Merge tag 'modules-for-v5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux

Pull module updates from Jessica Yu:
 "Summary of modules changes for the 5.6 merge window:

   - Add "MS" (SHF_MERGE|SHF_STRINGS) section flags to __ksymtab_strings
     to indicate to the linker that it can perform string deduplication
     (i.e., duplicate strings are reduced to a single copy in the string
     table). This means any repeated namespace string would be merged to
     just one entry in __ksymtab_strings.

   - Various code cleanups and small fixes (fix small memleak in error
     path, improve moduleparam docs, silence rcu warnings, improve error
     logging)"

* tag 'modules-for-v5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux:
  module.h: Annotate mod_kallsyms with __rcu
  module: avoid setting info->name early in case we can fall back to info->mod->name
  modsign: print module name along with error message
  kernel/module: Fix memleak in module_add_modinfo_attrs()
  export.h: reduce __ksymtab_strings string duplication by using "MS" section flags
  moduleparam: fix kerneldoc
  modules: lockdep: Suppress suspicious RCU usage warning

3 files changed, 101 insertions, 16 deletions

diff --git a/include/linux/export.h b/include/linux/export.h
index 627841448293..fceb5e855717 100644
--- a/include/linux/export.h
+++ b/include/linux/export.h
@@ -82,16 +82,29 @@ struct kernel_symbol {
 
 #else
 
-/* For every exported symbol, place a struct in the __ksymtab section */
-#define ___EXPORT_SYMBOL(sym, sec, ns)					\
-	extern typeof(sym) sym;						\
-	__CRC_SYMBOL(sym, sec);						\
-	static const char __kstrtab_##sym[]				\
-	__attribute__((section("__ksymtab_strings"), used, aligned(1)))	\
-	= #sym;								\
-	static const char __kstrtabns_##sym[]				\
-	__attribute__((section("__ksymtab_strings"), used, aligned(1)))	\
-	= ns;								\
+/*
+ * For every exported symbol, do the following:
+ *
+ * - If applicable, place a CRC entry in the __kcrctab section.
+ * - Put the name of the symbol and namespace (empty string "" for none) in
+ *   __ksymtab_strings.
+ * - Place a struct kernel_symbol entry in the __ksymtab section.
+ *
+ * note on .section use: we specify progbits since usage of the "M" (SHF_MERGE)
+ * section flag requires it. Use '%progbits' instead of '@progbits' since the
+ * former apparently works on all arches according to the binutils source.
+ */
+#define ___EXPORT_SYMBOL(sym, sec, ns)						\
+	extern typeof(sym) sym;							\
+	extern const char __kstrtab_##sym[];					\
+	extern const char __kstrtabns_##sym[];					\
+	__CRC_SYMBOL(sym, sec);							\
+	asm("	.section \"__ksymtab_strings\",\"aMS\",%progbits,1	\n"	\
+	    "__kstrtab_" #sym ":					\n"	\
+	    "	.asciz 	\"" #sym "\"					\n"	\
+	    "__kstrtabns_" #sym ":					\n"	\
+	    "	.asciz 	\"" ns "\"					\n"	\
+	    "	.previous						\n");	\
 	__KSYMTAB_ENTRY(sym, sec)
 
 #endif
diff --git a/include/linux/module.h b/include/linux/module.h
index 0c7366c317bd..edc63e6ff531 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -429,7 +429,7 @@ struct module {
 
 #ifdef CONFIG_KALLSYMS
 	/* Protected by RCU and/or module_mutex: use rcu_dereference() */
-	struct mod_kallsyms *kallsyms;
+	struct mod_kallsyms __rcu *kallsyms;
 	struct mod_kallsyms core_kallsyms;
 
 	/* Section attributes */
diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h
index e5c3e23919b8..3ef917ff0964 100644
--- a/include/linux/moduleparam.h
+++ b/include/linux/moduleparam.h
@@ -128,6 +128,9 @@ struct kparam_array
 
 /**
  * module_param_unsafe - same as module_param but taints kernel
+ * @name: the variable to alter, and exposed parameter name.
+ * @type: the type of the parameter
+ * @perm: visibility in sysfs.
  */
 #define module_param_unsafe(name, type, perm)			\
 	module_param_named_unsafe(name, name, type, perm)
@@ -150,6 +153,10 @@ struct kparam_array
 
 /**
  * module_param_named_unsafe - same as module_param_named but taints kernel
+ * @name: a valid C identifier which is the parameter name.
+ * @value: the actual lvalue to alter.
+ * @type: the type of the parameter
+ * @perm: visibility in sysfs.
  */
 #define module_param_named_unsafe(name, value, type, perm)		\
 	param_check_##type(name, &(value));				\
@@ -160,6 +167,7 @@ struct kparam_array
  * module_param_cb - general callback for a module/cmdline parameter
  * @name: a valid C identifier which is the parameter name.
  * @ops: the set & get operations for this parameter.
+ * @arg: args for @ops
  * @perm: visibility in sysfs.
  *
  * The ops can have NULL set or get functions.
@@ -171,36 +179,96 @@ struct kparam_array
 	__module_param_call(MODULE_PARAM_PREFIX, name, ops, arg, perm, -1,    \
 			    KERNEL_PARAM_FL_UNSAFE)
 
+#define __level_param_cb(name, ops, arg, perm, level)			\
+	__module_param_call(MODULE_PARAM_PREFIX, name, ops, arg, perm, level, 0)
 /**
- * <level>_param_cb - general callback for a module/cmdline parameter
- *                    to be evaluated before certain initcall level
+ * core_param_cb - general callback for a module/cmdline parameter
+ *                 to be evaluated before core initcall level
  * @name: a valid C identifier which is the parameter name.
  * @ops: the set & get operations for this parameter.
+ * @arg: args for @ops
  * @perm: visibility in sysfs.
  *
  * The ops can have NULL set or get functions.
  */
-#define __level_param_cb(name, ops, arg, perm, level)			\
-	__module_param_call(MODULE_PARAM_PREFIX, name, ops, arg, perm, level, 0)
-
 #define core_param_cb(name, ops, arg, perm)		\
 	__level_param_cb(name, ops, arg, perm, 1)
 
+/**
+ * postcore_param_cb - general callback for a module/cmdline parameter
+ *                     to be evaluated before postcore initcall level
+ * @name: a valid C identifier which is the parameter name.
+ * @ops: the set & get operations for this parameter.
+ * @arg: args for @ops
+ * @perm: visibility in sysfs.
+ *
+ * The ops can have NULL set or get functions.
+ */
 #define postcore_param_cb(name, ops, arg, perm)		\
 	__level_param_cb(name, ops, arg, perm, 2)
 
+/**
+ * arch_param_cb - general callback for a module/cmdline parameter
+ *                 to be evaluated before arch initcall level
+ * @name: a valid C identifier which is the parameter name.
+ * @ops: the set & get operations for this parameter.
+ * @arg: args for @ops
+ * @perm: visibility in sysfs.
+ *
+ * The ops can have NULL set or get functions.
+ */
 #define arch_param_cb(name, ops, arg, perm)		\
 	__level_param_cb(name, ops, arg, perm, 3)
 
+/**
+ * subsys_param_cb - general callback for a module/cmdline parameter
+ *                   to be evaluated before subsys initcall level
+ * @name: a valid C identifier which is the parameter name.
+ * @ops: the set & get operations for this parameter.
+ * @arg: args for @ops
+ * @perm: visibility in sysfs.
+ *
+ * The ops can have NULL set or get functions.
+ */
 #define subsys_param_cb(name, ops, arg, perm)		\
 	__level_param_cb(name, ops, arg, perm, 4)
 
+/**
+ * fs_param_cb - general callback for a module/cmdline parameter
+ *               to be evaluated before fs initcall level
+ * @name: a valid C identifier which is the parameter name.
+ * @ops: the set & get operations for this parameter.
+ * @arg: args for @ops
+ * @perm: visibility in sysfs.
+ *
+ * The ops can have NULL set or get functions.
+ */
 #define fs_param_cb(name, ops, arg, perm)		\
 	__level_param_cb(name, ops, arg, perm, 5)
 
+/**
+ * device_param_cb - general callback for a module/cmdline parameter
+ *                   to be evaluated before device initcall level
+ * @name: a valid C identifier which is the parameter name.
+ * @ops: the set & get operations for this parameter.
+ * @arg: args for @ops
+ * @perm: visibility in sysfs.
+ *
+ * The ops can have NULL set or get functions.
+ */
 #define device_param_cb(name, ops, arg, perm)		\
 	__level_param_cb(name, ops, arg, perm, 6)
 
+/**
+ * late_param_cb - general callback for a module/cmdline parameter
+ *                 to be evaluated before late initcall level
+ * @name: a valid C identifier which is the parameter name.
+ * @ops: the set & get operations for this parameter.
+ * @arg: args for @ops
+ * @perm: visibility in sysfs.
+ *
+ * The ops can have NULL set or get functions.
+ */
 #define late_param_cb(name, ops, arg, perm)		\
 	__level_param_cb(name, ops, arg, perm, 7)
 
@@ -263,6 +331,10 @@ static inline void kernel_param_unlock(struct module *mod)
 
 /**
  * core_param_unsafe - same as core_param but taints kernel
+ * @name: the name of the cmdline and sysfs parameter (often the same as var)
+ * @var: the variable
+ * @type: the type of the parameter
+ * @perm: visibility in sysfs
  */
 #define core_param_unsafe(name, var, type, perm)		\
 	param_check_##type(name, &(var));				\