[1/4] futex: Prepare for futex_wait_multiple()

Message ID 20210805190405.59110-2-andrealmeid@collabora.com
State Not applicable
Headers
Series futex2: Add wait on multiple futexes syscall |

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Context Check Description
dj/TryBot-apply_patch fail Patch failed to apply to master at the time it was sent

Commit Message

André Almeida Aug. 5, 2021, 7:04 p.m. UTC
  Make public functions and defines that will be used for
futex_wait_multiple() function in next commit.

Signed-off-by: André Almeida <andrealmeid@collabora.com>
---
 include/linux/futex.h | 60 +++++++++++++++++++++++++++++++++++++++++++
 kernel/futex.c        | 42 +-----------------------------
 2 files changed, 61 insertions(+), 41 deletions(-)
  

Comments

Thomas Gleixner Aug. 18, 2021, 8:22 a.m. UTC | #1
Andre,

On Thu, Aug 05 2021 at 16:04, André Almeida wrote:
> +/*
> + * Futex flags used to encode options to functions and preserve them across
> + * restarts.
> + */
> +#ifdef CONFIG_MMU
> +# define FLAGS_SHARED		0x01
> +#else
> +/*
> + * NOMMU does not have per process address space. Let the compiler optimize
> + * code away.
> + */
> +# define FLAGS_SHARED		0x00
> +#endif
> +#define FLAGS_CLOCKRT		0x02
> +#define FLAGS_HAS_TIMEOUT	0x04
> +
>  /*
>   * Futexes are matched on equal values of this key.
>   * The key type depends on whether it's a shared or private mapping.
> @@ -50,8 +66,52 @@ union futex_key {
>  	} both;
>  };
>  
> +/**
> + * struct futex_q - The hashed futex queue entry, one per waiting task
> + * @list:		priority-sorted list of tasks waiting on this futex
> + * @task:		the task waiting on the futex
> + * @lock_ptr:		the hash bucket lock
> + * @key:		the key the futex is hashed on
> + * @pi_state:		optional priority inheritance state
> + * @rt_waiter:		rt_waiter storage for use with requeue_pi
> + * @requeue_pi_key:	the requeue_pi target futex key
> + * @bitset:		bitset for the optional bitmasked wakeup
> + *
> + * We use this hashed waitqueue, instead of a normal wait_queue_entry_t, so
> + * we can wake only the relevant ones (hashed queues may be shared).
> + *
> + * A futex_q has a woken state, just like tasks have TASK_RUNNING.
> + * It is considered woken when plist_node_empty(&q->list) || q->lock_ptr == 0.
> + * The order of wakeup is always to make the first condition true, then
> + * the second.
> + *
> + * PI futexes are typically woken before they are removed from the hash list via
> + * the rt_mutex code. See unqueue_me_pi().
> + */
> +struct futex_q {
> +	struct plist_node list;
> +
> +	struct task_struct *task;
> +	spinlock_t *lock_ptr;
> +	union futex_key key;
> +	struct futex_pi_state *pi_state;
> +	struct rt_mutex_waiter *rt_waiter;
> +	union futex_key *requeue_pi_key;
> +	u32 bitset;
> +} __randomize_layout;
> +
>  #define FUTEX_KEY_INIT (union futex_key) { .both = { .ptr = 0ULL } }
>  
> +static const struct futex_q futex_q_init = {
> +	/* list gets initialized in queue_me()*/
> +	.key = FUTEX_KEY_INIT,
> +	.bitset = FUTEX_BITSET_MATCH_ANY
> +};
> +
> +inline struct hrtimer_sleeper *
> +futex_setup_timer(ktime_t *time, struct hrtimer_sleeper *timeout,
> +		  int flags, u64 range_ns);
> +

None of these things belong into the global header. Please move them to
kernel/futex.h.

Thanks,

        tglx
  

Patch

diff --git a/include/linux/futex.h b/include/linux/futex.h
index b70df27d7e85..f7a0f4a4b5f0 100644
--- a/include/linux/futex.h
+++ b/include/linux/futex.h
@@ -11,6 +11,22 @@  struct inode;
 struct mm_struct;
 struct task_struct;
 
+/*
+ * Futex flags used to encode options to functions and preserve them across
+ * restarts.
+ */
+#ifdef CONFIG_MMU
+# define FLAGS_SHARED		0x01
+#else
+/*
+ * NOMMU does not have per process address space. Let the compiler optimize
+ * code away.
+ */
+# define FLAGS_SHARED		0x00
+#endif
+#define FLAGS_CLOCKRT		0x02
+#define FLAGS_HAS_TIMEOUT	0x04
+
 /*
  * Futexes are matched on equal values of this key.
  * The key type depends on whether it's a shared or private mapping.
@@ -50,8 +66,52 @@  union futex_key {
 	} both;
 };
 
+/**
+ * struct futex_q - The hashed futex queue entry, one per waiting task
+ * @list:		priority-sorted list of tasks waiting on this futex
+ * @task:		the task waiting on the futex
+ * @lock_ptr:		the hash bucket lock
+ * @key:		the key the futex is hashed on
+ * @pi_state:		optional priority inheritance state
+ * @rt_waiter:		rt_waiter storage for use with requeue_pi
+ * @requeue_pi_key:	the requeue_pi target futex key
+ * @bitset:		bitset for the optional bitmasked wakeup
+ *
+ * We use this hashed waitqueue, instead of a normal wait_queue_entry_t, so
+ * we can wake only the relevant ones (hashed queues may be shared).
+ *
+ * A futex_q has a woken state, just like tasks have TASK_RUNNING.
+ * It is considered woken when plist_node_empty(&q->list) || q->lock_ptr == 0.
+ * The order of wakeup is always to make the first condition true, then
+ * the second.
+ *
+ * PI futexes are typically woken before they are removed from the hash list via
+ * the rt_mutex code. See unqueue_me_pi().
+ */
+struct futex_q {
+	struct plist_node list;
+
+	struct task_struct *task;
+	spinlock_t *lock_ptr;
+	union futex_key key;
+	struct futex_pi_state *pi_state;
+	struct rt_mutex_waiter *rt_waiter;
+	union futex_key *requeue_pi_key;
+	u32 bitset;
+} __randomize_layout;
+
 #define FUTEX_KEY_INIT (union futex_key) { .both = { .ptr = 0ULL } }
 
+static const struct futex_q futex_q_init = {
+	/* list gets initialized in queue_me()*/
+	.key = FUTEX_KEY_INIT,
+	.bitset = FUTEX_BITSET_MATCH_ANY
+};
+
+inline struct hrtimer_sleeper *
+futex_setup_timer(ktime_t *time, struct hrtimer_sleeper *timeout,
+		  int flags, u64 range_ns);
+
 #ifdef CONFIG_FUTEX
 enum {
 	FUTEX_STATE_OK,
diff --git a/kernel/futex.c b/kernel/futex.c
index 2ecb07575055..c07cb0f747ac 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -187,46 +187,6 @@  struct futex_pi_state {
 	union futex_key key;
 } __randomize_layout;
 
-/**
- * struct futex_q - The hashed futex queue entry, one per waiting task
- * @list:		priority-sorted list of tasks waiting on this futex
- * @task:		the task waiting on the futex
- * @lock_ptr:		the hash bucket lock
- * @key:		the key the futex is hashed on
- * @pi_state:		optional priority inheritance state
- * @rt_waiter:		rt_waiter storage for use with requeue_pi
- * @requeue_pi_key:	the requeue_pi target futex key
- * @bitset:		bitset for the optional bitmasked wakeup
- *
- * We use this hashed waitqueue, instead of a normal wait_queue_entry_t, so
- * we can wake only the relevant ones (hashed queues may be shared).
- *
- * A futex_q has a woken state, just like tasks have TASK_RUNNING.
- * It is considered woken when plist_node_empty(&q->list) || q->lock_ptr == 0.
- * The order of wakeup is always to make the first condition true, then
- * the second.
- *
- * PI futexes are typically woken before they are removed from the hash list via
- * the rt_mutex code. See unqueue_me_pi().
- */
-struct futex_q {
-	struct plist_node list;
-
-	struct task_struct *task;
-	spinlock_t *lock_ptr;
-	union futex_key key;
-	struct futex_pi_state *pi_state;
-	struct rt_mutex_waiter *rt_waiter;
-	union futex_key *requeue_pi_key;
-	u32 bitset;
-} __randomize_layout;
-
-static const struct futex_q futex_q_init = {
-	/* list gets initialized in queue_me()*/
-	.key = FUTEX_KEY_INIT,
-	.bitset = FUTEX_BITSET_MATCH_ANY
-};
-
 /*
  * Hash buckets are shared by all the futex_keys that hash to the same
  * location.  Each key may have multiple futex_q structures, one for each task
@@ -395,7 +355,7 @@  enum futex_access {
  * Return: Initialized hrtimer_sleeper structure or NULL if no timeout
  *	   value given
  */
-static inline struct hrtimer_sleeper *
+inline struct hrtimer_sleeper *
 futex_setup_timer(ktime_t *time, struct hrtimer_sleeper *timeout,
 		  int flags, u64 range_ns)
 {