107 lines
3.0 KiB
Diff
107 lines
3.0 KiB
Diff
From f2cacc38f730e9018d79d3c821b9a8af300a7ac2 Mon Sep 17 00:00:00 2001
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Message-Id: <f2cacc38f730e9018d79d3c821b9a8af300a7ac2.1601675151.git.zanussi@kernel.org>
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In-Reply-To: <5b5a156f9808b1acf1205606e03da117214549ea.1601675151.git.zanussi@kernel.org>
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References: <5b5a156f9808b1acf1205606e03da117214549ea.1601675151.git.zanussi@kernel.org>
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From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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Date: Fri, 31 Aug 2018 14:16:30 +0200
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Subject: [PATCH 021/333] of: allocate / free phandle cache outside of the
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devtree_lock
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Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.148-rt64.tar.xz
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The phandle cache code allocates memory while holding devtree_lock which
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is a raw_spinlock_t. Memory allocation (and free()) is not possible on
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RT while a raw_spinlock_t is held.
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Invoke the kfree() and kcalloc() while the lock is dropped.
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Cc: Rob Herring <robh+dt@kernel.org>
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Cc: Frank Rowand <frowand.list@gmail.com>
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Cc: devicetree@vger.kernel.org
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Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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---
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drivers/of/base.c | 19 +++++++++++++------
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1 file changed, 13 insertions(+), 6 deletions(-)
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diff --git a/drivers/of/base.c b/drivers/of/base.c
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index f0dbb7ad88cf..c59b30bab0e0 100644
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--- a/drivers/of/base.c
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+++ b/drivers/of/base.c
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@@ -130,31 +130,34 @@ static u32 phandle_cache_mask;
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/*
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* Caller must hold devtree_lock.
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*/
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-static void __of_free_phandle_cache(void)
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+static struct device_node** __of_free_phandle_cache(void)
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{
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u32 cache_entries = phandle_cache_mask + 1;
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u32 k;
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+ struct device_node **shadow;
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if (!phandle_cache)
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- return;
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+ return NULL;
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for (k = 0; k < cache_entries; k++)
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of_node_put(phandle_cache[k]);
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- kfree(phandle_cache);
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+ shadow = phandle_cache;
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phandle_cache = NULL;
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+ return shadow;
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}
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int of_free_phandle_cache(void)
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{
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unsigned long flags;
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+ struct device_node **shadow;
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raw_spin_lock_irqsave(&devtree_lock, flags);
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- __of_free_phandle_cache();
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+ shadow = __of_free_phandle_cache();
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raw_spin_unlock_irqrestore(&devtree_lock, flags);
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-
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+ kfree(shadow);
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return 0;
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}
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#if !defined(CONFIG_MODULES)
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@@ -189,10 +192,11 @@ void of_populate_phandle_cache(void)
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u32 cache_entries;
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struct device_node *np;
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u32 phandles = 0;
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+ struct device_node **shadow;
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raw_spin_lock_irqsave(&devtree_lock, flags);
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- __of_free_phandle_cache();
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+ shadow = __of_free_phandle_cache();
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for_each_of_allnodes(np)
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if (np->phandle && np->phandle != OF_PHANDLE_ILLEGAL)
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@@ -200,12 +204,14 @@ void of_populate_phandle_cache(void)
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if (!phandles)
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goto out;
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+ raw_spin_unlock_irqrestore(&devtree_lock, flags);
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cache_entries = roundup_pow_of_two(phandles);
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phandle_cache_mask = cache_entries - 1;
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phandle_cache = kcalloc(cache_entries, sizeof(*phandle_cache),
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GFP_ATOMIC);
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+ raw_spin_lock_irqsave(&devtree_lock, flags);
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if (!phandle_cache)
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goto out;
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@@ -217,6 +223,7 @@ void of_populate_phandle_cache(void)
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out:
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raw_spin_unlock_irqrestore(&devtree_lock, flags);
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+ kfree(shadow);
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}
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void __init of_core_init(void)
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--
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2.17.1
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