Date: Tue, 12 Mar 1996 13:52:29 +1100 (EST) From: David Dawes <dawes@rf900.physics.usyd.edu.au> To: j@uriah.heep.sax.de (J Wunsch) Cc: freebsd-current@FreeBSD.org Subject: Re: system() broken while mmap()ing something Message-ID: <199603120252.NAA01086@rf900.physics.usyd.edu.au> In-Reply-To: <199603112212.XAA00295@uriah.heep.sax.de> from "J Wunsch" at Mar 11, 96 11:12:34 pm
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>> I've attached a test program that does demonstrate a problem. The program
>> isn't what I originally had in mind. This one mmaps the BIOS, and in three
>> phases it "writes" to it, and reads back the result. Since the BIOS is
>> read-only, mismatches should occur in each phase, however on FreeBSD-current,
>> the last phase (after a system("/bin/ls > /tmp/l")) reports no mismatches.
>> On FreeBSD-2.0.5, mismatches are correctly reported at each phase.
>
>The results for me are:
>
>kernel version David's program XServer w/ Xkb enabled
> runs okay? doesn't crash system?
>
>Mar 9, 1996 No. No.
>
>Feb 3, 1996 Yes. No.
>
>Mar, 1995
>(GENERIC 2.0.5?) Yes. Yes.
>
>So, the test program only seems to show the most evil behaviour.
The test program also works fine with 2.1.0-RELEASE.
I've never seen the Xserver with Xkb crash the system on -current. I
just find that the server doesn't work correctly regarding usage of the
mmaped /dev/mem/area. For most servers this means a blank display.
The only -current kernels I've tried are the 960303 snap and one from
around 9 March (which fixed most of the probably unrelated panics I saw
with the 960303 version). I did see a panic with the 9 March version
at 2am this morning when /etc/daily started (good thing I was up watching
the Cricket World Cup :-).
David
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