1 /* Support for reading ELF files.
2 Copyright (C) 1999-2022 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 <https://www.gnu.org/licenses/>. */
18
19
20 int process_elf32_file (const char *file_name, const char *lib,
21 int *flag, unsigned int *isa_level, char **soname,
22 void *file_contents, size_t file_length);
23 int process_elf64_file (const char *file_name, const char *lib,
24 int *flag, unsigned int *isa_level, 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
process_elf_file(const char * file_name,const char * lib,int * flag,unsigned int * isa_level,char ** soname,void * file_contents,size_t file_length)40 process_elf_file (const char *file_name, const char *lib, int *flag,
41 unsigned int *isa_level, 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, isa_level, 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, isa_level, 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"
98