Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching

Pull livepatching updates from Jiri Kosina:

 - RO/NX attribute fixes for patch module relocations from Josh
   Poimboeuf.  As part of this effort, module.c has been cleaned up as
   well and livepatching is piggy-backing on this cleanup.  Rusty is OK
   with this whole lot going through livepatching tree.

 - symbol disambiguation support from Chris J Arges.  That series is
   also

        Reviewed-by: Miroslav Benes <mbenes@suse.cz>

   but this came in only after I've alredy pushed out.  Didn't want to
   rebase because of that, hence I am mentioning it here.

 - symbol lookup fix from Miroslav Benes

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching:
  livepatch: Cleanup module page permission changes
  module: keep percpu symbols in module's symtab
  module: clean up RO/NX handling.
  module: use a structure to encapsulate layout.
  gcov: use within_module() helper.
  module: Use the same logic for setting and unsetting RO/NX
  livepatch: function,sympos scheme in livepatch sysfs directory
  livepatch: add sympos as disambiguator field to klp_reloc
  livepatch: add old_sympos as disambiguator field to klp_func

2 files changed, 45 insertions, 47 deletions

diff --git a/include/linux/livepatch.h b/include/linux/livepatch.h
index 31db7a05dd36..a8828652f794 100644
--- a/include/linux/livepatch.h
+++ b/include/linux/livepatch.h
@@ -37,8 +37,9 @@ enum klp_state {
  * struct klp_func - function structure for live patching
  * @old_name:	name of the function to be patched
  * @new_func:	pointer to the patched function code
- * @old_addr:	a hint conveying at what address the old function
- *		can be found (optional, vmlinux patches only)
+ * @old_sympos: a hint indicating which symbol position the old function
+ *		can be found (optional)
+ * @old_addr:	the address of the function being patched
  * @kobj:	kobject for sysfs resources
  * @state:	tracks function-level patch application state
  * @stack_node:	list node for klp_ops func_stack list
@@ -48,16 +49,16 @@ struct klp_func {
 	const char *old_name;
 	void *new_func;
 	/*
-	 * The old_addr field is optional and can be used to resolve
-	 * duplicate symbol names in the vmlinux object.  If this
-	 * information is not present, the symbol is located by name
-	 * with kallsyms. If the name is not unique and old_addr is
-	 * not provided, the patch application fails as there is no
-	 * way to resolve the ambiguity.
+	 * The old_sympos field is optional and can be used to resolve
+	 * duplicate symbol names in livepatch objects. If this field is zero,
+	 * it is expected the symbol is unique, otherwise patching fails. If
+	 * this value is greater than zero then that occurrence of the symbol
+	 * in kallsyms for the given object is used.
 	 */
-	unsigned long old_addr;
+	unsigned long old_sympos;
 
 	/* internal */
+	unsigned long old_addr;
 	struct kobject kobj;
 	enum klp_state state;
 	struct list_head stack_node;
@@ -66,8 +67,7 @@ struct klp_func {
 /**
  * struct klp_reloc - relocation structure for live patching
  * @loc:	address where the relocation will be written
- * @val:	address of the referenced symbol (optional,
- *		vmlinux	patches only)
+ * @sympos:	position in kallsyms to disambiguate symbols (optional)
  * @type:	ELF relocation type
  * @name:	name of the referenced symbol (for lookup/verification)
  * @addend:	offset from the referenced symbol
@@ -75,7 +75,7 @@ struct klp_func {
  */
 struct klp_reloc {
 	unsigned long loc;
-	unsigned long val;
+	unsigned long sympos;
 	unsigned long type;
 	const char *name;
 	int addend;
diff --git a/include/linux/module.h b/include/linux/module.h
index 3a19c79918e0..4560d8f1545d 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -302,6 +302,28 @@ struct mod_tree_node {
 	struct latch_tree_node node;
 };
 
+struct module_layout {
+	/* The actual code + data. */
+	void *base;
+	/* Total size. */
+	unsigned int size;
+	/* The size of the executable code.  */
+	unsigned int text_size;
+	/* Size of RO section of the module (text+rodata) */
+	unsigned int ro_size;
+
+#ifdef CONFIG_MODULES_TREE_LOOKUP
+	struct mod_tree_node mtn;
+#endif
+};
+
+#ifdef CONFIG_MODULES_TREE_LOOKUP
+/* Only touch one cacheline for common rbtree-for-core-layout case. */
+#define __module_layout_align ____cacheline_aligned
+#else
+#define __module_layout_align
+#endif
+
 struct module {
 	enum module_state state;
 
@@ -366,37 +388,9 @@ struct module {
 	/* Startup function. */
 	int (*init)(void);
 
-	/*
-	 * If this is non-NULL, vfree() after init() returns.
-	 *
-	 * Cacheline align here, such that:
-	 *   module_init, module_core, init_size, core_size,
-	 *   init_text_size, core_text_size and mtn_core::{mod,node[0]}
-	 * are on the same cacheline.
-	 */
-	void *module_init	____cacheline_aligned;
-
-	/* Here is the actual code + data, vfree'd on unload. */
-	void *module_core;
-
-	/* Here are the sizes of the init and core sections */
-	unsigned int init_size, core_size;
-
-	/* The size of the executable code in each section.  */
-	unsigned int init_text_size, core_text_size;
-
-#ifdef CONFIG_MODULES_TREE_LOOKUP
-	/*
-	 * We want mtn_core::{mod,node[0]} to be in the same cacheline as the
-	 * above entries such that a regular lookup will only touch one
-	 * cacheline.
-	 */
-	struct mod_tree_node	mtn_core;
-	struct mod_tree_node	mtn_init;
-#endif
-
-	/* Size of RO sections of the module (text+rodata) */
-	unsigned int init_ro_size, core_ro_size;
+	/* Core layout: rbtree is accessed frequently, so keep together. */
+	struct module_layout core_layout __module_layout_align;
+	struct module_layout init_layout;
 
 	/* Arch-specific module values */
 	struct mod_arch_specific arch;
@@ -505,15 +499,15 @@ bool is_module_text_address(unsigned long addr);
 static inline bool within_module_core(unsigned long addr,
 				      const struct module *mod)
 {
-	return (unsigned long)mod->module_core <= addr &&
-	       addr < (unsigned long)mod->module_core + mod->core_size;
+	return (unsigned long)mod->core_layout.base <= addr &&
+	       addr < (unsigned long)mod->core_layout.base + mod->core_layout.size;
 }
 
 static inline bool within_module_init(unsigned long addr,
 				      const struct module *mod)
 {
-	return (unsigned long)mod->module_init <= addr &&
-	       addr < (unsigned long)mod->module_init + mod->init_size;
+	return (unsigned long)mod->init_layout.base <= addr &&
+	       addr < (unsigned long)mod->init_layout.base + mod->init_layout.size;
 }
 
 static inline bool within_module(unsigned long addr, const struct module *mod)
@@ -768,9 +762,13 @@ extern int module_sysfs_initialized;
 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
 extern void set_all_modules_text_rw(void);
 extern void set_all_modules_text_ro(void);
+extern void module_enable_ro(const struct module *mod);
+extern void module_disable_ro(const struct module *mod);
 #else
 static inline void set_all_modules_text_rw(void) { }
 static inline void set_all_modules_text_ro(void) { }
+static inline void module_enable_ro(const struct module *mod) { }
+static inline void module_disable_ro(const struct module *mod) { }
 #endif
 
 #ifdef CONFIG_GENERIC_BUG