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 /* Allocate the GOT at the end of the core sections. */
21 * module_frob_arch_sections - tweak got/plt s !! 33
22 * @hdr - pointer to elf header !! 34 struct got_entry {
23 * @sechdrs - pointer to elf load section head !! 35 struct got_entry *next;
24 * @secstrings - symbol names !! 36 Elf64_Sxword r_addend;
25 * @mod - pointer to module !! 37 int got_offset;
26 */ !! 38 };
27 int module_frob_arch_sections(Elf_Ehdr *hdr, E !! 39
28 char *secstrin !! 40 static inline void
29 struct module !! 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 }
>> 60
>> 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 }
>> 74
>> 75 int
>> 76 module_frob_arch_sections(Elf64_Ehdr *hdr, Elf64_Shdr *sechdrs,
>> 77 char *secstrings, struct module *me)
30 { 78 {
31 unsigned int i; !! 79 struct got_entry *chains;
32 int found = 0; !! 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 }
33 97
34 /* Look for .plt and/or .got.plt and/o !! 98 if (!symtab) {
35 for (i = 0; i < hdr->e_shnum; i++) { !! 99 printk(KERN_ERR "module %s: no symbol table\n", me->name);
36 DEBUGP("Section %d is %s\n", i !! 100 return -ENOEXEC;
37 secstrings + sechdrs[i] !! 101 }
38 if (strcmp(secstrings + sechdr !! 102 if (!got) {
39 found = i+1; !! 103 printk(KERN_ERR "module %s: no got section\n", me->name);
40 if (strcmp(secstrings + sechdr !! 104 return -ENOEXEC;
41 found = i+1; <<
42 if (strcmp(secstrings + sechdr <<
43 found = i+1; <<
44 } 105 }
45 106
46 /* At this time, we don't support modu !! 107 nsyms = symtab->sh_size / sizeof(Elf64_Sym);
47 if (found) { !! 108 chains = kcalloc(nsyms, sizeof(struct got_entry), GFP_KERNEL);
48 printk(KERN_WARNING !! 109 if (!chains) {
49 "Module '%s' contains !! 110 printk(KERN_ERR
50 mod->name); !! 111 "module %s: no memory for symbol chain buffer\n",
51 /* return -ENOEXEC; */ !! 112 me->name);
>> 113 return -ENOMEM;
52 } 114 }
53 115
>> 116 got->sh_size = 0;
>> 117 got->sh_addralign = 8;
>> 118 got->sh_type = SHT_NOBITS;
>> 119
>> 120 /* Examine all LITERAL relocations to find out what GOT entries
>> 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 }
>> 130
>> 131 /* Free the memory we allocated. */
>> 132 for (i = 0; i < nsyms; ++i) {
>> 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);
>> 140
54 return 0; 141 return 0;
55 } 142 }
56 143
57 /* !! 144 int
58 * apply_relocate_add - perform rela relocatio !! 145 apply_relocate_add(Elf64_Shdr *sechdrs, const char *strtab,
59 * @sechdrs - pointer to section headers !! 146 unsigned int symindex, unsigned int relsec,
60 * @strtab - some sort of start address? !! 147 struct module *me)
61 * @symindex - symbol index offset or somethin <<
62 * @relsec - address to relocate to? <<
63 * @module - pointer to module <<
64 * <<
65 * Perform rela relocations. <<
66 */ <<
67 int apply_relocate_add(Elf_Shdr *sechdrs, cons <<
68 unsigned int symindex, <<
69 struct module *module) <<
70 { 148 {
71 unsigned int i; !! 149 Elf64_Rela *rela = (void *)sechdrs[relsec].sh_addr;
72 Elf32_Sym *sym; !! 150 unsigned long i, n = sechdrs[relsec].sh_size / sizeof(*rela);
73 uint32_t *location; !! 151 Elf64_Sym *symtab, *sym;
74 uint32_t value; !! 152 void *base, *location;
75 unsigned int nrelocs = sechdrs[relsec] !! 153 unsigned long got, gp;
76 Elf32_Rela *rela = (void *)sechdrs[rel !! 154
77 Elf32_Word sym_info = sechdrs[relsec]. !! 155 DEBUGP("Applying relocate section %u to %u\n", relsec,
78 Elf32_Sym *sym_base = (Elf32_Sym *) se !! 156 sechdrs[relsec].sh_info);
79 void *loc_base = (void *) sechdrs[sym_ !! 157
80 !! 158 base = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr;
81 DEBUGP("Applying relocations in sectio !! 159 symtab = (Elf64_Sym *)sechdrs[symindex].sh_addr;
82 relsec, sym_info, loc_base); !! 160
83 !! 161 got = sechdrs[me->arch.gotsecindex].sh_addr;
84 for (i = 0; i < nrelocs; i++) { !! 162 gp = got + 0x8000;
85 !! 163
86 /* Symbol to relocate */ !! 164 for (i = 0; i < n; i++) {
87 sym = sym_base + ELF32_R_SYM(r !! 165 unsigned long r_sym = ELF64_R_SYM (rela[i].r_info);
88 !! 166 unsigned long r_type = ELF64_R_TYPE (rela[i].r_info);
89 /* Where to make the change */ !! 167 unsigned long r_got_offset = r_type >> 8;
90 location = loc_base + rela[i]. !! 168 unsigned long value, hi, lo;
91 !! 169 r_type &= 0xff;
92 /* `Everything is relative'. * !! 170
>> 171 /* This is where to make the change. */
>> 172 location = base + rela[i].r_offset;
>> 173
>> 174 /* This is the symbol it is referring to. Note that all
>> 175 unresolved symbols have been resolved. */
>> 176 sym = symtab + r_sym;
93 value = sym->st_value + rela[i 177 value = sym->st_value + rela[i].r_addend;
94 178
95 DEBUGP("%d: value=%08x loc=%p !! 179 switch (r_type) {
96 i, value, location, ELF !! 180 case R_ALPHA_NONE:
97 sym->st_name ? !! 181 break;
98 &strtab[sym->st_name] : !! 182 case R_ALPHA_REFLONG:
99 !! 183 *(u32 *)location = value;
100 switch (ELF32_R_TYPE(rela[i].r !! 184 break;
101 case R_HEXAGON_B22_PCREL: { !! 185 case R_ALPHA_REFQUAD:
102 int dist = (int)(value !! 186 /* BUG() can produce misaligned relocations. */
103 if ((dist < -0x0080000 !! 187 ((u32 *)location)[0] = value;
104 (dist >= 0x0080000 !! 188 ((u32 *)location)[1] = value >> 32;
105 printk(KERN_ER !! 189 break;
106 "%s: %s !! 190 case R_ALPHA_GPREL32:
107 module- !! 191 value -= gp;
108 "R_HEXA !! 192 if ((int)value != value)
109 dist, v !! 193 goto reloc_overflow;
110 sym->st !! 194 *(u32 *)location = value;
111 &strtab !! 195 break;
112 return -ENOEXE !! 196 case R_ALPHA_LITERAL:
113 } !! 197 hi = got + r_got_offset;
114 DEBUGP("B22_PCREL cont !! 198 lo = hi - gp;
115 *location &= ~0x01ff3f !! 199 if ((short)lo != lo)
116 *location |= 0x00003ff !! 200 goto reloc_overflow;
117 *location |= 0x01ff000 !! 201 *(u16 *)location = lo;
118 DEBUGP("Contents after !! 202 *(u64 *)hi = value;
>> 203 break;
>> 204 case R_ALPHA_LITUSE:
>> 205 break;
>> 206 case R_ALPHA_GPDISP:
>> 207 value = gp - (u64)location;
>> 208 lo = (short)value;
>> 209 hi = (int)(value - lo);
>> 210 if (hi + lo != value)
>> 211 goto reloc_overflow;
>> 212 *(u16 *)location = hi >> 16;
>> 213 *(u16 *)(location + rela[i].r_addend) = lo;
>> 214 break;
>> 215 case R_ALPHA_BRSGP:
>> 216 /* BRSGP is only allowed to bind to local symbols.
>> 217 If the section is undef, this means that the
>> 218 value was resolved from somewhere else. */
>> 219 if (sym->st_shndx == SHN_UNDEF)
>> 220 goto reloc_overflow;
>> 221 if ((sym->st_other & STO_ALPHA_STD_GPLOAD) ==
>> 222 STO_ALPHA_STD_GPLOAD)
>> 223 /* Omit the prologue. */
>> 224 value += 8;
>> 225 /* FALLTHRU */
>> 226 case R_ALPHA_BRADDR:
>> 227 value -= (u64)location + 4;
>> 228 if (value & 3)
>> 229 goto reloc_overflow;
>> 230 value = (long)value >> 2;
>> 231 if (value + (1<<21) >= 1<<22)
>> 232 goto reloc_overflow;
>> 233 value &= 0x1fffff;
>> 234 value |= *(u32 *)location & ~0x1fffff;
>> 235 *(u32 *)location = value;
>> 236 break;
>> 237 case R_ALPHA_HINT:
>> 238 break;
>> 239 case R_ALPHA_SREL32:
>> 240 value -= (u64)location;
>> 241 if ((int)value != value)
>> 242 goto reloc_overflow;
>> 243 *(u32 *)location = value;
>> 244 break;
>> 245 case R_ALPHA_SREL64:
>> 246 value -= (u64)location;
>> 247 *(u64 *)location = value;
>> 248 break;
>> 249 case R_ALPHA_GPRELHIGH:
>> 250 value = (long)(value - gp + 0x8000) >> 16;
>> 251 if ((short) value != value)
>> 252 goto reloc_overflow;
>> 253 *(u16 *)location = value;
>> 254 break;
>> 255 case R_ALPHA_GPRELLOW:
>> 256 value -= gp;
>> 257 *(u16 *)location = value;
>> 258 break;
>> 259 case R_ALPHA_GPREL16:
>> 260 value -= gp;
>> 261 if ((short) value != value)
>> 262 goto reloc_overflow;
>> 263 *(u16 *)location = value;
119 break; 264 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: 265 default:
142 printk(KERN_ERR "%s: u !! 266 printk(KERN_ERR "module %s: Unknown relocation: %lu\n",
143 module->name, !! 267 me->name, r_type);
144 ELF32_R_TYPE(re !! 268 return -ENOEXEC;
>> 269 reloc_overflow:
>> 270 if (ELF64_ST_TYPE (sym->st_info) == STT_SECTION)
>> 271 printk(KERN_ERR
>> 272 "module %s: Relocation (type %lu) overflow vs section %d\n",
>> 273 me->name, r_type, sym->st_shndx);
>> 274 else
>> 275 printk(KERN_ERR
>> 276 "module %s: Relocation (type %lu) overflow vs %s\n",
>> 277 me->name, r_type, strtab + sym->st_name);
145 return -ENOEXEC; 278 return -ENOEXEC;
146 } 279 }
147 } 280 }
>> 281
148 return 0; 282 return 0;
149 } 283 }
150 284
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