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);
+ return 0;
+}
+
+static int pci_liveupdate_freeze(void *arg, u64 *data)
+{
+ pr_info("freeze data[%llx]\n", *data);
+ return 0;
+}
+
+static void pci_liveupdate_cancel(void *arg, u64 data)
+{
+ pr_info("cancel data[%llx]\n", data);
+}
+
+static void pci_liveupdate_finish(void *arg, u64 data)
+{
+ pr_info("finish data[%llx]\n", data);
+}
+
+struct liveupdate_subsystem pci_liveupdate_ops = {
+ .prepare = pci_liveupdate_prepare,
+ .freeze = pci_liveupdate_freeze,
+ .cancel = pci_liveupdate_cancel,
+ .finish = pci_liveupdate_finish,
+ .name = PCI_SUBSYSTEM_NAME,
+};
+
+static int __init pci_liveupdate_init(void)
+{
+ int ret;
+
+ ret = liveupdate_register_subsystem(&pci_liveupdate_ops);
+ if (ret && liveupdate_state_updated())
+ panic("PCI liveupdate: Register subsystem failed: %d", ret);
+ WARN(ret, "PCI liveupdate: Register subsystem failed %d", ret);
+ return 0;
+}
+late_initcall_sync(pci_liveupdate_init);
--
2.51.0.384.g4c02a37b29-googOn 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?
Please don't do this, even in "debug" code, as it can escape into the
wild...
thanks,
greg k-h
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
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);
> + return 0;
> +}
> +
> +static int pci_liveupdate_freeze(void *arg, u64 *data)
> +{
> + pr_info("freeze data[%llx]\n", *data);
> + return 0;
> +}
> +
> +static void pci_liveupdate_cancel(void *arg, u64 data)
> +{
> + pr_info("cancel data[%llx]\n", data);
> +}
> +
> +static void pci_liveupdate_finish(void *arg, u64 data)
> +{
> + pr_info("finish data[%llx]\n", data);
> +}
> +
> +struct liveupdate_subsystem pci_liveupdate_ops = {
> + .prepare = pci_liveupdate_prepare,
> + .freeze = pci_liveupdate_freeze,
> + .cancel = pci_liveupdate_cancel,
> + .finish = pci_liveupdate_finish,
> + .name = PCI_SUBSYSTEM_NAME,
> +};
> +
> +static int __init pci_liveupdate_init(void)
> +{
> + int ret;
> +
> + ret = liveupdate_register_subsystem(&pci_liveupdate_ops);
> + if (ret && liveupdate_state_updated())
> + panic("PCI liveupdate: Register subsystem failed: %d", ret);
> + WARN(ret, "PCI liveupdate: Register subsystem failed %d", ret);
But this didn't fail.
And you just crashed the box if panic-on-warn is enabled, so if some
test infrastructure builds this first patch, boom.
{sigh}
If you are going to do a "dummy" driver, please make it at least work
and not do anything bad.
thanks,
greg k-h
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);
> > + return 0;
> > +}
> > +
> > +static int pci_liveupdate_freeze(void *arg, u64 *data)
> > +{
> > + pr_info("freeze data[%llx]\n", *data);
> > + return 0;
> > +}
> > +
> > +static void pci_liveupdate_cancel(void *arg, u64 data)
> > +{
> > + pr_info("cancel data[%llx]\n", data);
> > +}
> > +
> > +static void pci_liveupdate_finish(void *arg, u64 data)
> > +{
> > + pr_info("finish data[%llx]\n", data);
> > +}
> > +
> > +struct liveupdate_subsystem pci_liveupdate_ops = {
> > + .prepare = pci_liveupdate_prepare,
> > + .freeze = pci_liveupdate_freeze,
> > + .cancel = pci_liveupdate_cancel,
> > + .finish = pci_liveupdate_finish,
> > + .name = PCI_SUBSYSTEM_NAME,
> > +};
> > +
> > +static int __init pci_liveupdate_init(void)
> > +{
> > + int ret;
> > +
> > + ret = liveupdate_register_subsystem(&pci_liveupdate_ops);
> > + if (ret && liveupdate_state_updated())
> > + panic("PCI liveupdate: Register subsystem failed: %d", ret);
> > + WARN(ret, "PCI liveupdate: Register subsystem failed %d", ret);
>
> But this didn't fail.
>
> And you just crashed the box if panic-on-warn is enabled, so if some
> test infrastructure builds this first patch, boom.
Sorry that the second WARN should be removed. That is something during
the rebase conflict resolution somehow slipped through the crack.
I will remove the second WARN() there.
Thanks for catching it.
>
> {sigh}
>
> If you are going to do a "dummy" driver, please make it at least work
> and not do anything bad.
I did test it with a real machine and real PCI device, but I did not
have the panic-on-warn.
Again my bad. Sorry about that.
Chris
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