Since papr_scm_ndctl() can be called from outside papr_scm, its
exposed to the possibility of receiving NULL as value of 'cmd_rc'
argument. This patch updates papr_scm_ndctl() to protect against such
possibility by assigning it pointer to a local variable in case cmd_rc
== NULL.

Finally the patch also updates the 'default' clause of the switch-case
block removing a 'return' statement thereby ensuring that value of
'cmd_rc' is always logged when papr_scm_ndctl() returns.

Cc: "Aneesh Kumar K . V" <aneesh.ku...@linux.ibm.com>
Cc: Dan Williams <dan.j.willi...@intel.com>
Cc: Michael Ellerman <m...@ellerman.id.au>
Cc: Ira Weiny <ira.we...@intel.com>
Signed-off-by: Vaibhav Jain <vaib...@linux.ibm.com>
---
Changelog:

v9..v10
* New patch in the series
---
 arch/powerpc/platforms/pseries/papr_scm.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/platforms/pseries/papr_scm.c 
b/arch/powerpc/platforms/pseries/papr_scm.c
index 0c091622b15e..6512fe6a2874 100644
--- a/arch/powerpc/platforms/pseries/papr_scm.c
+++ b/arch/powerpc/platforms/pseries/papr_scm.c
@@ -355,11 +355,16 @@ static int papr_scm_ndctl(struct nvdimm_bus_descriptor 
*nd_desc,
 {
        struct nd_cmd_get_config_size *get_size_hdr;
        struct papr_scm_priv *p;
+       int rc;
 
        /* Only dimm-specific calls are supported atm */
        if (!nvdimm)
                return -EINVAL;
 
+       /* Use a local variable in case cmd_rc pointer is NULL */
+       if (!cmd_rc)
+               cmd_rc = &rc;
+
        p = nvdimm_provider_data(nvdimm);
 
        switch (cmd) {
@@ -381,12 +386,13 @@ static int papr_scm_ndctl(struct nvdimm_bus_descriptor 
*nd_desc,
                break;
 
        default:
-               return -EINVAL;
+               dev_dbg(&p->pdev->dev, "Unknown command = %d\n", cmd);
+               *cmd_rc = -EINVAL;
        }
 
        dev_dbg(&p->pdev->dev, "returned with cmd_rc = %d\n", *cmd_rc);
 
-       return 0;
+       return *cmd_rc;
 }
 
 static ssize_t flags_show(struct device *dev,
-- 
2.26.2

Reply via email to