In yocto merge 5cc3fddf0e2a ("Merge branch 'v4.18/standard/base' into
v4.18/standard/preempt-rt/base") there was a conflict between the
backport of upstream b8a9ac1a5b99 ("of: of_node_get()/of_node_put() nodes
held in phandle cache") and the rt-specific commit b75caf08b721 ("of:
allocate / free phandle cache outside of the devtree_lock")

Unfortunately the conflict resolution left a shadow variable introduced
by the rt patch as undefined, resulting in:

drivers/of/base.c:120:2: error: 'shadow' undeclared (first use in this function)
  shadow = phandle_cache;
  ^~~~~~

drivers/of/base.c: In function 'of_populate_phandle_cache':
drivers/of/base.c:182:7: warning: 'shadow' is used uninitialized in this 
function [-Wuninitialized]

Here we create a merge fix-up that basically aligns the impacted code to
match what is currently found in the 4.19-rt (as of v4.19.15-rt12).

Reported-by: Yue Tao <[email protected]>
Signed-off-by: Paul Gortmaker <[email protected]>

diff --git a/drivers/of/base.c b/drivers/of/base.c
index 904c7686f9d7..4a33ef482bcc 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -106,31 +106,34 @@ static u32 phandle_cache_mask;
 /*
  * Caller must hold devtree_lock.
  */
-static void __of_free_phandle_cache(void)
+static struct device_node** __of_free_phandle_cache(void)
 {
        u32 cache_entries = phandle_cache_mask + 1;
        u32 k;
+       struct device_node **shadow;
 
        if (!phandle_cache)
-               return;
+               return NULL;
 
        for (k = 0; k < cache_entries; k++)
                of_node_put(phandle_cache[k]);
 
        shadow = phandle_cache;
        phandle_cache = NULL;
+       return shadow;
 }
 
 int of_free_phandle_cache(void)
 {
        unsigned long flags;
+       struct device_node **shadow;
 
        raw_spin_lock_irqsave(&devtree_lock, flags);
 
-       __of_free_phandle_cache();
+       shadow = __of_free_phandle_cache();
 
        raw_spin_unlock_irqrestore(&devtree_lock, flags);
-
+       kfree(shadow);
        return 0;
 }
 #if !defined(CONFIG_MODULES)
@@ -169,27 +172,24 @@ void of_populate_phandle_cache(void)
 
        raw_spin_lock_irqsave(&devtree_lock, flags);
 
-       __of_free_phandle_cache();
+       shadow = __of_free_phandle_cache();
 
        for_each_of_allnodes(np)
                if (np->phandle && np->phandle != OF_PHANDLE_ILLEGAL)
                        phandles++;
 
-       raw_spin_unlock_irqrestore(&devtree_lock, flags);
-       kfree(shadow);
-
        if (!phandles)
-               return;
+               goto out;
+       raw_spin_unlock_irqrestore(&devtree_lock, flags);
 
        cache_entries = roundup_pow_of_two(phandles);
        phandle_cache_mask = cache_entries - 1;
 
-       shadow = kcalloc(cache_entries, sizeof(*phandle_cache), GFP_KERNEL);
-
-       if (!shadow)
-               return;
+       phandle_cache = kcalloc(cache_entries, sizeof(*phandle_cache),
+                               GFP_ATOMIC);
        raw_spin_lock_irqsave(&devtree_lock, flags);
-       phandle_cache = shadow;
+       if (!phandle_cache)
+               goto out;
 
        for_each_of_allnodes(np)
                if (np->phandle && np->phandle != OF_PHANDLE_ILLEGAL) {
@@ -197,7 +197,9 @@ void of_populate_phandle_cache(void)
                        phandle_cache[np->phandle & phandle_cache_mask] = np;
                }
 
+out:
        raw_spin_unlock_irqrestore(&devtree_lock, flags);
+       kfree(shadow);
 }
 
 void __init of_core_init(void)
-- 
2.7.4

-- 
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