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