Re: [PATCH v2 01/10] PCI/LUO: Register with Liveupdate Orchestrator

Chris Li
2025-09-30T23:41:57Z

On Tue, Sep 30, 2025 at 8:31 AM Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
>
> On Tue, Sep 16, 2025 at 12:45:09AM -0700, Chris Li wrote:
> > Register PCI subsystem with the Liveupdate Orchestrator
> > and provide noop liveupdate callbacks.
> >
> > Signed-off-by: Chris Li <chrisl@kernel.org>
> > ---
> > MAINTAINERS | 2 ++
> > drivers/pci/Makefile | 1 +
> > drivers/pci/liveupdate.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++
> > 3 files changed, 57 insertions(+)
> >
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index 91cec3288cc81aea199f730924eee1f5fda1fd72..85749a5da69f88544ccc749e9d723b1b54c0e3b7 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -14014,11 +14014,13 @@ F: tools/testing/selftests/livepatch/
> >
> > LIVE UPDATE
> > M: Pasha Tatashin <pasha.tatashin@soleen.com>
> > +M: Chris Li <chrisl@kernel.org>
> > L: linux-kernel@vger.kernel.org
> > S: Maintained
> > F: Documentation/ABI/testing/sysfs-kernel-liveupdate
> > F: Documentation/admin-guide/liveupdate.rst
> > F: drivers/misc/liveupdate/
> > +F: drivers/pci/liveupdate/
> > F: include/linux/liveupdate.h
> > F: include/uapi/linux/liveupdate.h
> > F: tools/testing/selftests/liveupdate/
> > diff --git a/drivers/pci/Makefile b/drivers/pci/Makefile
> > index 67647f1880fb8fb0629d680398f5b88d69aac660..aa1bac7aed7d12c641a6b55e56176fb3cdde4c91 100644
> > --- a/drivers/pci/Makefile
> > +++ b/drivers/pci/Makefile
> > @@ -37,6 +37,7 @@ obj-$(CONFIG_PCI_DOE) += doe.o
> > obj-$(CONFIG_PCI_DYNAMIC_OF_NODES) += of_property.o
> > obj-$(CONFIG_PCI_NPEM) += npem.o
> > obj-$(CONFIG_PCIE_TPH) += tph.o
> > +obj-$(CONFIG_LIVEUPDATE) += liveupdate.o
> >
> > # Endpoint library must be initialized before its users
> > obj-$(CONFIG_PCI_ENDPOINT) += endpoint/
> > diff --git a/drivers/pci/liveupdate.c b/drivers/pci/liveupdate.c
> > new file mode 100644
> > index 0000000000000000000000000000000000000000..86b4f3a2fb44781c6e323ba029db510450556fa9
> > --- /dev/null
> > +++ b/drivers/pci/liveupdate.c
> > @@ -0,0 +1,54 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +
> > +/*
> > + * Copyright (c) 2025, Google LLC.
> > + * Chris Li <chrisl@kernel.org>
> > + */
> > +
> > +#define pr_fmt(fmt) "PCI liveupdate: " fmt
> > +
> > +#include <linux/liveupdate.h>
> > +
> > +#define PCI_SUBSYSTEM_NAME "pci"
> > +
> > +static int pci_liveupdate_prepare(void *arg, u64 *data)
> > +{
> > + pr_info("prepare data[%llx]\n", *data);
>
> You do know that's a security bug, right?

Right, it is useful during debugging and inspecting the preserved data.

My bad and will remove the raw pointer.

>
> Please don't do this, even in "debug" code, as it can escape into the
> wild...

Fully agree. Thanks for catching it.

Chris