target/linux/generic/patches-4.4/204-module_strip.patch

   1 From: Felix Fietkau <nbd@nbd.name>
   2 Subject: [PATCH] build: add a hack for removing non-essential module info
   3
   4 Signed-off-by: Felix Fietkau <nbd@nbd.name>
   5 ---
   6 --- a/include/linux/module.h
   7 +++ b/include/linux/module.h
   8 @@ -169,9 +169,10 @@ void trim_init_extable(struct module *m)
   9
  10  /* Generic info of form tag = "info" */
  11  #define MODULE_INFO(tag, info) __MODULE_INFO(tag, tag, info)
  12 +#define MODULE_INFO_STRIP(tag, info) __MODULE_INFO_STRIP(tag, tag, info)
  13
  14  /* For userspace: you can also call me... */
  15 -#define MODULE_ALIAS(_alias) MODULE_INFO(alias, _alias)
  16 +#define MODULE_ALIAS(_alias) MODULE_INFO_STRIP(alias, _alias)
  17
  18  /* Soft module dependencies. See man modprobe.d for details.
  19   * Example: MODULE_SOFTDEP("pre: module-foo module-bar post: module-baz")
  20 @@ -212,12 +213,12 @@ void trim_init_extable(struct module *m)
  21   * Author(s), use "Name <email>" or just "Name", for multiple
  22   * authors use multiple MODULE_AUTHOR() statements/lines.
  23   */
  24 -#define MODULE_AUTHOR(_author) MODULE_INFO(author, _author)
  25 +#define MODULE_AUTHOR(_author) MODULE_INFO_STRIP(author, _author)
  26
  27  /* What your module does. */
  28 -#define MODULE_DESCRIPTION(_description) MODULE_INFO(description, _description)
  29 +#define MODULE_DESCRIPTION(_description) MODULE_INFO_STRIP(description, _description)
  30
  31 -#ifdef MODULE
  32 +#if defined(MODULE) && !defined(CONFIG_MODULE_STRIPPED)
  33  /* Creates an alias so file2alias.c can find device table. */
  34  #define MODULE_DEVICE_TABLE(type, name)                                        \
  35  extern const typeof(name) __mod_##type##__##name##_device_table                \
  36 @@ -244,7 +245,9 @@ extern const typeof(name) __mod_##type##
  37   */
  38
  39  #if defined(MODULE) || !defined(CONFIG_SYSFS)
  40 -#define MODULE_VERSION(_version) MODULE_INFO(version, _version)
  41 +#define MODULE_VERSION(_version) MODULE_INFO_STRIP(version, _version)
  42 +#elif defined(CONFIG_MODULE_STRIPPED)
  43 +#define MODULE_VERSION(_version) __MODULE_INFO_DISABLED(version)
  44  #else
  45  #define MODULE_VERSION(_version)                                       \
  46         static struct module_version_attribute ___modver_attr = {       \
  47 @@ -266,7 +269,7 @@ extern const typeof(name) __mod_##type##
  48  /* Optional firmware file (or files) needed by the module
  49   * format is simply firmware file name.  Multiple firmware
  50   * files require multiple MODULE_FIRMWARE() specifiers */
  51 -#define MODULE_FIRMWARE(_firmware) MODULE_INFO(firmware, _firmware)
  52 +#define MODULE_FIRMWARE(_firmware) MODULE_INFO_STRIP(firmware, _firmware)
  53
  54  /* Given an address, look for it in the exception tables */
  55  const struct exception_table_entry *search_exception_tables(unsigned long add);
  56 --- a/include/linux/moduleparam.h
  57 +++ b/include/linux/moduleparam.h
  58 @@ -16,6 +16,16 @@
  59  /* Chosen so that structs with an unsigned long line up. */
  60  #define MAX_PARAM_PREFIX_LEN (64 - sizeof(unsigned long))
  61
  62 +/* This struct is here for syntactic coherency, it is not used */
  63 +#define __MODULE_INFO_DISABLED(name)                                     \
  64 +  struct __UNIQUE_ID(name) {}
  65 +
  66 +#ifdef CONFIG_MODULE_STRIPPED
  67 +#define __MODULE_INFO_STRIP(tag, name, info) __MODULE_INFO_DISABLED(name)
  68 +#else
  69 +#define __MODULE_INFO_STRIP(tag, name, info) __MODULE_INFO(tag, name, info)
  70 +#endif
  71 +
  72  #ifdef MODULE
  73  #define __MODULE_INFO(tag, name, info)                                   \
  74  static const char __UNIQUE_ID(name)[]                                    \
  75 @@ -23,8 +33,7 @@ static const char __UNIQUE_ID(name)[]
  76    = __stringify(tag) "=" info
  77  #else  /* !MODULE */
  78  /* This struct is here for syntactic coherency, it is not used */
  79 -#define __MODULE_INFO(tag, name, info)                                   \
  80 -  struct __UNIQUE_ID(name) {}
  81 +#define __MODULE_INFO(tag, name, info) __MODULE_INFO_DISABLED(name)
  82  #endif
  83  #define __MODULE_PARM_TYPE(name, _type)                                          \
  84    __MODULE_INFO(parmtype, name##type, #name ":" _type)
  85 @@ -32,7 +41,7 @@ static const char __UNIQUE_ID(name)[]
  86  /* One for each parameter, describing how to use it.  Some files do
  87     multiple of these per line, so can't just use MODULE_INFO. */
  88  #define MODULE_PARM_DESC(_parm, desc) \
  89 -       __MODULE_INFO(parm, _parm, #_parm ":" desc)
  90 +       __MODULE_INFO_STRIP(parm, _parm, #_parm ":" desc)
  91
  92  struct kernel_param;
  93
  94 --- a/init/Kconfig
  95 +++ b/init/Kconfig
  96 @@ -2026,6 +2026,13 @@ config MODULE_COMPRESS_XZ
  97
  98  endchoice
  99
 100 +config MODULE_STRIPPED
 101 +       bool "Reduce module size"
 102 +       depends on MODULES
 103 +       help
 104 +         Remove module parameter descriptions, author info, version, aliases,
 105 +         device tables, etc.
 106 +
 107  endif # MODULES
 108
 109  config MODULES_TREE_LOOKUP
 110 --- a/kernel/module.c
 111 +++ b/kernel/module.c
 112 @@ -2864,6 +2864,7 @@ static struct module *setup_load_info(st
 113
 114  static int check_modinfo(struct module *mod, struct load_info *info, int flags)
 115  {
 116 +#ifndef CONFIG_MODULE_STRIPPED
 117         const char *modmagic = get_modinfo(info, "vermagic");
 118         int err;
 119
 120 @@ -2889,6 +2890,7 @@ static int check_modinfo(struct module *
 121                 pr_warn("%s: module is from the staging directory, the quality "
 122                         "is unknown, you have been warned.\n", mod->name);
 123         }
 124 +#endif
 125
 126         /* Set up license info based on the info section */
 127         set_license(mod, get_modinfo(info, "license"));
 128 --- a/scripts/mod/modpost.c
 129 +++ b/scripts/mod/modpost.c
 130 @@ -1963,7 +1963,9 @@ static void read_symbols(char *modname)
 131                 symname = remove_dot(info.strtab + sym->st_name);
 132
 133                 handle_modversions(mod, &info, sym, symname);
 134 +#ifndef CONFIG_MODULE_STRIPPED
 135                 handle_moddevtable(mod, &info, sym, symname);
 136 +#endif
 137         }
 138         if (!is_vmlinux(modname) ||
 139              (is_vmlinux(modname) && vmlinux_section_warnings))
 140 @@ -2107,7 +2109,9 @@ static void add_header(struct buffer *b,
 141         buf_printf(b, "#include <linux/vermagic.h>\n");
 142         buf_printf(b, "#include <linux/compiler.h>\n");
 143         buf_printf(b, "\n");
 144 +#ifndef CONFIG_MODULE_STRIPPED
 145         buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
 146 +#endif
 147         buf_printf(b, "\n");
 148         buf_printf(b, "__visible struct module __this_module\n");
 149         buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
 150 @@ -2124,16 +2128,20 @@ static void add_header(struct buffer *b,
 151
 152  static void add_intree_flag(struct buffer *b, int is_intree)
 153  {
 154 +#ifndef CONFIG_MODULE_STRIPPED
 155         if (is_intree)
 156                 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
 157 +#endif
 158  }
 159
 160  static void add_staging_flag(struct buffer *b, const char *name)
 161  {
 162 +#ifndef CONFIG_MODULE_STRIPPED
 163         static const char *staging_dir = "drivers/staging";
 164
 165         if (strncmp(staging_dir, name, strlen(staging_dir)) == 0)
 166                 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
 167 +#endif
 168  }
 169
 170  /* In kernel, this size is defined in linux/module.h;
 171 @@ -2237,11 +2245,13 @@ static void add_depends(struct buffer *b
 172
 173  static void add_srcversion(struct buffer *b, struct module *mod)
 174  {
 175 +#ifndef CONFIG_MODULE_STRIPPED
 176         if (mod->srcversion[0]) {
 177                 buf_printf(b, "\n");
 178                 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
 179                            mod->srcversion);
 180         }
 181 +#endif
 182  }
 183
 184  static void write_if_changed(struct buffer *b, const char *fname)
 185 @@ -2475,7 +2485,9 @@ int main(int argc, char **argv)
 186                 add_staging_flag(&buf, mod->name);
 187                 err |= add_versions(&buf, mod);
 188                 add_depends(&buf, mod, modules);
 189 +#ifndef CONFIG_MODULE_STRIPPED
 190                 add_moddevtable(&buf, mod);
 191 +#endif
 192                 add_srcversion(&buf, mod);
 193
 194                 sprintf(fname, "%s.mod.c", mod->name);