re: port-sparc/55573: sparc testbed logs many "coprocessor instruction" messages

[matthew green <mrg%eterna.com.au@localhost>]

The following reply was made to PR port-sparc/55573; it has been noted by GNATS.

From: matthew green <mrg%eterna.com.au@localhost>
To: gnats-bugs%netbsd.org@localhost, martin%netbsd.org@localhost
Cc: port-sparc-maintainer%netbsd.org@localhost, gnats-admin%netbsd.org@localhost,
    netbsd-bugs%netbsd.org@localhost, gson%gson.org@localhost (Andreas Gustafsson)
Subject: re: port-sparc/55573: sparc testbed logs many "coprocessor instruction" messages
Date: Fri, 14 Aug 2020 19:20:27 +1000

 Martin Husemann writes:
 > The following reply was made to PR port-sparc/55573; it has been noted b=
 y GNATS.
 > =
 
 > From: Martin Husemann <martin%duskware.de@localhost>
 > To: gnats-bugs%netbsd.org@localhost
 > Cc: =
 
 > Subject: Re: port-sparc/55573: sparc testbed logs many "coprocessor
 >  instruction" messages
 > Date: Fri, 14 Aug 2020 10:30:23 +0200
 > =
 
 >  On Fri, Aug 14, 2020 at 08:15:01AM +0000, Andreas Gustafsson wrote:
 >  >   [  15.0167285] coprocessor instruction
 >  =
 
 >  This is a FPU instruction with FPU disabled (trap T_CPDISABLED),
 >  sending a SIGILL to the process.
 >  =
 
 >  Wild guess: the in-kernel FPU changes modified the FPU disable method
 >  so we now get this instead of T_FPDISABLED (which would cause us to do
 >  proper FPU fixup).
 
 i think you're confused.  i had to look up sparc copro,
 thinking similar:
 
 #define T_FPDISABLED    0x04    /* (5) fp instr while fp disabled */
 #define T_CPDISABLED    0x24    /* (5) coprocessor instr while disabled */
 
 are different.  the latter happens for stuff that access
 the "%cN" registers, but i can't find code that does that
 in openssl...
 
 search for "cp_disabled" in the v8 manual for details.
 
 
 .mrg.