1 // SPDX-License-Identifier: GPL-2.0-only !! 1 /* Kernel module help for Alpha.
2 /* !! 2 Copyright (C) 2002 Richard Henderson.
3 * Copyright (C) 2007-2009 Michal Simek <monst <<
4 * Copyright (C) 2007-2009 PetaLogix <<
5 */ <<
6 3
7 #include <linux/export.h> !! 4 This program is free software; you can redistribute it and/or modify
>> 5 it under the terms of the GNU General Public License as published by
>> 6 the Free Software Foundation; either version 2 of the License, or
>> 7 (at your option) any later version.
>> 8
>> 9 This program is distributed in the hope that it will be useful,
>> 10 but WITHOUT ANY WARRANTY; without even the implied warranty of
>> 11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
>> 12 GNU General Public License for more details.
>> 13
>> 14 You should have received a copy of the GNU General Public License
>> 15 along with this program; if not, write to the Free Software
>> 16 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
>> 17 */
8 #include <linux/moduleloader.h> 18 #include <linux/moduleloader.h>
9 #include <linux/kernel.h> <<
10 #include <linux/elf.h> 19 #include <linux/elf.h>
11 #include <linux/vmalloc.h> 20 #include <linux/vmalloc.h>
12 #include <linux/fs.h> 21 #include <linux/fs.h>
13 #include <linux/string.h> 22 #include <linux/string.h>
14 #include <linux/pgtable.h> !! 23 #include <linux/kernel.h>
>> 24 #include <linux/slab.h>
15 25
16 #include <asm/cacheflush.h> !! 26 #if 0
>> 27 #define DEBUGP printk
>> 28 #else
>> 29 #define DEBUGP(fmt...)
>> 30 #endif
17 31
18 int apply_relocate_add(Elf32_Shdr *sechdrs, co !! 32 void *
19 unsigned int symindex, unsigned int re !! 33 module_alloc(unsigned long size)
20 { 34 {
>> 35 if (size == 0)
>> 36 return NULL;
>> 37 return vmalloc(size);
>> 38 }
21 39
22 unsigned int i; !! 40 void
23 Elf32_Rela *rela = (void *)sechdrs[rel !! 41 module_free(struct module *mod, void *module_region)
24 Elf32_Sym *sym; !! 42 {
25 unsigned long int *location; !! 43 vfree(module_region);
26 unsigned long int value; !! 44 }
27 45
28 pr_debug("Applying add relocation sect !! 46 /* Allocate the GOT at the end of the core sections. */
29 relsec, sechdrs[relsec].sh_inf <<
30 47
31 for (i = 0; i < sechdrs[relsec].sh_siz !! 48 struct got_entry {
>> 49 struct got_entry *next;
>> 50 Elf64_Sxword r_addend;
>> 51 int got_offset;
>> 52 };
>> 53
>> 54 static inline void
>> 55 process_reloc_for_got(Elf64_Rela *rela,
>> 56 struct got_entry *chains, Elf64_Xword *poffset)
>> 57 {
>> 58 unsigned long r_sym = ELF64_R_SYM (rela->r_info);
>> 59 unsigned long r_type = ELF64_R_TYPE (rela->r_info);
>> 60 Elf64_Sxword r_addend = rela->r_addend;
>> 61 struct got_entry *g;
>> 62
>> 63 if (r_type != R_ALPHA_LITERAL)
>> 64 return;
>> 65
>> 66 for (g = chains + r_sym; g ; g = g->next)
>> 67 if (g->r_addend == r_addend) {
>> 68 if (g->got_offset == 0) {
>> 69 g->got_offset = *poffset;
>> 70 *poffset += 8;
>> 71 }
>> 72 goto found_entry;
>> 73 }
32 74
33 location = (void *)sechdrs[sec !! 75 g = kmalloc (sizeof (*g), GFP_KERNEL);
34 rela[i].r_offs !! 76 g->next = chains[r_sym].next;
35 sym = (Elf32_Sym *)sechdrs[sym !! 77 g->r_addend = r_addend;
36 ELF32_R_SYM(rela[i].r_ !! 78 g->got_offset = *poffset;
37 value = sym->st_value + rela[i !! 79 *poffset += 8;
>> 80 chains[r_sym].next = g;
>> 81
>> 82 found_entry:
>> 83 /* Trick: most of the ELF64_R_TYPE field is unused. There are
>> 84 42 valid relocation types, and a 32-bit field. Co-opt the
>> 85 bits above 256 to store the got offset for this reloc. */
>> 86 rela->r_info |= g->got_offset << 8;
>> 87 }
38 88
39 switch (ELF32_R_TYPE(rela[i].r !! 89 int
>> 90 module_frob_arch_sections(Elf64_Ehdr *hdr, Elf64_Shdr *sechdrs,
>> 91 char *secstrings, struct module *me)
>> 92 {
>> 93 struct got_entry *chains;
>> 94 Elf64_Rela *rela;
>> 95 Elf64_Shdr *esechdrs, *symtab, *s, *got;
>> 96 unsigned long nsyms, nrela, i;
>> 97
>> 98 esechdrs = sechdrs + hdr->e_shnum;
>> 99 symtab = got = NULL;
>> 100
>> 101 /* Find out how large the symbol table is. Allocate one got_entry
>> 102 head per symbol. Normally this will be enough, but not always.
>> 103 We'll chain different offsets for the symbol down each head. */
>> 104 for (s = sechdrs; s < esechdrs; ++s)
>> 105 if (s->sh_type == SHT_SYMTAB)
>> 106 symtab = s;
>> 107 else if (!strcmp(".got", secstrings + s->sh_name)) {
>> 108 got = s;
>> 109 me->arch.gotsecindex = s - sechdrs;
>> 110 }
40 111
41 /* !! 112 if (!symtab) {
42 * Be careful! mb-gcc / mb-ld !! 113 printk(KERN_ERR "module %s: no symbol table\n", me->name);
43 * text and the reloc table. I !! 114 return -ENOEXEC;
44 * read the current contents o !! 115 }
45 * then store the result back !! 116 if (!got) {
46 */ !! 117 printk(KERN_ERR "module %s: no got section\n", me->name);
>> 118 return -ENOEXEC;
>> 119 }
47 120
48 case R_MICROBLAZE_32: !! 121 nsyms = symtab->sh_size / sizeof(Elf64_Sym);
49 *location = value; !! 122 chains = kcalloc(nsyms, sizeof(struct got_entry), GFP_KERNEL);
50 break; !! 123 if (!chains) {
>> 124 printk(KERN_ERR
>> 125 "module %s: no memory for symbol chain buffer\n",
>> 126 me->name);
>> 127 return -ENOMEM;
>> 128 }
51 129
52 case R_MICROBLAZE_64: !! 130 got->sh_size = 0;
53 location[0] = (locatio !! 131 got->sh_addralign = 8;
54 (value !! 132 got->sh_type = SHT_NOBITS;
55 location[1] = (locatio !! 133
56 (value !! 134 /* Examine all LITERAL relocations to find out what GOT entries
57 break; !! 135 are required. This sizes the GOT section as well. */
>> 136 for (s = sechdrs; s < esechdrs; ++s)
>> 137 if (s->sh_type == SHT_RELA) {
>> 138 nrela = s->sh_size / sizeof(Elf64_Rela);
>> 139 rela = (void *)hdr + s->sh_offset;
>> 140 for (i = 0; i < nrela; ++i)
>> 141 process_reloc_for_got(rela+i, chains,
>> 142 &got->sh_size);
>> 143 }
58 144
59 case R_MICROBLAZE_64_PCREL: !! 145 /* Free the memory we allocated. */
60 value -= (unsigned lon !! 146 for (i = 0; i < nsyms; ++i) {
61 location[0] = (locatio !! 147 struct got_entry *g, *n;
62 (value !! 148 for (g = chains[i].next; g ; g = n) {
63 location[1] = (locatio !! 149 n = g->next;
64 (value !! 150 kfree(g);
65 pr_debug("R_MICROBLAZE !! 151 }
66 value); !! 152 }
67 break; !! 153 kfree(chains);
68 154
69 case R_MICROBLAZE_32_PCREL_LO: !! 155 return 0;
70 pr_debug("R_MICROBLAZE !! 156 }
71 break; <<
72 157
73 case R_MICROBLAZE_64_NONE: !! 158 int
74 pr_debug("R_MICROBLAZE !! 159 apply_relocate(Elf64_Shdr *sechdrs, const char *strtab, unsigned int symindex,
75 break; !! 160 unsigned int relsec, struct module *me)
>> 161 {
>> 162 printk(KERN_ERR "module %s: REL relocation unsupported\n", me->name);
>> 163 return -ENOEXEC;
>> 164 }
76 165
77 case R_MICROBLAZE_NONE: !! 166 int
78 pr_debug("R_MICROBLAZE !! 167 apply_relocate_add(Elf64_Shdr *sechdrs, const char *strtab,
79 break; !! 168 unsigned int symindex, unsigned int relsec,
>> 169 struct module *me)
>> 170 {
>> 171 Elf64_Rela *rela = (void *)sechdrs[relsec].sh_addr;
>> 172 unsigned long i, n = sechdrs[relsec].sh_size / sizeof(*rela);
>> 173 Elf64_Sym *symtab, *sym;
>> 174 void *base, *location;
>> 175 unsigned long got, gp;
>> 176
>> 177 DEBUGP("Applying relocate section %u to %u\n", relsec,
>> 178 sechdrs[relsec].sh_info);
>> 179
>> 180 base = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr;
>> 181 symtab = (Elf64_Sym *)sechdrs[symindex].sh_addr;
>> 182
>> 183 /* The small sections were sorted to the end of the segment.
>> 184 The following should definitely cover them. */
>> 185 gp = (u64)me->module_core + me->core_size - 0x8000;
>> 186 got = sechdrs[me->arch.gotsecindex].sh_addr;
>> 187
>> 188 for (i = 0; i < n; i++) {
>> 189 unsigned long r_sym = ELF64_R_SYM (rela[i].r_info);
>> 190 unsigned long r_type = ELF64_R_TYPE (rela[i].r_info);
>> 191 unsigned long r_got_offset = r_type >> 8;
>> 192 unsigned long value, hi, lo;
>> 193 r_type &= 0xff;
>> 194
>> 195 /* This is where to make the change. */
>> 196 location = base + rela[i].r_offset;
>> 197
>> 198 /* This is the symbol it is referring to. Note that all
>> 199 unresolved symbols have been resolved. */
>> 200 sym = symtab + r_sym;
>> 201 value = sym->st_value + rela[i].r_addend;
80 202
>> 203 switch (r_type) {
>> 204 case R_ALPHA_NONE:
>> 205 break;
>> 206 case R_ALPHA_REFQUAD:
>> 207 /* BUG() can produce misaligned relocations. */
>> 208 ((u32 *)location)[0] = value;
>> 209 ((u32 *)location)[1] = value >> 32;
>> 210 break;
>> 211 case R_ALPHA_GPREL32:
>> 212 value -= gp;
>> 213 if ((int)value != value)
>> 214 goto reloc_overflow;
>> 215 *(u32 *)location = value;
>> 216 break;
>> 217 case R_ALPHA_LITERAL:
>> 218 hi = got + r_got_offset;
>> 219 lo = hi - gp;
>> 220 if ((short)lo != lo)
>> 221 goto reloc_overflow;
>> 222 *(u16 *)location = lo;
>> 223 *(u64 *)hi = value;
>> 224 break;
>> 225 case R_ALPHA_LITUSE:
>> 226 break;
>> 227 case R_ALPHA_GPDISP:
>> 228 value = gp - (u64)location;
>> 229 lo = (short)value;
>> 230 hi = (int)(value - lo);
>> 231 if (hi + lo != value)
>> 232 goto reloc_overflow;
>> 233 *(u16 *)location = hi >> 16;
>> 234 *(u16 *)(location + rela[i].r_addend) = lo;
>> 235 break;
>> 236 case R_ALPHA_BRSGP:
>> 237 /* BRSGP is only allowed to bind to local symbols.
>> 238 If the section is undef, this means that the
>> 239 value was resolved from somewhere else. */
>> 240 if (sym->st_shndx == SHN_UNDEF)
>> 241 goto reloc_overflow;
>> 242 if ((sym->st_other & STO_ALPHA_STD_GPLOAD) ==
>> 243 STO_ALPHA_STD_GPLOAD)
>> 244 /* Omit the prologue. */
>> 245 value += 8;
>> 246 /* FALLTHRU */
>> 247 case R_ALPHA_BRADDR:
>> 248 value -= (u64)location + 4;
>> 249 if (value & 3)
>> 250 goto reloc_overflow;
>> 251 value = (long)value >> 2;
>> 252 if (value + (1<<21) >= 1<<22)
>> 253 goto reloc_overflow;
>> 254 value &= 0x1fffff;
>> 255 value |= *(u32 *)location & ~0x1fffff;
>> 256 *(u32 *)location = value;
>> 257 break;
>> 258 case R_ALPHA_HINT:
>> 259 break;
>> 260 case R_ALPHA_SREL32:
>> 261 value -= (u64)location;
>> 262 if ((int)value != value)
>> 263 goto reloc_overflow;
>> 264 *(u32 *)location = value;
>> 265 break;
>> 266 case R_ALPHA_SREL64:
>> 267 value -= (u64)location;
>> 268 *(u64 *)location = value;
>> 269 break;
>> 270 case R_ALPHA_GPRELHIGH:
>> 271 value = (long)(value - gp + 0x8000) >> 16;
>> 272 if ((short) value != value)
>> 273 goto reloc_overflow;
>> 274 *(u16 *)location = value;
>> 275 break;
>> 276 case R_ALPHA_GPRELLOW:
>> 277 value -= gp;
>> 278 *(u16 *)location = value;
>> 279 break;
>> 280 case R_ALPHA_GPREL16:
>> 281 value -= gp;
>> 282 if ((short) value != value)
>> 283 goto reloc_overflow;
>> 284 *(u16 *)location = value;
>> 285 break;
81 default: 286 default:
82 pr_err("module %s: Unk !! 287 printk(KERN_ERR "module %s: Unknown relocation: %lu\n",
83 module->name, !! 288 me->name, r_type);
84 ELF32_R_TYPE(r !! 289 return -ENOEXEC;
>> 290 reloc_overflow:
>> 291 if (ELF64_ST_TYPE (sym->st_info) == STT_SECTION)
>> 292 printk(KERN_ERR
>> 293 "module %s: Relocation (type %lu) overflow vs section %d\n",
>> 294 me->name, r_type, sym->st_shndx);
>> 295 else
>> 296 printk(KERN_ERR
>> 297 "module %s: Relocation (type %lu) overflow vs %s\n",
>> 298 me->name, r_type, strtab + sym->st_name);
85 return -ENOEXEC; 299 return -ENOEXEC;
86 } 300 }
87 } 301 }
>> 302
88 return 0; 303 return 0;
89 } 304 }
90 305
91 int module_finalize(const Elf32_Ehdr *hdr, con !! 306 int
92 struct module *module) !! 307 module_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs,
>> 308 struct module *me)
93 { 309 {
94 flush_dcache(); <<
95 return 0; 310 return 0;
>> 311 }
>> 312
>> 313 void
>> 314 module_arch_cleanup(struct module *mod)
>> 315 {
96 } 316 }
97 317
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