This is a note to let you know that I've just added the patch titled
nvdimm: rectify the illogical code within nd_dax_probe()
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
nvdimm-rectify-the-illogical-code-within-nd_dax_prob.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 89810ab2d4084e33380a5b131b917d3c14ac8dd3
Author: Yi Yang <yiyang13@xxxxxxxxxx>
Date: Fri Nov 8 08:55:26 2024 +0000
nvdimm: rectify the illogical code within nd_dax_probe()
[ Upstream commit b61352101470f8b68c98af674e187cfaa7c43504 ]
When nd_dax is NULL, nd_pfn is consequently NULL as well. Nevertheless,
it is inadvisable to perform pointer arithmetic or address-taking on a
NULL pointer.
Introduce the nd_dax_devinit() function to enhance the code's logic and
improve its readability.
Signed-off-by: Yi Yang <yiyang13@xxxxxxxxxx>
Reviewed-by: Dave Jiang <dave.jiang@xxxxxxxxx>
Link: https://patch.msgid.link/20241108085526.527957-1-yiyang13@xxxxxxxxxx
Signed-off-by: Ira Weiny <ira.weiny@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/nvdimm/dax_devs.c b/drivers/nvdimm/dax_devs.c
index 99965077bac4f..e7b8211c19cc6 100644
--- a/drivers/nvdimm/dax_devs.c
+++ b/drivers/nvdimm/dax_devs.c
@@ -106,12 +106,12 @@ int nd_dax_probe(struct device *dev, struct nd_namespace_common *ndns)
nvdimm_bus_lock(&ndns->dev);
nd_dax = nd_dax_alloc(nd_region);
- nd_pfn = &nd_dax->nd_pfn;
- dax_dev = nd_pfn_devinit(nd_pfn, ndns);
+ dax_dev = nd_dax_devinit(nd_dax, ndns);
nvdimm_bus_unlock(&ndns->dev);
if (!dax_dev)
return -ENOMEM;
pfn_sb = devm_kmalloc(dev, sizeof(*pfn_sb), GFP_KERNEL);
+ nd_pfn = &nd_dax->nd_pfn;
nd_pfn->pfn_sb = pfn_sb;
rc = nd_pfn_validate(nd_pfn, DAX_SIG);
dev_dbg(dev, "dax: %s\n", rc == 0 ? dev_name(dax_dev) : "<none>");
diff --git a/drivers/nvdimm/nd.h b/drivers/nvdimm/nd.h
index 5467ebbb4a6b0..55ae9fa9db5bf 100644
--- a/drivers/nvdimm/nd.h
+++ b/drivers/nvdimm/nd.h
@@ -485,6 +485,13 @@ struct nd_dax *to_nd_dax(struct device *dev);
int nd_dax_probe(struct device *dev, struct nd_namespace_common *ndns);
bool is_nd_dax(struct device *dev);
struct device *nd_dax_create(struct nd_region *nd_region);
+static inline struct device *nd_dax_devinit(struct nd_dax *nd_dax,
+ struct nd_namespace_common *ndns)
+{
+ if (!nd_dax)
+ return NULL;
+ return nd_pfn_devinit(&nd_dax->nd_pfn, ndns);
+}
#else
static inline int nd_dax_probe(struct device *dev,
struct nd_namespace_common *ndns)
