include/linux/export-internal.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * Please do not include this explicitly.
   4  * This is used by C files generated by modpost.
   5  */
   6
   7 #ifndef __LINUX_EXPORT_INTERNAL_H__
   8 #define __LINUX_EXPORT_INTERNAL_H__
   9
  10 #include <linux/compiler.h>
  11 #include <linux/types.h>
  12
  13 #if defined(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS)
  14 /*
  15  * relative reference: this reduces the size by half on 64-bit architectures,
  16  * and eliminates the need for absolute relocations that require runtime
  17  * processing on relocatable kernels.
  18  */
  19 #define __KSYM_ALIGN            ".balign 4"
  20 #define __KSYM_REF(sym)         ".long " #sym "- ."
  21 #elif defined(CONFIG_64BIT)
  22 #define __KSYM_ALIGN            ".balign 8"
  23 #define __KSYM_REF(sym)         ".quad " #sym
  24 #else
  25 #define __KSYM_ALIGN            ".balign 4"
  26 #define __KSYM_REF(sym)         ".long " #sym
  27 #endif
  28
  29 /*
  30  * For every exported symbol, do the following:
  31  *
  32  * - Put the name of the symbol and namespace (empty string "" for none) in
  33  *   __ksymtab_strings.
  34  * - Place a struct kernel_symbol entry in the __ksymtab section.
  35  *
  36  * Note on .section use: we specify progbits since usage of the "M" (SHF_MERGE)
  37  * section flag requires it. Use '%progbits' instead of '@progbits' since the
  38  * former apparently works on all arches according to the binutils source.
  39  */
  40 #define __KSYMTAB(name, sym, sec, ns)                                           \
  41         asm("   .section \"__ksymtab_strings\",\"aMS\",%progbits,1"     "\n"    \
  42             "__kstrtab_" #name ":"                                      "\n"    \
  43             "   .asciz \"" #name "\""                                   "\n"    \
  44             "__kstrtabns_" #name ":"                                    "\n"    \
  45             "   .asciz \"" ns "\""                                      "\n"    \
  46             "   .previous"                                              "\n"    \
  47             "   .section \"___ksymtab" sec "+" #name "\", \"a\""        "\n"    \
  48                 __KSYM_ALIGN                                            "\n"    \
  49             "__ksymtab_" #name ":"                                      "\n"    \
  50                 __KSYM_REF(sym)                                         "\n"    \
  51                 __KSYM_REF(__kstrtab_ ##name)                           "\n"    \
  52                 __KSYM_REF(__kstrtabns_ ##name)                         "\n"    \
  53             "   .previous"                                              "\n"    \
  54         )
  55
  56 #if defined(CONFIG_PARISC) && defined(CONFIG_64BIT)
  57 #define KSYM_FUNC(name)         P%name
  58 #else
  59 #define KSYM_FUNC(name)         name
  60 #endif
  61
  62 #define KSYMTAB_FUNC(name, sec, ns)     __KSYMTAB(name, KSYM_FUNC(name), sec, ns)
  63 #define KSYMTAB_DATA(name, sec, ns)     __KSYMTAB(name, name, sec, ns)
  64
  65 #define SYMBOL_CRC(sym, crc, sec)   \
  66         asm(".section \"___kcrctab" sec "+" #sym "\",\"a\""     "\n" \
  67             ".balign 4"                                         "\n" \
  68             "__crc_" #sym ":"                                   "\n" \
  69             ".long " #crc                                       "\n" \
  70             ".previous"                                         "\n")
  71
  72 #endif /* __LINUX_EXPORT_INTERNAL_H__ */