finding out where the text/bss sits

[Brandon S. Allbery KB8JRR]

As quoted from <3324 at unisoft.UUCP> by aegl at unisoft.UUCP (Tony Luck):
+---------------
| josef at nixpbe.nixdorf.de (josef Moellers) writes:
| >Rather than bus-error-ing, how about a look at ye olde symboltable?
| >usually
| >_start	sits at the very beginning of the program code
| >etext	sits at the end of the program code
| >edata	sits at the end of the initialized data
| >end	sits at the end of the uninitialized data (bss)
| 
| Ah, but do you trust the symbol not to lie to you? And do you trust your kernel
+---------------

_start, etext, edata, end are magic symbols defined by ld when it creates an
executable.  My experience is that trying to use one of those names for your
own global(s) causes the link to fail....

+---------------
| to do all the things that it is supposed to do when mapping a process? Its
| surprising how many systems have had odd little bugs that the "checkaddr"
| program has shown up  (from forgetting to write protect the processes text to
| leaving a read-write copy of the kernel mapped into each processes address
| space!!!).
+---------------

What and where is "checkaddr"?  (Respond via MAIL, please.  And try to provide
a UUCP-able source for it, since I can't FTP --- failing that, give me an idea
of the size so I can decide if it's worth risking getting someone upset at me
for using them to mail stufffrom  bitftp at pucc....)

++Brandon
-- 
Me: Brandon S. Allbery			    VHF/UHF: KB8JRR on 220, 2m, 440
Internet: allbery at NCoast.ORG		    Packet: KB8JRR @ WA8BXN
America OnLine: KB8JRR			    AMPR: KB8JRR.AmPR.ORG [44.70.4.88]
uunet!usenet.ins.cwru.edu!ncoast!allbery    Delphi: ALLBERY