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