target/linux/generic/hack-5.4/204-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 @@ -157,6 +157,7 @@ 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 @@ -216,12 +217,12 @@ 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 typeof(name) __mod_##type##__##name##_device_table              \
  41 @@ -248,7 +249,9 @@ extern typeof(name) __mod_##type##__##na
  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         MODULE_INFO(version, _version);                                 \
  52 @@ -271,7 +274,7 @@ extern typeof(name) __mod_##type##__##na
  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  #define MODULE_IMPORT_NS(ns) MODULE_INFO(import_ns, #ns)
  60
  61 --- a/include/linux/moduleparam.h
  62 +++ b/include/linux/moduleparam.h
  63 @@ -20,10 +20,24 @@
  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    __used __attribute__((section(".modinfo"), unused, aligned(1)))        \
  81    = __MODULE_INFO_PREFIX __stringify(tag) "=" info
  82 +#else
  83 +#define __MODULE_INFO(tag, name, info) __MODULE_INFO_DISABLED(name)
  84 +#endif
  85
  86  #define __MODULE_PARM_TYPE(name, _type)                                          \
  87    __MODULE_INFO(parmtype, name##type, #name ":" _type)
  88 @@ -31,7 +45,7 @@ static const char __UNIQUE_ID(name)[]
  89  /* One for each parameter, describing how to use it.  Some files do
  90     multiple of these per line, so can't just use MODULE_INFO. */
  91  #define MODULE_PARM_DESC(_parm, desc) \
  92 -       __MODULE_INFO(parm, _parm, #_parm ":" desc)
  93 +       __MODULE_INFO_STRIP(parm, _parm, #_parm ":" desc)
  94
  95  struct kernel_param;
  96
  97 --- a/init/Kconfig
  98 +++ b/init/Kconfig
  99 @@ -2196,6 +2196,13 @@ config TRIM_UNUSED_KSYMS
 100
 101           If unsure, or if you need to build out-of-tree modules, say N.
 102
 103 +config MODULE_STRIPPED
 104 +       bool "Reduce module size"
 105 +       depends on MODULES
 106 +       help
 107 +         Remove module parameter descriptions, author info, version, aliases,
 108 +         device tables, etc.
 109 +
 110  endif # MODULES
 111
 112  config MODULES_TREE_LOOKUP
 113 --- a/kernel/module.c
 114 +++ b/kernel/module.c
 115 @@ -3142,9 +3142,11 @@ static int setup_load_info(struct load_i
 116
 117  static int check_modinfo(struct module *mod, struct load_info *info, int flags)
 118  {
 119 -       const char *modmagic = get_modinfo(info, "vermagic");
 120         int err;
 121
 122 +#ifndef CONFIG_MODULE_STRIPPED
 123 +       const char *modmagic = get_modinfo(info, "vermagic");
 124 +
 125         if (flags & MODULE_INIT_IGNORE_VERMAGIC)
 126                 modmagic = NULL;
 127
 128 @@ -3165,6 +3167,7 @@ static int check_modinfo(struct module *
 129                                 mod->name);
 130                 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
 131         }
 132 +#endif
 133
 134         check_modinfo_retpoline(mod, info);
 135
 136 --- a/scripts/mod/modpost.c
 137 +++ b/scripts/mod/modpost.c
 138 @@ -2056,7 +2056,9 @@ static void read_symbols(const char *mod
 139                 symname = remove_dot(info.strtab + sym->st_name);
 140
 141                 handle_modversions(mod, &info, sym, symname);
 142 +#ifndef CONFIG_MODULE_STRIPPED
 143                 handle_moddevtable(mod, &info, sym, symname);
 144 +#endif
 145         }
 146
 147         /* Apply symbol namespaces from __kstrtabns_<symbol> entries. */
 148 @@ -2270,8 +2272,10 @@ static void add_header(struct buffer *b,
 149         buf_printf(b, "\n");
 150         buf_printf(b, "BUILD_SALT;\n");
 151         buf_printf(b, "\n");
 152 +#ifndef CONFIG_MODULE_STRIPPED
 153         buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
 154         buf_printf(b, "MODULE_INFO(name, KBUILD_MODNAME);\n");
 155 +#endif
 156         buf_printf(b, "\n");
 157         buf_printf(b, "__visible struct module __this_module\n");
 158         buf_printf(b, "__section(.gnu.linkonce.this_module) = {\n");
 159 @@ -2288,8 +2292,10 @@ static void add_header(struct buffer *b,
 160
 161  static void add_intree_flag(struct buffer *b, int is_intree)
 162  {
 163 +#ifndef CONFIG_MODULE_STRIPPED
 164         if (is_intree)
 165                 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
 166 +#endif
 167  }
 168
 169  /* Cannot check for assembler */
 170 @@ -2302,8 +2308,10 @@ static void add_retpoline(struct buffer
 171
 172  static void add_staging_flag(struct buffer *b, const char *name)
 173  {
 174 +#ifndef CONFIG_MODULE_STRIPPED
 175         if (strstarts(name, "drivers/staging"))
 176                 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
 177 +#endif
 178  }
 179
 180  /**
 181 @@ -2387,11 +2395,13 @@ static void add_depends(struct buffer *b
 182
 183  static void add_srcversion(struct buffer *b, struct module *mod)
 184  {
 185 +#ifndef CONFIG_MODULE_STRIPPED
 186         if (mod->srcversion[0]) {
 187                 buf_printf(b, "\n");
 188                 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
 189                            mod->srcversion);
 190         }
 191 +#endif
 192  }
 193
 194  static void write_if_changed(struct buffer *b, const char *fname)
 195 @@ -2661,7 +2671,9 @@ int main(int argc, char **argv)
 196                 add_staging_flag(&buf, mod->name);
 197                 err |= add_versions(&buf, mod);
 198                 add_depends(&buf, mod);
 199 +#ifndef CONFIG_MODULE_STRIPPED
 200                 add_moddevtable(&buf, mod);
 201 +#endif
 202                 add_srcversion(&buf, mod);
 203
 204                 sprintf(fname, "%s.mod.c", mod->name);