linux-kernel - Re: [PATCH v14 0/9] Address error and recovery for AER and DPC

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]

Date:   Mon, 30 Apr 2018 17:40:02 -0500
From:   Bjorn Helgaas <helgaas@...nel.org>
To:     poza@...eaurora.org
Cc:     Bjorn Helgaas <bhelgaas@...gle.com>,
        Philippe Ombredanne <pombredanne@...b.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Kate Stewart <kstewart@...uxfoundation.org>,
        linux-pci@...r.kernel.org, linux-kernel@...r.kernel.org,
        Dongdong Liu <liudongdong3@...wei.com>,
        Keith Busch <keith.busch@...el.com>, Wei Zhang <wzhang@...com>,
        Sinan Kaya <okaya@...eaurora.org>,
        Timur Tabi <timur@...eaurora.org>
Subject: Re: [PATCH v14 0/9] Address error and recovery for AER and DPC

On Thu, Apr 26, 2018 at 11:00:52AM +0530, poza@...eaurora.org wrote:
> On 2018-04-23 20:53, Oza Pawandeep wrote:
> > This patch set brings in error handling support for DPC
> > 
> > The current implementation of AER and error message broadcasting to the
> > EP driver is tightly coupled and limited to AER service driver.
> > It is important to factor out broadcasting and other link handling
> > callbacks. So that not only when AER gets triggered, but also when DPC
> > get
> > triggered (for e.g. ERR_FATAL), callbacks are handled appropriately.
> > 
> > The goal of the patch-set is:
> > DPC should handle the error handling and recovery similar to AER,
> > because
> > finally both are attempting recovery in some or the other way,
> > and for that error handling and recovery framework has to be loosely
> > coupled.
> > ...

> Hi Bjorn,
> 
> I know I need to rebase this whole patch-set to 4.17 now.
> 
> But before I do that, can you please help to comment.

My overall comment is that I think the series will be simpler and read
better if you first change AER to do remove/re-enumerate, before doing
anything with DPC.

This could be done by extracting just the AER part of "PCI/AER/DPC:
Align FATAL error handling for AER and DPC" (i.e., adding
pcie_do_fatal_recovery()) and moving that to be the very first patch.

It's a small change in terms of code size, but significant to drivers,
and it's really the core of the series, so it would be good to clearly
establish the policy of:

  ERR_NONFATAL => call driver recovery entry points
  ERR_FATAL    => remove and re-enumerate

before bringing DPC into the picture.

Then the subsequent patches would all be more or less mechanical
changes to make DPC follow the same model.

Bjorn