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authorSascha Hauer <s.hauer@pengutronix.de>2020-06-11 20:43:56 +0200
committerSascha Hauer <s.hauer@pengutronix.de>2020-06-17 07:08:44 +0200
commitb31478f0ba4dcb4f9cc3e1c3c404c106702b4ccf (patch)
tree5cf5a5ceb260a1884b74a155dbbc6f87928e0e48
parent6c1e7688df94a9d4dfebeb62266f7fc91c209d8a (diff)
downloadbarebox-b31478f0ba4dcb4f9cc3e1c3c404c106702b4ccf.tar.gz
barebox-b31478f0ba4dcb4f9cc3e1c3c404c106702b4ccf.tar.xz
update list.h from Linux-5.7
This updates include/linux/list.h from Linux-5.7. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
-rw-r--r--drivers/usb/gadget/pxa27x_udc.c1
-rw-r--r--drivers/usb/musb/musb_core.c2
-rw-r--r--include/linux/compiler.h1
-rw-r--r--include/linux/list.h700
-rw-r--r--include/linux/poison.h26
-rw-r--r--include/linux/types.h12
6 files changed, 581 insertions, 161 deletions
diff --git a/drivers/usb/gadget/pxa27x_udc.c b/drivers/usb/gadget/pxa27x_udc.c
index 442c90ca05..30c9d7db7a 100644
--- a/drivers/usb/gadget/pxa27x_udc.c
+++ b/drivers/usb/gadget/pxa27x_udc.c
@@ -341,7 +341,6 @@ static int write_packet(struct pxa_ep *ep, struct pxa27x_request *req,
u8 *buf_8;
buf = (u32 *)(req->req.buf + req->req.actual);
- prefetch(buf);
length = min(req->req.length - req->req.actual, max);
req->req.actual += length;
diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
index b84da5516c..9fdef8679b 100644
--- a/drivers/usb/musb/musb_core.c
+++ b/drivers/usb/musb/musb_core.c
@@ -215,8 +215,6 @@ void musb_write_fifo(struct musb_hw_ep *hw_ep, u16 len, const u8 *src)
if (unlikely(len == 0))
return;
- prefetch((u8 *)src);
-
dev_dbg(musb->controller, "%cX ep%d fifo %p count %d buf %p\n",
'T', hw_ep->epnum, fifo, len, src);
diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index f597c7abae..f61a458414 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -250,7 +250,6 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s
__read_once_size(&(x), __u.__c, sizeof(x)); \
else \
__read_once_size_nocheck(&(x), __u.__c, sizeof(x)); \
- smp_read_barrier_depends(); /* Enforce dependency ordering from x */ \
__u.__val; \
})
#define READ_ONCE(x) __READ_ONCE(x, 1)
diff --git a/include/linux/list.h b/include/linux/list.h
index af5edc9a76..1341806b59 100644
--- a/include/linux/list.h
+++ b/include/linux/list.h
@@ -1,7 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_LIST_H
#define _LINUX_LIST_H
-#include <linux/stddef.h> /* for NULL */
+#include <linux/types.h>
+#include <linux/stddef.h>
+#include <linux/poison.h>
+#include <linux/const.h>
#include <linux/kernel.h>
/*
@@ -14,46 +18,60 @@
* using the generic single-entry routines.
*/
-#define LIST_POISON1 ((void *) 0x00100100)
-#define LIST_POISON2 ((void *) 0x00200200)
-static inline void prefetch(const void *x) {;}
-
-struct list_head {
- struct list_head *next, *prev;
-};
-
#define LIST_HEAD_INIT(name) { &(name), &(name) }
#define LIST_HEAD(name) \
struct list_head name = LIST_HEAD_INIT(name)
+/**
+ * INIT_LIST_HEAD - Initialize a list_head structure
+ * @list: list_head structure to be initialized.
+ *
+ * Initializes the list_head to point to itself. If it is a list header,
+ * the result is an empty list.
+ */
static inline void INIT_LIST_HEAD(struct list_head *list)
{
- list->next = list;
+ WRITE_ONCE(list->next, list);
list->prev = list;
}
+#ifdef CONFIG_DEBUG_LIST
+extern bool __list_add_valid(struct list_head *new,
+ struct list_head *prev,
+ struct list_head *next);
+extern bool __list_del_entry_valid(struct list_head *entry);
+#else
+static inline bool __list_add_valid(struct list_head *new,
+ struct list_head *prev,
+ struct list_head *next)
+{
+ return true;
+}
+static inline bool __list_del_entry_valid(struct list_head *entry)
+{
+ return true;
+}
+#endif
+
/*
* Insert a new entry between two known consecutive entries.
*
* This is only for internal list manipulation where we know
* the prev/next entries already!
*/
-#ifndef CONFIG_DEBUG_LIST
static inline void __list_add(struct list_head *new,
struct list_head *prev,
struct list_head *next)
{
+ if (!__list_add_valid(new, prev, next))
+ return;
+
next->prev = new;
new->next = next;
new->prev = prev;
- prev->next = new;
+ WRITE_ONCE(prev->next, new);
}
-#else
-extern void __list_add(struct list_head *new,
- struct list_head *prev,
- struct list_head *next);
-#endif
/**
* list_add - add a new entry
@@ -63,14 +81,10 @@ extern void __list_add(struct list_head *new,
* Insert a new entry after the specified head.
* This is good for implementing stacks.
*/
-#ifndef CONFIG_DEBUG_LIST
static inline void list_add(struct list_head *new, struct list_head *head)
{
__list_add(new, head, head->next);
}
-#else
-extern void list_add(struct list_head *new, struct list_head *head);
-#endif
/**
@@ -96,7 +110,29 @@ static inline void list_add_tail(struct list_head *new, struct list_head *head)
static inline void __list_del(struct list_head * prev, struct list_head * next)
{
next->prev = prev;
- prev->next = next;
+ WRITE_ONCE(prev->next, next);
+}
+
+/*
+ * Delete a list entry and clear the 'prev' pointer.
+ *
+ * This is a special-purpose list clearing method used in the networking code
+ * for lists allocated as per-cpu, where we don't want to incur the extra
+ * WRITE_ONCE() overhead of a regular list_del_init(). The code that uses this
+ * needs to check the node 'prev' pointer instead of calling list_empty().
+ */
+static inline void __list_del_clearprev(struct list_head *entry)
+{
+ __list_del(entry->prev, entry->next);
+ entry->prev = NULL;
+}
+
+static inline void __list_del_entry(struct list_head *entry)
+{
+ if (!__list_del_entry_valid(entry))
+ return;
+
+ __list_del(entry->prev, entry->next);
}
/**
@@ -105,16 +141,12 @@ static inline void __list_del(struct list_head * prev, struct list_head * next)
* Note: list_empty() on entry does not return true after this, the entry is
* in an undefined state.
*/
-#ifndef CONFIG_DEBUG_LIST
static inline void list_del(struct list_head *entry)
{
- __list_del(entry->prev, entry->next);
+ __list_del_entry(entry);
entry->next = LIST_POISON1;
entry->prev = LIST_POISON2;
}
-#else
-extern void list_del(struct list_head *entry);
-#endif
/**
* list_replace - replace old entry by new one
@@ -132,20 +164,44 @@ static inline void list_replace(struct list_head *old,
new->prev->next = new;
}
+/**
+ * list_replace_init - replace old entry by new one and initialize the old one
+ * @old : the element to be replaced
+ * @new : the new element to insert
+ *
+ * If @old was empty, it will be overwritten.
+ */
static inline void list_replace_init(struct list_head *old,
- struct list_head *new)
+ struct list_head *new)
{
list_replace(old, new);
INIT_LIST_HEAD(old);
}
/**
+ * list_swap - replace entry1 with entry2 and re-add entry1 at entry2's position
+ * @entry1: the location to place entry2
+ * @entry2: the location to place entry1
+ */
+static inline void list_swap(struct list_head *entry1,
+ struct list_head *entry2)
+{
+ struct list_head *pos = entry2->prev;
+
+ list_del(entry2);
+ list_replace(entry1, entry2);
+ if (pos == entry1)
+ pos = entry2;
+ list_add(entry1, pos);
+}
+
+/**
* list_del_init - deletes entry from list and reinitialize it.
* @entry: the element to delete from the list.
*/
static inline void list_del_init(struct list_head *entry)
{
- __list_del(entry->prev, entry->next);
+ __list_del_entry(entry);
INIT_LIST_HEAD(entry);
}
@@ -156,7 +212,7 @@ static inline void list_del_init(struct list_head *entry)
*/
static inline void list_move(struct list_head *list, struct list_head *head)
{
- __list_del(list->prev, list->next);
+ __list_del_entry(list);
list_add(list, head);
}
@@ -168,11 +224,45 @@ static inline void list_move(struct list_head *list, struct list_head *head)
static inline void list_move_tail(struct list_head *list,
struct list_head *head)
{
- __list_del(list->prev, list->next);
+ __list_del_entry(list);
list_add_tail(list, head);
}
/**
+ * list_bulk_move_tail - move a subsection of a list to its tail
+ * @head: the head that will follow our entry
+ * @first: first entry to move
+ * @last: last entry to move, can be the same as first
+ *
+ * Move all entries between @first and including @last before @head.
+ * All three entries must belong to the same linked list.
+ */
+static inline void list_bulk_move_tail(struct list_head *head,
+ struct list_head *first,
+ struct list_head *last)
+{
+ first->prev->next = last->next;
+ last->next->prev = first->prev;
+
+ head->prev->next = first;
+ first->prev = head->prev;
+
+ last->next = head;
+ head->prev = last;
+}
+
+/**
+ * list_is_first -- tests whether @list is the first entry in list @head
+ * @list: the entry to test
+ * @head: the head of the list
+ */
+static inline int list_is_first(const struct list_head *list,
+ const struct list_head *head)
+{
+ return list->prev == head;
+}
+
+/**
* list_is_last - tests whether @list is the last entry in list @head
* @list: the entry to test
* @head: the head of the list
@@ -189,7 +279,7 @@ static inline int list_is_last(const struct list_head *list,
*/
static inline int list_empty(const struct list_head *head)
{
- return head->next == head;
+ return READ_ONCE(head->next) == head;
}
/**
@@ -212,6 +302,38 @@ static inline int list_empty_careful(const struct list_head *head)
}
/**
+ * list_rotate_left - rotate the list to the left
+ * @head: the head of the list
+ */
+static inline void list_rotate_left(struct list_head *head)
+{
+ struct list_head *first;
+
+ if (!list_empty(head)) {
+ first = head->next;
+ list_move_tail(first, head);
+ }
+}
+
+/**
+ * list_rotate_to_front() - Rotate list to specific item.
+ * @list: The desired new front of the list.
+ * @head: The head of the list.
+ *
+ * Rotates list so that @list becomes the new front of the list.
+ */
+static inline void list_rotate_to_front(struct list_head *list,
+ struct list_head *head)
+{
+ /*
+ * Deletes the list head from the list denoted by @head and
+ * places it as the tail of @list, this effectively rotates the
+ * list so that @list is at the front.
+ */
+ list_move_tail(head, list);
+}
+
+/**
* list_is_singular - tests whether a list has just one entry.
* @head: the list to test.
*/
@@ -220,29 +342,112 @@ static inline int list_is_singular(const struct list_head *head)
return !list_empty(head) && (head->next == head->prev);
}
-static inline void __list_splice(struct list_head *list,
- struct list_head *head)
+static inline void __list_cut_position(struct list_head *list,
+ struct list_head *head, struct list_head *entry)
+{
+ struct list_head *new_first = entry->next;
+ list->next = head->next;
+ list->next->prev = list;
+ list->prev = entry;
+ entry->next = list;
+ head->next = new_first;
+ new_first->prev = head;
+}
+
+/**
+ * list_cut_position - cut a list into two
+ * @list: a new list to add all removed entries
+ * @head: a list with entries
+ * @entry: an entry within head, could be the head itself
+ * and if so we won't cut the list
+ *
+ * This helper moves the initial part of @head, up to and
+ * including @entry, from @head to @list. You should
+ * pass on @entry an element you know is on @head. @list
+ * should be an empty list or a list you do not care about
+ * losing its data.
+ *
+ */
+static inline void list_cut_position(struct list_head *list,
+ struct list_head *head, struct list_head *entry)
+{
+ if (list_empty(head))
+ return;
+ if (list_is_singular(head) &&
+ (head->next != entry && head != entry))
+ return;
+ if (entry == head)
+ INIT_LIST_HEAD(list);
+ else
+ __list_cut_position(list, head, entry);
+}
+
+/**
+ * list_cut_before - cut a list into two, before given entry
+ * @list: a new list to add all removed entries
+ * @head: a list with entries
+ * @entry: an entry within head, could be the head itself
+ *
+ * This helper moves the initial part of @head, up to but
+ * excluding @entry, from @head to @list. You should pass
+ * in @entry an element you know is on @head. @list should
+ * be an empty list or a list you do not care about losing
+ * its data.
+ * If @entry == @head, all entries on @head are moved to
+ * @list.
+ */
+static inline void list_cut_before(struct list_head *list,
+ struct list_head *head,
+ struct list_head *entry)
+{
+ if (head->next == entry) {
+ INIT_LIST_HEAD(list);
+ return;
+ }
+ list->next = head->next;
+ list->next->prev = list;
+ list->prev = entry->prev;
+ list->prev->next = list;
+ head->next = entry;
+ entry->prev = head;
+}
+
+static inline void __list_splice(const struct list_head *list,
+ struct list_head *prev,
+ struct list_head *next)
{
struct list_head *first = list->next;
struct list_head *last = list->prev;
- struct list_head *at = head->next;
- first->prev = head;
- head->next = first;
+ first->prev = prev;
+ prev->next = first;
- last->next = at;
- at->prev = last;
+ last->next = next;
+ next->prev = last;
+}
+
+/**
+ * list_splice - join two lists, this is designed for stacks
+ * @list: the new list to add.
+ * @head: the place to add it in the first list.
+ */
+static inline void list_splice(const struct list_head *list,
+ struct list_head *head)
+{
+ if (!list_empty(list))
+ __list_splice(list, head, head->next);
}
/**
- * list_splice - join two lists
+ * list_splice_tail - join two lists, each list being a queue
* @list: the new list to add.
* @head: the place to add it in the first list.
*/
-static inline void list_splice(struct list_head *list, struct list_head *head)
+static inline void list_splice_tail(struct list_head *list,
+ struct list_head *head)
{
if (!list_empty(list))
- __list_splice(list, head);
+ __list_splice(list, head->prev, head);
}
/**
@@ -256,7 +461,24 @@ static inline void list_splice_init(struct list_head *list,
struct list_head *head)
{
if (!list_empty(list)) {
- __list_splice(list, head);
+ __list_splice(list, head, head->next);
+ INIT_LIST_HEAD(list);
+ }
+}
+
+/**
+ * list_splice_tail_init - join two lists and reinitialise the emptied list
+ * @list: the new list to add.
+ * @head: the place to add it in the first list.
+ *
+ * Each of the lists is a queue.
+ * The list at @list is reinitialised
+ */
+static inline void list_splice_tail_init(struct list_head *list,
+ struct list_head *head)
+{
+ if (!list_empty(list)) {
+ __list_splice(list, head->prev, head);
INIT_LIST_HEAD(list);
}
}
@@ -265,7 +487,7 @@ static inline void list_splice_init(struct list_head *list,
* list_entry - get the struct for this entry
* @ptr: the &struct list_head pointer.
* @type: the type of the struct this is embedded in.
- * @member: the name of the list_struct within the struct.
+ * @member: the name of the list_head within the struct.
*/
#define list_entry(ptr, type, member) \
container_of(ptr, type, member)
@@ -274,7 +496,7 @@ static inline void list_splice_init(struct list_head *list,
* list_first_entry - get the first element from a list
* @ptr: the list head to take the element from.
* @type: the type of the struct this is embedded in.
- * @member: the name of the list_struct within the struct.
+ * @member: the name of the list_head within the struct.
*
* Note, that list is expected to be not empty.
*/
@@ -283,25 +505,44 @@ static inline void list_splice_init(struct list_head *list,
/**
* list_last_entry - get the last element from a list
- * @head: the list head to take the element from.
- * @type: the type of the struct this is embedded in.
- * @member: the name of the list_struct within the struct.
+ * @ptr: the list head to take the element from.
+ * @type: the type of the struct this is embedded in.
+ * @member: the name of the list_head within the struct.
*
* Note, that list is expected to be not empty.
*/
-#define list_last_entry(head, type, member) \
- list_entry((head)->prev, type, member)
+#define list_last_entry(ptr, type, member) \
+ list_entry((ptr)->prev, type, member)
/**
* list_first_entry_or_null - get the first element from a list
* @ptr: the list head to take the element from.
* @type: the type of the struct this is embedded in.
- * @member: the name of the list_struct within the struct.
+ * @member: the name of the list_head within the struct.
*
* Note that if the list is empty, it returns NULL.
*/
-#define list_first_entry_or_null(ptr, type, member) \
- (!list_empty(ptr) ? list_first_entry(ptr, type, member) : NULL)
+#define list_first_entry_or_null(ptr, type, member) ({ \
+ struct list_head *head__ = (ptr); \
+ struct list_head *pos__ = READ_ONCE(head__->next); \
+ pos__ != head__ ? list_entry(pos__, type, member) : NULL; \
+})
+
+/**
+ * list_next_entry - get the next element in list
+ * @pos: the type * to cursor
+ * @member: the name of the list_head within the struct.
+ */
+#define list_next_entry(pos, member) \
+ list_entry((pos)->member.next, typeof(*(pos)), member)
+
+/**
+ * list_prev_entry - get the prev element in list
+ * @pos: the type * to cursor
+ * @member: the name of the list_head within the struct.
+ */
+#define list_prev_entry(pos, member) \
+ list_entry((pos)->member.prev, typeof(*(pos)), member)
/**
* list_for_each - iterate over a list
@@ -309,21 +550,17 @@ static inline void list_splice_init(struct list_head *list,
* @head: the head for your list.
*/
#define list_for_each(pos, head) \
- for (pos = (head)->next; prefetch(pos->next), pos != (head); \
- pos = pos->next)
+ for (pos = (head)->next; pos != (head); pos = pos->next)
/**
- * __list_for_each - iterate over a list
+ * list_for_each_continue - continue iteration over a list
* @pos: the &struct list_head to use as a loop cursor.
* @head: the head for your list.
*
- * This variant differs from list_for_each() in that it's the
- * simplest possible list iteration code, no prefetching is done.
- * Use this for code that knows the list to be very short (empty
- * or 1 entry) most of the time.
+ * Continue to iterate over a list, continuing after the current position.
*/
-#define __list_for_each(pos, head) \
- for (pos = (head)->next; pos != (head); pos = pos->next)
+#define list_for_each_continue(pos, head) \
+ for (pos = pos->next; pos != (head); pos = pos->next)
/**
* list_for_each_prev - iterate over a list backwards
@@ -331,8 +568,7 @@ static inline void list_splice_init(struct list_head *list,
* @head: the head for your list.
*/
#define list_for_each_prev(pos, head) \
- for (pos = (head)->prev; prefetch(pos->prev), pos != (head); \
- pos = pos->prev)
+ for (pos = (head)->prev; pos != (head); pos = pos->prev)
/**
* list_for_each_safe - iterate over a list safe against removal of list entry
@@ -345,32 +581,43 @@ static inline void list_splice_init(struct list_head *list,
pos = n, n = pos->next)
/**
+ * list_for_each_prev_safe - iterate over a list backwards safe against removal of list entry
+ * @pos: the &struct list_head to use as a loop cursor.
+ * @n: another &struct list_head to use as temporary storage
+ * @head: the head for your list.
+ */
+#define list_for_each_prev_safe(pos, n, head) \
+ for (pos = (head)->prev, n = pos->prev; \
+ pos != (head); \
+ pos = n, n = pos->prev)
+
+/**
* list_for_each_entry - iterate over list of given type
* @pos: the type * to use as a loop cursor.
* @head: the head for your list.
- * @member: the name of the list_struct within the struct.
+ * @member: the name of the list_head within the struct.
*/
#define list_for_each_entry(pos, head, member) \
- for (pos = list_entry((head)->next, typeof(*pos), member); \
- prefetch(pos->member.next), &pos->member != (head); \
- pos = list_entry(pos->member.next, typeof(*pos), member))
+ for (pos = list_first_entry(head, typeof(*pos), member); \
+ &pos->member != (head); \
+ pos = list_next_entry(pos, member))
/**
* list_for_each_entry_reverse - iterate backwards over list of given type.
* @pos: the type * to use as a loop cursor.
* @head: the head for your list.
- * @member: the name of the list_struct within the struct.
+ * @member: the name of the list_head within the struct.
*/
#define list_for_each_entry_reverse(pos, head, member) \
- for (pos = list_entry((head)->prev, typeof(*pos), member); \
- prefetch(pos->member.prev), &pos->member != (head); \
- pos = list_entry(pos->member.prev, typeof(*pos), member))
+ for (pos = list_last_entry(head, typeof(*pos), member); \
+ &pos->member != (head); \
+ pos = list_prev_entry(pos, member))
/**
* list_prepare_entry - prepare a pos entry for use in list_for_each_entry_continue()
* @pos: the type * to use as a start point
* @head: the head of the list
- * @member: the name of the list_struct within the struct.
+ * @member: the name of the list_head within the struct.
*
* Prepares a pos entry for use as a start point in list_for_each_entry_continue().
*/
@@ -381,87 +628,129 @@ static inline void list_splice_init(struct list_head *list,
* list_for_each_entry_continue - continue iteration over list of given type
* @pos: the type * to use as a loop cursor.
* @head: the head for your list.
- * @member: the name of the list_struct within the struct.
+ * @member: the name of the list_head within the struct.
*
* Continue to iterate over list of given type, continuing after
* the current position.
*/
#define list_for_each_entry_continue(pos, head, member) \
- for (pos = list_entry(pos->member.next, typeof(*pos), member); \
- prefetch(pos->member.next), &pos->member != (head); \
- pos = list_entry(pos->member.next, typeof(*pos), member))
+ for (pos = list_next_entry(pos, member); \
+ &pos->member != (head); \
+ pos = list_next_entry(pos, member))
+
+/**
+ * list_for_each_entry_continue_reverse - iterate backwards from the given point
+ * @pos: the type * to use as a loop cursor.
+ * @head: the head for your list.
+ * @member: the name of the list_head within the struct.
+ *
+ * Start to iterate over list of given type backwards, continuing after
+ * the current position.
+ */
+#define list_for_each_entry_continue_reverse(pos, head, member) \
+ for (pos = list_prev_entry(pos, member); \
+ &pos->member != (head); \
+ pos = list_prev_entry(pos, member))
/**
* list_for_each_entry_from - iterate over list of given type from the current point
* @pos: the type * to use as a loop cursor.
* @head: the head for your list.
- * @member: the name of the list_struct within the struct.
+ * @member: the name of the list_head within the struct.
*
* Iterate over list of given type, continuing from current position.
*/
#define list_for_each_entry_from(pos, head, member) \
- for (; prefetch(pos->member.next), &pos->member != (head); \
- pos = list_entry(pos->member.next, typeof(*pos), member))
+ for (; &pos->member != (head); \
+ pos = list_next_entry(pos, member))
+
+/**
+ * list_for_each_entry_from_reverse - iterate backwards over list of given type
+ * from the current point
+ * @pos: the type * to use as a loop cursor.
+ * @head: the head for your list.
+ * @member: the name of the list_head within the struct.
+ *
+ * Iterate backwards over list of given type, continuing from current position.
+ */
+#define list_for_each_entry_from_reverse(pos, head, member) \
+ for (; &pos->member != (head); \
+ pos = list_prev_entry(pos, member))
/**
* list_for_each_entry_safe - iterate over list of given type safe against removal of list entry
* @pos: the type * to use as a loop cursor.
* @n: another type * to use as temporary storage
* @head: the head for your list.
- * @member: the name of the list_struct within the struct.
+ * @member: the name of the list_head within the struct.
*/
#define list_for_each_entry_safe(pos, n, head, member) \
- for (pos = list_entry((head)->next, typeof(*pos), member), \
- n = list_entry(pos->member.next, typeof(*pos), member); \
+ for (pos = list_first_entry(head, typeof(*pos), member), \
+ n = list_next_entry(pos, member); \
&pos->member != (head); \
- pos = n, n = list_entry(n->member.next, typeof(*n), member))
+ pos = n, n = list_next_entry(n, member))
/**
- * list_for_each_entry_safe_continue
+ * list_for_each_entry_safe_continue - continue list iteration safe against removal
* @pos: the type * to use as a loop cursor.
* @n: another type * to use as temporary storage
* @head: the head for your list.
- * @member: the name of the list_struct within the struct.
+ * @member: the name of the list_head within the struct.
*
* Iterate over list of given type, continuing after current point,
* safe against removal of list entry.
*/
#define list_for_each_entry_safe_continue(pos, n, head, member) \
- for (pos = list_entry(pos->member.next, typeof(*pos), member), \
- n = list_entry(pos->member.next, typeof(*pos), member); \
+ for (pos = list_next_entry(pos, member), \
+ n = list_next_entry(pos, member); \
&pos->member != (head); \
- pos = n, n = list_entry(n->member.next, typeof(*n), member))
+ pos = n, n = list_next_entry(n, member))
/**
- * list_for_each_entry_safe_from
+ * list_for_each_entry_safe_from - iterate over list from current point safe against removal
* @pos: the type * to use as a loop cursor.
* @n: another type * to use as temporary storage
* @head: the head for your list.
- * @member: the name of the list_struct within the struct.
+ * @member: the name of the list_head within the struct.
*
* Iterate over list of given type from current point, safe against
* removal of list entry.
*/
#define list_for_each_entry_safe_from(pos, n, head, member) \
- for (n = list_entry(pos->member.next, typeof(*pos), member); \
+ for (n = list_next_entry(pos, member); \
&pos->member != (head); \
- pos = n, n = list_entry(n->member.next, typeof(*n), member))
+ pos = n, n = list_next_entry(n, member))
/**
- * list_for_each_entry_safe_reverse
+ * list_for_each_entry_safe_reverse - iterate backwards over list safe against removal
* @pos: the type * to use as a loop cursor.
* @n: another type * to use as temporary storage
* @head: the head for your list.
- * @member: the name of the list_struct within the struct.
+ * @member: the name of the list_head within the struct.
*
* Iterate backwards over list of given type, safe against removal
* of list entry.
*/
#define list_for_each_entry_safe_reverse(pos, n, head, member) \
- for (pos = list_entry((head)->prev, typeof(*pos), member), \
- n = list_entry(pos->member.prev, typeof(*pos), member); \
+ for (pos = list_last_entry(head, typeof(*pos), member), \
+ n = list_prev_entry(pos, member); \
&pos->member != (head); \
- pos = n, n = list_entry(n->member.prev, typeof(*n), member))
+ pos = n, n = list_prev_entry(n, member))
+
+/**
+ * list_safe_reset_next - reset a stale list_for_each_entry_safe loop
+ * @pos: the loop cursor used in the list_for_each_entry_safe loop
+ * @n: temporary storage used in list_for_each_entry_safe
+ * @member: the name of the list_head within the struct.
+ *
+ * list_safe_reset_next is not safe to use in general if the list may be
+ * modified concurrently (eg. the lock is dropped in the loop body). An
+ * exception to this is if the cursor element (pos) is pinned in the list,
+ * and list_safe_reset_next is called after re-taking the lock and before
+ * completing the current iteration of the loop body.
+ */
+#define list_safe_reset_next(pos, n, member) \
+ n = list_next_entry(pos, member)
/**
* list_add_sort - add a new entry to a sorted list
@@ -473,7 +762,7 @@ static inline void list_splice_init(struct list_head *list,
* This is useful for implementing queues.
*/
static inline void list_add_sort(struct list_head *new, struct list_head *head,
- int (*compare)(struct list_head *a, struct list_head *b))
+ int (*compare)(struct list_head *a, struct list_head *b))
{
struct list_head *pos, *insert = head;
@@ -494,14 +783,6 @@ static inline void list_add_sort(struct list_head *new, struct list_head *head,
* You lose the ability to access the tail in O(1).
*/
-struct hlist_head {
- struct hlist_node *first;
-};
-
-struct hlist_node {
- struct hlist_node *next, **pprev;
-};
-
#define HLIST_HEAD_INIT { .first = NULL }
#define HLIST_HEAD(name) struct hlist_head name = { .first = NULL }
#define INIT_HLIST_HEAD(ptr) ((ptr)->first = NULL)
@@ -511,25 +792,58 @@ static inline void INIT_HLIST_NODE(struct hlist_node *h)
h->pprev = NULL;
}
+/**
+ * hlist_unhashed - Has node been removed from list and reinitialized?
+ * @h: Node to be checked
+ *
+ * Not that not all removal functions will leave a node in unhashed
+ * state. For example, hlist_nulls_del_init_rcu() does leave the
+ * node in unhashed state, but hlist_nulls_del() does not.
+ */
static inline int hlist_unhashed(const struct hlist_node *h)
{
return !h->pprev;
}
+/**
+ * hlist_unhashed_lockless - Version of hlist_unhashed for lockless use
+ * @h: Node to be checked
+ *
+ * This variant of hlist_unhashed() must be used in lockless contexts
+ * to avoid potential load-tearing. The READ_ONCE() is paired with the
+ * various WRITE_ONCE() in hlist helpers that are defined below.
+ */
+static inline int hlist_unhashed_lockless(const struct hlist_node *h)
+{
+ return !READ_ONCE(h->pprev);
+}
+
+/**
+ * hlist_empty - Is the specified hlist_head structure an empty hlist?
+ * @h: Structure to check.
+ */
static inline int hlist_empty(const struct hlist_head *h)
{
- return !h->first;
+ return !READ_ONCE(h->first);
}
static inline void __hlist_del(struct hlist_node *n)
{
struct hlist_node *next = n->next;
struct hlist_node **pprev = n->pprev;
- *pprev = next;
+
+ WRITE_ONCE(*pprev, next);
if (next)
- next->pprev = pprev;
+ WRITE_ONCE(next->pprev, pprev);
}
+/**
+ * hlist_del - Delete the specified hlist_node from its list
+ * @n: Node to delete.
+ *
+ * Note that this function leaves the node in hashed state. Use
+ * hlist_del_init() or similar instead to unhash @n.
+ */
static inline void hlist_del(struct hlist_node *n)
{
__hlist_del(n);
@@ -537,6 +851,12 @@ static inline void hlist_del(struct hlist_node *n)
n->pprev = LIST_POISON2;
}
+/**
+ * hlist_del_init - Delete the specified hlist_node from its list and initialize
+ * @n: Node to delete.
+ *
+ * Note that this function leaves the node in unhashed state.
+ */
static inline void hlist_del_init(struct hlist_node *n)
{
if (!hlist_unhashed(n)) {
@@ -545,95 +865,161 @@ static inline void hlist_del_init(struct hlist_node *n)
}
}
+/**
+ * hlist_add_head - add a new entry at the beginning of the hlist
+ * @n: new entry to be added
+ * @h: hlist head to add it after
+ *
+ * Insert a new entry after the specified head.
+ * This is good for implementing stacks.
+ */
static inline void hlist_add_head(struct hlist_node *n, struct hlist_head *h)
{
struct hlist_node *first = h->first;
- n->next = first;
+ WRITE_ONCE(n->next, first);
if (first)
- first->pprev = &n->next;
- h->first = n;
- n->pprev = &h->first;
+ WRITE_ONCE(first->pprev, &n->next);
+ WRITE_ONCE(h->first, n);
+ WRITE_ONCE(n->pprev, &h->first);
}
-/* next must be != NULL */
+/**
+ * hlist_add_before - add a new entry before the one specified
+ * @n: new entry to be added
+ * @next: hlist node to add it before, which must be non-NULL
+ */
static inline void hlist_add_before(struct hlist_node *n,
- struct hlist_node *next)
+ struct hlist_node *next)
+{
+ WRITE_ONCE(n->pprev, next->pprev);
+ WRITE_ONCE(n->next, next);
+ WRITE_ONCE(next->pprev, &n->next);
+ WRITE_ONCE(*(n->pprev), n);
+}
+
+/**
+ * hlist_add_behing - add a new entry after the one specified
+ * @n: new entry to be added
+ * @prev: hlist node to add it after, which must be non-NULL
+ */
+static inline void hlist_add_behind(struct hlist_node *n,
+ struct hlist_node *prev)
{
- n->pprev = next->pprev;
- n->next = next;
- next->pprev = &n->next;
- *(n->pprev) = n;
+ WRITE_ONCE(n->next, prev->next);
+ WRITE_ONCE(prev->next, n);
+ WRITE_ONCE(n->pprev, &prev->next);
+
+ if (n->next)
+ WRITE_ONCE(n->next->pprev, &n->next);
+}
+
+/**
+ * hlist_add_fake - create a fake hlist consisting of a single headless node
+ * @n: Node to make a fake list out of
+ *
+ * This makes @n appear to be its own predecessor on a headless hlist.
+ * The point of this is to allow things like hlist_del() to work correctly
+ * in cases where there is no list.
+ */
+static inline void hlist_add_fake(struct hlist_node *n)
+{
+ n->pprev = &n->next;
}
-static inline void hlist_add_after(struct hlist_node *n,
- struct hlist_node *next)
+/**
+ * hlist_fake: Is this node a fake hlist?
+ * @h: Node to check for being a self-referential fake hlist.
+ */
+static inline bool hlist_fake(struct hlist_node *h)
+{
+ return h->pprev == &h->next;
+}
+
+/**
+ * hlist_is_singular_node - is node the only element of the specified hlist?
+ * @n: Node to check for singularity.
+ * @h: Header for potentially singular list.
+ *
+ * Check whether the node is the only node of the head without
+ * accessing head, thus avoiding unnecessary cache misses.
+ */
+static inline bool
+hlist_is_singular_node(struct hlist_node *n, struct hlist_head *h)
{
- next->next = n->next;
- n->next = next;
- next->pprev = &n->next;
+ return !n->next && n->pprev == &h->first;
+}
- if(next->next)
- next->next->pprev = &next->next;
+/**
+ * hlist_move_list - Move an hlist
+ * @old: hlist_head for old list.
+ * @new: hlist_head for new list.
+ *
+ * Move a list from one list head to another. Fixup the pprev
+ * reference of the first entry if it exists.
+ */
+static inline void hlist_move_list(struct hlist_head *old,
+ struct hlist_head *new)
+{
+ new->first = old->first;
+ if (new->first)
+ new->first->pprev = &new->first;
+ old->first = NULL;
}
#define hlist_entry(ptr, type, member) container_of(ptr,type,member)
#define hlist_for_each(pos, head) \
- for (pos = (head)->first; pos && ({ prefetch(pos->next); 1; }); \
- pos = pos->next)
+ for (pos = (head)->first; pos ; pos = pos->next)
#define hlist_for_each_safe(pos, n, head) \
for (pos = (head)->first; pos && ({ n = pos->next; 1; }); \
pos = n)
+#define hlist_entry_safe(ptr, type, member) \
+ ({ typeof(ptr) ____ptr = (ptr); \
+ ____ptr ? hlist_entry(____ptr, type, member) : NULL; \
+ })
+
/**
* hlist_for_each_entry - iterate over list of given type
- * @tpos: the type * to use as a loop cursor.
- * @pos: the &struct hlist_node to use as a loop cursor.
+ * @pos: the type * to use as a loop cursor.
* @head: the head for your list.
* @member: the name of the hlist_node within the struct.
*/
-#define hlist_for_each_entry(tpos, pos, head, member) \
- for (pos = (head)->first; \
- pos && ({ prefetch(pos->next); 1;}) && \
- ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
- pos = pos->next)
+#define hlist_for_each_entry(pos, head, member) \
+ for (pos = hlist_entry_safe((head)->first, typeof(*(pos)), member);\
+ pos; \
+ pos = hlist_entry_safe((pos)->member.next, typeof(*(pos)), member))
/**
* hlist_for_each_entry_continue - iterate over a hlist continuing after current point
- * @tpos: the type * to use as a loop cursor.
- * @pos: the &struct hlist_node to use as a loop cursor.
+ * @pos: the type * to use as a loop cursor.
* @member: the name of the hlist_node within the struct.
*/
-#define hlist_for_each_entry_continue(tpos, pos, member) \
- for (pos = (pos)->next; \
- pos && ({ prefetch(pos->next); 1;}) && \
- ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
- pos = pos->next)
+#define hlist_for_each_entry_continue(pos, member) \
+ for (pos = hlist_entry_safe((pos)->member.next, typeof(*(pos)), member);\
+ pos; \
+ pos = hlist_entry_safe((pos)->member.next, typeof(*(pos)), member))
/**
* hlist_for_each_entry_from - iterate over a hlist continuing from current point
- * @tpos: the type * to use as a loop cursor.
- * @pos: the &struct hlist_node to use as a loop cursor.
+ * @pos: the type * to use as a loop cursor.
* @member: the name of the hlist_node within the struct.
*/
-#define hlist_for_each_entry_from(tpos, pos, member) \
- for (; pos && ({ prefetch(pos->next); 1;}) && \
- ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
- pos = pos->next)
+#define hlist_for_each_entry_from(pos, member) \
+ for (; pos; \
+ pos = hlist_entry_safe((pos)->member.next, typeof(*(pos)), member))
/**
* hlist_for_each_entry_safe - iterate over list of given type safe against removal of list entry
- * @tpos: the type * to use as a loop cursor.
- * @pos: the &struct hlist_node to use as a loop cursor.
- * @n: another &struct hlist_node to use as temporary storage
+ * @pos: the type * to use as a loop cursor.
+ * @n: a &struct hlist_node to use as temporary storage
* @head: the head for your list.
* @member: the name of the hlist_node within the struct.
*/
-#define hlist_for_each_entry_safe(tpos, pos, n, head, member) \
- for (pos = (head)->first; \
- pos && ({ n = pos->next; 1; }) && \
- ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
- pos = n)
+#define hlist_for_each_entry_safe(pos, n, head, member) \
+ for (pos = hlist_entry_safe((head)->first, typeof(*pos), member);\
+ pos && ({ n = pos->member.next; 1; }); \
+ pos = hlist_entry_safe(n, typeof(*pos), member))
#endif
diff --git a/include/linux/poison.h b/include/linux/poison.h
new file mode 100644
index 0000000000..b92eb2f95b
--- /dev/null
+++ b/include/linux/poison.h
@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_POISON_H
+#define _LINUX_POISON_H
+
+/********** include/linux/list.h **********/
+
+/*
+ * Architectures might want to move the poison pointer offset
+ * into some well-recognized area such as 0xdead000000000000,
+ * that is also not mappable by user-space exploits:
+ */
+#ifdef CONFIG_ILLEGAL_POINTER_VALUE
+# define POISON_POINTER_DELTA _AC(CONFIG_ILLEGAL_POINTER_VALUE, UL)
+#else
+# define POISON_POINTER_DELTA 0
+#endif
+
+/*
+ * These are non-NULL pointers that will result in page faults
+ * under normal circumstances, used to verify that nobody uses
+ * non-initialized list entries.
+ */
+#define LIST_POISON1 ((void *) 0x100 + POISON_POINTER_DELTA)
+#define LIST_POISON2 ((void *) 0x122 + POISON_POINTER_DELTA)
+
+#endif
diff --git a/include/linux/types.h b/include/linux/types.h
index c19d1dc053..fa7684e31e 100644
--- a/include/linux/types.h
+++ b/include/linux/types.h
@@ -206,4 +206,16 @@ struct ustat {
char f_fpack[6];
};
+struct list_head {
+ struct list_head *next, *prev;
+};
+
+struct hlist_head {
+ struct hlist_node *first;
+};
+
+struct hlist_node {
+ struct hlist_node *next, **pprev;
+};
+
#endif /* _LINUX_TYPES_H */