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 * Kernel module loader for Hexagon !! 3 Copyright (C) 2002 Richard Henderson.
4 * <<
5 * Copyright (c) 2010-2011, The Linux Foundati <<
6 */ <<
7 4
8 #include <asm/module.h> !! 5 */
9 #include <linux/elf.h> <<
10 #include <linux/module.h> <<
11 #include <linux/moduleloader.h> 6 #include <linux/moduleloader.h>
>> 7 #include <linux/elf.h>
12 #include <linux/vmalloc.h> 8 #include <linux/vmalloc.h>
>> 9 #include <linux/fs.h>
>> 10 #include <linux/string.h>
>> 11 #include <linux/kernel.h>
>> 12 #include <linux/slab.h>
13 13
14 #if 0 14 #if 0
15 #define DEBUGP printk 15 #define DEBUGP printk
16 #else 16 #else
17 #define DEBUGP(fmt , ...) !! 17 #define DEBUGP(fmt...)
18 #endif 18 #endif
19 19
20 /* !! 20 /* Allocate the GOT at the end of the core sections. */
21 * module_frob_arch_sections - tweak got/plt s !! 21
22 * @hdr - pointer to elf header !! 22 struct got_entry {
23 * @sechdrs - pointer to elf load section head !! 23 struct got_entry *next;
24 * @secstrings - symbol names !! 24 Elf64_Sxword r_addend;
25 * @mod - pointer to module !! 25 int got_offset;
26 */ !! 26 };
27 int module_frob_arch_sections(Elf_Ehdr *hdr, E !! 27
28 char *secstrin !! 28 static inline void
29 struct module !! 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 }
>> 48
>> 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 }
>> 62
>> 63 int
>> 64 module_frob_arch_sections(Elf64_Ehdr *hdr, Elf64_Shdr *sechdrs,
>> 65 char *secstrings, struct module *me)
30 { 66 {
31 unsigned int i; !! 67 struct got_entry *chains;
32 int found = 0; !! 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 }
33 85
34 /* Look for .plt and/or .got.plt and/o !! 86 if (!symtab) {
35 for (i = 0; i < hdr->e_shnum; i++) { !! 87 printk(KERN_ERR "module %s: no symbol table\n", me->name);
36 DEBUGP("Section %d is %s\n", i !! 88 return -ENOEXEC;
37 secstrings + sechdrs[i] !! 89 }
38 if (strcmp(secstrings + sechdr !! 90 if (!got) {
39 found = i+1; !! 91 printk(KERN_ERR "module %s: no got section\n", me->name);
40 if (strcmp(secstrings + sechdr !! 92 return -ENOEXEC;
41 found = i+1; <<
42 if (strcmp(secstrings + sechdr <<
43 found = i+1; <<
44 } 93 }
45 94
46 /* At this time, we don't support modu !! 95 nsyms = symtab->sh_size / sizeof(Elf64_Sym);
47 if (found) { !! 96 chains = kcalloc(nsyms, sizeof(struct got_entry), GFP_KERNEL);
48 printk(KERN_WARNING !! 97 if (!chains) {
49 "Module '%s' contains !! 98 printk(KERN_ERR
50 mod->name); !! 99 "module %s: no memory for symbol chain buffer\n",
51 /* return -ENOEXEC; */ !! 100 me->name);
>> 101 return -ENOMEM;
52 } 102 }
53 103
>> 104 got->sh_size = 0;
>> 105 got->sh_addralign = 8;
>> 106 got->sh_type = SHT_NOBITS;
>> 107
>> 108 /* Examine all LITERAL relocations to find out what GOT entries
>> 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 }
>> 118
>> 119 /* Free the memory we allocated. */
>> 120 for (i = 0; i < nsyms; ++i) {
>> 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);
>> 128
54 return 0; 129 return 0;
55 } 130 }
56 131
57 /* !! 132 int
58 * apply_relocate_add - perform rela relocatio !! 133 apply_relocate_add(Elf64_Shdr *sechdrs, const char *strtab,
59 * @sechdrs - pointer to section headers !! 134 unsigned int symindex, unsigned int relsec,
60 * @strtab - some sort of start address? !! 135 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 { 136 {
71 unsigned int i; !! 137 Elf64_Rela *rela = (void *)sechdrs[relsec].sh_addr;
72 Elf32_Sym *sym; !! 138 unsigned long i, n = sechdrs[relsec].sh_size / sizeof(*rela);
73 uint32_t *location; !! 139 Elf64_Sym *symtab, *sym;
74 uint32_t value; !! 140 void *base, *location;
75 unsigned int nrelocs = sechdrs[relsec] !! 141 unsigned long got, gp;
76 Elf32_Rela *rela = (void *)sechdrs[rel !! 142
77 Elf32_Word sym_info = sechdrs[relsec]. !! 143 DEBUGP("Applying relocate section %u to %u\n", relsec,
78 Elf32_Sym *sym_base = (Elf32_Sym *) se !! 144 sechdrs[relsec].sh_info);
79 void *loc_base = (void *) sechdrs[sym_ !! 145
80 !! 146 base = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr;
81 DEBUGP("Applying relocations in sectio !! 147 symtab = (Elf64_Sym *)sechdrs[symindex].sh_addr;
82 relsec, sym_info, loc_base); !! 148
83 !! 149 /* The small sections were sorted to the end of the segment.
84 for (i = 0; i < nrelocs; i++) { !! 150 The following should definitely cover them. */
85 !! 151 gp = (u64)me->core_layout.base + me->core_layout.size - 0x8000;
86 /* Symbol to relocate */ !! 152 got = sechdrs[me->arch.gotsecindex].sh_addr;
87 sym = sym_base + ELF32_R_SYM(r !! 153
88 !! 154 for (i = 0; i < n; i++) {
89 /* Where to make the change */ !! 155 unsigned long r_sym = ELF64_R_SYM (rela[i].r_info);
90 location = loc_base + rela[i]. !! 156 unsigned long r_type = ELF64_R_TYPE (rela[i].r_info);
91 !! 157 unsigned long r_got_offset = r_type >> 8;
92 /* `Everything is relative'. * !! 158 unsigned long value, hi, lo;
>> 159 r_type &= 0xff;
>> 160
>> 161 /* This is where to make the change. */
>> 162 location = base + rela[i].r_offset;
>> 163
>> 164 /* This is the symbol it is referring to. Note that all
>> 165 unresolved symbols have been resolved. */
>> 166 sym = symtab + r_sym;
93 value = sym->st_value + rela[i 167 value = sym->st_value + rela[i].r_addend;
94 168
95 DEBUGP("%d: value=%08x loc=%p !! 169 switch (r_type) {
96 i, value, location, ELF !! 170 case R_ALPHA_NONE:
97 sym->st_name ? <<
98 &strtab[sym->st_name] : <<
99 <<
100 switch (ELF32_R_TYPE(rela[i].r <<
101 case R_HEXAGON_B22_PCREL: { <<
102 int dist = (int)(value <<
103 if ((dist < -0x0080000 <<
104 (dist >= 0x0080000 <<
105 printk(KERN_ER <<
106 "%s: %s <<
107 module- <<
108 "R_HEXA <<
109 dist, v <<
110 sym->st <<
111 &strtab <<
112 return -ENOEXE <<
113 } <<
114 DEBUGP("B22_PCREL cont <<
115 *location &= ~0x01ff3f <<
116 *location |= 0x00003ff <<
117 *location |= 0x01ff000 <<
118 DEBUGP("Contents after <<
119 break; 171 break;
120 } !! 172 case R_ALPHA_REFLONG:
121 case R_HEXAGON_HI16: !! 173 *(u32 *)location = value;
122 value = (value>>16) & !! 174 break;
>> 175 case R_ALPHA_REFQUAD:
>> 176 /* BUG() can produce misaligned relocations. */
>> 177 ((u32 *)location)[0] = value;
>> 178 ((u32 *)location)[1] = value >> 32;
>> 179 break;
>> 180 case R_ALPHA_GPREL32:
>> 181 value -= gp;
>> 182 if ((int)value != value)
>> 183 goto reloc_overflow;
>> 184 *(u32 *)location = value;
>> 185 break;
>> 186 case R_ALPHA_LITERAL:
>> 187 hi = got + r_got_offset;
>> 188 lo = hi - gp;
>> 189 if ((short)lo != lo)
>> 190 goto reloc_overflow;
>> 191 *(u16 *)location = lo;
>> 192 *(u64 *)hi = value;
>> 193 break;
>> 194 case R_ALPHA_LITUSE:
>> 195 break;
>> 196 case R_ALPHA_GPDISP:
>> 197 value = gp - (u64)location;
>> 198 lo = (short)value;
>> 199 hi = (int)(value - lo);
>> 200 if (hi + lo != value)
>> 201 goto reloc_overflow;
>> 202 *(u16 *)location = hi >> 16;
>> 203 *(u16 *)(location + rela[i].r_addend) = lo;
>> 204 break;
>> 205 case R_ALPHA_BRSGP:
>> 206 /* BRSGP is only allowed to bind to local symbols.
>> 207 If the section is undef, this means that the
>> 208 value was resolved from somewhere else. */
>> 209 if (sym->st_shndx == SHN_UNDEF)
>> 210 goto reloc_overflow;
>> 211 if ((sym->st_other & STO_ALPHA_STD_GPLOAD) ==
>> 212 STO_ALPHA_STD_GPLOAD)
>> 213 /* Omit the prologue. */
>> 214 value += 8;
123 fallthrough; 215 fallthrough;
124 case R_HEXAGON_LO16: !! 216 case R_ALPHA_BRADDR:
125 *location &= ~0x00c03f !! 217 value -= (u64)location + 4;
126 *location |= value & 0 !! 218 if (value & 3)
127 *location |= (value & !! 219 goto reloc_overflow;
128 break; !! 220 value = (long)value >> 2;
129 case R_HEXAGON_32: !! 221 if (value + (1<<21) >= 1<<22)
130 *location = value; !! 222 goto reloc_overflow;
131 break; !! 223 value &= 0x1fffff;
132 case R_HEXAGON_32_PCREL: !! 224 value |= *(u32 *)location & ~0x1fffff;
133 *location = value - (u !! 225 *(u32 *)location = value;
134 break; !! 226 break;
135 case R_HEXAGON_PLT_B22_PCREL: !! 227 case R_ALPHA_HINT:
136 case R_HEXAGON_GOTOFF_LO16: !! 228 break;
137 case R_HEXAGON_GOTOFF_HI16: !! 229 case R_ALPHA_SREL32:
138 printk(KERN_ERR "%s: G !! 230 value -= (u64)location;
139 module->name); !! 231 if ((int)value != value)
140 return -ENOEXEC; !! 232 goto reloc_overflow;
>> 233 *(u32 *)location = value;
>> 234 break;
>> 235 case R_ALPHA_SREL64:
>> 236 value -= (u64)location;
>> 237 *(u64 *)location = value;
>> 238 break;
>> 239 case R_ALPHA_GPRELHIGH:
>> 240 value = (long)(value - gp + 0x8000) >> 16;
>> 241 if ((short) value != value)
>> 242 goto reloc_overflow;
>> 243 *(u16 *)location = value;
>> 244 break;
>> 245 case R_ALPHA_GPRELLOW:
>> 246 value -= gp;
>> 247 *(u16 *)location = value;
>> 248 break;
>> 249 case R_ALPHA_GPREL16:
>> 250 value -= gp;
>> 251 if ((short) value != value)
>> 252 goto reloc_overflow;
>> 253 *(u16 *)location = value;
>> 254 break;
141 default: 255 default:
142 printk(KERN_ERR "%s: u !! 256 printk(KERN_ERR "module %s: Unknown relocation: %lu\n",
143 module->name, !! 257 me->name, r_type);
144 ELF32_R_TYPE(re !! 258 return -ENOEXEC;
>> 259 reloc_overflow:
>> 260 if (ELF64_ST_TYPE (sym->st_info) == STT_SECTION)
>> 261 printk(KERN_ERR
>> 262 "module %s: Relocation (type %lu) overflow vs section %d\n",
>> 263 me->name, r_type, sym->st_shndx);
>> 264 else
>> 265 printk(KERN_ERR
>> 266 "module %s: Relocation (type %lu) overflow vs %s\n",
>> 267 me->name, r_type, strtab + sym->st_name);
145 return -ENOEXEC; 268 return -ENOEXEC;
146 } 269 }
147 } 270 }
>> 271
148 return 0; 272 return 0;
149 } 273 }
150 274
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