[linux-yocto] [PATCH 4.18-rt] of: phandle_cache merge fixup for preempt-rt
Paul Gortmaker
paul.gortmaker at windriver.com
Thu Mar 21 12:11:03 PDT 2019
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 <Yue.Tao at windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker at windriver.com>
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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