Resource fitting/assignment code checks if there's a remainder in add_list (aka. realloc_head in the inner functions) using BUG_ON(). This problem typically results in a mere PCI device resource assignment failure which does not warrant using BUG_ON(). The machine could well come up usable even if this condition occurs because the realloc_head relates to resources which are optional anyway. Change BUG_ON() to WARN_ON_ONCE() and free the list if it it's not empty. Reported-by: Tudor Ambarus <tudor.ambarus@xxxxxxxxxx> Link: https://lore.kernel.org/linux-pci/5f103643-5e1c-43c6-b8fe-9617d3b5447c@xxxxxxxxxx/ Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx> --- The cause for the regression reported by Tudor is not understood yet, but this change seems useful regardless given somebody has now hit one of these BUG_ON()s. drivers/pci/setup-bus.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c index 54d6f4fa3ce1..a0d815557f5c 100644 --- a/drivers/pci/setup-bus.c +++ b/drivers/pci/setup-bus.c @@ -2298,8 +2298,8 @@ void pci_assign_unassigned_root_bus_resources(struct pci_bus *bus) /* Depth last, allocate resources and update the hardware. */ __pci_bus_assign_resources(bus, add_list, &fail_head); - if (add_list) - BUG_ON(!list_empty(add_list)); + if (WARN_ON_ONCE(add_list && !list_empty(add_list))) + free_list(add_list); tried_times++; /* Any device complain? */ @@ -2361,7 +2361,8 @@ void pci_assign_unassigned_bridge_resources(struct pci_dev *bridge) pci_bridge_distribute_available_resources(bridge, &add_list); __pci_bridge_assign_resources(bridge, &add_list, &fail_head); - BUG_ON(!list_empty(&add_list)); + if (WARN_ON_ONCE(!list_empty(&add_list))) + free_list(&add_list); tried_times++; if (list_empty(&fail_head)) @@ -2437,7 +2438,8 @@ int pci_reassign_bridge_resources(struct pci_dev *bridge, unsigned long type) __pci_bus_size_bridges(bridge->subordinate, &added); __pci_bridge_assign_resources(bridge, &added, &failed); - BUG_ON(!list_empty(&added)); + if (WARN_ON_ONCE(!list_empty(&added))) + free_list(&added); if (!list_empty(&failed)) { ret = -ENOSPC; @@ -2493,6 +2495,7 @@ void pci_assign_unassigned_bus_resources(struct pci_bus *bus) __pci_bus_size_bridges(dev->subordinate, &add_list); up_read(&pci_bus_sem); __pci_bus_assign_resources(bus, &add_list, NULL); - BUG_ON(!list_empty(&add_list)); + if (WARN_ON_ONCE(!list_empty(&add_list))) + free_list(&add_list); } EXPORT_SYMBOL_GPL(pci_assign_unassigned_bus_resources); base-commit: 0af2f6be1b4281385b618cb86ad946eded089ac8 -- 2.39.5
