When we're handling a pgm int in SIE, we want to return to the SIE cleanup after handling the exception. That's why we set pgm_old_psw to the sie_exit label in fixup_pgm_int. On nullifing pgm ints, fixup_pgm_int will also forward the old PSW such that we don't cause an pgm int again. However, when we want to return to the sie_exit label, this is not needed (since we've manually set pgm_old_psw). Instead, forwarding the PSW might cause us to skip an instruction or end up in the middle of an instruction. So, let's just skip the rest of the fixup in case we're inside SIE. Note that we're intentionally not fixing up the PSW in the guest; that's best left to the test at hand by registering their own psw fixup. Reviewed-by: Janosch Frank <frankja@xxxxxxxxxxxxx> Reviewed-by: Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20231106163738.1116942-5-nrb@xxxxxxxxxxxxx Signed-off-by: Nico Boehr <nrb@xxxxxxxxxxxxx> --- lib/s390x/interrupt.c | 1 + 1 file changed, 1 insertion(+) diff --git a/lib/s390x/interrupt.c b/lib/s390x/interrupt.c index e990c18..f7843a8 100644 --- a/lib/s390x/interrupt.c +++ b/lib/s390x/interrupt.c @@ -145,6 +145,7 @@ static void fixup_pgm_int(struct stack_frame_int *stack) if (lowcore.pgm_old_psw.addr >= (uint64_t)&sie_entry && lowcore.pgm_old_psw.addr <= (uint64_t)&sie_exit) { lowcore.pgm_old_psw.addr = (uint64_t)&sie_exit; + return; } switch (lowcore.pgm_int_code) { -- 2.41.0
