Subject: Re: dynamic sysctl
To: NetBSD Kernel Technical Discussion List <email@example.com>
From: Andrew Brown <firstname.lastname@example.org>
Date: 11/15/2003 12:43:15
On Fri, Nov 14, 2003 at 06:37:14PM -0500, Greg A. Woods wrote:
>[ On Wednesday, November 12, 2003 at 22:39:10 (-0500), Andrew Brown wrote: ]
>> at one point, i groveled through all the archives, scribbled down all
>> the requirements people had for such a system, and either filed them
>> away as "no...not doing that" (a small number of them) or as "okay,
>> that part's done" (most of them), but i don't have that list any more.
>One related userland issue from my own ToDo list:
ah, yes, but only perhaps related to rewriting it...
>- /sbin/sysctl should use strvis(VIS_WHITE) or similar make sure any
> strings it prints are in a guaranteed canonical printable form. Of
> course it should also use strunvis() to allow the printable form to be
> used as "input" for -w too.
have you filed a pr on this?
>Currently the major need for this is with hw.cnmagic. The way
>/etc/rc.d/sysctl reads /etc/sysctl.conf makes it impossible to use some
>character sequences, and for those that do work having raw escape
>sequences in /etc/sysctl.conf is rather in-elegant to say the least.
>For example since the serial console on my AS4000 seems to ignore a
>BREAK signal, at least for the purposes of telling the kernel to drop
>into DDB, I decided to use a similar escape sequence for hw.cnmagic to
>the one used to get the attention of its console monitor processor
>("^]^]rcm"). Luckily this particular sequence works in /etc/sysctl.conf
>without need for quoting magic or other fancy tricks, but it still looks
>ugly (or is invisible) in any editor and the true value is hidden from
>view when displayed (and luckily the console monitor processor is smart
>enough to ignore output from the host console too else displaying the
>value on the console would cause it to drop into DDB! ;-):
># grep hw.cnmagic /etc/sysctl.conf | od -c
>0000000 h w . c n m a g i c = 035 035 d d b
># sysctl hw.cnmagic
>hw.cnmagic = ddb
># sysctl hw.cnmagic | od -c
>0000000 h w . c n m a g i c = 035 035 d
>0000020 d b \n
yes, well, that doesn't seem all that hard to fix, and it even strikes
me that perhaps you're not using current where i think it may already
have been. i can't tell right now, though...need coffee. :)
try current? even if just to see how it works?
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