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authorDan Williams <dan.j.williams@intel.com>2017-04-24 15:43:05 -0700
committerDan Williams <dan.j.williams@intel.com>2017-04-24 16:01:56 -0700
commitbc042fdfbb92b5b13421316b4548e2d6e98eed37 (patch)
treed560c809c43acb727daed3f90d9eb3849e5fd19a /drivers/nvdimm
parentfbabd829fe76a72a6444f64361cf8b2a9848639d (diff)
libnvdimm, region: fix flush hint detection crash
In the case where a dimm does not have any associated flush hints the ndrd->flush_wpq array may be uninitialized leading to crashes with the following signature: BUG: unable to handle kernel NULL pointer dereference at 0000000000000010 IP: region_visible+0x10f/0x160 [libnvdimm] Call Trace: internal_create_group+0xbe/0x2f0 sysfs_create_groups+0x40/0x80 device_add+0x2d8/0x650 nd_async_device_register+0x12/0x40 [libnvdimm] async_run_entry_fn+0x39/0x170 process_one_work+0x212/0x6c0 ? process_one_work+0x197/0x6c0 worker_thread+0x4e/0x4a0 kthread+0x10c/0x140 ? process_one_work+0x6c0/0x6c0 ? kthread_create_on_node+0x60/0x60 ret_from_fork+0x31/0x40 Cc: <stable@vger.kernel.org> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Fixes: f284a4f23752 ("libnvdimm: introduce nvdimm_flush() and nvdimm_has_flush()") Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/nvdimm')
-rw-r--r--drivers/nvdimm/region_devs.c11
1 files changed, 7 insertions, 4 deletions
diff --git a/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c
index 8de5a04644a1..24abceda986a 100644
--- a/drivers/nvdimm/region_devs.c
+++ b/drivers/nvdimm/region_devs.c
@@ -1000,17 +1000,20 @@ EXPORT_SYMBOL_GPL(nvdimm_flush);
*/
int nvdimm_has_flush(struct nd_region *nd_region)
{
- struct nd_region_data *ndrd = dev_get_drvdata(&nd_region->dev);
int i;
/* no nvdimm == flushing capability unknown */
if (nd_region->ndr_mappings == 0)
return -ENXIO;
- for (i = 0; i < nd_region->ndr_mappings; i++)
- /* flush hints present, flushing required */
- if (ndrd_get_flush_wpq(ndrd, i, 0))
+ for (i = 0; i < nd_region->ndr_mappings; i++) {
+ struct nd_mapping *nd_mapping = &nd_region->mapping[i];
+ struct nvdimm *nvdimm = nd_mapping->nvdimm;
+
+ /* flush hints present / available */
+ if (nvdimm->num_flush)
return 1;
+ }
/*
* The platform defines dimm devices without hints, assume