diff options
| author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2018-08-31 14:16:30 +0200 |
|---|---|---|
| committer | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2019-07-11 17:28:04 +0200 |
| commit | 6a30bfd44010bd533e52d86a636e6bf418065b53 (patch) | |
| tree | 68da117d69f06fc4f9e8a9158ea7df8c43a9c7b5 | |
| parent | 279affa4a0609c915fdc57fe784a55d6ac3d1ef7 (diff) | |
| download | linux-rt-devel-6a30bfd44010bd533e52d86a636e6bf418065b53.tar.gz | |
of: allocate / free phandle cache outside of the devtree_lock
The phandle cache code allocates memory while holding devtree_lock which
is a raw_spinlock_t. Memory allocation (and free()) is not possible on
RT while a raw_spinlock_t is held.
Invoke the kfree() and kcalloc() while the lock is dropped.
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: devicetree@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
| -rw-r--r-- | drivers/of/base.c | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/drivers/of/base.c b/drivers/of/base.c index 20e0e7ee4edf95..a44c889a6e6ccf 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -138,31 +138,34 @@ 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]); - kfree(phandle_cache); + 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) @@ -197,10 +200,11 @@ void of_populate_phandle_cache(void) u32 cache_entries; struct device_node *np; u32 phandles = 0; + struct device_node **shadow; 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) @@ -208,12 +212,14 @@ void of_populate_phandle_cache(void) if (!phandles) goto out; + raw_spin_unlock_irqrestore(&devtree_lock, flags); cache_entries = roundup_pow_of_two(phandles); phandle_cache_mask = cache_entries - 1; phandle_cache = kcalloc(cache_entries, sizeof(*phandle_cache), GFP_ATOMIC); + raw_spin_lock_irqsave(&devtree_lock, flags); if (!phandle_cache) goto out; @@ -225,6 +231,7 @@ void of_populate_phandle_cache(void) out: raw_spin_unlock_irqrestore(&devtree_lock, flags); + kfree(shadow); } void __init of_core_init(void) |