port-hppa/59305: kernel longjmp(9) fails to make setjmp(9) return 1

[campbell+netbsd%mumble.net@localhost]

>Number:         59305
>Category:       port-hppa
>Synopsis:       kernel longjmp(9) fails to make setjmp(9) return 1
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    port-hppa-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Apr 17 05:10:00 +0000 2025
>Originator:     Taylor R Campbell
>Release:        current
>Organization:
Hppa, Skip, and a Jump Foundation
>Environment:
>Description:
Kernel longjmp(9) is supposed to make setjmp(9) return 1 -- it doesn't take a second argument for the return value.  But the hppa code does this:

    303 	bv	%r0(%rp)
    304 	copy	%arg1,%ret0	/* Move return value to where it belongs. */

https://nxr.netbsd.org/xref/src/sys/arch/hppa/hppa/support.S?r=1.7#303

So it returns whatever garbage happens to be in a1.
>How-To-Repeat:
code inspection
mess with ddb, probably
>Fix:
Change

copy %arg1,%ret0

to however you spell `load immediate value 1 into %ret0' in hppaish.