On 17/12/2020 23.16, Matthew Rosato wrote:
> In pcistb_service_handler, a call is made to validate that the memory
> region can be accessed. However, the call is made using the entire length
> of the pcistb operation, which can be larger than the allowed memory
> access size (8). Since we already know that the provided buffer is a
> multiple of 8, fix the call to memory_region_access_valid to iterate
> over the memory region in the same way as the subsequent call to
> memory_region_dispatch_write.
>
> Fixes: 863f6f52b7 ("s390: implement pci instructions")
> Signed-off-by: Matthew Rosato <mjros...@linux.ibm.com>
> ---
> hw/s390x/s390-pci-inst.c | 10 ++++++----
> 1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/hw/s390x/s390-pci-inst.c b/hw/s390x/s390-pci-inst.c
> index e230293..76b08a3 100644
> --- a/hw/s390x/s390-pci-inst.c
> +++ b/hw/s390x/s390-pci-inst.c
> @@ -821,10 +821,12 @@ int pcistb_service_call(S390CPU *cpu, uint8_t r1,
> uint8_t r3, uint64_t gaddr,
> mr = s390_get_subregion(mr, offset, len);
> offset -= mr->addr;
>
> - if (!memory_region_access_valid(mr, offset, len, true,
> - MEMTXATTRS_UNSPECIFIED)) {
> - s390_program_interrupt(env, PGM_OPERAND, ra);
> - return 0;
> + for (i = 0; i < len; i += 8) {
> + if (!memory_region_access_valid(mr, offset + i, 8, true,
> + MEMTXATTRS_UNSPECIFIED)) {
> + s390_program_interrupt(env, PGM_OPERAND, ra);
> + return 0;
> + }
> }
>
> if (s390_cpu_virt_mem_read(cpu, gaddr, ar, buffer, len)) {
>
Reviewed-by: Thomas Huth <th...@redhat.com>
