target/linux/generic/hack-4.9/204-module_strip.patch

   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
   5
   6 Signed-off-by: Felix Fietkau <nbd@nbd.name>
   7 ---
   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(-)
  14
  15 diff --git a/include/linux/module.h b/include/linux/module.h
  16 index 0c3207d26ac0..08b58474bfd2 100644
  17 --- a/include/linux/module.h
  18 +++ b/include/linux/module.h
  19 @@ -159,6 +159,7 @@ extern void cleanup_module(void);
  20
  21  /* Generic info of form tag = "info" */
  22  #define MODULE_INFO(tag, info) __MODULE_INFO(tag, tag, info)
  23 +#define MODULE_INFO_STRIP(tag, info) __MODULE_INFO_STRIP(tag, tag, info)
  24
  25  /* For userspace: you can also call me... */
  26  #define MODULE_ALIAS(_alias) MODULE_INFO(alias, _alias)
  27 @@ -202,12 +203,12 @@ extern void cleanup_module(void);
  28   * Author(s), use "Name <email>" or just "Name", for multiple
  29   * authors use multiple MODULE_AUTHOR() statements/lines.
  30   */
  31 -#define MODULE_AUTHOR(_author) MODULE_INFO(author, _author)
  32 +#define MODULE_AUTHOR(_author) MODULE_INFO_STRIP(author, _author)
  33
  34  /* What your module does. */
  35 -#define MODULE_DESCRIPTION(_description) MODULE_INFO(description, _description)
  36 +#define MODULE_DESCRIPTION(_description) MODULE_INFO_STRIP(description, _description)
  37
  38 -#ifdef MODULE
  39 +#if defined(MODULE) && !defined(CONFIG_MODULE_STRIPPED)
  40  /* Creates an alias so file2alias.c can find device table. */
  41  #define MODULE_DEVICE_TABLE(type, name)                                        \
  42  extern const typeof(name) __mod_##type##__##name##_device_table                \
  43 @@ -234,7 +235,9 @@ extern const typeof(name) __mod_##type##__##name##_device_table             \
  44   */
  45
  46  #if defined(MODULE) || !defined(CONFIG_SYSFS)
  47 -#define MODULE_VERSION(_version) MODULE_INFO(version, _version)
  48 +#define MODULE_VERSION(_version) MODULE_INFO_STRIP(version, _version)
  49 +#elif defined(CONFIG_MODULE_STRIPPED)
  50 +#define MODULE_VERSION(_version) __MODULE_INFO_DISABLED(version)
  51  #else
  52  #define MODULE_VERSION(_version)                                       \
  53         static struct module_version_attribute ___modver_attr = {       \
  54 @@ -256,7 +259,7 @@ extern const typeof(name) __mod_##type##__##name##_device_table             \
  55  /* Optional firmware file (or files) needed by the module
  56   * format is simply firmware file name.  Multiple firmware
  57   * files require multiple MODULE_FIRMWARE() specifiers */
  58 -#define MODULE_FIRMWARE(_firmware) MODULE_INFO(firmware, _firmware)
  59 +#define MODULE_FIRMWARE(_firmware) MODULE_INFO_STRIP(firmware, _firmware)
  60
  61  struct notifier_block;
  62
  63 diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h
  64 index 52666d90ca94..f0db3592906a 100644
  65 --- a/include/linux/moduleparam.h
  66 +++ b/include/linux/moduleparam.h
  67 @@ -16,6 +16,16 @@
  68  /* Chosen so that structs with an unsigned long line up. */
  69  #define MAX_PARAM_PREFIX_LEN (64 - sizeof(unsigned long))
  70
  71 +/* This struct is here for syntactic coherency, it is not used */
  72 +#define __MODULE_INFO_DISABLED(name)                                     \
  73 +  struct __UNIQUE_ID(name) {}
  74 +
  75 +#ifdef CONFIG_MODULE_STRIPPED
  76 +#define __MODULE_INFO_STRIP(tag, name, info) __MODULE_INFO_DISABLED(name)
  77 +#else
  78 +#define __MODULE_INFO_STRIP(tag, name, info) __MODULE_INFO(tag, name, info)
  79 +#endif
  80 +
  81  #ifdef MODULE
  82  #define __MODULE_INFO(tag, name, info)                                   \
  83  static const char __UNIQUE_ID(name)[]                                    \
  84 @@ -23,8 +33,7 @@ static const char __UNIQUE_ID(name)[]                                   \
  85    = __stringify(tag) "=" info
  86  #else  /* !MODULE */
  87  /* This struct is here for syntactic coherency, it is not used */
  88 -#define __MODULE_INFO(tag, name, info)                                   \
  89 -  struct __UNIQUE_ID(name) {}
  90 +#define __MODULE_INFO(tag, name, info) __MODULE_INFO_DISABLED(name)
  91  #endif
  92  #define __MODULE_PARM_TYPE(name, _type)                                          \
  93    __MODULE_INFO(parmtype, name##type, #name ":" _type)
  94 @@ -32,7 +41,7 @@ static const char __UNIQUE_ID(name)[]                                   \
  95  /* One for each parameter, describing how to use it.  Some files do
  96     multiple of these per line, so can't just use MODULE_INFO. */
  97  #define MODULE_PARM_DESC(_parm, desc) \
  98 -       __MODULE_INFO(parm, _parm, #_parm ":" desc)
  99 +       __MODULE_INFO_STRIP(parm, _parm, #_parm ":" desc)
 100
 101  struct kernel_param;
 102
 103 diff --git a/init/Kconfig b/init/Kconfig
 104 index 34407f15e6d3..9f2c0cabbc97 100644
 105 --- a/init/Kconfig
 106 +++ b/init/Kconfig
 107 @@ -2095,6 +2095,13 @@ config TRIM_UNUSED_KSYMS
 108
 109           If unsure, or if you need to build out-of-tree modules, say N.
 110
 111 +config MODULE_STRIPPED
 112 +       bool "Reduce module size"
 113 +       depends on MODULES
 114 +       help
 115 +         Remove module parameter descriptions, author info, version, aliases,
 116 +         device tables, etc.
 117 +
 118  endif # MODULES
 119
 120  config MODULES_TREE_LOOKUP
 121 diff --git a/kernel/module.c b/kernel/module.c
 122 index 0e54d5bf0097..80b5ac4181c6 100644
 123 --- a/kernel/module.c
 124 +++ b/kernel/module.c
 125 @@ -2945,9 +2945,11 @@ static struct module *setup_load_info(struct load_info *info, int flags)
 126
 127  static int check_modinfo(struct module *mod, struct load_info *info, int flags)
 128  {
 129 -       const char *modmagic = get_modinfo(info, "vermagic");
 130         int err;
 131
 132 +#ifndef CONFIG_MODULE_STRIPPED
 133 +       const char *modmagic = get_modinfo(info, "vermagic");
 134 +
 135         if (flags & MODULE_INIT_IGNORE_VERMAGIC)
 136                 modmagic = NULL;
 137
 138 @@ -2968,6 +2970,7 @@ static int check_modinfo(struct module *mod, struct load_info *info, int flags)
 139                                 mod->name);
 140                 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
 141         }
 142 +#endif
 143
 144         if (get_modinfo(info, "staging")) {
 145                 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
 146 diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
 147 index bd8349759095..80f214adbe44 100644
 148 --- a/scripts/mod/modpost.c
 149 +++ b/scripts/mod/modpost.c
 150 @@ -1964,7 +1964,9 @@ static void read_symbols(char *modname)
 151                 symname = remove_dot(info.strtab + sym->st_name);
 152
 153                 handle_modversions(mod, &info, sym, symname);
 154 +#ifndef CONFIG_MODULE_STRIPPED
 155                 handle_moddevtable(mod, &info, sym, symname);
 156 +#endif
 157         }
 158         if (!is_vmlinux(modname) ||
 159              (is_vmlinux(modname) && vmlinux_section_warnings))
 160 @@ -2108,7 +2110,9 @@ static void add_header(struct buffer *b, struct module *mod)
 161         buf_printf(b, "#include <linux/vermagic.h>\n");
 162         buf_printf(b, "#include <linux/compiler.h>\n");
 163         buf_printf(b, "\n");
 164 +#ifndef CONFIG_MODULE_STRIPPED
 165         buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
 166 +#endif
 167         buf_printf(b, "\n");
 168         buf_printf(b, "__visible struct module __this_module\n");
 169         buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
 170 @@ -2125,16 +2129,20 @@ static void add_header(struct buffer *b, struct module *mod)
 171
 172  static void add_intree_flag(struct buffer *b, int is_intree)
 173  {
 174 +#ifndef CONFIG_MODULE_STRIPPED
 175         if (is_intree)
 176                 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
 177 +#endif
 178  }
 179
 180  static void add_staging_flag(struct buffer *b, const char *name)
 181  {
 182 +#ifndef CONFIG_MODULE_STRIPPED
 183         static const char *staging_dir = "drivers/staging";
 184
 185         if (strncmp(staging_dir, name, strlen(staging_dir)) == 0)
 186                 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
 187 +#endif
 188  }
 189
 190  /* In kernel, this size is defined in linux/module.h;
 191 @@ -2238,11 +2246,13 @@ static void add_depends(struct buffer *b, struct module *mod,
 192
 193  static void add_srcversion(struct buffer *b, struct module *mod)
 194  {
 195 +#ifndef CONFIG_MODULE_STRIPPED
 196         if (mod->srcversion[0]) {
 197                 buf_printf(b, "\n");
 198                 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
 199                            mod->srcversion);
 200         }
 201 +#endif
 202  }
 203
 204  static void write_if_changed(struct buffer *b, const char *fname)
 205 @@ -2476,7 +2486,9 @@ int main(int argc, char **argv)
 206                 add_staging_flag(&buf, mod->name);
 207                 err |= add_versions(&buf, mod);
 208                 add_depends(&buf, mod, modules);
 209 +#ifndef CONFIG_MODULE_STRIPPED
 210                 add_moddevtable(&buf, mod);
 211 +#endif
 212                 add_srcversion(&buf, mod);
 213
 214                 sprintf(fname, "%s.mod.c", mod->name);
 215 --
 216 2.11.0
 217