On Wed, 25 Sep 2019 16:45:30 +1000
David Gibson <da...@gibson.dropbear.id.au> wrote:
> The irq claim and free paths for both XICS and XIVE check for some
> validity conditions. Some of these represent genuine runtime failures,
> however others - particularly checking that the basic irq number is in a
> sane range - could only fail in the case of bugs in the callin code.
> Therefore use assert()s instead of runtime failures for those.
>
> In addition the non backend-specific part of the claim/free paths should
> only be used for PAPR external irqs, that is in the range SPAPR_XIRQ_BASE
> to the maximum irq number. Put assert()s for that into the top level
> dispatchers as well.
>
> Signed-off-by: David Gibson <da...@gibson.dropbear.id.au>
> ---
> hw/intc/spapr_xive.c | 8 ++------
> hw/ppc/spapr_irq.c | 18 ++++++++++--------
> 2 files changed, 12 insertions(+), 14 deletions(-)
>
> diff --git a/hw/intc/spapr_xive.c b/hw/intc/spapr_xive.c
> index c1c97192a7..47b5ec0b56 100644
> --- a/hw/intc/spapr_xive.c
> +++ b/hw/intc/spapr_xive.c
> @@ -532,9 +532,7 @@ bool spapr_xive_irq_claim(SpaprXive *xive, uint32_t lisn,
> bool lsi)
> {
> XiveSource *xsrc = &xive->source;
>
> - if (lisn >= xive->nr_irqs) {
> - return false;
> - }
> + assert(lisn < xive->nr_irqs);
>
> /*
> * Set default values when allocating an IRQ number
> @@ -559,9 +557,7 @@ bool spapr_xive_irq_claim(SpaprXive *xive, uint32_t lisn,
> bool lsi)
>
> bool spapr_xive_irq_free(SpaprXive *xive, uint32_t lisn)
> {
> - if (lisn >= xive->nr_irqs) {
> - return false;
> - }
> + assert(lisn < xive->nr_irqs);
>
> xive->eat[lisn].w &= cpu_to_be64(~EAS_VALID);
> return true;
> diff --git a/hw/ppc/spapr_irq.c b/hw/ppc/spapr_irq.c
> index c40357a985..261d66ba17 100644
> --- a/hw/ppc/spapr_irq.c
> +++ b/hw/ppc/spapr_irq.c
> @@ -118,11 +118,7 @@ static int spapr_irq_claim_xics(SpaprMachineState
> *spapr, int irq, bool lsi,
> ICSState *ics = spapr->ics;
>
> assert(ics);
> -
> - if (!ics_valid_irq(ics, irq)) {
> - error_setg(errp, "IRQ %d is invalid", irq);
> - return -1;
> - }
> + assert(ics_valid_irq(ics, irq));
>
> if (!ics_irq_free(ics, irq - ics->offset)) {
> error_setg(errp, "IRQ %d is not free", irq);
> @@ -138,9 +134,9 @@ static void spapr_irq_free_xics(SpaprMachineState *spapr,
> int irq)
> ICSState *ics = spapr->ics;
> uint32_t srcno = irq - ics->offset;
>
> - if (ics_valid_irq(ics, irq)) {
> - memset(&ics->irqs[srcno], 0, sizeof(ICSIRQState));
> - }
> + assert(ics_valid_irq(ics, irq));
> +
> + memset(&ics->irqs[srcno], 0, sizeof(ICSIRQState));
> }
>
> static void spapr_irq_print_info_xics(SpaprMachineState *spapr, Monitor *mon)
> @@ -628,6 +624,9 @@ void spapr_irq_init(SpaprMachineState *spapr, Error
> **errp)
>
> int spapr_irq_claim(SpaprMachineState *spapr, int irq, bool lsi, Error
> **errp)
> {
> + assert(irq >= SPAPR_XIRQ_BASE);
> + assert(irq < (spapr->irq->nr_xirqs + SPAPR_XIRQ_BASE));
> +
> return spapr->irq->claim(spapr, irq, lsi, errp);
> }
>
> @@ -635,6 +634,9 @@ void spapr_irq_free(SpaprMachineState *spapr, int irq,
> int num)
> {
> int i;
>
> + assert(irq >= SPAPR_XIRQ_BASE);
> + assert((irq+num) <= (spapr->irq->nr_xirqs + SPAPR_XIRQ_BASE));
Non surprisingly this makes checkpatch unhappy:
ERROR: spaces required around that '+' (ctx:VxV)
#91: FILE: hw/ppc/spapr_irq.c:638:
+ assert((irq+num) <= (spapr->irq->nr_xirqs + SPAPR_XIRQ_BASE));
With that fixed,
Reviewed-by: Greg Kurz <gr...@kaod.org>
> +
> for (i = irq; i < (irq + num); i++) {
> spapr->irq->free(spapr, irq);
> }
