module: Move latched RB-tree support to a separate file

No functional change.

This patch migrates module latched RB-tree support
(e.g. see __module_address()) from core module code
into kernel/module/tree_lookup.c.

Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>

diff --git a/kernel/module/Makefile b/kernel/module/Makefile
index ed3aacb..88774e3 100644 (file)
--- a/kernel/module/Makefile
+++ b/kernel/module/Makefile
@@ -11,3 +11,4 @@ obj-y += main.o
 obj-$(CONFIG_MODULE_DECOMPRESS) += decompress.o
 obj-$(CONFIG_MODULE_SIG) += signing.o
 obj-$(CONFIG_LIVEPATCH) += livepatch.o
+obj-$(CONFIG_MODULES_TREE_LOOKUP) += tree_lookup.o

diff --git a/kernel/module/internal.h b/kernel/module/internal.h
index ad7a444..f1682e3 100644 (file)
--- a/kernel/module/internal.h
+++ b/kernel/module/internal.h
@@ -9,6 +9,7 @@
 #include <linux/compiler.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
+#include <linux/rculist.h>
 
 #ifndef ARCH_SHF_SMALL
 #define ARCH_SHF_SMALL 0
@@ -93,3 +94,35 @@ static inline void module_decompress_cleanup(struct load_info *info)
 {
 }
 #endif
+
+#ifdef CONFIG_MODULES_TREE_LOOKUP
+struct mod_tree_root {
+       struct latch_tree_root root;
+       unsigned long addr_min;
+       unsigned long addr_max;
+};
+
+extern struct mod_tree_root mod_tree;
+
+void mod_tree_insert(struct module *mod);
+void mod_tree_remove_init(struct module *mod);
+void mod_tree_remove(struct module *mod);
+struct module *mod_find(unsigned long addr);
+#else /* !CONFIG_MODULES_TREE_LOOKUP */
+
+static inline void mod_tree_insert(struct module *mod) { }
+static inline void mod_tree_remove_init(struct module *mod) { }
+static inline void mod_tree_remove(struct module *mod) { }
+static inline struct module *mod_find(unsigned long addr)
+{
+       struct module *mod;
+
+       list_for_each_entry_rcu(mod, &modules, list,
+                               lockdep_is_held(&module_mutex)) {
+               if (within_module(addr, mod))
+                       return mod;
+       }
+
+       return NULL;
+}
+#endif /* CONFIG_MODULES_TREE_LOOKUP */

diff --git a/kernel/module/main.c b/kernel/module/main.c
index 9151438..0d0fdd8 100644 (file)
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -90,138 +90,16 @@ static DECLARE_WORK(init_free_wq, do_free_init);
 static LLIST_HEAD(init_free_list);
 
 #ifdef CONFIG_MODULES_TREE_LOOKUP
-
-/*
- * 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_layout *layout = container_of(n, struct module_layout, mtn.node);
-
-       return (unsigned long)layout->base;
-}
-
-static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n)
-{
-       struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
-
-       return (unsigned long)layout->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 struct mod_tree_root {
-       struct latch_tree_root root;
-       unsigned long addr_min;
-       unsigned long addr_max;
-} mod_tree __cacheline_aligned = {
+struct mod_tree_root mod_tree __cacheline_aligned = {
        .addr_min = -1UL,
 };
 
 #define module_addr_min mod_tree.addr_min
 #define module_addr_max mod_tree.addr_max
 
-static noinline void __mod_tree_insert(struct mod_tree_node *node)
-{
-       latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops);
-}
-
-static void __mod_tree_remove(struct mod_tree_node *node)
-{
-       latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops);
-}
-
-/*
- * These modifications: insert, remove_init and remove; are serialized by the
- * module_mutex.
- */
-static void mod_tree_insert(struct module *mod)
-{
-       mod->core_layout.mtn.mod = mod;
-       mod->init_layout.mtn.mod = mod;
-
-       __mod_tree_insert(&mod->core_layout.mtn);
-       if (mod->init_layout.size)
-               __mod_tree_insert(&mod->init_layout.mtn);
-}
-
-static void mod_tree_remove_init(struct module *mod)
-{
-       if (mod->init_layout.size)
-               __mod_tree_remove(&mod->init_layout.mtn);
-}
-
-static void mod_tree_remove(struct module *mod)
-{
-       __mod_tree_remove(&mod->core_layout.mtn);
-       mod_tree_remove_init(mod);
-}
-
-static struct module *mod_find(unsigned long addr)
-{
-       struct latch_tree_node *ltn;
-
-       ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops);
-       if (!ltn)
-               return NULL;
-
-       return container_of(ltn, struct mod_tree_node, node)->mod;
-}
-
-#else /* MODULES_TREE_LOOKUP */
-
-static unsigned long module_addr_min = -1UL, module_addr_max = 0;
-
-static void mod_tree_insert(struct module *mod) { }
-static void mod_tree_remove_init(struct module *mod) { }
-static void mod_tree_remove(struct module *mod) { }
-
-static struct module *mod_find(unsigned long addr)
-{
-       struct module *mod;
-
-       list_for_each_entry_rcu(mod, &modules, list,
-                               lockdep_is_held(&module_mutex)) {
-               if (within_module(addr, mod))
-                       return mod;
-       }
-
-       return NULL;
-}
-
-#endif /* MODULES_TREE_LOOKUP */
+#else /* !CONFIG_MODULES_TREE_LOOKUP */
+static unsigned long module_addr_min = -1UL, module_addr_max;
+#endif /* CONFIG_MODULES_TREE_LOOKUP */
 
 /*
  * Bounds of module text, for speeding up __module_address.

diff --git a/kernel/module/tree_lookup.c b/kernel/module/tree_lookup.c
new file mode 100644 (file)
index 0000000..0bc4ec3
--- /dev/null
+++ b/kernel/module/tree_lookup.c
@@ -0,0 +1,109 @@
+// 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_layout *layout = container_of(n, struct module_layout, mtn.node);
+
+       return (unsigned long)layout->base;
+}
+
+static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n)
+{
+       struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
+
+       return (unsigned long)layout->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)
+{
+       latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops);
+}
+
+static void __mod_tree_remove(struct mod_tree_node *node)
+{
+       latch_tree_erase(&node->node, &mod_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)
+{
+       mod->core_layout.mtn.mod = mod;
+       mod->init_layout.mtn.mod = mod;
+
+       __mod_tree_insert(&mod->core_layout.mtn);
+       if (mod->init_layout.size)
+               __mod_tree_insert(&mod->init_layout.mtn);
+}
+
+void mod_tree_remove_init(struct module *mod)
+{
+       if (mod->init_layout.size)
+               __mod_tree_remove(&mod->init_layout.mtn);
+}
+
+void mod_tree_remove(struct module *mod)
+{
+       __mod_tree_remove(&mod->core_layout.mtn);
+       mod_tree_remove_init(mod);
+}
+
+struct module *mod_find(unsigned long addr)
+{
+       struct latch_tree_node *ltn;
+
+       ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops);
+       if (!ltn)
+               return NULL;
+
+       return container_of(ltn, struct mod_tree_node, node)->mod;
+}