[PATCH] powerpc/pseries: Fix exception handling in pSeries_reconfig_add_node()

[Markus Elfring]

Date: Fri, 17 Mar 2023 09:26:13 +0100

The label “out_err” was used to jump to another pointer check despite of
the detail in the implementation of the function “pSeries_reconfig_add_node”
that it was determined already that the corresponding variable contained
a null pointer (because of a failed function call in two cases).

1. Thus return directly after a call of the function “kzalloc” failed.

2. Use more appropriate labels instead.

3. Delete a redundant check.

4. Omit an explicit initialisation for the local variable “err”.

This issue was detected by using the Coccinelle software.

Fixes: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac ("Linux-2.6.12-rc2")
Signed-off-by: Markus Elfring <elfring at users.sourceforge.net>
---
 arch/powerpc/platforms/pseries/reconfig.c | 26 ++++++++++++-----------
 1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/arch/powerpc/platforms/pseries/reconfig.c b/arch/powerpc/platforms/pseries/reconfig.c
index 599bd2c78514..14154f48ef63 100644
--- a/arch/powerpc/platforms/pseries/reconfig.c
+++ b/arch/powerpc/platforms/pseries/reconfig.c
@@ -23,15 +23,17 @@
 static int pSeries_reconfig_add_node(const char *path, struct property *proplist)
 {
     struct device_node *np;
-    int err = -ENOMEM;
+    int err;
 
     np = kzalloc(sizeof(*np), GFP_KERNEL);
     if (!np)
-        goto out_err;
+        return -ENOMEM;
 
     np->full_name = kstrdup(kbasename(path), GFP_KERNEL);
-    if (!np->full_name)
-        goto out_err;
+    if (!np->full_name) {
+        err = -ENOMEM;
+        goto free_device_node;
+    }
 
     np->properties = proplist;
     of_node_set_flag(np, OF_DYNAMIC);
@@ -40,25 +42,25 @@ static int pSeries_reconfig_add_node(const char *path, struct property *proplist
     np->parent = pseries_of_derive_parent(path);
     if (IS_ERR(np->parent)) {
         err = PTR_ERR(np->parent);
-        goto out_err;
+        goto free_name;
     }
 
     err = of_attach_node(np);
     if (err) {
         printk(KERN_ERR "Failed to add device node %s\n", path);
-        goto out_err;
+        goto put_node;
     }
 
     of_node_put(np->parent);
 
     return 0;
 
-out_err:
-    if (np) {
-        of_node_put(np->parent);
-        kfree(np->full_name);
-        kfree(np);
-    }
+put_node:
+    of_node_put(np->parent);
+free_name:
+    kfree(np->full_name);
+free_device_node:
+    kfree(np);
     return err;
 }
 
--
2.40.0