Bug in v7 backup or printf on 11/34

Jack Jansen jack at vu44.UUCP
Fri Jan 6 05:58:43 AEST 1984


There is a bug in the v7 backup routine. It cannot backup things
like    movb    .....,(r3)+
This isn't a problem for C programs, but the first few lines of
doprnt.s read something like
     sub     $128.+12.,sp
     ....
     mov     sp,r3
and later on, the 128 bytes following r3 are used as a buffer.
So, if you have the hard luck that you enter doprnt with 'sp'
pointing to an existing location, but sp-128. not, you're in
trouble.
 I didn't bother fixing the bug (altough I would be interested in
a fix, of course), I just added a
	tst	(sp)
instruction after the 'sub' in doprnt.s

	Jack Jansen, VU Amsterdam, mcvax!vu44!jack



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