sysdeps/unix/sysv/linux/riscv/readelflib.c

   1 /* Support for reading ELF files.
   2    Copyright (C) 1999-2019 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19
  20 int process_elf32_file (const char *file_name, const char *lib, int *flag,
  21                         unsigned int *osversion, char **soname,
  22                         void *file_contents, size_t file_length);
  23 int process_elf64_file (const char *file_name, const char *lib, int *flag,
  24                         unsigned int *osversion, char **soname,
  25                         void *file_contents, size_t file_length);
  26
  27 /* The ELF flags supported by our current glibc port:
  28    - EF_RISCV_FLOAT_ABI: We support the soft and double ABIs.
  29    - EF_RISCV_RVC: While the Linux ABI mandates the presence of the C
  30      extension, we can still support libraries compiled without that extension
  31      so we just ignore this flag.
  32    - EF_RISCV_RVE: glibc (and Linux) don't support RV32E based systems.
  33    - EF_RISCV_TSO: The TSO extension isn't supported, as doing so would require
  34      some mechanism to ensure that the TSO extension is enabled which doesn't
  35      currently exist.  */
  36 #define SUPPORTED_ELF_FLAGS (EF_RISCV_FLOAT_ABI | EF_RISCV_RVC)
  37
  38 /* Returns 0 if everything is ok, != 0 in case of error.  */
  39 int
  40 process_elf_file (const char *file_name, const char *lib, int *flag,
  41                   unsigned int *osversion, char **soname, void *file_contents,
  42                   size_t file_length)
  43 {
  44   ElfW(Ehdr) *elf_header = (ElfW(Ehdr) *) file_contents;
  45   Elf32_Ehdr *elf32_header = (Elf32_Ehdr *) elf_header;
  46   Elf64_Ehdr *elf64_header = (Elf64_Ehdr *) elf_header;
  47   int ret;
  48   long flags;
  49
  50   /* RISC-V libraries are always libc.so.6+.  */
  51   *flag = FLAG_ELF_LIBC6;
  52
  53   if (elf_header->e_ident [EI_CLASS] == ELFCLASS32)
  54     {
  55       ret = process_elf32_file (file_name, lib, flag, osversion, soname,
  56                                 file_contents, file_length);
  57       flags = elf32_header->e_flags;
  58     }
  59   else
  60     {
  61       ret = process_elf64_file (file_name, lib, flag, osversion, soname,
  62                                 file_contents, file_length);
  63       flags = elf64_header->e_flags;
  64     }
  65
  66   /* RISC-V linkers encode the floating point ABI as part of the ELF headers.  */
  67   switch (flags & EF_RISCV_FLOAT_ABI)
  68     {
  69       case EF_RISCV_FLOAT_ABI_SOFT:
  70         *flag |= FLAG_RISCV_FLOAT_ABI_SOFT;
  71         break;
  72       case EF_RISCV_FLOAT_ABI_DOUBLE:
  73         *flag |= FLAG_RISCV_FLOAT_ABI_DOUBLE;
  74         break;
  75       default:
  76         return 1;
  77     }
  78
  79   /* If there are any other ELF flags set then glibc doesn't support this
  80      library.  */
  81   if (flags & ~SUPPORTED_ELF_FLAGS)
  82     return 1;
  83
  84   return ret;
  85 }
  86
  87 #undef __ELF_NATIVE_CLASS
  88 #undef process_elf_file
  89 #define process_elf_file process_elf32_file
  90 #define __ELF_NATIVE_CLASS 32
  91 #include "elf/readelflib.c"
  92
  93 #undef __ELF_NATIVE_CLASS
  94 #undef process_elf_file
  95 #define process_elf_file process_elf64_file
  96 #define __ELF_NATIVE_CLASS 64
  97 #include "elf/readelflib.c"