kernel_optimize_test/include/linux/rbtree_augmented.h
Kees Cook f231aebfc4 rbtree: use designated initializers
Prepare to mark sensitive kernel structures for randomization by making
sure they're using designated initializers.  These were identified
during allyesconfig builds of x86, arm, and arm64, with most initializer
fixes extracted from grsecurity.

Link: http://lkml.kernel.org/r/20161217010253.GA140470@beast
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Jie Chen <fykcee1@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-24 17:46:57 -08:00

265 lines
7.9 KiB
C

/*
Red Black Trees
(C) 1999 Andrea Arcangeli <andrea@suse.de>
(C) 2002 David Woodhouse <dwmw2@infradead.org>
(C) 2012 Michel Lespinasse <walken@google.com>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
linux/include/linux/rbtree_augmented.h
*/
#ifndef _LINUX_RBTREE_AUGMENTED_H
#define _LINUX_RBTREE_AUGMENTED_H
#include <linux/compiler.h>
#include <linux/rbtree.h>
/*
* Please note - only struct rb_augment_callbacks and the prototypes for
* rb_insert_augmented() and rb_erase_augmented() are intended to be public.
* The rest are implementation details you are not expected to depend on.
*
* See Documentation/rbtree.txt for documentation and samples.
*/
struct rb_augment_callbacks {
void (*propagate)(struct rb_node *node, struct rb_node *stop);
void (*copy)(struct rb_node *old, struct rb_node *new);
void (*rotate)(struct rb_node *old, struct rb_node *new);
};
extern void __rb_insert_augmented(struct rb_node *node, struct rb_root *root,
void (*augment_rotate)(struct rb_node *old, struct rb_node *new));
/*
* Fixup the rbtree and update the augmented information when rebalancing.
*
* On insertion, the user must update the augmented information on the path
* leading to the inserted node, then call rb_link_node() as usual and
* rb_augment_inserted() instead of the usual rb_insert_color() call.
* If rb_augment_inserted() rebalances the rbtree, it will callback into
* a user provided function to update the augmented information on the
* affected subtrees.
*/
static inline void
rb_insert_augmented(struct rb_node *node, struct rb_root *root,
const struct rb_augment_callbacks *augment)
{
__rb_insert_augmented(node, root, augment->rotate);
}
#define RB_DECLARE_CALLBACKS(rbstatic, rbname, rbstruct, rbfield, \
rbtype, rbaugmented, rbcompute) \
static inline void \
rbname ## _propagate(struct rb_node *rb, struct rb_node *stop) \
{ \
while (rb != stop) { \
rbstruct *node = rb_entry(rb, rbstruct, rbfield); \
rbtype augmented = rbcompute(node); \
if (node->rbaugmented == augmented) \
break; \
node->rbaugmented = augmented; \
rb = rb_parent(&node->rbfield); \
} \
} \
static inline void \
rbname ## _copy(struct rb_node *rb_old, struct rb_node *rb_new) \
{ \
rbstruct *old = rb_entry(rb_old, rbstruct, rbfield); \
rbstruct *new = rb_entry(rb_new, rbstruct, rbfield); \
new->rbaugmented = old->rbaugmented; \
} \
static void \
rbname ## _rotate(struct rb_node *rb_old, struct rb_node *rb_new) \
{ \
rbstruct *old = rb_entry(rb_old, rbstruct, rbfield); \
rbstruct *new = rb_entry(rb_new, rbstruct, rbfield); \
new->rbaugmented = old->rbaugmented; \
old->rbaugmented = rbcompute(old); \
} \
rbstatic const struct rb_augment_callbacks rbname = { \
.propagate = rbname ## _propagate, \
.copy = rbname ## _copy, \
.rotate = rbname ## _rotate \
};
#define RB_RED 0
#define RB_BLACK 1
#define __rb_parent(pc) ((struct rb_node *)(pc & ~3))
#define __rb_color(pc) ((pc) & 1)
#define __rb_is_black(pc) __rb_color(pc)
#define __rb_is_red(pc) (!__rb_color(pc))
#define rb_color(rb) __rb_color((rb)->__rb_parent_color)
#define rb_is_red(rb) __rb_is_red((rb)->__rb_parent_color)
#define rb_is_black(rb) __rb_is_black((rb)->__rb_parent_color)
static inline void rb_set_parent(struct rb_node *rb, struct rb_node *p)
{
rb->__rb_parent_color = rb_color(rb) | (unsigned long)p;
}
static inline void rb_set_parent_color(struct rb_node *rb,
struct rb_node *p, int color)
{
rb->__rb_parent_color = (unsigned long)p | color;
}
static inline void
__rb_change_child(struct rb_node *old, struct rb_node *new,
struct rb_node *parent, struct rb_root *root)
{
if (parent) {
if (parent->rb_left == old)
WRITE_ONCE(parent->rb_left, new);
else
WRITE_ONCE(parent->rb_right, new);
} else
WRITE_ONCE(root->rb_node, new);
}
static inline void
__rb_change_child_rcu(struct rb_node *old, struct rb_node *new,
struct rb_node *parent, struct rb_root *root)
{
if (parent) {
if (parent->rb_left == old)
rcu_assign_pointer(parent->rb_left, new);
else
rcu_assign_pointer(parent->rb_right, new);
} else
rcu_assign_pointer(root->rb_node, new);
}
extern void __rb_erase_color(struct rb_node *parent, struct rb_root *root,
void (*augment_rotate)(struct rb_node *old, struct rb_node *new));
static __always_inline struct rb_node *
__rb_erase_augmented(struct rb_node *node, struct rb_root *root,
const struct rb_augment_callbacks *augment)
{
struct rb_node *child = node->rb_right;
struct rb_node *tmp = node->rb_left;
struct rb_node *parent, *rebalance;
unsigned long pc;
if (!tmp) {
/*
* Case 1: node to erase has no more than 1 child (easy!)
*
* Note that if there is one child it must be red due to 5)
* and node must be black due to 4). We adjust colors locally
* so as to bypass __rb_erase_color() later on.
*/
pc = node->__rb_parent_color;
parent = __rb_parent(pc);
__rb_change_child(node, child, parent, root);
if (child) {
child->__rb_parent_color = pc;
rebalance = NULL;
} else
rebalance = __rb_is_black(pc) ? parent : NULL;
tmp = parent;
} else if (!child) {
/* Still case 1, but this time the child is node->rb_left */
tmp->__rb_parent_color = pc = node->__rb_parent_color;
parent = __rb_parent(pc);
__rb_change_child(node, tmp, parent, root);
rebalance = NULL;
tmp = parent;
} else {
struct rb_node *successor = child, *child2;
tmp = child->rb_left;
if (!tmp) {
/*
* Case 2: node's successor is its right child
*
* (n) (s)
* / \ / \
* (x) (s) -> (x) (c)
* \
* (c)
*/
parent = successor;
child2 = successor->rb_right;
augment->copy(node, successor);
} else {
/*
* Case 3: node's successor is leftmost under
* node's right child subtree
*
* (n) (s)
* / \ / \
* (x) (y) -> (x) (y)
* / /
* (p) (p)
* / /
* (s) (c)
* \
* (c)
*/
do {
parent = successor;
successor = tmp;
tmp = tmp->rb_left;
} while (tmp);
child2 = successor->rb_right;
WRITE_ONCE(parent->rb_left, child2);
WRITE_ONCE(successor->rb_right, child);
rb_set_parent(child, successor);
augment->copy(node, successor);
augment->propagate(parent, successor);
}
tmp = node->rb_left;
WRITE_ONCE(successor->rb_left, tmp);
rb_set_parent(tmp, successor);
pc = node->__rb_parent_color;
tmp = __rb_parent(pc);
__rb_change_child(node, successor, tmp, root);
if (child2) {
successor->__rb_parent_color = pc;
rb_set_parent_color(child2, parent, RB_BLACK);
rebalance = NULL;
} else {
unsigned long pc2 = successor->__rb_parent_color;
successor->__rb_parent_color = pc;
rebalance = __rb_is_black(pc2) ? parent : NULL;
}
tmp = successor;
}
augment->propagate(tmp, NULL);
return rebalance;
}
static __always_inline void
rb_erase_augmented(struct rb_node *node, struct rb_root *root,
const struct rb_augment_callbacks *augment)
{
struct rb_node *rebalance = __rb_erase_augmented(node, root, augment);
if (rebalance)
__rb_erase_color(rebalance, root, augment->rotate);
}
#endif /* _LINUX_RBTREE_AUGMENTED_H */