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 --- a/include/linux/module.h
  16 +++ b/include/linux/module.h
  17 @@ -159,6 +159,7 @@ extern void cleanup_module(void);
  18
  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)
  22
  23  /* For userspace: you can also call me... */
  24  #define MODULE_ALIAS(_alias) MODULE_INFO(alias, _alias)
  25 @@ -202,12 +203,12 @@ extern void cleanup_module(void);
  26   * Author(s), use "Name <email>" or just "Name", for multiple
  27   * authors use multiple MODULE_AUTHOR() statements/lines.
  28   */
  29 -#define MODULE_AUTHOR(_author) MODULE_INFO(author, _author)
  30 +#define MODULE_AUTHOR(_author) MODULE_INFO_STRIP(author, _author)
  31
  32  /* What your module does. */
  33 -#define MODULE_DESCRIPTION(_description) MODULE_INFO(description, _description)
  34 +#define MODULE_DESCRIPTION(_description) MODULE_INFO_STRIP(description, _description)
  35
  36 -#ifdef MODULE
  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 const typeof(name) __mod_##type##__##name##_device_table                \
  41 @@ -234,7 +235,9 @@ extern const typeof(name) __mod_##type##
  42   */
  43
  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)
  49  #else
  50  #define MODULE_VERSION(_version)                                       \
  51         static struct module_version_attribute ___modver_attr = {       \
  52 @@ -256,7 +259,7 @@ extern const typeof(name) __mod_##type##
  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)
  58
  59  struct notifier_block;
  60
  61 --- a/include/linux/moduleparam.h
  62 +++ b/include/linux/moduleparam.h
  63 @@ -16,6 +16,16 @@
  64  /* Chosen so that structs with an unsigned long line up. */
  65  #define MAX_PARAM_PREFIX_LEN (64 - sizeof(unsigned long))
  66
  67 +/* This struct is here for syntactic coherency, it is not used */
  68 +#define __MODULE_INFO_DISABLED(name)                                     \
  69 +  struct __UNIQUE_ID(name) {}
  70 +
  71 +#ifdef CONFIG_MODULE_STRIPPED
  72 +#define __MODULE_INFO_STRIP(tag, name, info) __MODULE_INFO_DISABLED(name)
  73 +#else
  74 +#define __MODULE_INFO_STRIP(tag, name, info) __MODULE_INFO(tag, name, info)
  75 +#endif
  76 +
  77  #ifdef MODULE
  78  #define __MODULE_INFO(tag, name, info)                                   \
  79  static const char __UNIQUE_ID(name)[]                                    \
  80 @@ -23,8 +33,7 @@ static const char __UNIQUE_ID(name)[]
  81    = __stringify(tag) "=" info
  82  #else  /* !MODULE */
  83  /* This struct is here for syntactic coherency, it is not used */
  84 -#define __MODULE_INFO(tag, name, info)                                   \
  85 -  struct __UNIQUE_ID(name) {}
  86 +#define __MODULE_INFO(tag, name, info) __MODULE_INFO_DISABLED(name)
  87  #endif
  88  #define __MODULE_PARM_TYPE(name, _type)                                          \
  89    __MODULE_INFO(parmtype, name##type, #name ":" _type)
  90 @@ -32,7 +41,7 @@ static const char __UNIQUE_ID(name)[]
  91  /* One for each parameter, describing how to use it.  Some files do
  92     multiple of these per line, so can't just use MODULE_INFO. */
  93  #define MODULE_PARM_DESC(_parm, desc) \
  94 -       __MODULE_INFO(parm, _parm, #_parm ":" desc)
  95 +       __MODULE_INFO_STRIP(parm, _parm, #_parm ":" desc)
  96
  97  struct kernel_param;
  98
  99 --- a/init/Kconfig
 100 +++ b/init/Kconfig
 101 @@ -2122,6 +2122,13 @@ config TRIM_UNUSED_KSYMS
 102
 103           If unsure, or if you need to build out-of-tree modules, say N.
 104
 105 +config MODULE_STRIPPED
 106 +       bool "Reduce module size"
 107 +       depends on MODULES
 108 +       help
 109 +         Remove module parameter descriptions, author info, version, aliases,
 110 +         device tables, etc.
 111 +
 112  endif # MODULES
 113
 114  config MODULES_TREE_LOOKUP
 115 --- a/kernel/module.c
 116 +++ b/kernel/module.c
 117 @@ -2968,9 +2968,11 @@ static struct module *setup_load_info(st
 118
 119  static int check_modinfo(struct module *mod, struct load_info *info, int flags)
 120  {
 121 -       const char *modmagic = get_modinfo(info, "vermagic");
 122         int err;
 123
 124 +#ifndef CONFIG_MODULE_STRIPPED
 125 +       const char *modmagic = get_modinfo(info, "vermagic");
 126 +
 127         if (flags & MODULE_INIT_IGNORE_VERMAGIC)
 128                 modmagic = NULL;
 129
 130 @@ -2991,6 +2993,7 @@ static int check_modinfo(struct module *
 131                                 mod->name);
 132                 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
 133         }
 134 +#endif
 135
 136         check_modinfo_retpoline(mod, info);
 137
 138 --- a/scripts/mod/modpost.c
 139 +++ b/scripts/mod/modpost.c
 140 @@ -1965,7 +1965,9 @@ static void read_symbols(char *modname)
 141                 symname = remove_dot(info.strtab + sym->st_name);
 142
 143                 handle_modversions(mod, &info, sym, symname);
 144 +#ifndef CONFIG_MODULE_STRIPPED
 145                 handle_moddevtable(mod, &info, sym, symname);
 146 +#endif
 147         }
 148         if (!is_vmlinux(modname) ||
 149              (is_vmlinux(modname) && vmlinux_section_warnings))
 150 @@ -2109,7 +2111,9 @@ static void add_header(struct buffer *b,
 151         buf_printf(b, "#include <linux/vermagic.h>\n");
 152         buf_printf(b, "#include <linux/compiler.h>\n");
 153         buf_printf(b, "\n");
 154 +#ifndef CONFIG_MODULE_STRIPPED
 155         buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
 156 +#endif
 157         buf_printf(b, "\n");
 158         buf_printf(b, "__visible struct module __this_module\n");
 159         buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
 160 @@ -2126,24 +2130,30 @@ static void add_header(struct buffer *b,
 161
 162  static void add_intree_flag(struct buffer *b, int is_intree)
 163  {
 164 +#ifndef CONFIG_MODULE_STRIPPED
 165         if (is_intree)
 166                 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
 167 +#endif
 168  }
 169
 170  /* Cannot check for assembler */
 171  static void add_retpoline(struct buffer *b)
 172  {
 173 +#ifndef CONFIG_MODULE_STRIPPED
 174         buf_printf(b, "\n#ifdef RETPOLINE\n");
 175         buf_printf(b, "MODULE_INFO(retpoline, \"Y\");\n");
 176         buf_printf(b, "#endif\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 @@ -2247,11 +2257,13 @@ static void add_depends(struct buffer *b
 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 @@ -2486,7 +2498,9 @@ 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);