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Date: Wed, 12 Jul 1995 05:21:38 +1000
From: Bruce Evans <bde@zeta.org.au>
Message-Id: <199507111921.FAA26105@godzilla.zeta.org.au>
To: bde@freefall.cdrom.com, rgrimes@gndrsh.aac.dev.com
Subject: Re: cvs commit: src/sys/i386/isa syscons.c syscons.h
Cc: CVS-commiters@freefall.cdrom.com, cvs-sys@freefall.cdrom.com
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>>   Modified:    sys/i386/isa  syscons.c syscons.h
>>   Log:
>>   Fix races in scstart().  q_to_b() wasn't called at spltty(), so there
>>   were two races:
>>   - q_to_b() might unexpectedly return 0 (e.g, after a keyboard signal
>>     flushes the output queue and isn't echoed).  ansi_put() interprets
>>     0 bytes as 4GB...

>Might this fix the problem that has been reported as ``switching VT's
>at a rate of 1 a second for about 2 to 3 minutes will result in a system
>hang?''

Probably not.  I think attempting to print 4GB will just print some garbage
and then panic when an unmapped page is hit.

Bruce