Re: port-i386/43655 (integer division by zero delivers SIGFPE with wrong siginfo code on i386)

[Taylor R Campbell <campbell+netbsd%mumble.net@localhost>]

The following reply was made to PR port-i386/43655; it has been noted by GNATS.

From: Taylor R Campbell <campbell+netbsd%mumble.net@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: port-i386-maintainer%netbsd.org@localhost, 
kern-bug-people%netbsd.org@localhost,
        netbsd-bugs%netbsd.org@localhost, gnats-admin%netbsd.org@localhost,
        martin%NetBSD.org@localhost
Subject: Re: port-i386/43655 (integer division by zero delivers SIGFPE with 
wrong siginfo code on i386)
Date: Fri, 23 Jul 2010 15:12:23 +0000

    Date: Fri, 23 Jul 2010 07:44:39 +0000 (UTC)
    From: martin%NetBSD.org@localhost
 
    arch specific problem
 
 I'm cc'ing port-i386-maintainer because it looks like amd64 has the
 same problem, from this snippet in amd64/amd64/trap.c:
 
                 case T_DIVIDE|T_USER:
                         ksi.ksi_code = FPE_FLTDIV;
 
 T_DIVIDE is the code delivered by trap 0 in amd64/amd64/vector.S,
 which is the trap for integer division by zero.  I think changing that
 and the analogous line in i386/i386/trap.c to use FPE_INTDIV should
 fix the problem, but I haven't tested to confirm this.  FPE_FLTDIV is
 delivered for floating-point division by zero separately, in
 i386/isa/npx.c for i386 and in amd64/amd64/fpu.c for amd64.
 
 Nearby in both trap.c files is FPE_FLTOVF for integer overflow (traps
 4 and 5), and, in i386/i386/trap.c, FPE_INTOVF for FPU exceptions
 (trap #x10, in what seems to be an unusual case, when NNPX = 0).  This
 code needs to exchange some INTs and FLTs, methinks.