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  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:	Sat, 03 Apr 2010 12:41:21 -0700
From: (Eric W. Biederman)
To:	Joerg Roedel <>
Cc:	Chris Wright <>,
	Joerg Roedel <>,,,,,,,
Subject: Re: [PATCH 3/4] Revert "x86: disable IOMMUs on kernel crash"

Joerg Roedel <> writes:

> On Sat, Apr 03, 2010 at 10:49:09AM -0700, Eric W. Biederman wrote:
>> Joerg Roedel <> writes:
>> > Another problem: This also breaks if the kdump kernel has no
>> > iommu-support.
>> Not a problem.  We require a lot of things of the kdump kernel,
>> and it is immediately apparent in a basic sanity test.
> Only if the sanity test is done on an iommu machine which I don't want
> to rely on.

That makes no sense.

The requirements on the kdump kernel has always been that it somehow
figure out to recover a machine that is in a random hardware state.
That requires drivers for the hardware, that is critical to the
machines operation.

The easy test for sysadmins is to do:
echo > /proc/sysrq-trigger

Anyone who thinks the result from one piece of hardware applies to
another is deluded.

We have been down the path of doing lots of things in the crashing
kernel with lkcd, in practice it was worthless in the event of real
world crashes.

kexec on panic isn't perfect but it at least is an architecture that
works often enough to be usable.  It does require testing to make certain
the basic code paths don't regress, but even so it is a lot easier
to maintain and keep useful than any alternative I know of.

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