target/linux/generic/pending-3.18/204-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 @@ -84,6 +84,7 @@ 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 @@ -127,12 +128,12 @@ void trim_init_extable(struct module *m)
  17   * Author(s), use "Name <email>" or just "Name", for multiple
  18   * authors use multiple MODULE_AUTHOR() statements/lines.
  19   */
  20 -#define MODULE_AUTHOR(_author) MODULE_INFO(author, _author)
  21 +#define MODULE_AUTHOR(_author) MODULE_INFO_STRIP(author, _author)
  22
  23  /* What your module does. */
  24 -#define MODULE_DESCRIPTION(_description) MODULE_INFO(description, _description)
  25 +#define MODULE_DESCRIPTION(_description) MODULE_INFO_STRIP(description, _description)
  26
  27 -#ifdef MODULE
  28 +#if defined(MODULE) && !defined(CONFIG_MODULE_STRIPPED)
  29  /* Creates an alias so file2alias.c can find device table. */
  30  #define MODULE_DEVICE_TABLE(type, name)                                        \
  31  extern const typeof(name) __mod_##type##__##name##_device_table                \
  32 @@ -159,7 +160,9 @@ extern const typeof(name) __mod_##type##
  33   */
  34
  35  #if defined(MODULE) || !defined(CONFIG_SYSFS)
  36 -#define MODULE_VERSION(_version) MODULE_INFO(version, _version)
  37 +#define MODULE_VERSION(_version) MODULE_INFO_STRIP(version, _version)
  38 +#elif defined(CONFIG_MODULE_STRIPPED)
  39 +#define MODULE_VERSION(_version) __MODULE_INFO_DISABLED(version)
  40  #else
  41  #define MODULE_VERSION(_version)                                       \
  42         static struct module_version_attribute ___modver_attr = {       \
  43 @@ -181,7 +184,7 @@ extern const typeof(name) __mod_##type##
  44  /* Optional firmware file (or files) needed by the module
  45   * format is simply firmware file name.  Multiple firmware
  46   * files require multiple MODULE_FIRMWARE() specifiers */
  47 -#define MODULE_FIRMWARE(_firmware) MODULE_INFO(firmware, _firmware)
  48 +#define MODULE_FIRMWARE(_firmware) MODULE_INFO_STRIP(firmware, _firmware)
  49
  50  /* Given an address, look for it in the exception tables */
  51  const struct exception_table_entry *search_exception_tables(unsigned long add);
  52 --- a/include/linux/moduleparam.h
  53 +++ b/include/linux/moduleparam.h
  54 @@ -16,6 +16,16 @@
  55  /* Chosen so that structs with an unsigned long line up. */
  56  #define MAX_PARAM_PREFIX_LEN (64 - sizeof(unsigned long))
  57
  58 +/* This struct is here for syntactic coherency, it is not used */
  59 +#define __MODULE_INFO_DISABLED(name)                                     \
  60 +  struct __UNIQUE_ID(name) {}
  61 +
  62 +#ifdef CONFIG_MODULE_STRIPPED
  63 +#define __MODULE_INFO_STRIP(tag, name, info) __MODULE_INFO_DISABLED(name)
  64 +#else
  65 +#define __MODULE_INFO_STRIP(tag, name, info) __MODULE_INFO(tag, name, info)
  66 +#endif
  67 +
  68  #ifdef MODULE
  69  #define __MODULE_INFO(tag, name, info)                                   \
  70  static const char __UNIQUE_ID(name)[]                                    \
  71 @@ -23,8 +33,7 @@ static const char __UNIQUE_ID(name)[]
  72    = __stringify(tag) "=" info
  73  #else  /* !MODULE */
  74  /* This struct is here for syntactic coherency, it is not used */
  75 -#define __MODULE_INFO(tag, name, info)                                   \
  76 -  struct __UNIQUE_ID(name) {}
  77 +#define __MODULE_INFO(tag, name, info) __MODULE_INFO_DISABLED(name)
  78  #endif
  79  #define __MODULE_PARM_TYPE(name, _type)                                          \
  80    __MODULE_INFO(parmtype, name##type, #name ":" _type)
  81 @@ -32,7 +41,7 @@ static const char __UNIQUE_ID(name)[]
  82  /* One for each parameter, describing how to use it.  Some files do
  83     multiple of these per line, so can't just use MODULE_INFO. */
  84  #define MODULE_PARM_DESC(_parm, desc) \
  85 -       __MODULE_INFO(parm, _parm, #_parm ":" desc)
  86 +       __MODULE_INFO_STRIP(parm, _parm, #_parm ":" desc)
  87
  88  struct kernel_param;
  89
  90 --- a/init/Kconfig
  91 +++ b/init/Kconfig
  92 @@ -1987,6 +1987,13 @@ config MODULE_COMPRESS_XZ
  93
  94  endchoice
  95
  96 +config MODULE_STRIPPED
  97 +       bool "Reduce module size"
  98 +       depends on MODULES
  99 +       help
 100 +         Remove module parameter descriptions, author info, version, aliases,
 101 +         device tables, etc.
 102 +
 103  endif # MODULES
 104
 105  config INIT_ALL_POSSIBLE
 106 --- a/kernel/module.c
 107 +++ b/kernel/module.c
 108 @@ -2699,6 +2699,7 @@ static struct module *setup_load_info(st
 109
 110  static int check_modinfo(struct module *mod, struct load_info *info, int flags)
 111  {
 112 +#ifndef CONFIG_MODULE_STRIPPED
 113         const char *modmagic = get_modinfo(info, "vermagic");
 114         int err;
 115
 116 @@ -2724,6 +2725,7 @@ static int check_modinfo(struct module *
 117                 pr_warn("%s: module is from the staging directory, the quality "
 118                         "is unknown, you have been warned.\n", mod->name);
 119         }
 120 +#endif
 121
 122         /* Set up license info based on the info section */
 123         set_license(mod, get_modinfo(info, "license"));
 124 --- a/scripts/mod/modpost.c
 125 +++ b/scripts/mod/modpost.c
 126 @@ -1760,7 +1760,9 @@ static void read_symbols(char *modname)
 127                 symname = remove_dot(info.strtab + sym->st_name);
 128
 129                 handle_modversions(mod, &info, sym, symname);
 130 +#ifndef CONFIG_MODULE_STRIPPED
 131                 handle_moddevtable(mod, &info, sym, symname);
 132 +#endif
 133         }
 134         if (!is_vmlinux(modname) ||
 135              (is_vmlinux(modname) && vmlinux_section_warnings))
 136 @@ -1904,7 +1906,9 @@ static void add_header(struct buffer *b,
 137         buf_printf(b, "#include <linux/vermagic.h>\n");
 138         buf_printf(b, "#include <linux/compiler.h>\n");
 139         buf_printf(b, "\n");
 140 +#ifndef CONFIG_MODULE_STRIPPED
 141         buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
 142 +#endif
 143         buf_printf(b, "\n");
 144         buf_printf(b, "__visible struct module __this_module\n");
 145         buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
 146 @@ -1921,16 +1925,20 @@ static void add_header(struct buffer *b,
 147
 148  static void add_intree_flag(struct buffer *b, int is_intree)
 149  {
 150 +#ifndef CONFIG_MODULE_STRIPPED
 151         if (is_intree)
 152                 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
 153 +#endif
 154  }
 155
 156  static void add_staging_flag(struct buffer *b, const char *name)
 157  {
 158 +#ifndef CONFIG_MODULE_STRIPPED
 159         static const char *staging_dir = "drivers/staging";
 160
 161         if (strncmp(staging_dir, name, strlen(staging_dir)) == 0)
 162                 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
 163 +#endif
 164  }
 165
 166  /**
 167 @@ -2023,11 +2031,13 @@ static void add_depends(struct buffer *b
 168
 169  static void add_srcversion(struct buffer *b, struct module *mod)
 170  {
 171 +#ifndef CONFIG_MODULE_STRIPPED
 172         if (mod->srcversion[0]) {
 173                 buf_printf(b, "\n");
 174                 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
 175                            mod->srcversion);
 176         }
 177 +#endif
 178  }
 179
 180  static void write_if_changed(struct buffer *b, const char *fname)
 181 @@ -2258,7 +2268,9 @@ int main(int argc, char **argv)
 182                 add_staging_flag(&buf, mod->name);
 183                 err |= add_versions(&buf, mod);
 184                 add_depends(&buf, mod, modules);
 185 +#ifndef CONFIG_MODULE_STRIPPED
 186                 add_moddevtable(&buf, mod);
 187 +#endif
 188                 add_srcversion(&buf, mod);
 189
 190                 sprintf(fname, "%s.mod.c", mod->name);