CVS commit: src/tests/kernel

["Taylor R Campbell" <riastradh%netbsd.org@localhost>]

Module Name:    src
Committed By:   riastradh
Date:           Fri Feb 28 16:08:19 UTC 2025

Modified Files:
        src/tests/kernel: Makefile t_execregs.c
        src/tests/kernel/arch/hppa: execregs.c execregs.h h_execregs.S

Log Message:
t_execregs: Test some more registers on hppa.

Looks like we're missing zeroing of floating-point registers too, as
well as the carry/borrow and divide step correction bits in the
semi-secret PSW register.

Unfortunately, while investigating this, I discovered that qemu's
hppa implementation doesn't implement fpu traps even if the fpu is
disabled (relevant bits of CR 10 `CCR', Coprocessor Control Register,
are cleared), which breaks fpu switching on NetBSD.  So I can't test
properly this myself.  We should maybe just change NetBSD from lazy
fpu switching to eager fpu switching anyway to thwart Spectre-class
attacks if there's any hppa hardware out there that does speculative
execution.

PR kern/59084: exec/spawn leaks register content


To generate a diff of this commit:
cvs rdiff -u -r1.85 -r1.86 src/tests/kernel/Makefile
cvs rdiff -u -r1.1 -r1.2 src/tests/kernel/t_execregs.c
cvs rdiff -u -r1.1 -r1.2 src/tests/kernel/arch/hppa/execregs.c \
    src/tests/kernel/arch/hppa/execregs.h \
    src/tests/kernel/arch/hppa/h_execregs.S

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.