1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
|
From a779a482fb9b9f8fcdf8b2519c789b4b9bb5dd05 Mon Sep 17 00:00:00 2001
From: Felix Fietkau <nbd@nbd.name>
Date: Fri, 7 Jul 2017 16:56:48 +0200
Subject: build: add a hack for removing non-essential module info
Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
include/linux/module.h | 13 ++++++++-----
include/linux/moduleparam.h | 15 ++++++++++++---
init/Kconfig | 7 +++++++
kernel/module.c | 5 ++++-
scripts/mod/modpost.c | 12 ++++++++++++
5 files changed, 43 insertions(+), 9 deletions(-)
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -161,6 +161,7 @@ extern void cleanup_module(void);
/* Generic info of form tag = "info" */
#define MODULE_INFO(tag, info) __MODULE_INFO(tag, tag, info)
+#define MODULE_INFO_STRIP(tag, info) __MODULE_INFO_STRIP(tag, tag, info)
/* For userspace: you can also call me... */
#define MODULE_ALIAS(_alias) MODULE_INFO(alias, _alias)
@@ -230,12 +231,12 @@ extern void cleanup_module(void);
* Author(s), use "Name <email>" or just "Name", for multiple
* authors use multiple MODULE_AUTHOR() statements/lines.
*/
-#define MODULE_AUTHOR(_author) MODULE_INFO(author, _author)
+#define MODULE_AUTHOR(_author) MODULE_INFO_STRIP(author, _author)
/* What your module does. */
-#define MODULE_DESCRIPTION(_description) MODULE_INFO(description, _description)
+#define MODULE_DESCRIPTION(_description) MODULE_INFO_STRIP(description, _description)
-#ifdef MODULE
+#if defined(MODULE) && !defined(CONFIG_MODULE_STRIPPED)
/* Creates an alias so file2alias.c can find device table. */
#define MODULE_DEVICE_TABLE(type, name) \
extern typeof(name) __mod_##type##__##name##_device_table \
@@ -262,7 +263,9 @@ extern typeof(name) __mod_##type##__##na
*/
#if defined(MODULE) || !defined(CONFIG_SYSFS)
-#define MODULE_VERSION(_version) MODULE_INFO(version, _version)
+#define MODULE_VERSION(_version) MODULE_INFO_STRIP(version, _version)
+#elif defined(CONFIG_MODULE_STRIPPED)
+#define MODULE_VERSION(_version) __MODULE_INFO_DISABLED(version)
#else
#define MODULE_VERSION(_version) \
MODULE_INFO(version, _version); \
@@ -285,7 +288,7 @@ extern typeof(name) __mod_##type##__##na
/* Optional firmware file (or files) needed by the module
* format is simply firmware file name. Multiple firmware
* files require multiple MODULE_FIRMWARE() specifiers */
-#define MODULE_FIRMWARE(_firmware) MODULE_INFO(firmware, _firmware)
+#define MODULE_FIRMWARE(_firmware) MODULE_INFO_STRIP(firmware, _firmware)
#define MODULE_IMPORT_NS(ns) MODULE_INFO(import_ns, #ns)
--- a/include/linux/moduleparam.h
+++ b/include/linux/moduleparam.h
@@ -20,6 +20,16 @@
/* Chosen so that structs with an unsigned long line up. */
#define MAX_PARAM_PREFIX_LEN (64 - sizeof(unsigned long))
+/* This struct is here for syntactic coherency, it is not used */
+#define __MODULE_INFO_DISABLED(name) \
+ struct __UNIQUE_ID(name) {}
+
+#ifdef CONFIG_MODULE_STRIPPED
+#define __MODULE_INFO_STRIP(tag, name, info) __MODULE_INFO_DISABLED(name)
+#else
+#define __MODULE_INFO_STRIP(tag, name, info) __MODULE_INFO(tag, name, info)
+#endif
+
#define __MODULE_INFO(tag, name, info) \
static const char __UNIQUE_ID(name)[] \
__used __section(".modinfo") __attribute__((unused, aligned(1))) \
@@ -31,7 +41,7 @@ static const char __UNIQUE_ID(name)[]
/* One for each parameter, describing how to use it. Some files do
multiple of these per line, so can't just use MODULE_INFO. */
#define MODULE_PARM_DESC(_parm, desc) \
- __MODULE_INFO(parm, _parm, #_parm ":" desc)
+ __MODULE_INFO_STRIP(parm, _parm, #_parm ":" desc)
struct kernel_param;
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -2347,6 +2347,13 @@ config UNUSED_KSYMS_WHITELIST
one per line. The path can be absolute, or relative to the kernel
source tree.
+config MODULE_STRIPPED
+ bool "Reduce module size"
+ depends on MODULES
+ help
+ Remove module parameter descriptions, author info, version, aliases,
+ device tables, etc.
+
endif # MODULES
config MODULES_TREE_LOOKUP
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -1285,6 +1285,7 @@ static struct module_attribute *modinfo_
static const char vermagic[] = VERMAGIC_STRING;
+#if defined(CONFIG_MODVERSIONS) || !defined(CONFIG_MODULE_STRIPPED)
static int try_to_force_load(struct module *mod, const char *reason)
{
#ifdef CONFIG_MODULE_FORCE_LOAD
@@ -1296,6 +1297,7 @@ static int try_to_force_load(struct modu
return -ENOEXEC;
#endif
}
+#endif
#ifdef CONFIG_MODVERSIONS
@@ -3251,9 +3253,11 @@ static int setup_load_info(struct load_i
static int check_modinfo(struct module *mod, struct load_info *info, int flags)
{
- const char *modmagic = get_modinfo(info, "vermagic");
int err;
+#ifndef CONFIG_MODULE_STRIPPED
+ const char *modmagic = get_modinfo(info, "vermagic");
+
if (flags & MODULE_INIT_IGNORE_VERMAGIC)
modmagic = NULL;
@@ -3274,6 +3278,7 @@ static int check_modinfo(struct module *
mod->name);
add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
}
+#endif
check_modinfo_retpoline(mod, info);
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -2037,7 +2037,9 @@ static void read_symbols(const char *mod
symname = remove_dot(info.strtab + sym->st_name);
handle_symbol(mod, &info, sym, symname);
+#ifndef CONFIG_MODULE_STRIPPED
handle_moddevtable(mod, &info, sym, symname);
+#endif
}
for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
@@ -2250,8 +2252,10 @@ static void add_header(struct buffer *b,
buf_printf(b, "\n");
buf_printf(b, "BUILD_SALT;\n");
buf_printf(b, "\n");
+#ifndef CONFIG_MODULE_STRIPPED
buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
buf_printf(b, "MODULE_INFO(name, KBUILD_MODNAME);\n");
+#endif
buf_printf(b, "\n");
buf_printf(b, "__visible struct module __this_module\n");
buf_printf(b, "__section(\".gnu.linkonce.this_module\") = {\n");
@@ -2268,8 +2272,10 @@ static void add_header(struct buffer *b,
static void add_intree_flag(struct buffer *b, int is_intree)
{
+#ifndef CONFIG_MODULE_STRIPPED
if (is_intree)
buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
+#endif
}
/* Cannot check for assembler */
@@ -2282,8 +2288,10 @@ static void add_retpoline(struct buffer
static void add_staging_flag(struct buffer *b, const char *name)
{
+#ifndef CONFIG_MODULE_STRIPPED
if (strstarts(name, "drivers/staging"))
buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
+#endif
}
/**
@@ -2367,11 +2375,13 @@ static void add_depends(struct buffer *b
static void add_srcversion(struct buffer *b, struct module *mod)
{
+#ifndef CONFIG_MODULE_STRIPPED
if (mod->srcversion[0]) {
buf_printf(b, "\n");
buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
mod->srcversion);
}
+#endif
}
static void write_buf(struct buffer *b, const char *fname)
@@ -2630,7 +2640,9 @@ int main(int argc, char **argv)
add_staging_flag(&buf, mod->name);
err |= add_versions(&buf, mod);
add_depends(&buf, mod);
+#ifndef CONFIG_MODULE_STRIPPED
add_moddevtable(&buf, mod);
+#endif
add_srcversion(&buf, mod);
sprintf(fname, "%s.mod.c", mod->name);
|
