Am 12.11.19 um 08:29 schrieb Uwe Kleine-König:
> On Tue, Nov 12, 2019 at 06:23:47AM +0100, Greg Kroah-Hartman wrote:
>> On Mon, Nov 11, 2019 at 09:10:41PM +0100, Andreas Färber wrote:
>>> Am 11.11.19 um 07:40 schrieb Greg Kroah-Hartman:
>>>> On Mon, Nov 11, 2019 at 06:42:05AM +0100, Andreas Färber wrote:
>>>>> Am 11.11.19 um 06:27 schrieb Greg Kroah-Hartman:
>>>>>> On Mon, Nov 11, 2019 at 05:56:09AM +0100, Andreas Färber wrote:
>>>>>>> Use of soc_device_to_device() in driver modules causes a build failure.
>>>>>>> Given that the helper is nicely documented in include/linux/sys_soc.h,
>>>>>>> let's export it as GPL symbol.
>>>>>>
>>>>>> I thought we were fixing the soc drivers to not need this. What
>>>>>> happened to that effort? I thought I had patches in my tree (or
>>>>>> someone's tree) that did some of this work already, such that this
>>>>>> symbol isn't needed anymore.
>>>>>
>>>>> I do still see this function used in next-20191108 in drivers/soc/.
>>>>>
>>>>> I'll be happy to adjust my RFC driver if someone points me to how!
>>>>
>>>> Look at c31e73121f4c ("base: soc: Handle custom soc information sysfs
>>>> entries") for how you can just use the default attributes for the soc to
>>>> create the needed sysfs files, instead of having to do it "by hand"
>>>> which is racy and incorrect.
>>>
>>> Unrelated.
>>>
>>>>> Given the current struct layout, a type cast might work (but ugly).
>>>>> Or if we stay with my current RFC driver design, we could use the
>>>>> platform_device instead of the soc_device (which would clutter the
>>>>> screen more than "soc soc0:") or resort to pr_info() w/o device.
>>>>
>>>> Ick, no, don't cast blindly. What do you need the pointer for? Is this
>>>> for in-tree code?
>>>
>>> No, an RFC patchset: https://patchwork.kernel.org/cover/11224261/
>>>
>>> As I indicated above, I used it for a dev_info(), which I can easily
>>> avoid by using pr_info() instead:
>>>
>>> diff --git a/drivers/soc/realtek/chip.c b/drivers/soc/realtek/chip.c
>>> index e5078c6731fd..f9380e831659 100644
>>> --- a/drivers/soc/realtek/chip.c
>>> +++ b/drivers/soc/realtek/chip.c
>>> @@ -178,8 +178,7 @@ static int rtd_soc_probe(struct platform_device *pdev)
>>>
>>> platform_set_drvdata(pdev, soc_dev);
>>>
>>> - dev_info(soc_device_to_device(soc_dev),
>>> - "%s %s (0x%08x) rev %s (0x%08x) detected\n",
>>> + pr_info("%s %s (0x%08x) rev %s (0x%08x) detected\n",
>>> soc_dev_attr->family, soc_dev_attr->soc_id, chip_id,
>>> soc_dev_attr->revision, chip_rev);
>>
>> First off, the driver should not be spitting out noise for when all goes
>> well like this :)
>
> I didn't follow the discussion closely, but I think I want to object
> here a bit. While I agree that each driver emitting some stuff to the
> log buffer is hardly helpful, seeing the exact SoC details is indeed
> useful at times. With my Debian kernel team member hat on, I'd say
> keep this information. This way the SoC details make it into kernel bug
> reports without effort on our side.
Seconded. For example, RTD1295 will support LSADC only from revision B00
on (and it's not the first time I'm seeing such things in the industry).
So if a user complains, it will be helpful to see that information.
Referencing your Amlogic review, with all due respect for its authors,
the common framework here just lets that information evaporate into the
deeps of sysfs. People who know can check /sys/bus/soc/devices/soc0, but
ordinary users will at most upload dmesg output to a Bugzilla ticket.
And it was precisely info-level boot output from the Amlogic GX driver
that made me aware of this common framework and inspired me to later
contribute such a driver elsewhere myself. That's not a bad effect. ;)
So if anything, we should standardize that output and move it into
soc_device_register(): "<family> <soc_id> [rev <revision>] detected"
with suitable NULL checks? (what I did above for Realtek, minus hex)
The info level seems correct to me - it allows people to use a different
log_level if they only care about warnings or errors on the console;
it's not debug info for that driver, except in my case the accompanying
hex numbers that I'd be happy to drop in favor of standardization.
Another aspect here is that the overall amount of soc_device_register()
users is just an estimated one third above the analysis shared before.
In particular server platforms, be it arm64 or x86_64, that potentially
have more than one SoC integrated in a multi-socket configuration, don't
feed into this soc bus at all! Therefore my comment that
dev_info()-printed "soc soc0:" is kind of useless if there's only one
SoC on those boards. I'm not aware of any tool or a more common file
aggregating this information, certainly not /proc/cpuinfo and I'm not
aware of any special "lssoc" tool either. And if there's no ACPI/DMI
driver feeding support-relevant information into this framework to be
generally useful, I don't expect the big distros to spend time on
improving its usability.
So if we move info output into base/soc.c, we could continue using
dev_info() with "soc"-grep'able prefix in the hopes that someday we'll
have more than one soc device on the bus and will need to distinguish;
otherwise yes, pr_info() would change the output format for Amlogic (and
so would a harmonization of the text), but does anyone really care in
practice? Tools shouldn't be relying on its output format, and humans
will understand equally either way.
Finally, arch/arm seems unique in that it has the machine_desc mechanism
that allows individual SoCs to force creating their soc_device early and
using it as parent for further DT-created platform_devices. With arm64
we've lost that ability, and nios2 is not using it either.
A bad side effect (with SUSE hat on) is that this parent design pattern
does not allow to build such drivers as modules, which means that distro
configs using arm's multi-platform, e.g., CONFIG_ARCH_MULTI_V7 will get
unnecessary code creep as new platforms get added over time (beyond the
basic clk, pinctrl, tty and maybe timer).
Even if it were possible to call into a driver module that early, using
it as parent would seem to imply that all the references by its children
would not allow to unload the module, which I'd consider a flawed design
for such an "optional" read-once driver. If we want the device hierarchy
to have a soc root then most DT based platforms will have a /soc DT node
anyway (although no device_type = "soc") that we probably could have a
device registered for in common code rather than each SoC platform
handling that differently? That might then make soc_register_device()
not the creator of the device (if pre-existent) but the supplier of data
to that core device, which should then allow to unload the data provider
with just the sysfs data disappearing until re-inserted (speeding up the
develop-and-test cycle on say not-so-resource-constrained platforms).
On the other hand, one might argue that such information should just be
parsed by EBBR-conformant bootloaders and be passed to the kernel via
standard UEFI interfaces and DMI tables. But I'm not aware of Barebox
having implemented any of that yet, and even for U-Boot (e.g., Realtek
based consumer devices...) not everyone has the GPL sources or tools to
update their bootloader. So, having the kernel we control gather
information relevant to kernel developers does make some sense to me.
Thoughts?
Regards,
Andreas
P.S. Sorry that a seemingly trivial one-line 0-day fix derailed into
this fundamental use case discussion.
arch/arm/mach-ep93xx/core.c: soc_dev = soc_device_register(soc_dev_attr);
arch/arm/mach-imx/cpu.c: soc_dev = soc_device_register(soc_dev_attr);
arch/arm/mach-mvebu/mvebu-soc-id.c: soc_dev =
soc_device_register(soc_dev_attr);
arch/arm/mach-mxs/mach-mxs.c: soc_dev = soc_device_register(soc_dev_attr);
arch/arm/mach-omap2/id.c: soc_dev = soc_device_register(soc_dev_attr);
arch/arm/mach-tegra/tegra.c: struct device *parent =
tegra_soc_device_register();
arch/arm/mach-zynq/common.c: soc_dev = soc_device_register(soc_dev_attr);
arch/nios2/platform/platform.c: soc_dev =
soc_device_register(soc_dev_attr);
drivers/soc/amlogic/meson-gx-socinfo.c: soc_dev =
soc_device_register(soc_dev_attr);
drivers/soc/amlogic/meson-mx-socinfo.c: soc_dev =
soc_device_register(soc_dev_attr);
drivers/soc/atmel/soc.c: soc_dev = soc_device_register(soc_dev_attr);
drivers/soc/bcm/brcmstb/common.c: soc_dev =
soc_device_register(soc_dev_attr);
drivers/soc/fsl/guts.c: soc_dev = soc_device_register(&soc_dev_attr);
drivers/soc/imx/soc-imx-scu.c: soc_dev = soc_device_register(soc_dev_attr);
drivers/soc/imx/soc-imx8.c: soc_dev = soc_device_register(soc_dev_attr);
drivers/soc/qcom/socinfo.c: qs->soc_dev =
soc_device_register(&qs->attr);
drivers/soc/realtek/chip.c: soc_dev = soc_device_register(soc_dev_attr);
drivers/soc/renesas/renesas-soc.c: soc_dev =
soc_device_register(soc_dev_attr);
drivers/soc/samsung/exynos-chipid.c: soc_dev =
soc_device_register(soc_dev_attr);
drivers/soc/tegra/fuse/fuse-tegra.c: dev = soc_device_register(attr);
drivers/soc/ux500/ux500-soc-id.c: soc_dev =
soc_device_register(soc_dev_attr);
drivers/soc/versatile/soc-integrator.c: soc_dev =
soc_device_register(soc_dev_attr);
drivers/soc/versatile/soc-realview.c: soc_dev =
soc_device_register(soc_dev_attr);
--
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
GF: Felix Imendörffer
HRB 36809 (AG Nürnberg)
Hi,
following the proposal at the last Device Tree Evolution call I'd like to
propose an agenda for Wednesday that Steve could complement (see below).
You may want to add or remove agenda items...
We need to synchronize with "kernel day" agenda as some of us need to
attend both events.
Cheers
FF
4h: DeviceTree Lead Project
-
to be defined by Steve McIntyre
4h: DependableBoot Lead Project
-
1h: status and deliverable planning for next cycle
-
EBBR specs next steps? compliance.
-
UEFI SecureBoot
-
EFI payload authentication
-
UEFI Secure variable handling
-
Linux kernel UEFI variable caching and updates (as a capsule
update)
-
Define other ‘must-have’ UEFI features (i.e DBT??)
-
firmwareTPM
-
UEFI MeasuredBoot
-
32bits UEFI support
-
Qemu EBBR
-
implications of our work on EDKII
-
1h: Robust boot "research" & PoC for next cycle
-
anti-brickable incl. TF-A: “philosophy” and hints to implement
-
UEFI watchdog: when to call UEFI exit-boot-services?
-
2h: overall boot architecture evolution
-
interdependencies between TF-A, TrustZone (SPM, OPTEE, SCPI), OS,
SCMI - many things are happening and I am not sure we understand tricky
interactions that may result in race conditions (for instance
SCMI in OPTEE
kernel and its relations with UEFI runtime services). The idea
is to try to
identify the hairiest issues that we should analyze post Connect.
-
Boot orchestration
-
"Contracts" / list all the assumptions
--
François-Frédéric Ozog | *Director Linaro Edge & Fog Computing Group*
T: +33.67221.6485
francois.ozog(a)linaro.org | Skype: ffozog
Evidently I've managed to overlap the EBBR monthly with the 96Boards SC monthly meeting. Does anyone object to rescheduling the EBBR monthly to be the 1st Tuesday of each month? (starting next week).
g.
________________________________________
From: Grant Likely
Sent: 12 March 2019 11:38
To: rob.herring(a)linaro.org; Ben Eckermann; Dong Wei; perobins(a)redhat.com; ryan.harkin(a)linaro.org; Udit Kumar; wmills(a)ti.com; nicolas.dechesne(a)linaro.org; Tom Rini; Peter Robinson; Tony Wu; tom.rini(a)konsulko.com; Yang Zhang; Nicusor Penisoara; Andreas Färber; Michal Simek; David Rusling; Peter Jones; Mark Brown; Matthias Brugger; daniel.thompson(a)linaro.org
Subject: EBBR Monthly - 4th Tuesday
When: 28 May 2019 15:00-16:00.
Where: WebEx
Biweekly EBBR status call
- Online meeting: https://arm-onsite.webex.com/meet/gralik01
- Phone
- Access code: 809 053 990
- 1-408-792-6300 Call-in toll number (US/Canada)
- 1-877-668-4490 Call-in toll-free number (US/Canada)
- 44-203-478-5285 Call-in toll number (UK)
- 08-002061177 Call-in toll-free (UK)
More access numbers:
https://arm-onsite.webex.com/cmp3300/webcomponents/widget/globalcallin/glob…
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
Quick poll: who would be interested in a U-Boot/EBBR plugfest event collocates with ELC-EU this year (week of 28th Oct)?
In the EBBR meetings we’ve tossed around the idea of an U-Boot/EBBR plugfest to work out compatibility issues between OS distros and upstream U-Boot SBC support. The idea is to get a number of SBCs supported by mainline U-Boot with UEFI features turned on, along with U-Boot & OS developers and hold a 1 day debug sprint to work out how many platforms can work with ‘stock’ OS images. Details to be worked out if this looks viable.
I’ve asked the LF folks if they have space on either Thursday 31st Oct or Friday 1st Nov. They are checking availability, but no commitments have been made. It would help to know if this date and location is feasible.
What do you think? Would you come to a plug fest attached to ELC-EU? Would you be interested in helping to organise? Or, is there another time & location that would work better?
Cheers,
g.
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
Hi,
I'm now working on implementing UEFI secure boot on U-boot,
in particular, adding "dbt" (timestamp-based revocation) support
as described in UEFI specification, section 32.5.1 paragraph#7.
# To be honest, the description is quite hard for me to understand.
# I've got what it means only after reading corresponding EDK2 code.
My question is: Is there any signing tool on linux, with which
we can directly "timestamp" a PE image with RFC3161-compliant timestamp?
I know that "signtool" in Microsoft's Windows SDK has this feature,
but I wonder what tool major distros use for this purpose.
(They also need to use windows for creating their own distributions?)
I don't think it is very difficult to add the feature to existing
tools like "sbsign," but it would be nice to use "proven" tools
for testing.
Thanks,
-Takahiro Akashi
I hope somebody in the kernel community is looking at making sure the piece
of memory is RO:
https://wikileaks.org/ciav7p1/cms/page_36896783.html
Anyone knows about that?
Cheers
FF
--
François-Frédéric Ozog | *Director Linaro Edge & Fog Computing Group*
T: +33.67221.6485
francois.ozog(a)linaro.org | Skype: ffozog
Hi All,
Monthly EBBR meeting is scheduled for today. So far I've got the
following agenda items:
- Update on Devicetree Evolution project at Linaro (System Devicetree,
separate dts repo, spec updates)
- EBBR Plugfest options and planning committee
- Policy on DTBs shipped with OS -- does EBBR need to address this
explicitly?
Email if you have any other items.
g.
________________________________________
From: Grant Likely
Sent: 12 March 2019 11:38
To: rob.herring(a)linaro.org; Ben Eckermann; Dong Wei;
perobins(a)redhat.com; ryan.harkin(a)linaro.org; Udit Kumar; wmills(a)ti.com;
nicolas.dechesne(a)linaro.org; Tom Rini; Peter Robinson; Tony Wu;
tom.rini(a)konsulko.com; Yang Zhang; daniel.thompson(a)linaro.org; Nicusor
Penisoara; Andreas Färber; Michal Simek; David Rusling; Peter Jones;
Mark Brown; Matthias Brugger
Subject: EBBR Monthly - 4th Tuesday
When: 25 June 2019 15:00-16:00.
Where: WebEx
Biweekly EBBR status call
- Online meeting: https://arm-onsite.webex.com/meet/gralik01
- Phone
- Access code: 809 053 990
- 1-408-792-6300 Call-in toll number (US/Canada)
- 1-877-668-4490 Call-in toll-free number (US/Canada)
- 44-203-478-5285 Call-in toll number (UK)
- 08-002061177 Call-in toll-free (UK)
More access numbers:
https://arm-onsite.webex.com/cmp3300/webcomponents/widget/globalcallin/glob…
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
So trying to summarize the DT side track discussion in a different thread:
(
Shall we organize a virtual design sprint before the end of the month?
I'd like to create a section from the discussion in Boot Flows documen
)
I - Current situation is:
- DT provided by Linux kernel because it was “easier” and there was no
upstream home
- ACPI is provided by firmware (to make things simple), non secure OS can
patch them in case of issues, SecureBoot prevents those patches
OS provided DT is a cool developer facility in the context of floating DT
bindings and lack of proper upstream project. But conceptually speaking, DT
is not an OS thing and is not a firmware thing: it is a board thing that
may be massaged by firmware and consumed by OS.
With EBBR we seek a clean and salable solution that make the DT as simple
as ACPI.
II - Desired DT for EBBR policy
1) "upstream" DT
1.1) who provides DT
Board vendor make a <reference DT> that describes every hardware piece,
firmware provides a DT to OS, OS may be able to validate the DT but not
override it in secureboot production. For security and boot latency
consideration, firmware may actually need two DTs: a stripped version from
<reference DT> to operate on the minimal set of devices it want to bring up
the OS (say the <firmware DT>), a pruned/adapted version from <reference
DT> , ie without devices firmware wants to control and conforms to EBBR
spec (say the <OS DT>).
1.2) upstream <reference DT>
The board reference DT> shall be valid regardless of the firmware (may be
trusted firmware, uboot, edkII, linuxBoot...) not mentioning OS! There are
many candidates but I start to think Linaro could host a DT and EBBR
companion community project: "EBBR DTs" that will contain all the
<reference DT> from every EBBR compliant board vendor.
(Other boards can continue the mess, it is irrelevant EBBR, and us.
SecureBoot, MeasuredBoot implementations will assume EBBR compliance)
2) who sign what with what key
If we think of the following use case: Silicon Vendor provides a chip, a
board vendor provides a board, ABB builds a controller, Caterpillar creates
a mining truck with the controller, Rio Tinto operates the trck.
One possible (just designed to show case the need of various keysets) trust
chain is:
- Board key db is loaded with a board vendor, ABB and caterpillar certs.
- Trusted firmware: ABB doesn't want to deal with this, so the Board
vendor provides and signs trusted firmware, with key_tf.
- untrusted firmware: ABB selects the <firmware DT> and <OS DT> signs
both DTs and firmware with key_firmware. Trusted Firmware will validate the
signatures as key DB is loaded with ABB cert.
- grub and the OS: Caterpillar signs them with key_os (What is signed
and how it is verified is still a big discussion topic and the origin of
the sidetrack on DT)
- applications: Rio Tinto insurance company may be given the authority
to sign hosted OPTEE applications with a different key.
3) OS payload signing and verification: was the original topic of the
discussion and shall continue in the other thread.
4) operational considerations
In non SecureBoot environment, DT can be patched by OS (same as ACPI).
OS may decide to verify validaty of provided DT (mechanism yet to be
defined)
"dtb=" kernel command line parameter is still possible in non secure boot
but forbiden in secureBoot.
Le mer. 5 juin 2019 à 08:35, Tom Rini <trini(a)konsulko.com> a écrit :
> On Wed, Jun 05, 2019 at 08:29:37AM +0200, Ard Biesheuvel wrote:
> > On Wed, 5 Jun 2019 at 00:34, Tom Rini <trini(a)konsulko.com> wrote:
> > >
> > > On Tue, Jun 04, 2019 at 06:14:16PM -0400, Francois Ozog wrote:
> > > > Le mar. 4 juin 2019 à 17:31, Tom Rini <trini(a)konsulko.com> a écrit :
> > > >
> > ...
> > > > I think it may be good to validate but not provide. There is no Linux
> > > > provided ACPI table right ? So I get the point to validate a DT.
> > >
> > > There's "Linux provided" ACPI tables when someone has to decompile,
> > > fixup and re-compile their DSDT files.
> > >
> > > Or perhaps a better way to think of it is that yes, there's "Linux
> > > provided ACPI tables" when vendors are developing their hardware and
> > > correcting their ACPI tables. Same thing with DT, by and large (as
> > > overlays and secure boot are a can of worms to worry about later).
> >
> > Secure boot enabled Linux does not permit this model. Side loading of
> > DSDTs/SSDTs is disabled by the hardening patchset that all the distros
> > carry for secure boot enabled kernels.
>
> That sounds a little broken then. It should be doable so long as the
> files are signed appropriately. It's also rarer because the ACPI tables
> are functionally validated before they're put into production. That's
> largely the case here, except when we're talking about updating them for
> new support or just like the case above, fixing a problem with them.
>
> --
> Tom
>
Hi
I was tasked to come back to Linaro TSC with an answer on Linaro and kernel
lockdown for UEFI SecureBoot, hence the call for feed back.
So I did some research... The kernel lockdown does not seem to be a full
consensus yet:
https://news.ycombinator.com/item?id=16761827
I agree with Linus
<https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1654795.html>:
we should distinguish UEFI SecureBoot and how to achieve a highly secured
Operating System runtime environment.
1) UEFI SecureBoot: boot chain trust
My understanding is that UEFI SecureBoot ensures that the booted UEFI
payload is trusted.
Should the UEFI payload (a Linux OS) not be that secure it is irrelevant to
the UEFI SecureBoot itself.
2) Trustable Linux system
A trustable Linux system is UEFI SecureBoot loaded and make addition
precautions to avoid attacks and attacks to the boot chain.
If we think of a highly secured Linux, the kernel lockdown is certainly
highly desirable but just as many other aspects:
- iommu must be enabled to protect against DMA attacks
- sysfs needs to be cleaned (access rights are not tight enough)
- debugfs need to be banned (problem: some production control operations
are wrongly in debugfs)
-SE Linux
- IMA
- ...
In my view, we shall not mix the goal and the means to achieve the goal....
For instance, kernel lock down prevents iopl system call which prevents UIO
and UIO enabled DPDK drivers.
A vendor may evaluate that the security level achieved without kernel
lockdown is in line with its objectives to achieve a trustable Linux
system: loadable modules disabled by the kernel, kernel embedded initramfs,
IMA...
As a result, UEFI SecureBoot to secure the boot chain combined with
selected Linux hardening can achieve a Trustable Linux System.
As per LEDGE both are highly important I would say that 1) does not need
2) to be complete.
The way to achieve 2) is project dependent.
The LEDGE RP will need kernel lockdown because we will allow loadable
modules.
SoC vendors deriving a product out of LEDGE RP, may take different
provisions as per customer projects, in particular, they may derive a
version without lockdown but still trustable.
There is an additional twists to this.
UEFI SecureBoot does not mandate Microsoft signed keys.
But if you use Microsoft keys, I was warned that Microsoft may revoke
certificates for non locked down systems.
This warning illustrate the absolute need for independence related to UEFI
SecureBoot: I can't imagine a system in Europe (particularly in
military) prevented to boot because Microsoft revoked a certificate!!!
Cheers
FF
--
François-Frédéric Ozog | *Director Linaro Edge & Fog Computing Group*
T: +33.67221.6485
francois.ozog(a)linaro.org | Skype: ffozog
EBBR reqfers to chapter 2.6 "Requirements" of the UEFI spec if no
special exceptions are provided.
The UEFI spec requires to support HII resources in the LoadImage() boot
service. If an image contains a HII resource it has to install the
EFI_HII_PACKAGE_LIST_PROTOCOL on the image handle. But chapter 2.6 does
not generally require support for HII protocols.
It would be helpful to clarify if supporting HII resources in the
LoadImage() boot service is required to be EBBR compliant. I would
prefer EBBR not to require this as it adds a lot of complexity to the
firmware.
The UEFI spec further requires supporting loading images via the
EFI_LOAD_FILE_PROTOCOL and the EFI_LOAD_FILE2_PROTOCOL. This might also
be a candidate for skipping in the EBBR.
Best regards
Heinrich Schuchardt
