diff options
Diffstat (limited to 'debian/patches-rt/0021-of-allocate-free-phandle-cache-outside-of-the-devtre.patch')
| -rw-r--r-- | debian/patches-rt/0021-of-allocate-free-phandle-cache-outside-of-the-devtre.patch | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/debian/patches-rt/0021-of-allocate-free-phandle-cache-outside-of-the-devtre.patch b/debian/patches-rt/0021-of-allocate-free-phandle-cache-outside-of-the-devtre.patch new file mode 100644 index 000000000..9b53b3722 --- /dev/null +++ b/debian/patches-rt/0021-of-allocate-free-phandle-cache-outside-of-the-devtre.patch @@ -0,0 +1,103 @@ +From aafa075abaa80a17d9ac105e72ab235ddb573aac Mon Sep 17 00:00:00 2001 +From: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +Date: Fri, 31 Aug 2018 14:16:30 +0200 +Subject: [PATCH 021/347] of: allocate / free phandle cache outside of the + devtree_lock +Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.246-rt110.tar.xz + +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> +--- + drivers/of/base.c | 19 +++++++++++++------ + 1 file changed, 13 insertions(+), 6 deletions(-) + +diff --git a/drivers/of/base.c b/drivers/of/base.c +index f0dbb7ad88cf..c59b30bab0e0 100644 +--- a/drivers/of/base.c ++++ b/drivers/of/base.c +@@ -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) +-- +2.36.1 + |