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:	Sun, 14 Sep 2014 21:31:16 -0700
From:	Grant Likely <>
To:	Catalin Marinas <>
Cc:	"" <>,
	"Rafael J. Wysocki" <>,
	Mark Rutland <>,
	Olof Johansson <>,
	"" <>,
	Arnd Bergmann <>,
	Sudeep Holla <>,
	Will Deacon <>,
	Jason Cooper <>,
	Marc Zyngier <>,
	Bjorn Helgaas <>,
	Daniel Lezcano <>,
	Mark Brown <>, Rob Herring <>,
	Robert Richter <>,
	Lv Zheng <>,
	Robert Moore <>,
	Lorenzo Pieralisi <>,
	Liviu Dudau <>,
	Randy Dunlap <>,
	Charles Garcia-Tobin <>,
	"" <>,
	"" <>,
	"" <>
Subject: Re: [PATCH v3 00/17] Introduce ACPI for ARM64 based on ACPI 5.1

On Thu, 11 Sep 2014 16:37:39 +0100, Catalin Marinas <> wrote:
> On Thu, Sep 11, 2014 at 02:29:34PM +0100, Grant Likely wrote:
> > Regarding the requests to refactor ACPICA to work better for ARM. I
> > completely agree that it should be done, but I do not think it should be
> > a prerequisite to getting this core support merged. That kind of
> > refactoring is far easier to justify when it has immediate improvement
> > on the mainline codebase, and it gives us a working baseline to test
> > against. Doing it the other way around just makes things harder.
> I have to disagree here. As I said, I'm perfectly fine with refactoring
> happening later but I'm not happy with compiling in code with undefined
> behaviour on ARM that may actually be executed at run-time.
> I'm being told one of the main advantages of ACPI is forward
> compatibility: running older kernels on newer hardware (potentially with
> newer ACPI version tables). ACPI 5.1 includes partial support for ARM
> but the S and C states are not defined yet. We therefore assume that
> hardware vendors deploying servers using ACPI would not provide such
> yet to be defined information in ACPI 5.1 tables.

We're good on this front. ACPI-future platforms aren't allowed to use
new features when booting an older kernel. ACPI has a mechanism to check
version numbers. Similarly, when ACPI-future defines those states, the
kernel shouldn't expose them to an older platform.

> What if in a year time we get ACPI 5.2 or 6 (or an errata update)
> covering the S and C states for ARM? I would expect hardware vendors
> to take advantage and provide such information in ACPI tables. Can we
> guarantee that a kernel with the current ACPI patches wouldn't blow up
> when it tries to interpret the new tables?

Yes - at least as much as we can guarantee anything in systems

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

Powered by blists - more mailing lists