[kvm-unit-tests PATCH v8 5/6] s390x: lib: fix program interrupt handler if sclp_busy was set

Claudio Imbrenda
2020-01-20T18:43:06Z

Fix the program interrupt handler for the case where sclp_busy is set.

The interrupt handler will attempt to write an error message on the
console using the SCLP, and will wait for sclp_busy to become false
before doing so. If an exception happenes between setting the flag and
the SCLP call, or if the call itself raises an exception, we need to
clear the flag so we can successfully print the error message.

Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
---
lib/s390x/interrupt.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/lib/s390x/interrupt.c b/lib/s390x/interrupt.c
index 05f30be..ccb376a 100644
--- a/lib/s390x/interrupt.c
+++ b/lib/s390x/interrupt.c
@@ -106,10 +106,13 @@ static void fixup_pgm_int(void)

void handle_pgm_int(void)
{
- if (!pgm_int_expected)
+ if (!pgm_int_expected) {
+ /* Force sclp_busy to false, otherwise we will loop forever */
+ sclp_handle_ext();
report_abort("Unexpected program interrupt: %d at %#lx, ilen %d\n",
lc->pgm_int_code, lc->pgm_old_psw.addr,
lc->pgm_int_id);
+ }

pgm_int_expected = false;
fixup_pgm_int();
--
2.24.1