mirros/rockchip-kernel
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

of: allocate / free phandle cache outside of the devtree_lock

Browse Source 
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>
This commit is contained in:
Sebastian Andrzej Siewior
2018-08-31 14:16:30 +02:00
committed by jianlong.wang
parent 602efa9335
commit 899fbaf4e2
1 changed files with 13 additions and 6 deletions
Download Patch File Download Diff File Expand all files Collapse all files

19
drivers/of/base.c
View File

@@ -130,31 +130,34 @@ 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)
@@ -189,10 +192,11 @@ 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)
@@ -200,12 +204,14 @@ 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;
@@ -217,6 +223,7 @@ void of_populate_phandle_cache(void)
out:
raw_spin_unlock_irqrestore(&devtree_lock, flags);
kfree(shadow);
}
void __init of_core_init(void)