Re: x86/stack protector: X86_32_LAZY_GS=n hangs kernel on old processors

From: tedheadster
Date: Tue Feb 13 2018 - 11:58:09 EST


> On Tue, Feb 13, 2018 at 11:40:17AM -0500, tedheadster wrote:
>> in your patch "x86: make lazy %gs optional on x86_32" were you able
>> to test it on really old processors? In 4.16.0-rc1, X86_32_LAZY_GS got
>> toggled from 'y' to 'n' in my default config because of changes to the
>> stack protector code. It hangs my ancient i486 test machine right
>> after 'Booting the kernel'.
>
> I didn't have access to an i486 at the time or ever since, so it
> wasn't tested there. If this is specific to i486, flagging it so in
> the config probably isn't the end of the world at this point.

Tejun,
I will be able to test this on other 32bit hardware at the end of
the week. Hopefully I'll be able to identify which processors it does
not work on (i486/i586/i686).

- Matthew