@@ -1031,13 +1031,14 @@ static void openpic_cpu_write_internal(void *opaque, hwaddr addr,
s_IRQ = IRQ_get_next(opp, &dst->servicing);
/* Check queued interrupts. */
n_IRQ = IRQ_get_next(opp, &dst->raised);
- src = &opp->src[n_IRQ];
- if (n_IRQ != -1 &&
- (s_IRQ == -1 ||
- IVPR_PRIORITY(src->ivpr) > dst->servicing.priority)) {
- DPRINTF("Raise OpenPIC INT output cpu %d irq %d",
- idx, n_IRQ);
- qemu_irq_raise(opp->dst[idx].irqs[OPENPIC_OUTPUT_INT]);
+ if (n_IRQ != -1) {
+ src = &opp->src[n_IRQ];
+ if (s_IRQ == -1 ||
+ IVPR_PRIORITY(src->ivpr) > dst->servicing.priority) {
+ DPRINTF("Raise OpenPIC INT output cpu %d irq %d",
+ idx, n_IRQ);
+ qemu_irq_raise(opp->dst[idx].irqs[OPENPIC_OUTPUT_INT]);
+ }
}
break;
default:
The clang sanitizer complains about the code in the EOI handling of openpic_cpu_write_internal(): UBSAN_OPTIONS=halt_on_error=1:abort_on_error=1 ./build/clang/qemu-system-ppc -M mac99,graphics=off -display none -kernel day15/invaders.elf ../../hw/intc/openpic.c:1034:16: runtime error: index -1 out of bounds for type 'IRQSource[264]' (aka 'struct IRQSource[264]') SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior ../../hw/intc/openpic.c:1034:16 in This is because we do src = &opp->src[n_IRQ]; when n_IRQ may be -1. This is in practice harmless because if n_IRQ is -1 then we don't do anything with the src pointer, but it is undefined behaviour. (This has been present since this device was first added to QEMU.) Rearrange the code so we only do the array index when n_IRQ is not -1. Cc: qemu-stable@nongnu.org Fixes: e9df014c0b ("Implement embedded IRQ controller for PowerPC 6xx/740 & 75") Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk> Message-id: 20241105180205.3074071-1-peter.maydell@linaro.org --- hw/intc/openpic.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-)