Ralf Baechle | 6ede812 | 2012-08-14 17:13:45 +0200 | [diff] [blame] | 1 | /* |
| 2 | * This program is free software; you can redistribute it and/or modify |
| 3 | * it under the terms of the GNU General Public License as published by |
| 4 | * the Free Software Foundation; either version 2 of the License, or |
| 5 | * (at your option) any later version. |
| 6 | * |
| 7 | * This program is distributed in the hope that it will be useful, |
| 8 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 9 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 10 | * GNU General Public License for more details. |
| 11 | * |
| 12 | * You should have received a copy of the GNU General Public License |
| 13 | * along with this program; if not, write to the Free Software |
| 14 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 15 | * |
| 16 | * Copyright (C) 2001 Rusty Russell. |
| 17 | * Copyright (C) 2003, 2004 Ralf Baechle (ralf@linux-mips.org) |
| 18 | * Copyright (C) 2005 Thiemo Seufer |
Paul Burton | ad8319e | 2016-02-04 13:05:04 +0000 | [diff] [blame^] | 19 | * Copyright (C) 2015 Imagination Technologies Ltd. |
Ralf Baechle | 6ede812 | 2012-08-14 17:13:45 +0200 | [diff] [blame] | 20 | */ |
| 21 | |
| 22 | #include <linux/elf.h> |
| 23 | #include <linux/err.h> |
| 24 | #include <linux/errno.h> |
| 25 | #include <linux/moduleloader.h> |
| 26 | |
| 27 | extern int apply_r_mips_none(struct module *me, u32 *location, Elf_Addr v); |
| 28 | |
| 29 | static int apply_r_mips_32_rela(struct module *me, u32 *location, Elf_Addr v) |
| 30 | { |
| 31 | *location = v; |
| 32 | |
| 33 | return 0; |
| 34 | } |
| 35 | |
| 36 | static int apply_r_mips_26_rela(struct module *me, u32 *location, Elf_Addr v) |
| 37 | { |
| 38 | if (v % 4) { |
Steven J. Hill | 55d791f | 2016-02-04 13:05:03 +0000 | [diff] [blame] | 39 | pr_err("module %s: dangerous R_MIPS_26 RELA relocation\n", |
Ralf Baechle | 6ede812 | 2012-08-14 17:13:45 +0200 | [diff] [blame] | 40 | me->name); |
| 41 | return -ENOEXEC; |
| 42 | } |
| 43 | |
| 44 | if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) { |
Steven J. Hill | 55d791f | 2016-02-04 13:05:03 +0000 | [diff] [blame] | 45 | pr_err("module %s: relocation overflow\n", me->name); |
Ralf Baechle | 6ede812 | 2012-08-14 17:13:45 +0200 | [diff] [blame] | 46 | return -ENOEXEC; |
| 47 | } |
| 48 | |
| 49 | *location = (*location & ~0x03ffffff) | ((v >> 2) & 0x03ffffff); |
| 50 | |
| 51 | return 0; |
| 52 | } |
| 53 | |
| 54 | static int apply_r_mips_hi16_rela(struct module *me, u32 *location, Elf_Addr v) |
| 55 | { |
| 56 | *location = (*location & 0xffff0000) | |
Ralf Baechle | 7034228 | 2013-01-22 12:59:30 +0100 | [diff] [blame] | 57 | ((((long long) v + 0x8000LL) >> 16) & 0xffff); |
Ralf Baechle | 6ede812 | 2012-08-14 17:13:45 +0200 | [diff] [blame] | 58 | |
| 59 | return 0; |
| 60 | } |
| 61 | |
| 62 | static int apply_r_mips_lo16_rela(struct module *me, u32 *location, Elf_Addr v) |
| 63 | { |
| 64 | *location = (*location & 0xffff0000) | (v & 0xffff); |
| 65 | |
| 66 | return 0; |
| 67 | } |
| 68 | |
Paul Burton | ad8319e | 2016-02-04 13:05:04 +0000 | [diff] [blame^] | 69 | static int apply_r_mips_pc_rela(struct module *me, u32 *location, Elf_Addr v, |
| 70 | unsigned bits) |
| 71 | { |
| 72 | unsigned long mask = GENMASK(bits - 1, 0); |
| 73 | unsigned long se_bits; |
| 74 | long offset; |
| 75 | |
| 76 | if (v % 4) { |
| 77 | pr_err("module %s: dangerous R_MIPS_PC%u RELA relocation\n", |
| 78 | me->name, bits); |
| 79 | return -ENOEXEC; |
| 80 | } |
| 81 | |
| 82 | offset = ((long)v - (long)location) >> 2; |
| 83 | |
| 84 | /* check the sign bit onwards are identical - ie. we didn't overflow */ |
| 85 | se_bits = (offset & BIT(bits - 1)) ? ~0ul : 0; |
| 86 | if ((offset & ~mask) != (se_bits & ~mask)) { |
| 87 | pr_err("module %s: relocation overflow\n", me->name); |
| 88 | return -ENOEXEC; |
| 89 | } |
| 90 | |
| 91 | *location = (*location & ~mask) | (offset & mask); |
| 92 | |
| 93 | return 0; |
| 94 | } |
| 95 | |
| 96 | static int apply_r_mips_pc16_rela(struct module *me, u32 *location, Elf_Addr v) |
| 97 | { |
| 98 | return apply_r_mips_pc_rela(me, location, v, 16); |
| 99 | } |
| 100 | |
| 101 | static int apply_r_mips_pc21_rela(struct module *me, u32 *location, Elf_Addr v) |
| 102 | { |
| 103 | return apply_r_mips_pc_rela(me, location, v, 21); |
| 104 | } |
| 105 | |
| 106 | static int apply_r_mips_pc26_rela(struct module *me, u32 *location, Elf_Addr v) |
| 107 | { |
| 108 | return apply_r_mips_pc_rela(me, location, v, 26); |
| 109 | } |
| 110 | |
Ralf Baechle | 6ede812 | 2012-08-14 17:13:45 +0200 | [diff] [blame] | 111 | static int apply_r_mips_64_rela(struct module *me, u32 *location, Elf_Addr v) |
| 112 | { |
| 113 | *(Elf_Addr *)location = v; |
| 114 | |
| 115 | return 0; |
| 116 | } |
| 117 | |
| 118 | static int apply_r_mips_higher_rela(struct module *me, u32 *location, |
| 119 | Elf_Addr v) |
| 120 | { |
| 121 | *location = (*location & 0xffff0000) | |
Ralf Baechle | 7034228 | 2013-01-22 12:59:30 +0100 | [diff] [blame] | 122 | ((((long long) v + 0x80008000LL) >> 32) & 0xffff); |
Ralf Baechle | 6ede812 | 2012-08-14 17:13:45 +0200 | [diff] [blame] | 123 | |
| 124 | return 0; |
| 125 | } |
| 126 | |
| 127 | static int apply_r_mips_highest_rela(struct module *me, u32 *location, |
| 128 | Elf_Addr v) |
| 129 | { |
| 130 | *location = (*location & 0xffff0000) | |
Ralf Baechle | 7034228 | 2013-01-22 12:59:30 +0100 | [diff] [blame] | 131 | ((((long long) v + 0x800080008000LL) >> 48) & 0xffff); |
Ralf Baechle | 6ede812 | 2012-08-14 17:13:45 +0200 | [diff] [blame] | 132 | |
| 133 | return 0; |
| 134 | } |
| 135 | |
| 136 | static int (*reloc_handlers_rela[]) (struct module *me, u32 *location, |
| 137 | Elf_Addr v) = { |
| 138 | [R_MIPS_NONE] = apply_r_mips_none, |
| 139 | [R_MIPS_32] = apply_r_mips_32_rela, |
| 140 | [R_MIPS_26] = apply_r_mips_26_rela, |
| 141 | [R_MIPS_HI16] = apply_r_mips_hi16_rela, |
| 142 | [R_MIPS_LO16] = apply_r_mips_lo16_rela, |
Paul Burton | ad8319e | 2016-02-04 13:05:04 +0000 | [diff] [blame^] | 143 | [R_MIPS_PC16] = apply_r_mips_pc16_rela, |
Ralf Baechle | 6ede812 | 2012-08-14 17:13:45 +0200 | [diff] [blame] | 144 | [R_MIPS_64] = apply_r_mips_64_rela, |
| 145 | [R_MIPS_HIGHER] = apply_r_mips_higher_rela, |
Paul Burton | ad8319e | 2016-02-04 13:05:04 +0000 | [diff] [blame^] | 146 | [R_MIPS_HIGHEST] = apply_r_mips_highest_rela, |
| 147 | [R_MIPS_PC21_S2] = apply_r_mips_pc21_rela, |
| 148 | [R_MIPS_PC26_S2] = apply_r_mips_pc26_rela, |
Ralf Baechle | 6ede812 | 2012-08-14 17:13:45 +0200 | [diff] [blame] | 149 | }; |
| 150 | |
| 151 | int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab, |
| 152 | unsigned int symindex, unsigned int relsec, |
| 153 | struct module *me) |
| 154 | { |
| 155 | Elf_Mips_Rela *rel = (void *) sechdrs[relsec].sh_addr; |
Paul Burton | 04211a5 | 2016-02-04 13:05:02 +0000 | [diff] [blame] | 156 | int (*handler)(struct module *me, u32 *location, Elf_Addr v); |
Ralf Baechle | 6ede812 | 2012-08-14 17:13:45 +0200 | [diff] [blame] | 157 | Elf_Sym *sym; |
| 158 | u32 *location; |
Paul Burton | 04211a5 | 2016-02-04 13:05:02 +0000 | [diff] [blame] | 159 | unsigned int i, type; |
Ralf Baechle | 6ede812 | 2012-08-14 17:13:45 +0200 | [diff] [blame] | 160 | Elf_Addr v; |
| 161 | int res; |
| 162 | |
| 163 | pr_debug("Applying relocate section %u to %u\n", relsec, |
| 164 | sechdrs[relsec].sh_info); |
| 165 | |
| 166 | for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) { |
| 167 | /* This is where to make the change */ |
| 168 | location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr |
| 169 | + rel[i].r_offset; |
| 170 | /* This is the symbol it is referring to */ |
| 171 | sym = (Elf_Sym *)sechdrs[symindex].sh_addr |
| 172 | + ELF_MIPS_R_SYM(rel[i]); |
| 173 | if (IS_ERR_VALUE(sym->st_value)) { |
| 174 | /* Ignore unresolved weak symbol */ |
| 175 | if (ELF_ST_BIND(sym->st_info) == STB_WEAK) |
| 176 | continue; |
Steven J. Hill | 55d791f | 2016-02-04 13:05:03 +0000 | [diff] [blame] | 177 | pr_warn("%s: Unknown symbol %s\n", |
Ralf Baechle | 6ede812 | 2012-08-14 17:13:45 +0200 | [diff] [blame] | 178 | me->name, strtab + sym->st_name); |
| 179 | return -ENOENT; |
| 180 | } |
| 181 | |
Paul Burton | 04211a5 | 2016-02-04 13:05:02 +0000 | [diff] [blame] | 182 | type = ELF_MIPS_R_TYPE(rel[i]); |
Ralf Baechle | 6ede812 | 2012-08-14 17:13:45 +0200 | [diff] [blame] | 183 | |
Paul Burton | 04211a5 | 2016-02-04 13:05:02 +0000 | [diff] [blame] | 184 | if (type < ARRAY_SIZE(reloc_handlers_rela)) |
| 185 | handler = reloc_handlers_rela[type]; |
| 186 | else |
| 187 | handler = NULL; |
| 188 | |
| 189 | if (!handler) { |
| 190 | pr_err("%s: Unknown relocation type %u\n", |
| 191 | me->name, type); |
| 192 | return -EINVAL; |
| 193 | } |
| 194 | |
| 195 | v = sym->st_value + rel[i].r_addend; |
| 196 | res = handler(me, location, v); |
Ralf Baechle | 6ede812 | 2012-08-14 17:13:45 +0200 | [diff] [blame] | 197 | if (res) |
| 198 | return res; |
| 199 | } |
| 200 | |
| 201 | return 0; |
| 202 | } |