5.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Yi Yang <yiyang13@xxxxxxxxxx> [ 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> --- drivers/nvdimm/dax_devs.c | 4 ++-- drivers/nvdimm/nd.h | 7 +++++++ 2 files changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/nvdimm/dax_devs.c b/drivers/nvdimm/dax_devs.c index 6d22b0f83b3b0..c882534dbe84c 100644 --- a/drivers/nvdimm/dax_devs.c +++ b/drivers/nvdimm/dax_devs.c @@ -113,12 +113,12 @@ 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 ee5c04070ef91..23d011b01fa61 100644 --- a/drivers/nvdimm/nd.h +++ b/drivers/nvdimm/nd.h @@ -326,6 +326,13 @@ 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) -- 2.43.0
