1 // SPDX-License-Identifier: GPL-2.0-only !! 1 /* Kernel module help for Alpha.
2 /* !! 2 Copyright (C) 2002 Richard Henderson.
3 * Kernel module loader for Hexagon <<
4 * <<
5 * Copyright (c) 2010-2011, The Linux Foundati <<
6 */ <<
7 3
8 #include <asm/module.h> !! 4 This program is free software; you can redistribute it and/or modify
9 #include <linux/elf.h> !! 5 it under the terms of the GNU General Public License as published by
10 #include <linux/module.h> !! 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 */
11 #include <linux/moduleloader.h> 18 #include <linux/moduleloader.h>
>> 19 #include <linux/elf.h>
12 #include <linux/vmalloc.h> 20 #include <linux/vmalloc.h>
>> 21 #include <linux/fs.h>
>> 22 #include <linux/string.h>
>> 23 #include <linux/kernel.h>
>> 24 #include <linux/slab.h>
13 25
14 #if 0 26 #if 0
15 #define DEBUGP printk 27 #define DEBUGP printk
16 #else 28 #else
17 #define DEBUGP(fmt , ...) !! 29 #define DEBUGP(fmt...)
18 #endif 30 #endif
19 31
20 /* !! 32 void *
21 * module_frob_arch_sections - tweak got/plt s !! 33 module_alloc(unsigned long size)
22 * @hdr - pointer to elf header !! 34 {
23 * @sechdrs - pointer to elf load section head !! 35 if (size == 0)
24 * @secstrings - symbol names !! 36 return NULL;
25 * @mod - pointer to module !! 37 return vmalloc(size);
26 */ !! 38 }
27 int module_frob_arch_sections(Elf_Ehdr *hdr, E !! 39
28 char *secstrin !! 40 void
29 struct module !! 41 module_free(struct module *mod, void *module_region)
30 { !! 42 {
31 unsigned int i; !! 43 vfree(module_region);
32 int found = 0; !! 44 }
33 !! 45
34 /* Look for .plt and/or .got.plt and/o !! 46 /* Allocate the GOT at the end of the core sections. */
35 for (i = 0; i < hdr->e_shnum; i++) { !! 47
36 DEBUGP("Section %d is %s\n", i !! 48 struct got_entry {
37 secstrings + sechdrs[i] !! 49 struct got_entry *next;
38 if (strcmp(secstrings + sechdr !! 50 Elf64_Addr r_offset;
39 found = i+1; !! 51 int got_offset;
40 if (strcmp(secstrings + sechdr !! 52 };
41 found = i+1; !! 53
42 if (strcmp(secstrings + sechdr !! 54 static inline void
43 found = i+1; !! 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_Addr r_offset = rela->r_offset;
>> 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_offset == r_offset) {
>> 68 if (g->got_offset == 0) {
>> 69 g->got_offset = *poffset;
>> 70 *poffset += 8;
>> 71 }
>> 72 goto found_entry;
>> 73 }
>> 74
>> 75 g = kmalloc (sizeof (*g), GFP_KERNEL);
>> 76 g->next = chains[r_sym].next;
>> 77 g->r_offset = r_offset;
>> 78 g->got_offset = *poffset;
>> 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 }
>> 88
>> 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 }
>> 111
>> 112 if (!symtab) {
>> 113 printk(KERN_ERR "module %s: no symbol table\n", me->name);
>> 114 return -ENOEXEC;
>> 115 }
>> 116 if (!got) {
>> 117 printk(KERN_ERR "module %s: no got section\n", me->name);
>> 118 return -ENOEXEC;
44 } 119 }
45 120
46 /* At this time, we don't support modu !! 121 nsyms = symtab->sh_size / sizeof(Elf64_Sym);
47 if (found) { !! 122 chains = kmalloc(nsyms * sizeof(struct got_entry), GFP_KERNEL);
48 printk(KERN_WARNING !! 123 memset(chains, 0, nsyms * sizeof(struct got_entry));
49 "Module '%s' contains !! 124
50 mod->name); !! 125 got->sh_size = 0;
51 /* return -ENOEXEC; */ !! 126 got->sh_addralign = 8;
>> 127 got->sh_type = SHT_NOBITS;
>> 128
>> 129 /* Examine all LITERAL relocations to find out what GOT entries
>> 130 are required. This sizes the GOT section as well. */
>> 131 for (s = sechdrs; s < esechdrs; ++s)
>> 132 if (s->sh_type == SHT_RELA) {
>> 133 nrela = s->sh_size / sizeof(Elf64_Rela);
>> 134 rela = (void *)hdr + s->sh_offset;
>> 135 for (i = 0; i < nrela; ++i)
>> 136 process_reloc_for_got(rela+i, chains,
>> 137 &got->sh_size);
>> 138 }
>> 139
>> 140 /* Free the memory we allocated. */
>> 141 for (i = 0; i < nsyms; ++i) {
>> 142 struct got_entry *g, *n;
>> 143 for (g = chains[i].next; g ; g = n) {
>> 144 n = g->next;
>> 145 kfree(g);
>> 146 }
52 } 147 }
>> 148 kfree(chains);
53 149
54 return 0; 150 return 0;
55 } 151 }
56 152
57 /* !! 153 int
58 * apply_relocate_add - perform rela relocatio !! 154 apply_relocate(Elf64_Shdr *sechdrs, const char *strtab, unsigned int symindex,
59 * @sechdrs - pointer to section headers !! 155 unsigned int relsec, struct module *me)
60 * @strtab - some sort of start address? !! 156 {
61 * @symindex - symbol index offset or somethin !! 157 printk(KERN_ERR "module %s: REL relocation unsupported\n", me->name);
62 * @relsec - address to relocate to? !! 158 return -ENOEXEC;
63 * @module - pointer to module !! 159 }
64 * <<
65 * Perform rela relocations. <<
66 */ <<
67 int apply_relocate_add(Elf_Shdr *sechdrs, cons <<
68 unsigned int symindex, <<
69 struct module *module) <<
70 { <<
71 unsigned int i; <<
72 Elf32_Sym *sym; <<
73 uint32_t *location; <<
74 uint32_t value; <<
75 unsigned int nrelocs = sechdrs[relsec] <<
76 Elf32_Rela *rela = (void *)sechdrs[rel <<
77 Elf32_Word sym_info = sechdrs[relsec]. <<
78 Elf32_Sym *sym_base = (Elf32_Sym *) se <<
79 void *loc_base = (void *) sechdrs[sym_ <<
80 <<
81 DEBUGP("Applying relocations in sectio <<
82 relsec, sym_info, loc_base); <<
83 <<
84 for (i = 0; i < nrelocs; i++) { <<
85 <<
86 /* Symbol to relocate */ <<
87 sym = sym_base + ELF32_R_SYM(r <<
88 <<
89 /* Where to make the change */ <<
90 location = loc_base + rela[i]. <<
91 160
92 /* `Everything is relative'. * !! 161 int
>> 162 apply_relocate_add(Elf64_Shdr *sechdrs, const char *strtab,
>> 163 unsigned int symindex, unsigned int relsec,
>> 164 struct module *me)
>> 165 {
>> 166 Elf64_Rela *rela = (void *)sechdrs[relsec].sh_addr;
>> 167 unsigned long i, n = sechdrs[relsec].sh_size / sizeof(*rela);
>> 168 Elf64_Sym *symtab, *sym;
>> 169 void *base, *location;
>> 170 unsigned long got, gp;
>> 171
>> 172 DEBUGP("Applying relocate section %u to %u\n", relsec,
>> 173 sechdrs[relsec].sh_info);
>> 174
>> 175 base = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr;
>> 176 symtab = (Elf64_Sym *)sechdrs[symindex].sh_addr;
>> 177
>> 178 /* The small sections were sorted to the end of the segment.
>> 179 The following should definitely cover them. */
>> 180 gp = (u64)me->module_core + me->core_size - 0x8000;
>> 181 got = sechdrs[me->arch.gotsecindex].sh_addr;
>> 182
>> 183 for (i = 0; i < n; i++) {
>> 184 unsigned long r_sym = ELF64_R_SYM (rela[i].r_info);
>> 185 unsigned long r_type = ELF64_R_TYPE (rela[i].r_info);
>> 186 unsigned long r_got_offset = r_type >> 8;
>> 187 unsigned long value, hi, lo;
>> 188 r_type &= 0xff;
>> 189
>> 190 /* This is where to make the change. */
>> 191 location = base + rela[i].r_offset;
>> 192
>> 193 /* This is the symbol it is referring to. Note that all
>> 194 unresolved symbols have been resolved. */
>> 195 sym = symtab + r_sym;
93 value = sym->st_value + rela[i 196 value = sym->st_value + rela[i].r_addend;
94 197
95 DEBUGP("%d: value=%08x loc=%p !! 198 switch (r_type) {
96 i, value, location, ELF !! 199 case R_ALPHA_NONE:
97 sym->st_name ? !! 200 break;
98 &strtab[sym->st_name] : !! 201 case R_ALPHA_REFQUAD:
99 !! 202 /* BUG() can produce misaligned relocations. */
100 switch (ELF32_R_TYPE(rela[i].r !! 203 ((u32 *)location)[0] = value;
101 case R_HEXAGON_B22_PCREL: { !! 204 ((u32 *)location)[1] = value >> 32;
102 int dist = (int)(value !! 205 break;
103 if ((dist < -0x0080000 !! 206 case R_ALPHA_GPREL32:
104 (dist >= 0x0080000 !! 207 value -= gp;
105 printk(KERN_ER !! 208 if ((int)value != value)
106 "%s: %s !! 209 goto reloc_overflow;
107 module- !! 210 *(u32 *)location = value;
108 "R_HEXA !! 211 break;
109 dist, v !! 212 case R_ALPHA_LITERAL:
110 sym->st !! 213 hi = got + r_got_offset;
111 &strtab !! 214 lo = hi - gp;
112 return -ENOEXE !! 215 if ((short)lo != lo)
113 } !! 216 goto reloc_overflow;
114 DEBUGP("B22_PCREL cont !! 217 *(u16 *)location = lo;
115 *location &= ~0x01ff3f !! 218 *(u64 *)hi = value;
116 *location |= 0x00003ff !! 219 break;
117 *location |= 0x01ff000 !! 220 case R_ALPHA_LITUSE:
118 DEBUGP("Contents after !! 221 break;
>> 222 case R_ALPHA_GPDISP:
>> 223 value = gp - (u64)location;
>> 224 lo = (short)value;
>> 225 hi = (int)(value - lo);
>> 226 if (hi + lo != value)
>> 227 goto reloc_overflow;
>> 228 *(u16 *)location = hi >> 16;
>> 229 *(u16 *)(location + rela[i].r_addend) = lo;
>> 230 break;
>> 231 case R_ALPHA_BRSGP:
>> 232 /* BRSGP is only allowed to bind to local symbols.
>> 233 If the section is undef, this means that the
>> 234 value was resolved from somewhere else. */
>> 235 if (sym->st_shndx == SHN_UNDEF)
>> 236 goto reloc_overflow;
>> 237 /* FALLTHRU */
>> 238 case R_ALPHA_BRADDR:
>> 239 value -= (u64)location + 4;
>> 240 if (value & 3)
>> 241 goto reloc_overflow;
>> 242 value = (long)value >> 2;
>> 243 if (value + (1<<21) >= 1<<22)
>> 244 goto reloc_overflow;
>> 245 value &= 0x1fffff;
>> 246 value |= *(u32 *)location & ~0x1fffff;
>> 247 *(u32 *)location = value;
>> 248 break;
>> 249 case R_ALPHA_HINT:
>> 250 break;
>> 251 case R_ALPHA_SREL32:
>> 252 value -= (u64)location;
>> 253 if ((int)value != value)
>> 254 goto reloc_overflow;
>> 255 *(u32 *)location = value;
>> 256 break;
>> 257 case R_ALPHA_SREL64:
>> 258 value -= (u64)location;
>> 259 *(u64 *)location = value;
>> 260 break;
>> 261 case R_ALPHA_GPRELHIGH:
>> 262 value = (value - gp + 0x8000) >> 16;
>> 263 if ((short) value != value)
>> 264 goto reloc_overflow;
>> 265 *(u16 *)location = value;
>> 266 break;
>> 267 case R_ALPHA_GPRELLOW:
>> 268 value -= gp;
>> 269 *(u16 *)location = value;
>> 270 break;
>> 271 case R_ALPHA_GPREL16:
>> 272 value -= gp;
>> 273 if ((short) value != value)
>> 274 goto reloc_overflow;
>> 275 *(u16 *)location = value;
119 break; 276 break;
120 } <<
121 case R_HEXAGON_HI16: <<
122 value = (value>>16) & <<
123 fallthrough; <<
124 case R_HEXAGON_LO16: <<
125 *location &= ~0x00c03f <<
126 *location |= value & 0 <<
127 *location |= (value & <<
128 break; <<
129 case R_HEXAGON_32: <<
130 *location = value; <<
131 break; <<
132 case R_HEXAGON_32_PCREL: <<
133 *location = value - (u <<
134 break; <<
135 case R_HEXAGON_PLT_B22_PCREL: <<
136 case R_HEXAGON_GOTOFF_LO16: <<
137 case R_HEXAGON_GOTOFF_HI16: <<
138 printk(KERN_ERR "%s: G <<
139 module->name); <<
140 return -ENOEXEC; <<
141 default: 277 default:
142 printk(KERN_ERR "%s: u !! 278 printk(KERN_ERR "module %s: Unknown relocation: %lu\n",
143 module->name, !! 279 me->name, r_type);
144 ELF32_R_TYPE(re !! 280 return -ENOEXEC;
>> 281 reloc_overflow:
>> 282 if (ELF64_ST_TYPE (sym->st_info) == STT_SECTION)
>> 283 printk(KERN_ERR
>> 284 "module %s: Relocation overflow vs section %d\n",
>> 285 me->name, sym->st_shndx);
>> 286 else
>> 287 printk(KERN_ERR
>> 288 "module %s: Relocation overflow vs %s\n",
>> 289 me->name, strtab + sym->st_name);
145 return -ENOEXEC; 290 return -ENOEXEC;
146 } 291 }
147 } 292 }
>> 293
>> 294 return 0;
>> 295 }
>> 296
>> 297 int
>> 298 module_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs,
>> 299 struct module *me)
>> 300 {
148 return 0; 301 return 0;
>> 302 }
>> 303
>> 304 void
>> 305 module_arch_cleanup(struct module *mod)
>> 306 {
149 } 307 }
150 308
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