linux-zen-desktop/kernel/module/tree_lookup.c

113 lines
2.6 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Modules tree lookup
*
* Copyright (C) 2015 Peter Zijlstra
* Copyright (C) 2015 Rusty Russell
*/
#include <linux/module.h>
#include <linux/rbtree_latch.h>
#include "internal.h"
/*
* Use a latched RB-tree for __module_address(); this allows us to use
* RCU-sched lookups of the address from any context.
*
* This is conditional on PERF_EVENTS || TRACING because those can really hit
* __module_address() hard by doing a lot of stack unwinding; potentially from
* NMI context.
*/
static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n)
{
struct module_memory *mod_mem = container_of(n, struct module_memory, mtn.node);
return (unsigned long)mod_mem->base;
}
static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n)
{
struct module_memory *mod_mem = container_of(n, struct module_memory, mtn.node);
return (unsigned long)mod_mem->size;
}
static __always_inline bool
mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b)
{
return __mod_tree_val(a) < __mod_tree_val(b);
}
static __always_inline int
mod_tree_comp(void *key, struct latch_tree_node *n)
{
unsigned long val = (unsigned long)key;
unsigned long start, end;
start = __mod_tree_val(n);
if (val < start)
return -1;
end = start + __mod_tree_size(n);
if (val >= end)
return 1;
return 0;
}
static const struct latch_tree_ops mod_tree_ops = {
.less = mod_tree_less,
.comp = mod_tree_comp,
};
static noinline void __mod_tree_insert(struct mod_tree_node *node, struct mod_tree_root *tree)
{
latch_tree_insert(&node->node, &tree->root, &mod_tree_ops);
}
static void __mod_tree_remove(struct mod_tree_node *node, struct mod_tree_root *tree)
{
latch_tree_erase(&node->node, &tree->root, &mod_tree_ops);
}
/*
* These modifications: insert, remove_init and remove; are serialized by the
* module_mutex.
*/
void mod_tree_insert(struct module *mod)
{
for_each_mod_mem_type(type) {
mod->mem[type].mtn.mod = mod;
if (mod->mem[type].size)
__mod_tree_insert(&mod->mem[type].mtn, &mod_tree);
}
}
void mod_tree_remove_init(struct module *mod)
{
for_class_mod_mem_type(type, init) {
if (mod->mem[type].size)
__mod_tree_remove(&mod->mem[type].mtn, &mod_tree);
}
}
void mod_tree_remove(struct module *mod)
{
for_each_mod_mem_type(type) {
if (mod->mem[type].size)
__mod_tree_remove(&mod->mem[type].mtn, &mod_tree);
}
}
struct module *mod_find(unsigned long addr, struct mod_tree_root *tree)
{
struct latch_tree_node *ltn;
ltn = latch_tree_find((void *)addr, &tree->root, &mod_tree_ops);
if (!ltn)
return NULL;
return container_of(ltn, struct mod_tree_node, node)->mod;
}