libnvdimm: fix devm_nvdimm_memremap() error path From: Dan Williams The internal alloc_nvdimm_map() helper might file, particularly if the memory region is already busy. Report request_mem_region() failures and check for the failure. Reported-by: Ryan Chen Signed-off-by: Dan Williams --- drivers/nvdimm/core.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/nvdimm/core.c b/drivers/nvdimm/core.c index 715583f69d28..14066add20f0 100644 --- a/drivers/nvdimm/core.c +++ b/drivers/nvdimm/core.c @@ -99,8 +99,11 @@ static struct nvdimm_map *alloc_nvdimm_map(struct device *dev, nvdimm_map->size = size; kref_init(&nvdimm_map->kref); - if (!request_mem_region(offset, size, dev_name(&nvdimm_bus->dev))) + if (!request_mem_region(offset, size, dev_name(&nvdimm_bus->dev))) { + dev_err(&nvdimm_bus->dev, "failed to request %pa + %ld for %s\n", + &offset, size, dev_name(dev)); goto err_request_region; + } if (flags) nvdimm_map->mem = memremap(offset, size, flags); @@ -171,6 +174,9 @@ void *devm_nvdimm_memremap(struct device *dev, resource_size_t offset, kref_get(&nvdimm_map->kref); nvdimm_bus_unlock(dev); + if (!nvdimm_map) + return NULL; + if (devm_add_action_or_reset(dev, nvdimm_map_put, nvdimm_map)) return NULL;