linux-kernel - Re: [PATCH v2 11/11] Remove devres from pci

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <8734jtl3xm.ffs@tglx>
Date: Fri, 15 Nov 2024 01:46:13 +0100
From: Thomas Gleixner <tglx@...utronix.de>
To: Philipp Stanner <pstanner@...hat.com>, Damien Le Moal
 <dlemoal@...nel.org>, Niklas Cassel <cassel@...nel.org>, Basavaraj Natikar
 <basavaraj.natikar@....com>, Jiri Kosina <jikos@...nel.org>, Benjamin
 Tissoires <bentiss@...nel.org>, Arnd Bergmann <arnd@...db.de>, Greg
 Kroah-Hartman <gregkh@...uxfoundation.org>, Alex Dubov <oakad@...oo.com>,
 Sudarsana Kalluru <skalluru@...vell.com>, Manish Chopra
 <manishc@...vell.com>, Andrew Lunn <andrew+netdev@...n.ch>, "David S.
 Miller" <davem@...emloft.net>, Eric Dumazet <edumazet@...gle.com>, Jakub
 Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>, Rasesh Mody
 <rmody@...vell.com>, GR-Linux-NIC-Dev@...vell.com, Igor Mitsyanko
 <imitsyanko@...ntenna.com>, Sergey Matyukevich <geomatsi@...il.com>, Kalle
 Valo <kvalo@...nel.org>, Sanjay R Mehta <sanju.mehta@....com>, Shyam Sundar
 S K <Shyam-sundar.S-k@....com>, Jon Mason <jdmason@...zu.us>, Dave Jiang
 <dave.jiang@...el.com>, Allen Hubbe <allenbh@...il.com>, Bjorn Helgaas
 <bhelgaas@...gle.com>, Alex Williamson <alex.williamson@...hat.com>,
 Juergen Gross <jgross@...e.com>, Stefano Stabellini
 <sstabellini@...nel.org>, Oleksandr Tyshchenko
 <oleksandr_tyshchenko@...m.com>, Mario Limonciello
 <mario.limonciello@....com>, Chen Ni <nichen@...as.ac.cn>, Ricky Wu
 <ricky_wu@...ltek.com>, Al Viro <viro@...iv.linux.org.uk>, Breno Leitao
 <leitao@...ian.org>, Kevin Tian <kevin.tian@...el.com>, Mostafa Saleh
 <smostafa@...gle.com>, Andy Shevchenko
 <andriy.shevchenko@...ux.intel.com>, Jason Gunthorpe <jgg@...pe.ca>, Yi
 Liu <yi.l.liu@...el.com>, Kunwu Chan <chentao@...inos.cn>, Ankit Agrawal
 <ankita@...dia.com>, Christian Brauner <brauner@...nel.org>, Reinette
 Chatre <reinette.chatre@...el.com>, Eric
 Auger <eric.auger@...hat.com>, Ye Bin <yebin10@...wei.com>
Cc: linux-ide@...r.kernel.org, linux-kernel@...r.kernel.org,
 linux-input@...r.kernel.org, netdev@...r.kernel.org,
 linux-wireless@...r.kernel.org, ntb@...ts.linux.dev,
 linux-pci@...r.kernel.org, kvm@...r.kernel.org,
 xen-devel@...ts.xenproject.org
Subject: Re: [PATCH v2 11/11] Remove devres from pci_intx()

On Thu, Nov 14 2024 at 10:05, Philipp Stanner wrote:
> On Wed, 2024-11-13 at 17:22 +0100, Thomas Gleixner wrote:
>> On Wed, Nov 13 2024 at 13:41, Philipp Stanner wrote:
>> > pci_intx() is a hybrid function which can sometimes be managed
>> > through
>> > devres. This hybrid nature is undesirable.
>> > 
>> > Since all users of pci_intx() have by now been ported either to
>> > always-managed pcim_intx() or never-managed pci_intx_unmanaged(),
>> > the
>> > devres functionality can be removed from pci_intx().
>> > 
>> > Consequently, pci_intx_unmanaged() is now redundant, because
>> > pci_intx()
>> > itself is now unmanaged.
>> > 
>> > Remove the devres functionality from pci_intx(). Have all users of
>> > pci_intx_unmanaged() call pci_intx(). Remove pci_intx_unmanaged().
>> > 
>> > Signed-off-by: Philipp Stanner <pstanner@...hat.com>
>> > ---
>> >  drivers/misc/cardreader/rtsx_pcr.c            |  2 +-
>> >  drivers/misc/tifm_7xx1.c                      |  6 +--
>> >  .../net/ethernet/broadcom/bnx2x/bnx2x_main.c  |  2 +-
>> >  drivers/net/ethernet/brocade/bna/bnad.c       |  2 +-
>> >  drivers/ntb/hw/amd/ntb_hw_amd.c               |  4 +-
>> >  drivers/ntb/hw/intel/ntb_hw_gen1.c            |  2 +-
>> >  drivers/pci/devres.c                          |  4 +-
>> >  drivers/pci/msi/api.c                         |  2 +-
>> >  drivers/pci/msi/msi.c                         |  2 +-
>> >  drivers/pci/pci.c                             | 43 +--------------
>> > ----
>> >  drivers/vfio/pci/vfio_pci_core.c              |  2 +-
>> >  drivers/vfio/pci/vfio_pci_intrs.c             | 10 ++---
>> >  drivers/xen/xen-pciback/conf_space_header.c   |  2 +-
>> >  include/linux/pci.h                           |  1 -
>> >  14 files changed, 22 insertions(+), 62 deletions(-)
>> 
>> Now I'm utterly confused. This undoes the pci_intx_unmanaged() churn
>> which you carefully split into several patches first.
>
> Have you read the email I have linked?
>
> There is also the cover-letter (does anyone in the community ever read
> those?) which explicitly states:
>
> "Patch "Remove devres from pci_intx()" obviously reverts the previous
> patches that made drivers use pci_intx_unmanaged(). But this way it's
> easier to review and approve. It also makes sure that each checked out
> commit should provide correct behavior, not just the entire series as a
> whole."

I read it and I assume your intention was to force an eye on every use
case of pci_intx() and not just on those which need to be converted to
pcim_intx().

I'm not convinced that this is needed, but fair enough.