target/linux/generic/hack-5.15/204-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 @@ -164,6 +164,7 @@ 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 @@ -233,12 +234,12 @@ 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 @@ -265,7 +266,9 @@ 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 @@ -288,7 +291,7 @@ 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 @@ -20,6 +20,16 @@
  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  #define __MODULE_INFO(tag, name, info)                                   \
  78         static const char __UNIQUE_ID(name)[]                             \
  79                 __used __section(".modinfo") __aligned(1)                 \
  80 @@ -31,7 +41,7 @@
  81  /* One for each parameter, describing how to use it.  Some files do
  82     multiple of these per line, so can't just use MODULE_INFO. */
  83  #define MODULE_PARM_DESC(_parm, desc) \
  84 -       __MODULE_INFO(parm, _parm, #_parm ":" desc)
  85 +       __MODULE_INFO_STRIP(parm, _parm, #_parm ":" desc)
  86
  87  struct kernel_param;
  88
  89 --- a/init/Kconfig
  90 +++ b/init/Kconfig
  91 @@ -2356,6 +2356,13 @@ config UNUSED_KSYMS_WHITELIST
  92           one per line. The path can be absolute, or relative to the kernel
  93           source tree.
  94
  95 +config MODULE_STRIPPED
  96 +       bool "Reduce module size"
  97 +       depends on MODULES
  98 +       help
  99 +         Remove module parameter descriptions, author info, version, aliases,
 100 +         device tables, etc.
 101 +
 102  endif # MODULES
 103
 104  config MODULES_TREE_LOOKUP
 105 --- a/kernel/module.c
 106 +++ b/kernel/module.c
 107 @@ -1218,6 +1218,7 @@ static struct module_attribute *modinfo_
 108
 109  static const char vermagic[] = VERMAGIC_STRING;
 110
 111 +#if defined(CONFIG_MODVERSIONS) || !defined(CONFIG_MODULE_STRIPPED)
 112  static int try_to_force_load(struct module *mod, const char *reason)
 113  {
 114  #ifdef CONFIG_MODULE_FORCE_LOAD
 115 @@ -1229,6 +1230,7 @@ static int try_to_force_load(struct modu
 116         return -ENOEXEC;
 117  #endif
 118  }
 119 +#endif
 120
 121  #ifdef CONFIG_MODVERSIONS
 122
 123 @@ -3274,9 +3276,11 @@ static int setup_load_info(struct load_i
 124
 125  static int check_modinfo(struct module *mod, struct load_info *info, int flags)
 126  {
 127 -       const char *modmagic = get_modinfo(info, "vermagic");
 128         int err;
 129
 130 +#ifndef CONFIG_MODULE_STRIPPED
 131 +       const char *modmagic = get_modinfo(info, "vermagic");
 132 +
 133         if (flags & MODULE_INIT_IGNORE_VERMAGIC)
 134                 modmagic = NULL;
 135
 136 @@ -3297,6 +3301,7 @@ static int check_modinfo(struct module *
 137                                 mod->name);
 138                 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
 139         }
 140 +#endif
 141
 142         check_modinfo_retpoline(mod, info);
 143
 144 --- a/scripts/mod/modpost.c
 145 +++ b/scripts/mod/modpost.c
 146 @@ -2000,7 +2000,9 @@ static void read_symbols(const char *mod
 147                 symname = remove_dot(info.strtab + sym->st_name);
 148
 149                 handle_symbol(mod, &info, sym, symname);
 150 +#ifndef CONFIG_MODULE_STRIPPED
 151                 handle_moddevtable(mod, &info, sym, symname);
 152 +#endif
 153         }
 154
 155         for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
 156 @@ -2179,8 +2181,10 @@ static void add_header(struct buffer *b,
 157         buf_printf(b, "BUILD_SALT;\n");
 158         buf_printf(b, "BUILD_LTO_INFO;\n");
 159         buf_printf(b, "\n");
 160 +#ifndef CONFIG_MODULE_STRIPPED
 161         buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
 162         buf_printf(b, "MODULE_INFO(name, KBUILD_MODNAME);\n");
 163 +#endif
 164         buf_printf(b, "\n");
 165         buf_printf(b, "__visible struct module __this_module\n");
 166         buf_printf(b, "__section(\".gnu.linkonce.this_module\") = {\n");
 167 @@ -2197,8 +2201,10 @@ static void add_header(struct buffer *b,
 168
 169  static void add_intree_flag(struct buffer *b, int is_intree)
 170  {
 171 +#ifndef CONFIG_MODULE_STRIPPED
 172         if (is_intree)
 173                 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
 174 +#endif
 175  }
 176
 177  /* Cannot check for assembler */
 178 @@ -2211,8 +2217,10 @@ static void add_retpoline(struct buffer
 179
 180  static void add_staging_flag(struct buffer *b, const char *name)
 181  {
 182 +#ifndef CONFIG_MODULE_STRIPPED
 183         if (strstarts(name, "drivers/staging"))
 184                 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
 185 +#endif
 186  }
 187
 188  /**
 189 @@ -2292,11 +2300,13 @@ static void add_depends(struct buffer *b
 190
 191  static void add_srcversion(struct buffer *b, struct module *mod)
 192  {
 193 +#ifndef CONFIG_MODULE_STRIPPED
 194         if (mod->srcversion[0]) {
 195                 buf_printf(b, "\n");
 196                 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
 197                            mod->srcversion);
 198         }
 199 +#endif
 200  }
 201
 202  static void write_buf(struct buffer *b, const char *fname)
 203 @@ -2545,7 +2555,9 @@ int main(int argc, char **argv)
 204                 add_staging_flag(&buf, mod->name);
 205                 add_versions(&buf, mod);
 206                 add_depends(&buf, mod);
 207 +#ifndef CONFIG_MODULE_STRIPPED
 208                 add_moddevtable(&buf, mod);
 209 +#endif
 210                 add_srcversion(&buf, mod);
 211
 212                 sprintf(fname, "%s.mod.c", mod->name);