0100, Greg KH wrote: > > > On Wed, Dec 11, 2024 at 11:59:54AM +0100, Greg KH wrote: > > > > On Wed, Dec 11, 2024 at 11:48:23AM +0100, Greg KH wrote: > > > > > On Wed, Dec 11, 2024 at 11:45:20AM +0100, Greg KH wrote: > > > > > > On Tue, Dec 10, 2024 at 11:46:28PM +0100, Danilo Krummrich wrote: > > > > > > > In a subsequent patch we introduce the `Registration` abstraction used > > > > > > > to register driver structures. Some subsystems require the module name on > > > > > > > driver registration (e.g. PCI in __pci_register_driver()), hence pass > > > > > > > the module name to `Module::init`. > > > > > > > > > > > > Nit, we don't need the NAME of the PCI driver (well, we do like it, but > > > > > > that's not the real thing), we want the pointer to the module structure > > > > > > in the register_driver call. > > > > > > > > > > > > Does this provide for that? I'm thinking it does, but it's not the > > > > > > "name" that is the issue here. > > > > > > > > > > Wait, no, you really do want the name, don't you. You refer to > > > > > "module.0" to get the module structure pointer (if I'm reading the code > > > > > right), but as you have that pointer already, why can't you just use > > > > > module->name there as well as you have a pointer to a valid module > > > > > structure that has the name already embedded in it. > > > > > > > > In digging further, it's used by the pci code to call into lower layers, > > > > but why it's using a different string other than the module name string > > > > is beyond me. Looks like this goes way back before git was around, and > > > > odds are it's my fault for something I wrote a long time ago. > > > > > > > > I'll see if I can just change the driver core to not need a name at all, > > > > and pull it from the module which would make all of this go away in the > > > > end. Odds are something will break but who knows... > > > > > > Nope, things break, the "name" is there to handle built-in modules (as > > > the module pointer will be NULL.) > > > > > > So what you really want is not the module->name (as I don't think that > > > will be set), but you want KBUILD_MODNAME which the build system sets. > > > > That's correct, and the reason why I pass through this name argument. > > > > Sorry I wasn't able to reply earlier to save you some time. > > > > > You shouldn't need to pass the name through all of the subsystems here, > > > just rely on the build system instead. > > > > > > Or does the Rust side not have KBUILD_MODNAME? > > > > AFAIK, it doesn't (or didn't have at the time I wrote the patch). > > > > @Miguel: Can we access KBUILD_MODNAME conveniently? > > Actually, I now remember there was another reason why I pass it through in > `Module::init`. > > Even if we had env!(KBUILD_MODNAME) already, I'd want to use it from the bus > abstraction code, e.g. rust/kernel/pci.rs. But since this is generic code, it > won't get the KBUILD_MODNAME from the module that is using the bus abstraction. Rust can't do that in a macro somehow that all pci rust drivers can pull from? thanks, greg k-h