1// SPDX-License-Identifier: GPL-2.0-or-later 2/* 3 * Modules tree lookup 4 * 5 * Copyright (C) 2015 Peter Zijlstra 6 * Copyright (C) 2015 Rusty Russell 7 */ 8 9#include <linux/module.h> 10#include <linux/rbtree_latch.h> 11#include "internal.h" 12 13/* 14 * Use a latched RB-tree for __module_address(); this allows us to use 15 * RCU-sched lookups of the address from any context. 16 * 17 * This is conditional on PERF_EVENTS || TRACING because those can really hit 18 * __module_address() hard by doing a lot of stack unwinding; potentially from 19 * NMI context. 20 */ 21 22static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n) 23{ 24 struct module_memory *mod_mem = container_of(n, struct module_memory, mtn.node); 25 26 return (unsigned long)mod_mem->base; 27} 28 29static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n) 30{ 31 struct module_memory *mod_mem = container_of(n, struct module_memory, mtn.node); 32 33 return (unsigned long)mod_mem->size; 34} 35 36static __always_inline bool 37mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b) 38{ 39 return __mod_tree_val(a) < __mod_tree_val(b); 40} 41 42static __always_inline int 43mod_tree_comp(void *key, struct latch_tree_node *n) 44{ 45 unsigned long val = (unsigned long)key; 46 unsigned long start, end; 47 48 start = __mod_tree_val(n); 49 if (val < start) 50 return -1; 51 52 end = start + __mod_tree_size(n); 53 if (val >= end) 54 return 1; 55 56 return 0; 57} 58 59static const struct latch_tree_ops mod_tree_ops = { 60 .less = mod_tree_less, 61 .comp = mod_tree_comp, 62}; 63 64static noinline void __mod_tree_insert(struct mod_tree_node *node, struct mod_tree_root *tree) 65{ 66 latch_tree_insert(&node->node, &tree->root, &mod_tree_ops); 67} 68 69static void __mod_tree_remove(struct mod_tree_node *node, struct mod_tree_root *tree) 70{ 71 latch_tree_erase(&node->node, &tree->root, &mod_tree_ops); 72} 73 74/* 75 * These modifications: insert, remove_init and remove; are serialized by the 76 * module_mutex. 77 */ 78void mod_tree_insert(struct module *mod) 79{ 80 for_each_mod_mem_type(type) { 81 mod->mem[type].mtn.mod = mod; 82 if (mod->mem[type].size) 83 __mod_tree_insert(&mod->mem[type].mtn, &mod_tree); 84 } 85} 86 87void mod_tree_remove_init(struct module *mod) 88{ 89 for_class_mod_mem_type(type, init) { 90 if (mod->mem[type].size) 91 __mod_tree_remove(&mod->mem[type].mtn, &mod_tree); 92 } 93} 94 95void mod_tree_remove(struct module *mod) 96{ 97 for_each_mod_mem_type(type) { 98 if (mod->mem[type].size) 99 __mod_tree_remove(&mod->mem[type].mtn, &mod_tree); 100 } 101} 102 103struct module *mod_find(unsigned long addr, struct mod_tree_root *tree) 104{ 105 struct latch_tree_node *ltn; 106 107 ltn = latch_tree_find((void *)addr, &tree->root, &mod_tree_ops); 108 if (!ltn) 109 return NULL; 110 111 return container_of(ltn, struct mod_tree_node, node)->mod; 112} 113