From d2ccde1c8e90d38cee87a1b0309ad2827f3fd30d Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Mon, 11 Dec 2023 02:45:28 +0000
Subject: [PATCH] add boot partition size
---
kernel/include/linux/rcuwait.h | 66 ++++++++++++++++++++------------
1 files changed, 41 insertions(+), 25 deletions(-)
diff --git a/kernel/include/linux/rcuwait.h b/kernel/include/linux/rcuwait.h
index 90bfa32..61c56cc 100644
--- a/kernel/include/linux/rcuwait.h
+++ b/kernel/include/linux/rcuwait.h
@@ -3,22 +3,18 @@
#define _LINUX_RCUWAIT_H_
#include <linux/rcupdate.h>
+#include <linux/sched/signal.h>
/*
* rcuwait provides a way of blocking and waking up a single
- * task in an rcu-safe manner; where it is forbidden to use
- * after exit_notify(). task_struct is not properly rcu protected,
- * unless dealing with rcu-aware lists, ie: find_task_by_*().
+ * task in an rcu-safe manner.
*
- * Alternatively we have task_rcu_dereference(), but the return
- * semantics have different implications which would break the
- * wakeup side. The only time @task is non-nil is when a user is
- * blocked (or checking if it needs to) on a condition, and reset
- * as soon as we know that the condition has succeeded and are
- * awoken.
+ * The only time @task is non-nil is when a user is blocked (or
+ * checking if it needs to) on a condition, and reset as soon as we
+ * know that the condition has succeeded and are awoken.
*/
struct rcuwait {
- struct task_struct *task;
+ struct task_struct __rcu *task;
};
#define __RCUWAIT_INITIALIZER(name) \
@@ -29,36 +25,56 @@
w->task = NULL;
}
-extern void rcuwait_wake_up(struct rcuwait *w);
+/*
+ * Note: this provides no serialization and, just as with waitqueues,
+ * requires care to estimate as to whether or not the wait is active.
+ */
+static inline int rcuwait_active(struct rcuwait *w)
+{
+ return !!rcu_access_pointer(w->task);
+}
+
+extern int rcuwait_wake_up(struct rcuwait *w);
/*
* The caller is responsible for locking around rcuwait_wait_event(),
- * such that writes to @task are properly serialized.
+ * and [prepare_to/finish]_rcuwait() such that writes to @task are
+ * properly serialized.
*/
-#define rcuwait_wait_event(w, condition) \
+
+static inline void prepare_to_rcuwait(struct rcuwait *w)
+{
+ rcu_assign_pointer(w->task, current);
+}
+
+static inline void finish_rcuwait(struct rcuwait *w)
+{
+ rcu_assign_pointer(w->task, NULL);
+ __set_current_state(TASK_RUNNING);
+}
+
+#define rcuwait_wait_event(w, condition, state) \
({ \
- /* \
- * Complain if we are called after do_exit()/exit_notify(), \
- * as we cannot rely on the rcu critical region for the \
- * wakeup side. \
- */ \
- WARN_ON(current->exit_state); \
- \
- rcu_assign_pointer((w)->task, current); \
+ int __ret = 0; \
+ prepare_to_rcuwait(w); \
for (;;) { \
/* \
* Implicit barrier (A) pairs with (B) in \
* rcuwait_wake_up(). \
*/ \
- set_current_state(TASK_UNINTERRUPTIBLE); \
+ set_current_state(state); \
if (condition) \
break; \
\
+ if (signal_pending_state(state, current)) { \
+ __ret = -EINTR; \
+ break; \
+ } \
+ \
schedule(); \
} \
- \
- WRITE_ONCE((w)->task, NULL); \
- __set_current_state(TASK_RUNNING); \
+ finish_rcuwait(w); \
+ __ret; \
})
#endif /* _LINUX_RCUWAIT_H_ */
--
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