179 lines
7.2 KiB
Diff
179 lines
7.2 KiB
Diff
From ba1606a46ad4d99deaf51539cd49b3fe67f8900f Mon Sep 17 00:00:00 2001
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Message-Id: <ba1606a46ad4d99deaf51539cd49b3fe67f8900f.1601675152.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: Tue, 26 Feb 2019 16:56:02 +0100
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Subject: [PATCH 139/333] rbtree: don't include the rcu header
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MIME-Version: 1.0
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Content-Type: text/plain; charset=UTF-8
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Content-Transfer-Encoding: 8bit
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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 RCU header pulls in spinlock.h and fails due not yet defined types:
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|In file included from include/linux/spinlock.h:275:0,
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| from include/linux/rcupdate.h:38,
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| from include/linux/rbtree.h:34,
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| from include/linux/rtmutex.h:17,
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| from include/linux/spinlock_types.h:18,
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| from kernel/bounds.c:13:
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|include/linux/rwlock_rt.h:16:38: error: unknown type name ‘rwlock_t’
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| extern void __lockfunc rt_write_lock(rwlock_t *rwlock);
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| ^
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This patch moves the required RCU function from the rcupdate.h header file into
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a new header file which can be included by both users.
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Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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---
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include/linux/rbtree.h | 2 +-
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include/linux/rcu_assign_pointer.h | 54 ++++++++++++++++++++++++++++++
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include/linux/rcupdate.h | 49 +--------------------------
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3 files changed, 56 insertions(+), 49 deletions(-)
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create mode 100644 include/linux/rcu_assign_pointer.h
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diff --git a/include/linux/rbtree.h b/include/linux/rbtree.h
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index fcbeed4053ef..2aa2aec354c2 100644
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--- a/include/linux/rbtree.h
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+++ b/include/linux/rbtree.h
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@@ -31,7 +31,7 @@
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#include <linux/kernel.h>
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#include <linux/stddef.h>
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-#include <linux/rcupdate.h>
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+#include <linux/rcu_assign_pointer.h>
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struct rb_node {
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unsigned long __rb_parent_color;
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diff --git a/include/linux/rcu_assign_pointer.h b/include/linux/rcu_assign_pointer.h
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new file mode 100644
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index 000000000000..7066962a4379
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--- /dev/null
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+++ b/include/linux/rcu_assign_pointer.h
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@@ -0,0 +1,54 @@
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+#ifndef __LINUX_RCU_ASSIGN_POINTER_H__
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+#define __LINUX_RCU_ASSIGN_POINTER_H__
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+#include <linux/compiler.h>
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+#include <asm/barrier.h>
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+
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+/**
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+ * RCU_INITIALIZER() - statically initialize an RCU-protected global variable
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+ * @v: The value to statically initialize with.
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+ */
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+#define RCU_INITIALIZER(v) (typeof(*(v)) __force __rcu *)(v)
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+
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+/**
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+ * rcu_assign_pointer() - assign to RCU-protected pointer
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+ * @p: pointer to assign to
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+ * @v: value to assign (publish)
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+ *
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+ * Assigns the specified value to the specified RCU-protected
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+ * pointer, ensuring that any concurrent RCU readers will see
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+ * any prior initialization.
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+ *
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+ * Inserts memory barriers on architectures that require them
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+ * (which is most of them), and also prevents the compiler from
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+ * reordering the code that initializes the structure after the pointer
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+ * assignment. More importantly, this call documents which pointers
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+ * will be dereferenced by RCU read-side code.
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+ *
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+ * In some special cases, you may use RCU_INIT_POINTER() instead
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+ * of rcu_assign_pointer(). RCU_INIT_POINTER() is a bit faster due
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+ * to the fact that it does not constrain either the CPU or the compiler.
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+ * That said, using RCU_INIT_POINTER() when you should have used
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+ * rcu_assign_pointer() is a very bad thing that results in
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+ * impossible-to-diagnose memory corruption. So please be careful.
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+ * See the RCU_INIT_POINTER() comment header for details.
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+ *
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+ * Note that rcu_assign_pointer() evaluates each of its arguments only
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+ * once, appearances notwithstanding. One of the "extra" evaluations
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+ * is in typeof() and the other visible only to sparse (__CHECKER__),
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+ * neither of which actually execute the argument. As with most cpp
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+ * macros, this execute-arguments-only-once property is important, so
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+ * please be careful when making changes to rcu_assign_pointer() and the
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+ * other macros that it invokes.
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+ */
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+#define rcu_assign_pointer(p, v) \
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+({ \
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+ uintptr_t _r_a_p__v = (uintptr_t)(v); \
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+ \
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+ if (__builtin_constant_p(v) && (_r_a_p__v) == (uintptr_t)NULL) \
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+ WRITE_ONCE((p), (typeof(p))(_r_a_p__v)); \
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+ else \
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+ smp_store_release(&p, RCU_INITIALIZER((typeof(p))_r_a_p__v)); \
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+ _r_a_p__v; \
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+})
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+
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+#endif
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diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
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index 027c58cdbb6e..e6733d7911e9 100644
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--- a/include/linux/rcupdate.h
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+++ b/include/linux/rcupdate.h
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@@ -42,6 +42,7 @@
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#include <linux/lockdep.h>
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#include <asm/processor.h>
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#include <linux/cpumask.h>
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+#include <linux/rcu_assign_pointer.h>
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#define ULONG_CMP_GE(a, b) (ULONG_MAX / 2 >= (a) - (b))
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#define ULONG_CMP_LT(a, b) (ULONG_MAX / 2 < (a) - (b))
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@@ -369,54 +370,6 @@ static inline void rcu_preempt_sleep_check(void) { }
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((typeof(*p) __force __kernel *)(________p1)); \
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})
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-/**
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- * RCU_INITIALIZER() - statically initialize an RCU-protected global variable
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- * @v: The value to statically initialize with.
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- */
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-#define RCU_INITIALIZER(v) (typeof(*(v)) __force __rcu *)(v)
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-
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-/**
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- * rcu_assign_pointer() - assign to RCU-protected pointer
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- * @p: pointer to assign to
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- * @v: value to assign (publish)
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- *
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- * Assigns the specified value to the specified RCU-protected
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- * pointer, ensuring that any concurrent RCU readers will see
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- * any prior initialization.
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- *
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- * Inserts memory barriers on architectures that require them
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- * (which is most of them), and also prevents the compiler from
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- * reordering the code that initializes the structure after the pointer
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- * assignment. More importantly, this call documents which pointers
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- * will be dereferenced by RCU read-side code.
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- *
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- * In some special cases, you may use RCU_INIT_POINTER() instead
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- * of rcu_assign_pointer(). RCU_INIT_POINTER() is a bit faster due
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- * to the fact that it does not constrain either the CPU or the compiler.
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- * That said, using RCU_INIT_POINTER() when you should have used
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- * rcu_assign_pointer() is a very bad thing that results in
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- * impossible-to-diagnose memory corruption. So please be careful.
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- * See the RCU_INIT_POINTER() comment header for details.
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- *
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- * Note that rcu_assign_pointer() evaluates each of its arguments only
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- * once, appearances notwithstanding. One of the "extra" evaluations
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- * is in typeof() and the other visible only to sparse (__CHECKER__),
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- * neither of which actually execute the argument. As with most cpp
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- * macros, this execute-arguments-only-once property is important, so
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- * please be careful when making changes to rcu_assign_pointer() and the
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- * other macros that it invokes.
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- */
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-#define rcu_assign_pointer(p, v) \
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-({ \
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- uintptr_t _r_a_p__v = (uintptr_t)(v); \
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- \
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- if (__builtin_constant_p(v) && (_r_a_p__v) == (uintptr_t)NULL) \
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- WRITE_ONCE((p), (typeof(p))(_r_a_p__v)); \
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- else \
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- smp_store_release(&p, RCU_INITIALIZER((typeof(p))_r_a_p__v)); \
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- _r_a_p__v; \
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-})
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-
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/**
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* rcu_swap_protected() - swap an RCU and a regular pointer
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* @rcu_ptr: RCU pointer
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--
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2.17.1
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