1 From a779a482fb9b9f8fcdf8b2519c789b4b9bb5dd05 Mon Sep 17 00:00:00 2001
2 From: Felix Fietkau <nbd@nbd.name>
3 Date: Fri, 7 Jul 2017 16:56:48 +0200
4 Subject: build: add a hack for removing non-essential module info
6 Signed-off-by: Felix Fietkau <nbd@nbd.name>
8 include/linux/module.h | 13 ++++++++-----
9 include/linux/moduleparam.h | 15 ++++++++++++---
10 init/Kconfig | 7 +++++++
11 kernel/module.c | 5 ++++-
12 scripts/mod/modpost.c | 12 ++++++++++++
13 5 files changed, 43 insertions(+), 9 deletions(-)
15 --- a/include/linux/module.h
16 +++ b/include/linux/module.h
17 @@ -164,6 +164,7 @@ extern void cleanup_module(void);
19 /* Generic info of form tag = "info" */
20 #define MODULE_INFO(tag, info) __MODULE_INFO(tag, tag, info)
21 +#define MODULE_INFO_STRIP(tag, info) __MODULE_INFO_STRIP(tag, tag, info)
23 /* For userspace: you can also call me... */
24 #define MODULE_ALIAS(_alias) MODULE_INFO(alias, _alias)
25 @@ -233,12 +234,12 @@ extern void cleanup_module(void);
26 * Author(s), use "Name <email>" or just "Name", for multiple
27 * authors use multiple MODULE_AUTHOR() statements/lines.
29 -#define MODULE_AUTHOR(_author) MODULE_INFO(author, _author)
30 +#define MODULE_AUTHOR(_author) MODULE_INFO_STRIP(author, _author)
32 /* What your module does. */
33 -#define MODULE_DESCRIPTION(_description) MODULE_INFO(description, _description)
34 +#define MODULE_DESCRIPTION(_description) MODULE_INFO_STRIP(description, _description)
37 +#if defined(MODULE) && !defined(CONFIG_MODULE_STRIPPED)
38 /* Creates an alias so file2alias.c can find device table. */
39 #define MODULE_DEVICE_TABLE(type, name) \
40 extern typeof(name) __mod_##type##__##name##_device_table \
41 @@ -265,7 +266,9 @@ extern typeof(name) __mod_##type##__##na
44 #if defined(MODULE) || !defined(CONFIG_SYSFS)
45 -#define MODULE_VERSION(_version) MODULE_INFO(version, _version)
46 +#define MODULE_VERSION(_version) MODULE_INFO_STRIP(version, _version)
47 +#elif defined(CONFIG_MODULE_STRIPPED)
48 +#define MODULE_VERSION(_version) __MODULE_INFO_DISABLED(version)
50 #define MODULE_VERSION(_version) \
51 MODULE_INFO(version, _version); \
52 @@ -288,7 +291,7 @@ extern typeof(name) __mod_##type##__##na
53 /* Optional firmware file (or files) needed by the module
54 * format is simply firmware file name. Multiple firmware
55 * files require multiple MODULE_FIRMWARE() specifiers */
56 -#define MODULE_FIRMWARE(_firmware) MODULE_INFO(firmware, _firmware)
57 +#define MODULE_FIRMWARE(_firmware) MODULE_INFO_STRIP(firmware, _firmware)
59 #define MODULE_IMPORT_NS(ns) MODULE_INFO(import_ns, __stringify(ns))
61 --- a/include/linux/moduleparam.h
62 +++ b/include/linux/moduleparam.h
64 /* Chosen so that structs with an unsigned long line up. */
65 #define MAX_PARAM_PREFIX_LEN (64 - sizeof(unsigned long))
67 +/* This struct is here for syntactic coherency, it is not used */
68 +#define __MODULE_INFO_DISABLED(name) \
69 + struct __UNIQUE_ID(name) {}
71 +#ifdef CONFIG_MODULE_STRIPPED
72 +#define __MODULE_INFO_STRIP(tag, name, info) __MODULE_INFO_DISABLED(name)
74 +#define __MODULE_INFO_STRIP(tag, name, info) __MODULE_INFO(tag, name, info)
77 #define __MODULE_INFO(tag, name, info) \
78 static const char __UNIQUE_ID(name)[] \
79 __used __section(".modinfo") __aligned(1) \
81 /* One for each parameter, describing how to use it. Some files do
82 multiple of these per line, so can't just use MODULE_INFO. */
83 #define MODULE_PARM_DESC(_parm, desc) \
84 - __MODULE_INFO(parm, _parm, #_parm ":" desc)
85 + __MODULE_INFO_STRIP(parm, _parm, #_parm ":" desc)
89 --- a/kernel/module/Kconfig
90 +++ b/kernel/module/Kconfig
91 @@ -389,4 +389,11 @@ config MODULES_TREE_LOOKUP
93 depends on PERF_EVENTS || TRACING || CFI_CLANG
95 +config MODULE_STRIPPED
96 + bool "Reduce module size"
99 + Remove module parameter descriptions, author info, version, aliases,
100 + device tables, etc.
103 --- a/kernel/module/main.c
104 +++ b/kernel/module/main.c
105 @@ -997,6 +997,7 @@ size_t modinfo_attrs_count = ARRAY_SIZE(
107 static const char vermagic[] = VERMAGIC_STRING;
109 +#if defined(CONFIG_MODVERSIONS) || !defined(CONFIG_MODULE_STRIPPED)
110 int try_to_force_load(struct module *mod, const char *reason)
112 #ifdef CONFIG_MODULE_FORCE_LOAD
113 @@ -1008,6 +1009,7 @@ int try_to_force_load(struct module *mod
119 /* Parse tag=value strings from .modinfo section */
120 char *module_next_tag_pair(char *string, unsigned long *secsize)
121 @@ -2075,9 +2077,11 @@ static void module_augment_kernel_taints
123 static int check_modinfo(struct module *mod, struct load_info *info, int flags)
125 - const char *modmagic = get_modinfo(info, "vermagic");
128 +#ifndef CONFIG_MODULE_STRIPPED
129 + const char *modmagic = get_modinfo(info, "vermagic");
131 if (flags & MODULE_INIT_IGNORE_VERMAGIC)
134 @@ -2091,6 +2095,7 @@ static int check_modinfo(struct module *
135 info->name, modmagic, vermagic);
140 err = check_modinfo_livepatch(mod, info);
142 --- a/scripts/mod/modpost.c
143 +++ b/scripts/mod/modpost.c
144 @@ -1690,7 +1690,9 @@ static void read_symbols(const char *mod
145 symname = remove_dot(info.strtab + sym->st_name);
147 handle_symbol(mod, &info, sym, symname);
148 +#ifndef CONFIG_MODULE_STRIPPED
149 handle_moddevtable(mod, &info, sym, symname);
153 check_sec_ref(mod, &info);
154 @@ -1863,8 +1865,10 @@ static void add_header(struct buffer *b,
155 buf_printf(b, "BUILD_SALT;\n");
156 buf_printf(b, "BUILD_LTO_INFO;\n");
158 +#ifndef CONFIG_MODULE_STRIPPED
159 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
160 buf_printf(b, "MODULE_INFO(name, KBUILD_MODNAME);\n");
163 buf_printf(b, "__visible struct module __this_module\n");
164 buf_printf(b, "__section(\".gnu.linkonce.this_module\") = {\n");
165 @@ -1878,8 +1882,10 @@ static void add_header(struct buffer *b,
166 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n");
167 buf_printf(b, "};\n");
169 +#ifndef CONFIG_MODULE_STRIPPED
170 if (!external_module)
171 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
176 @@ -1887,8 +1893,10 @@ static void add_header(struct buffer *b,
177 "MODULE_INFO(retpoline, \"Y\");\n"
180 +#ifndef CONFIG_MODULE_STRIPPED
181 if (strstarts(mod->name, "drivers/staging"))
182 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
185 if (strstarts(mod->name, "tools/testing"))
186 buf_printf(b, "\nMODULE_INFO(test, \"Y\");\n");
187 @@ -1998,11 +2006,13 @@ static void add_depends(struct buffer *b
189 static void add_srcversion(struct buffer *b, struct module *mod)
191 +#ifndef CONFIG_MODULE_STRIPPED
192 if (mod->srcversion[0]) {
194 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
200 static void write_buf(struct buffer *b, const char *fname)
201 @@ -2085,7 +2095,9 @@ static void write_mod_c_file(struct modu
202 add_exported_symbols(&buf, mod);
203 add_versions(&buf, mod);
204 add_depends(&buf, mod);
205 +#ifndef CONFIG_MODULE_STRIPPED
206 add_moddevtable(&buf, mod);
208 add_srcversion(&buf, mod);
210 ret = snprintf(fname, sizeof(fname), "%s.mod.c", mod->name);