target/linux/generic/backport-5.4/030-modpost-add-a-helper-to-get-data-pointed-by-a-symbol.patch

   1 From afa0459daa7b08c7b2c879705b69d39b734a11d0 Mon Sep 17 00:00:00 2001
   2 From: Masahiro Yamada <yamada.masahiro@socionext.com>
   3 Date: Fri, 15 Nov 2019 02:42:21 +0900
   4 Subject: [PATCH] modpost: add a helper to get data pointed by a symbol
   5
   6 When CONFIG_MODULE_REL_CRCS is enabled, the value of __crc_* is not
   7 an absolute value, but the address to the CRC data embedded in the
   8 .rodata section.
   9
  10 Getting the data pointed by the symbol value is somewhat complex.
  11 Split it out into a new helper, sym_get_data().
  12
  13 I will reuse it to refactor namespace_from_kstrtabns() in the next
  14 commit.
  15
  16 Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
  17 ---
  18  scripts/mod/modpost.c | 17 +++++++++++++----
  19  1 file changed, 13 insertions(+), 4 deletions(-)
  20
  21 --- a/scripts/mod/modpost.c
  22 +++ b/scripts/mod/modpost.c
  23 @@ -312,6 +312,18 @@ static const char *sec_name(struct elf_i
  24         return sech_name(elf, &elf->sechdrs[secindex]);
  25  }
  26
  27 +static void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym)
  28 +{
  29 +       Elf_Shdr *sechdr = &info->sechdrs[sym->st_shndx];
  30 +       unsigned long offset;
  31 +
  32 +       offset = sym->st_value;
  33 +       if (info->hdr->e_type != ET_REL)
  34 +               offset -= sechdr->sh_addr;
  35 +
  36 +       return (void *)info->hdr + sechdr->sh_offset + offset;
  37 +}
  38 +
  39  #define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0)
  40
  41  static enum export export_from_secname(struct elf_info *elf, unsigned int sec)
  42 @@ -701,10 +713,7 @@ static void handle_modversions(struct mo
  43                         unsigned int *crcp;
  44
  45                         /* symbol points to the CRC in the ELF object */
  46 -                       crcp = (void *)info->hdr + sym->st_value +
  47 -                              info->sechdrs[sym->st_shndx].sh_offset -
  48 -                              (info->hdr->e_type != ET_REL ?
  49 -                               info->sechdrs[sym->st_shndx].sh_addr : 0);
  50 +                       crcp = sym_get_data(info, sym);
  51                         crc = TO_NATIVE(*crcp);
  52                 }
  53                 sym_update_crc(symname + strlen("__crc_"), mod, crc,