1 // SPDX-License-Identifier: GPL-2.0 !! 1 /* Kernel module help for Alpha.
2 // Copyright (C) 2018 Hangzhou C-SKY Microsyst !! 2 Copyright (C) 2002 Richard Henderson.
3 3
>> 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 */
4 #include <linux/moduleloader.h> 18 #include <linux/moduleloader.h>
5 #include <linux/elf.h> 19 #include <linux/elf.h>
6 #include <linux/mm.h> <<
7 #include <linux/vmalloc.h> 20 #include <linux/vmalloc.h>
8 #include <linux/slab.h> <<
9 #include <linux/fs.h> 21 #include <linux/fs.h>
10 #include <linux/string.h> 22 #include <linux/string.h>
11 #include <linux/kernel.h> 23 #include <linux/kernel.h>
12 #include <linux/spinlock.h> !! 24 #include <linux/slab.h>
>> 25
>> 26 #if 0
>> 27 #define DEBUGP printk
>> 28 #else
>> 29 #define DEBUGP(fmt...)
>> 30 #endif
>> 31
>> 32 void *
>> 33 module_alloc(unsigned long size)
>> 34 {
>> 35 if (size == 0)
>> 36 return NULL;
>> 37 return vmalloc(size);
>> 38 }
13 39
14 #ifdef CONFIG_CPU_CK810 !! 40 void
15 #define IS_BSR32(hi16, lo16) (((hi1 !! 41 module_free(struct module *mod, void *module_region)
16 #define IS_JSRI32(hi16, lo16) ((hi16 !! 42 {
>> 43 vfree(module_region);
>> 44 }
17 45
18 #define CHANGE_JSRI_TO_LRW(addr) do { !! 46 /* Allocate the GOT at the end of the core sections. */
19 *(uint16_t *)(addr) = (*(uint16_t *)(a <<
20 *((uint16_t *)(addr) + 1) = *((uint16_ <<
21 } while (0) <<
22 47
23 #define SET_JSR32_R26(addr) do { !! 48 struct got_entry {
24 *(uint16_t *)(addr) = 0xE8Fa; !! 49 struct got_entry *next;
25 *((uint16_t *)(addr) + 1) = 0x0000; !! 50 Elf64_Sxword r_addend;
26 } while (0) !! 51 int got_offset;
>> 52 };
27 53
28 static void jsri_2_lrw_jsr(uint32_t *location) !! 54 static inline void
>> 55 process_reloc_for_got(Elf64_Rela *rela,
>> 56 struct got_entry *chains, Elf64_Xword *poffset)
29 { 57 {
30 uint16_t *location_tmp = (uint16_t *)l !! 58 unsigned long r_sym = ELF64_R_SYM (rela->r_info);
>> 59 unsigned long r_type = ELF64_R_TYPE (rela->r_info);
>> 60 Elf64_Sxword r_addend = rela->r_addend;
>> 61 struct got_entry *g;
31 62
32 if (IS_BSR32(*location_tmp, *(location !! 63 if (r_type != R_ALPHA_LITERAL)
33 return; 64 return;
34 65
35 if (IS_JSRI32(*location_tmp, *(locatio !! 66 for (g = chains + r_sym; g ; g = g->next)
36 /* jsri 0x... --> lrw r26, 0x !! 67 if (g->r_addend == r_addend) {
37 CHANGE_JSRI_TO_LRW(location); !! 68 if (g->got_offset == 0) {
38 /* lsli r0, r0 --> jsr r26 */ !! 69 g->got_offset = *poffset;
39 SET_JSR32_R26(location + 1); !! 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_addend = r_addend;
>> 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;
>> 119 }
>> 120
>> 121 nsyms = symtab->sh_size / sizeof(Elf64_Sym);
>> 122 chains = kcalloc(nsyms, sizeof(struct got_entry), GFP_KERNEL);
>> 123 if (!chains) {
>> 124 printk(KERN_ERR
>> 125 "module %s: no memory for symbol chain buffer\n",
>> 126 me->name);
>> 127 return -ENOMEM;
>> 128 }
>> 129
>> 130 got->sh_size = 0;
>> 131 got->sh_addralign = 8;
>> 132 got->sh_type = SHT_NOBITS;
>> 133
>> 134 /* Examine all LITERAL relocations to find out what GOT entries
>> 135 are required. This sizes the GOT section as well. */
>> 136 for (s = sechdrs; s < esechdrs; ++s)
>> 137 if (s->sh_type == SHT_RELA) {
>> 138 nrela = s->sh_size / sizeof(Elf64_Rela);
>> 139 rela = (void *)hdr + s->sh_offset;
>> 140 for (i = 0; i < nrela; ++i)
>> 141 process_reloc_for_got(rela+i, chains,
>> 142 &got->sh_size);
>> 143 }
>> 144
>> 145 /* Free the memory we allocated. */
>> 146 for (i = 0; i < nsyms; ++i) {
>> 147 struct got_entry *g, *n;
>> 148 for (g = chains[i].next; g ; g = n) {
>> 149 n = g->next;
>> 150 kfree(g);
>> 151 }
40 } 152 }
>> 153 kfree(chains);
>> 154
>> 155 return 0;
41 } 156 }
42 #else !! 157
43 static inline void jsri_2_lrw_jsr(uint32_t *lo !! 158 int
>> 159 apply_relocate(Elf64_Shdr *sechdrs, const char *strtab, unsigned int symindex,
>> 160 unsigned int relsec, struct module *me)
44 { 161 {
45 return; !! 162 printk(KERN_ERR "module %s: REL relocation unsupported\n", me->name);
>> 163 return -ENOEXEC;
46 } 164 }
47 #endif <<
48 165
49 int apply_relocate_add(Elf32_Shdr *sechdrs, co !! 166 int
50 unsigned int symindex, unsigne !! 167 apply_relocate_add(Elf64_Shdr *sechdrs, const char *strtab,
>> 168 unsigned int symindex, unsigned int relsec,
>> 169 struct module *me)
51 { 170 {
52 unsigned int i; !! 171 Elf64_Rela *rela = (void *)sechdrs[relsec].sh_addr;
53 Elf32_Rela *rel = (void *) sechdr !! 172 unsigned long i, n = sechdrs[relsec].sh_size / sizeof(*rela);
54 Elf32_Sym *sym; !! 173 Elf64_Sym *symtab, *sym;
55 uint32_t *location; !! 174 void *base, *location;
56 short *temp; !! 175 unsigned long got, gp;
57 !! 176
58 for (i = 0; i < sechdrs[relsec].sh_siz !! 177 DEBUGP("Applying relocate section %u to %u\n", relsec,
59 /* This is where to make the c !! 178 sechdrs[relsec].sh_info);
60 location = (void *)sechdrs[sec !! 179
61 !! 180 base = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr;
62 sym = (Elf32_Sym *)sechdrs[sym !! 181 symtab = (Elf64_Sym *)sechdrs[symindex].sh_addr;
63 !! 182
64 !! 183 /* The small sections were sorted to the end of the segment.
65 switch (ELF32_R_TYPE(rel[i].r_ !! 184 The following should definitely cover them. */
66 case R_CSKY_32: !! 185 gp = (u64)me->module_core + me->core_size - 0x8000;
67 /* We add the value in !! 186 got = sechdrs[me->arch.gotsecindex].sh_addr;
68 *location = rel[i].r_a !! 187
69 break; !! 188 for (i = 0; i < n; i++) {
70 case R_CSKY_PC32: !! 189 unsigned long r_sym = ELF64_R_SYM (rela[i].r_info);
71 /* Add the value, subt !! 190 unsigned long r_type = ELF64_R_TYPE (rela[i].r_info);
72 *location = rel[i].r_a !! 191 unsigned long r_got_offset = r_type >> 8;
73 !! 192 unsigned long value, hi, lo;
74 break; !! 193 r_type &= 0xff;
75 case R_CSKY_PCRELJSR_IMM11BY2: !! 194
76 break; !! 195 /* This is where to make the change. */
77 case R_CSKY_PCRELJSR_IMM26BY2: !! 196 location = base + rela[i].r_offset;
78 jsri_2_lrw_jsr(locatio !! 197
79 break; !! 198 /* This is the symbol it is referring to. Note that all
80 case R_CSKY_ADDR_HI16: !! 199 unresolved symbols have been resolved. */
81 temp = ((short *)loca !! 200 sym = symtab + r_sym;
82 *temp = (short) !! 201 value = sym->st_value + rela[i].r_addend;
83 ((rel[i].r_add !! 202
84 break; !! 203 switch (r_type) {
85 case R_CSKY_ADDR_LO16: !! 204 case R_ALPHA_NONE:
86 temp = ((short *)loca !! 205 break;
87 *temp = (short) !! 206 case R_ALPHA_REFQUAD:
88 ((rel[i].r_add !! 207 /* BUG() can produce misaligned relocations. */
>> 208 ((u32 *)location)[0] = value;
>> 209 ((u32 *)location)[1] = value >> 32;
>> 210 break;
>> 211 case R_ALPHA_GPREL32:
>> 212 value -= gp;
>> 213 if ((int)value != value)
>> 214 goto reloc_overflow;
>> 215 *(u32 *)location = value;
>> 216 break;
>> 217 case R_ALPHA_LITERAL:
>> 218 hi = got + r_got_offset;
>> 219 lo = hi - gp;
>> 220 if ((short)lo != lo)
>> 221 goto reloc_overflow;
>> 222 *(u16 *)location = lo;
>> 223 *(u64 *)hi = value;
>> 224 break;
>> 225 case R_ALPHA_LITUSE:
>> 226 break;
>> 227 case R_ALPHA_GPDISP:
>> 228 value = gp - (u64)location;
>> 229 lo = (short)value;
>> 230 hi = (int)(value - lo);
>> 231 if (hi + lo != value)
>> 232 goto reloc_overflow;
>> 233 *(u16 *)location = hi >> 16;
>> 234 *(u16 *)(location + rela[i].r_addend) = lo;
>> 235 break;
>> 236 case R_ALPHA_BRSGP:
>> 237 /* BRSGP is only allowed to bind to local symbols.
>> 238 If the section is undef, this means that the
>> 239 value was resolved from somewhere else. */
>> 240 if (sym->st_shndx == SHN_UNDEF)
>> 241 goto reloc_overflow;
>> 242 if ((sym->st_other & STO_ALPHA_STD_GPLOAD) ==
>> 243 STO_ALPHA_STD_GPLOAD)
>> 244 /* Omit the prologue. */
>> 245 value += 8;
>> 246 /* FALLTHRU */
>> 247 case R_ALPHA_BRADDR:
>> 248 value -= (u64)location + 4;
>> 249 if (value & 3)
>> 250 goto reloc_overflow;
>> 251 value = (long)value >> 2;
>> 252 if (value + (1<<21) >= 1<<22)
>> 253 goto reloc_overflow;
>> 254 value &= 0x1fffff;
>> 255 value |= *(u32 *)location & ~0x1fffff;
>> 256 *(u32 *)location = value;
>> 257 break;
>> 258 case R_ALPHA_HINT:
>> 259 break;
>> 260 case R_ALPHA_SREL32:
>> 261 value -= (u64)location;
>> 262 if ((int)value != value)
>> 263 goto reloc_overflow;
>> 264 *(u32 *)location = value;
>> 265 break;
>> 266 case R_ALPHA_SREL64:
>> 267 value -= (u64)location;
>> 268 *(u64 *)location = value;
>> 269 break;
>> 270 case R_ALPHA_GPRELHIGH:
>> 271 value = (long)(value - gp + 0x8000) >> 16;
>> 272 if ((short) value != value)
>> 273 goto reloc_overflow;
>> 274 *(u16 *)location = value;
>> 275 break;
>> 276 case R_ALPHA_GPRELLOW:
>> 277 value -= gp;
>> 278 *(u16 *)location = value;
>> 279 break;
>> 280 case R_ALPHA_GPREL16:
>> 281 value -= gp;
>> 282 if ((short) value != value)
>> 283 goto reloc_overflow;
>> 284 *(u16 *)location = value;
89 break; 285 break;
90 default: 286 default:
91 pr_err("module %s: Unk !! 287 printk(KERN_ERR "module %s: Unknown relocation: %lu\n",
92 me->name, ELF3 !! 288 me->name, r_type);
>> 289 return -ENOEXEC;
>> 290 reloc_overflow:
>> 291 if (ELF64_ST_TYPE (sym->st_info) == STT_SECTION)
>> 292 printk(KERN_ERR
>> 293 "module %s: Relocation (type %lu) overflow vs section %d\n",
>> 294 me->name, r_type, sym->st_shndx);
>> 295 else
>> 296 printk(KERN_ERR
>> 297 "module %s: Relocation (type %lu) overflow vs %s\n",
>> 298 me->name, r_type, strtab + sym->st_name);
93 return -ENOEXEC; 299 return -ENOEXEC;
94 } 300 }
95 } 301 }
>> 302
>> 303 return 0;
>> 304 }
>> 305
>> 306 int
>> 307 module_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs,
>> 308 struct module *me)
>> 309 {
96 return 0; 310 return 0;
>> 311 }
>> 312
>> 313 void
>> 314 module_arch_cleanup(struct module *mod)
>> 315 {
97 } 316 }
98 317
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