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>
>> 25
>> 26 #if 0
>> 27 #define DEBUGP printk
>> 28 #else
>> 29 #define DEBUGP(fmt...)
>> 30 #endif
>> 31
>> 32 /* Allocate the GOT at the end of the core sections. */
>> 33
>> 34 struct got_entry {
>> 35 struct got_entry *next;
>> 36 Elf64_Sxword r_addend;
>> 37 int got_offset;
>> 38 };
>> 39
>> 40 static inline void
>> 41 process_reloc_for_got(Elf64_Rela *rela,
>> 42 struct got_entry *chains, Elf64_Xword *poffset)
>> 43 {
>> 44 unsigned long r_sym = ELF64_R_SYM (rela->r_info);
>> 45 unsigned long r_type = ELF64_R_TYPE (rela->r_info);
>> 46 Elf64_Sxword r_addend = rela->r_addend;
>> 47 struct got_entry *g;
>> 48
>> 49 if (r_type != R_ALPHA_LITERAL)
>> 50 return;
>> 51
>> 52 for (g = chains + r_sym; g ; g = g->next)
>> 53 if (g->r_addend == r_addend) {
>> 54 if (g->got_offset == 0) {
>> 55 g->got_offset = *poffset;
>> 56 *poffset += 8;
>> 57 }
>> 58 goto found_entry;
>> 59 }
15 60
16 #include <asm/cacheflush.h> !! 61 g = kmalloc (sizeof (*g), GFP_KERNEL);
>> 62 g->next = chains[r_sym].next;
>> 63 g->r_addend = r_addend;
>> 64 g->got_offset = *poffset;
>> 65 *poffset += 8;
>> 66 chains[r_sym].next = g;
>> 67
>> 68 found_entry:
>> 69 /* Trick: most of the ELF64_R_TYPE field is unused. There are
>> 70 42 valid relocation types, and a 32-bit field. Co-opt the
>> 71 bits above 256 to store the got offset for this reloc. */
>> 72 rela->r_info |= g->got_offset << 8;
>> 73 }
17 74
18 int apply_relocate_add(Elf32_Shdr *sechdrs, co !! 75 int
19 unsigned int symindex, unsigned int re !! 76 module_frob_arch_sections(Elf64_Ehdr *hdr, Elf64_Shdr *sechdrs,
>> 77 char *secstrings, struct module *me)
20 { 78 {
>> 79 struct got_entry *chains;
>> 80 Elf64_Rela *rela;
>> 81 Elf64_Shdr *esechdrs, *symtab, *s, *got;
>> 82 unsigned long nsyms, nrela, i;
>> 83
>> 84 esechdrs = sechdrs + hdr->e_shnum;
>> 85 symtab = got = NULL;
>> 86
>> 87 /* Find out how large the symbol table is. Allocate one got_entry
>> 88 head per symbol. Normally this will be enough, but not always.
>> 89 We'll chain different offsets for the symbol down each head. */
>> 90 for (s = sechdrs; s < esechdrs; ++s)
>> 91 if (s->sh_type == SHT_SYMTAB)
>> 92 symtab = s;
>> 93 else if (!strcmp(".got", secstrings + s->sh_name)) {
>> 94 got = s;
>> 95 me->arch.gotsecindex = s - sechdrs;
>> 96 }
21 97
22 unsigned int i; !! 98 if (!symtab) {
23 Elf32_Rela *rela = (void *)sechdrs[rel !! 99 printk(KERN_ERR "module %s: no symbol table\n", me->name);
24 Elf32_Sym *sym; !! 100 return -ENOEXEC;
25 unsigned long int *location; !! 101 }
26 unsigned long int value; !! 102 if (!got) {
27 !! 103 printk(KERN_ERR "module %s: no got section\n", me->name);
28 pr_debug("Applying add relocation sect !! 104 return -ENOEXEC;
29 relsec, sechdrs[relsec].sh_inf !! 105 }
30 <<
31 for (i = 0; i < sechdrs[relsec].sh_siz <<
32 <<
33 location = (void *)sechdrs[sec <<
34 rela[i].r_offs <<
35 sym = (Elf32_Sym *)sechdrs[sym <<
36 ELF32_R_SYM(rela[i].r_ <<
37 value = sym->st_value + rela[i <<
38 106
39 switch (ELF32_R_TYPE(rela[i].r !! 107 nsyms = symtab->sh_size / sizeof(Elf64_Sym);
>> 108 chains = kcalloc(nsyms, sizeof(struct got_entry), GFP_KERNEL);
>> 109 if (!chains) {
>> 110 printk(KERN_ERR
>> 111 "module %s: no memory for symbol chain buffer\n",
>> 112 me->name);
>> 113 return -ENOMEM;
>> 114 }
40 115
41 /* !! 116 got->sh_size = 0;
42 * Be careful! mb-gcc / mb-ld !! 117 got->sh_addralign = 8;
43 * text and the reloc table. I !! 118 got->sh_type = SHT_NOBITS;
44 * read the current contents o !! 119
45 * then store the result back !! 120 /* Examine all LITERAL relocations to find out what GOT entries
46 */ !! 121 are required. This sizes the GOT section as well. */
>> 122 for (s = sechdrs; s < esechdrs; ++s)
>> 123 if (s->sh_type == SHT_RELA) {
>> 124 nrela = s->sh_size / sizeof(Elf64_Rela);
>> 125 rela = (void *)hdr + s->sh_offset;
>> 126 for (i = 0; i < nrela; ++i)
>> 127 process_reloc_for_got(rela+i, chains,
>> 128 &got->sh_size);
>> 129 }
47 130
48 case R_MICROBLAZE_32: !! 131 /* Free the memory we allocated. */
49 *location = value; !! 132 for (i = 0; i < nsyms; ++i) {
50 break; !! 133 struct got_entry *g, *n;
>> 134 for (g = chains[i].next; g ; g = n) {
>> 135 n = g->next;
>> 136 kfree(g);
>> 137 }
>> 138 }
>> 139 kfree(chains);
51 140
52 case R_MICROBLAZE_64: !! 141 return 0;
53 location[0] = (locatio !! 142 }
54 (value <<
55 location[1] = (locatio <<
56 (value <<
57 break; <<
58 143
59 case R_MICROBLAZE_64_PCREL: !! 144 int
60 value -= (unsigned lon !! 145 apply_relocate_add(Elf64_Shdr *sechdrs, const char *strtab,
61 location[0] = (locatio !! 146 unsigned int symindex, unsigned int relsec,
62 (value !! 147 struct module *me)
63 location[1] = (locatio !! 148 {
64 (value !! 149 Elf64_Rela *rela = (void *)sechdrs[relsec].sh_addr;
65 pr_debug("R_MICROBLAZE !! 150 unsigned long i, n = sechdrs[relsec].sh_size / sizeof(*rela);
66 value); !! 151 Elf64_Sym *symtab, *sym;
67 break; !! 152 void *base, *location;
>> 153 unsigned long got, gp;
>> 154
>> 155 DEBUGP("Applying relocate section %u to %u\n", relsec,
>> 156 sechdrs[relsec].sh_info);
>> 157
>> 158 base = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr;
>> 159 symtab = (Elf64_Sym *)sechdrs[symindex].sh_addr;
>> 160
>> 161 /* The small sections were sorted to the end of the segment.
>> 162 The following should definitely cover them. */
>> 163 gp = (u64)me->core_layout.base + me->core_layout.size - 0x8000;
>> 164 got = sechdrs[me->arch.gotsecindex].sh_addr;
>> 165
>> 166 for (i = 0; i < n; i++) {
>> 167 unsigned long r_sym = ELF64_R_SYM (rela[i].r_info);
>> 168 unsigned long r_type = ELF64_R_TYPE (rela[i].r_info);
>> 169 unsigned long r_got_offset = r_type >> 8;
>> 170 unsigned long value, hi, lo;
>> 171 r_type &= 0xff;
>> 172
>> 173 /* This is where to make the change. */
>> 174 location = base + rela[i].r_offset;
>> 175
>> 176 /* This is the symbol it is referring to. Note that all
>> 177 unresolved symbols have been resolved. */
>> 178 sym = symtab + r_sym;
>> 179 value = sym->st_value + rela[i].r_addend;
68 180
69 case R_MICROBLAZE_32_PCREL_LO: !! 181 switch (r_type) {
70 pr_debug("R_MICROBLAZE !! 182 case R_ALPHA_NONE:
71 break; 183 break;
72 !! 184 case R_ALPHA_REFLONG:
73 case R_MICROBLAZE_64_NONE: !! 185 *(u32 *)location = value;
74 pr_debug("R_MICROBLAZE <<
75 break; 186 break;
76 !! 187 case R_ALPHA_REFQUAD:
77 case R_MICROBLAZE_NONE: !! 188 /* BUG() can produce misaligned relocations. */
78 pr_debug("R_MICROBLAZE !! 189 ((u32 *)location)[0] = value;
>> 190 ((u32 *)location)[1] = value >> 32;
>> 191 break;
>> 192 case R_ALPHA_GPREL32:
>> 193 value -= gp;
>> 194 if ((int)value != value)
>> 195 goto reloc_overflow;
>> 196 *(u32 *)location = value;
>> 197 break;
>> 198 case R_ALPHA_LITERAL:
>> 199 hi = got + r_got_offset;
>> 200 lo = hi - gp;
>> 201 if ((short)lo != lo)
>> 202 goto reloc_overflow;
>> 203 *(u16 *)location = lo;
>> 204 *(u64 *)hi = value;
>> 205 break;
>> 206 case R_ALPHA_LITUSE:
>> 207 break;
>> 208 case R_ALPHA_GPDISP:
>> 209 value = gp - (u64)location;
>> 210 lo = (short)value;
>> 211 hi = (int)(value - lo);
>> 212 if (hi + lo != value)
>> 213 goto reloc_overflow;
>> 214 *(u16 *)location = hi >> 16;
>> 215 *(u16 *)(location + rela[i].r_addend) = lo;
>> 216 break;
>> 217 case R_ALPHA_BRSGP:
>> 218 /* BRSGP is only allowed to bind to local symbols.
>> 219 If the section is undef, this means that the
>> 220 value was resolved from somewhere else. */
>> 221 if (sym->st_shndx == SHN_UNDEF)
>> 222 goto reloc_overflow;
>> 223 if ((sym->st_other & STO_ALPHA_STD_GPLOAD) ==
>> 224 STO_ALPHA_STD_GPLOAD)
>> 225 /* Omit the prologue. */
>> 226 value += 8;
>> 227 /* FALLTHRU */
>> 228 case R_ALPHA_BRADDR:
>> 229 value -= (u64)location + 4;
>> 230 if (value & 3)
>> 231 goto reloc_overflow;
>> 232 value = (long)value >> 2;
>> 233 if (value + (1<<21) >= 1<<22)
>> 234 goto reloc_overflow;
>> 235 value &= 0x1fffff;
>> 236 value |= *(u32 *)location & ~0x1fffff;
>> 237 *(u32 *)location = value;
>> 238 break;
>> 239 case R_ALPHA_HINT:
>> 240 break;
>> 241 case R_ALPHA_SREL32:
>> 242 value -= (u64)location;
>> 243 if ((int)value != value)
>> 244 goto reloc_overflow;
>> 245 *(u32 *)location = value;
>> 246 break;
>> 247 case R_ALPHA_SREL64:
>> 248 value -= (u64)location;
>> 249 *(u64 *)location = value;
>> 250 break;
>> 251 case R_ALPHA_GPRELHIGH:
>> 252 value = (long)(value - gp + 0x8000) >> 16;
>> 253 if ((short) value != value)
>> 254 goto reloc_overflow;
>> 255 *(u16 *)location = value;
>> 256 break;
>> 257 case R_ALPHA_GPRELLOW:
>> 258 value -= gp;
>> 259 *(u16 *)location = value;
>> 260 break;
>> 261 case R_ALPHA_GPREL16:
>> 262 value -= gp;
>> 263 if ((short) value != value)
>> 264 goto reloc_overflow;
>> 265 *(u16 *)location = value;
79 break; 266 break;
80 <<
81 default: 267 default:
82 pr_err("module %s: Unk !! 268 printk(KERN_ERR "module %s: Unknown relocation: %lu\n",
83 module->name, !! 269 me->name, r_type);
84 ELF32_R_TYPE(r !! 270 return -ENOEXEC;
>> 271 reloc_overflow:
>> 272 if (ELF64_ST_TYPE (sym->st_info) == STT_SECTION)
>> 273 printk(KERN_ERR
>> 274 "module %s: Relocation (type %lu) overflow vs section %d\n",
>> 275 me->name, r_type, sym->st_shndx);
>> 276 else
>> 277 printk(KERN_ERR
>> 278 "module %s: Relocation (type %lu) overflow vs %s\n",
>> 279 me->name, r_type, strtab + sym->st_name);
85 return -ENOEXEC; 280 return -ENOEXEC;
86 } 281 }
87 } 282 }
88 return 0; <<
89 } <<
90 283
91 int module_finalize(const Elf32_Ehdr *hdr, con <<
92 struct module *module) <<
93 { <<
94 flush_dcache(); <<
95 return 0; 284 return 0;
96 } 285 }
97 286
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