Messages in this thread | | | Date | Tue, 18 Nov 2008 16:06:59 +0100 | From | Ingo Molnar <> | Subject | Re: [PATCH] x86: alternative identifier for Phoenix BIOS |
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* Alan Cox <alan@lxorguk.ukuu.org.uk> wrote:
> On Sat, 15 Nov 2008 17:55:20 -0800 > "H. Peter Anvin" <hpa@zytor.com> wrote: > > > Philipp Kohlbecher wrote: > > > My laptop (a Samsung X20) contains a Phoenix BIOS and would benefit from > > > patch 1e22436eba84edfec9c25e5a25d09062c4f91ca9 (x86: reserve low 64K on > > > AMI and Phoenix BIOS boxen). > > > > > > However, according to /sys/class/dmi/id/bios_vendor, the BIOS identifies > > > its vendor as "Phoenix Technologies LTD" (sans the comma). > > > > Given that AMI and Phoenix combined is something like 80% of the BIOS > > market, if not more, it might simply be easier to make it unconditional, > > or make it a whitelist instead. > > Far more useful would be to make people aware of the problem. If the > BIOS is scribbling in the low 64K of RAM not just BIOS areas, and > doing so outside of ACPI marked areas they need to fix the BIOS > ASAP. If they leave their BIOSes randomly scribbling in operating > system memory areas then as with previous (hardware related) cases > of vendors knowingly shipping corrupting equipment they'll be > building up a huge class action legal liability. > > As such making sure the vendor knows in a way they cannot deny is a > very useful activity.
CONFIG_X86_CHECK_BIOS_CORRUPTION=y will do that, it prints:
Corrupted low memory at 0x1000 (4096 phys) = 0x1234 Memory corruption detected in low memory < stack trace >
if enough distros turn it on (at least in their debug kernels) it creates the right kind of user pressure.
This debug feature to catch BIOS-generated low-memory corruption is already upstream.
Ingo
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