Some regions may not have any address space allocated. Skip them when validating HPA order otherwise a crash like the following may result: devm_cxl_add_region: cxl_acpi cxl_acpi.0: decoder3.4: created region9 BUG: kernel NULL pointer dereference, address: 0000000000000000 [..] RIP: 0010:store_targetN+0x655/0x1740 [cxl_core] [..] Call Trace: <TASK> kernfs_fop_write_iter+0x144/0x200 vfs_write+0x24a/0x4d0 ksys_write+0x69/0xf0 do_syscall_64+0x3a/0x90 store_targetN+0x655/0x1740: alloc_region_ref at drivers/cxl/core/region.c:676 (inlined by) cxl_port_attach_region at drivers/cxl/core/region.c:850 (inlined by) cxl_region_attach at drivers/cxl/core/region.c:1290 (inlined by) attach_target at drivers/cxl/core/region.c:1410 (inlined by) store_targetN at drivers/cxl/core/region.c:1453
Unified · Split
| @@ -658,6 +658,9 @@ static struct cxl_region_ref *alloc_region_ref(struct cxl_port *port, · 657 unmodified lines | ||
| 658 | 658 | xa_for_each(&port->regions, index, iter) { |
| 659 | 659 | struct cxl_region_params *ip = &iter->region->params; |
| 660 | 660 | |
| 661 | + if (!ip->res) | |
| 662 | + continue; | |
| 663 | + | |
| 661 | 664 | if (ip->res->start > p->res->start) { |
| 662 | 665 | dev_dbg(&cxlr->dev, |
| 663 | 666 | "%s: HPA order violation %s:%pr vs %pr\n", |