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Merge branch 'for-3.18-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj...
[linux/fpc-iii.git] / arch / s390 / kernel / module.c
blobb89b59158b9592317479422b14cfb8e7779fa722
1 /*
2 * Kernel module help for s390.
3 *
4 * S390 version
5 * Copyright IBM Corp. 2002, 2003
6 * Author(s): Arnd Bergmann (arndb@de.ibm.com)
7 * Martin Schwidefsky (schwidefsky@de.ibm.com)
8 *
9 * based on i386 version
10 * Copyright (C) 2001 Rusty Russell.
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
16 *
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
21 *
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, write to the Free Software
24 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
25 */
26 #include <linux/module.h>
27 #include <linux/elf.h>
28 #include <linux/vmalloc.h>
29 #include <linux/fs.h>
30 #include <linux/string.h>
31 #include <linux/kernel.h>
32 #include <linux/moduleloader.h>
33 #include <linux/bug.h>
34
35 #if 0
36 #define DEBUGP printk
37 #else
38 #define DEBUGP(fmt , ...)
39 #endif
40
41 #ifndef CONFIG_64BIT
42 #define PLT_ENTRY_SIZE 12
43 #else /* CONFIG_64BIT */
44 #define PLT_ENTRY_SIZE 20
45 #endif /* CONFIG_64BIT */
46
47 #ifdef CONFIG_64BIT
48 void *module_alloc(unsigned long size)
49 {
50 if (PAGE_ALIGN(size) > MODULES_LEN)
51 return NULL;
52 return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END,
53 GFP_KERNEL, PAGE_KERNEL, NUMA_NO_NODE,
54 __builtin_return_address(0));
55 }
56 #endif
57
58 /* Free memory returned from module_alloc */
59 void module_free(struct module *mod, void *module_region)
60 {
61 if (mod) {
62 vfree(mod->arch.syminfo);
63 mod->arch.syminfo = NULL;
64 }
65 vfree(module_region);
66 }
67
68 static void check_rela(Elf_Rela *rela, struct module *me)
69 {
70 struct mod_arch_syminfo *info;
71
72 info = me->arch.syminfo + ELF_R_SYM (rela->r_info);
73 switch (ELF_R_TYPE (rela->r_info)) {
74 case R_390_GOT12: /* 12 bit GOT offset. */
75 case R_390_GOT16: /* 16 bit GOT offset. */
76 case R_390_GOT20: /* 20 bit GOT offset. */
77 case R_390_GOT32: /* 32 bit GOT offset. */
78 case R_390_GOT64: /* 64 bit GOT offset. */
79 case R_390_GOTENT: /* 32 bit PC rel. to GOT entry shifted by 1. */
80 case R_390_GOTPLT12: /* 12 bit offset to jump slot. */
81 case R_390_GOTPLT16: /* 16 bit offset to jump slot. */
82 case R_390_GOTPLT20: /* 20 bit offset to jump slot. */
83 case R_390_GOTPLT32: /* 32 bit offset to jump slot. */
84 case R_390_GOTPLT64: /* 64 bit offset to jump slot. */
85 case R_390_GOTPLTENT: /* 32 bit rel. offset to jump slot >> 1. */
86 if (info->got_offset == -1UL) {
87 info->got_offset = me->arch.got_size;
88 me->arch.got_size += sizeof(void*);
89 }
90 break;
91 case R_390_PLT16DBL: /* 16 bit PC rel. PLT shifted by 1. */
92 case R_390_PLT32DBL: /* 32 bit PC rel. PLT shifted by 1. */
93 case R_390_PLT32: /* 32 bit PC relative PLT address. */
94 case R_390_PLT64: /* 64 bit PC relative PLT address. */
95 case R_390_PLTOFF16: /* 16 bit offset from GOT to PLT. */
96 case R_390_PLTOFF32: /* 32 bit offset from GOT to PLT. */
97 case R_390_PLTOFF64: /* 16 bit offset from GOT to PLT. */
98 if (info->plt_offset == -1UL) {
99 info->plt_offset = me->arch.plt_size;
100 me->arch.plt_size += PLT_ENTRY_SIZE;
101 }
102 break;
103 case R_390_COPY:
104 case R_390_GLOB_DAT:
105 case R_390_JMP_SLOT:
106 case R_390_RELATIVE:
107 /* Only needed if we want to support loading of
108 modules linked with -shared. */
109 break;
110 }
111 }
112
113 /*
114 * Account for GOT and PLT relocations. We can't add sections for
115 * got and plt but we can increase the core module size.
116 */
117 int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
118 char *secstrings, struct module *me)
119 {
120 Elf_Shdr *symtab;
121 Elf_Sym *symbols;
122 Elf_Rela *rela;
123 char *strings;
124 int nrela, i, j;
125
126 /* Find symbol table and string table. */
127 symtab = NULL;
128 for (i = 0; i < hdr->e_shnum; i++)
129 switch (sechdrs[i].sh_type) {
130 case SHT_SYMTAB:
131 symtab = sechdrs + i;
132 break;
133 }
134 if (!symtab) {
135 printk(KERN_ERR "module %s: no symbol table\n", me->name);
136 return -ENOEXEC;
137 }
138
139 /* Allocate one syminfo structure per symbol. */
140 me->arch.nsyms = symtab->sh_size / sizeof(Elf_Sym);
141 me->arch.syminfo = vmalloc(me->arch.nsyms *
142 sizeof(struct mod_arch_syminfo));
143 if (!me->arch.syminfo)
144 return -ENOMEM;
145 symbols = (void *) hdr + symtab->sh_offset;
146 strings = (void *) hdr + sechdrs[symtab->sh_link].sh_offset;
147 for (i = 0; i < me->arch.nsyms; i++) {
148 if (symbols[i].st_shndx == SHN_UNDEF &&
149 strcmp(strings + symbols[i].st_name,
150 "_GLOBAL_OFFSET_TABLE_") == 0)
151 /* "Define" it as absolute. */
152 symbols[i].st_shndx = SHN_ABS;
153 me->arch.syminfo[i].got_offset = -1UL;
154 me->arch.syminfo[i].plt_offset = -1UL;
155 me->arch.syminfo[i].got_initialized = 0;
156 me->arch.syminfo[i].plt_initialized = 0;
157 }
158
159 /* Search for got/plt relocations. */
160 me->arch.got_size = me->arch.plt_size = 0;
161 for (i = 0; i < hdr->e_shnum; i++) {
162 if (sechdrs[i].sh_type != SHT_RELA)
163 continue;
164 nrela = sechdrs[i].sh_size / sizeof(Elf_Rela);
165 rela = (void *) hdr + sechdrs[i].sh_offset;
166 for (j = 0; j < nrela; j++)
167 check_rela(rela + j, me);
168 }
169
170 /* Increase core size by size of got & plt and set start
171 offsets for got and plt. */
172 me->core_size = ALIGN(me->core_size, 4);
173 me->arch.got_offset = me->core_size;
174 me->core_size += me->arch.got_size;
175 me->arch.plt_offset = me->core_size;
176 me->core_size += me->arch.plt_size;
177 return 0;
178 }
179
180 static int apply_rela_bits(Elf_Addr loc, Elf_Addr val,
181 int sign, int bits, int shift)
182 {
183 unsigned long umax;
184 long min, max;
185
186 if (val & ((1UL << shift) - 1))
187 return -ENOEXEC;
188 if (sign) {
189 val = (Elf_Addr)(((long) val) >> shift);
190 min = -(1L << (bits - 1));
191 max = (1L << (bits - 1)) - 1;
192 if ((long) val < min || (long) val > max)
193 return -ENOEXEC;
194 } else {
195 val >>= shift;
196 umax = ((1UL << (bits - 1)) << 1) - 1;
197 if ((unsigned long) val > umax)
198 return -ENOEXEC;
199 }
200
201 if (bits == 8)
202 *(unsigned char *) loc = val;
203 else if (bits == 12)
204 *(unsigned short *) loc = (val & 0xfff) |
205 (*(unsigned short *) loc & 0xf000);
206 else if (bits == 16)
207 *(unsigned short *) loc = val;
208 else if (bits == 20)
209 *(unsigned int *) loc = (val & 0xfff) << 16 |
210 (val & 0xff000) >> 4 |
211 (*(unsigned int *) loc & 0xf00000ff);
212 else if (bits == 32)
213 *(unsigned int *) loc = val;
214 else if (bits == 64)
215 *(unsigned long *) loc = val;
216 return 0;
217 }
218
219 static int apply_rela(Elf_Rela *rela, Elf_Addr base, Elf_Sym *symtab,
220 const char *strtab, struct module *me)
221 {
222 struct mod_arch_syminfo *info;
223 Elf_Addr loc, val;
224 int r_type, r_sym;
225 int rc = -ENOEXEC;
226
227 /* This is where to make the change */
228 loc = base + rela->r_offset;
229 /* This is the symbol it is referring to. Note that all
230 undefined symbols have been resolved. */
231 r_sym = ELF_R_SYM(rela->r_info);
232 r_type = ELF_R_TYPE(rela->r_info);
233 info = me->arch.syminfo + r_sym;
234 val = symtab[r_sym].st_value;
235
236 switch (r_type) {
237 case R_390_NONE: /* No relocation. */
238 rc = 0;
239 break;
240 case R_390_8: /* Direct 8 bit. */
241 case R_390_12: /* Direct 12 bit. */
242 case R_390_16: /* Direct 16 bit. */
243 case R_390_20: /* Direct 20 bit. */
244 case R_390_32: /* Direct 32 bit. */
245 case R_390_64: /* Direct 64 bit. */
246 val += rela->r_addend;
247 if (r_type == R_390_8)
248 rc = apply_rela_bits(loc, val, 0, 8, 0);
249 else if (r_type == R_390_12)
250 rc = apply_rela_bits(loc, val, 0, 12, 0);
251 else if (r_type == R_390_16)
252 rc = apply_rela_bits(loc, val, 0, 16, 0);
253 else if (r_type == R_390_20)
254 rc = apply_rela_bits(loc, val, 1, 20, 0);
255 else if (r_type == R_390_32)
256 rc = apply_rela_bits(loc, val, 0, 32, 0);
257 else if (r_type == R_390_64)
258 rc = apply_rela_bits(loc, val, 0, 64, 0);
259 break;
260 case R_390_PC16: /* PC relative 16 bit. */
261 case R_390_PC16DBL: /* PC relative 16 bit shifted by 1. */
262 case R_390_PC32DBL: /* PC relative 32 bit shifted by 1. */
263 case R_390_PC32: /* PC relative 32 bit. */
264 case R_390_PC64: /* PC relative 64 bit. */
265 val += rela->r_addend - loc;
266 if (r_type == R_390_PC16)
267 rc = apply_rela_bits(loc, val, 1, 16, 0);
268 else if (r_type == R_390_PC16DBL)
269 rc = apply_rela_bits(loc, val, 1, 16, 1);
270 else if (r_type == R_390_PC32DBL)
271 rc = apply_rela_bits(loc, val, 1, 32, 1);
272 else if (r_type == R_390_PC32)
273 rc = apply_rela_bits(loc, val, 1, 32, 0);
274 else if (r_type == R_390_PC64)
275 rc = apply_rela_bits(loc, val, 1, 64, 0);
276 break;
277 case R_390_GOT12: /* 12 bit GOT offset. */
278 case R_390_GOT16: /* 16 bit GOT offset. */
279 case R_390_GOT20: /* 20 bit GOT offset. */
280 case R_390_GOT32: /* 32 bit GOT offset. */
281 case R_390_GOT64: /* 64 bit GOT offset. */
282 case R_390_GOTENT: /* 32 bit PC rel. to GOT entry shifted by 1. */
283 case R_390_GOTPLT12: /* 12 bit offset to jump slot. */
284 case R_390_GOTPLT20: /* 20 bit offset to jump slot. */
285 case R_390_GOTPLT16: /* 16 bit offset to jump slot. */
286 case R_390_GOTPLT32: /* 32 bit offset to jump slot. */
287 case R_390_GOTPLT64: /* 64 bit offset to jump slot. */
288 case R_390_GOTPLTENT: /* 32 bit rel. offset to jump slot >> 1. */
289 if (info->got_initialized == 0) {
290 Elf_Addr *gotent;
291
292 gotent = me->module_core + me->arch.got_offset +
293 info->got_offset;
294 *gotent = val;
295 info->got_initialized = 1;
296 }
297 val = info->got_offset + rela->r_addend;
298 if (r_type == R_390_GOT12 ||
299 r_type == R_390_GOTPLT12)
300 rc = apply_rela_bits(loc, val, 0, 12, 0);
301 else if (r_type == R_390_GOT16 ||
302 r_type == R_390_GOTPLT16)
303 rc = apply_rela_bits(loc, val, 0, 16, 0);
304 else if (r_type == R_390_GOT20 ||
305 r_type == R_390_GOTPLT20)
306 rc = apply_rela_bits(loc, val, 1, 20, 0);
307 else if (r_type == R_390_GOT32 ||
308 r_type == R_390_GOTPLT32)
309 rc = apply_rela_bits(loc, val, 0, 32, 0);
310 else if (r_type == R_390_GOT64 ||
311 r_type == R_390_GOTPLT64)
312 rc = apply_rela_bits(loc, val, 0, 64, 0);
313 else if (r_type == R_390_GOTENT ||
314 r_type == R_390_GOTPLTENT) {
315 val += (Elf_Addr) me->module_core - loc;
316 rc = apply_rela_bits(loc, val, 1, 32, 1);
317 }
318 break;
319 case R_390_PLT16DBL: /* 16 bit PC rel. PLT shifted by 1. */
320 case R_390_PLT32DBL: /* 32 bit PC rel. PLT shifted by 1. */
321 case R_390_PLT32: /* 32 bit PC relative PLT address. */
322 case R_390_PLT64: /* 64 bit PC relative PLT address. */
323 case R_390_PLTOFF16: /* 16 bit offset from GOT to PLT. */
324 case R_390_PLTOFF32: /* 32 bit offset from GOT to PLT. */
325 case R_390_PLTOFF64: /* 16 bit offset from GOT to PLT. */
326 if (info->plt_initialized == 0) {
327 unsigned int *ip;
328 ip = me->module_core + me->arch.plt_offset +
329 info->plt_offset;
330 #ifndef CONFIG_64BIT
331 ip[0] = 0x0d105810; /* basr 1,0; l 1,6(1); br 1 */
332 ip[1] = 0x100607f1;
333 ip[2] = val;
334 #else /* CONFIG_64BIT */
335 ip[0] = 0x0d10e310; /* basr 1,0; lg 1,10(1); br 1 */
336 ip[1] = 0x100a0004;
337 ip[2] = 0x07f10000;
338 ip[3] = (unsigned int) (val >> 32);
339 ip[4] = (unsigned int) val;
340 #endif /* CONFIG_64BIT */
341 info->plt_initialized = 1;
342 }
343 if (r_type == R_390_PLTOFF16 ||
344 r_type == R_390_PLTOFF32 ||
345 r_type == R_390_PLTOFF64)
346 val = me->arch.plt_offset - me->arch.got_offset +
347 info->plt_offset + rela->r_addend;
348 else {
349 if (!((r_type == R_390_PLT16DBL &&
350 val - loc + 0xffffUL < 0x1ffffeUL) ||
351 (r_type == R_390_PLT32DBL &&
352 val - loc + 0xffffffffULL < 0x1fffffffeULL)))
353 val = (Elf_Addr) me->module_core +
354 me->arch.plt_offset +
355 info->plt_offset;
356 val += rela->r_addend - loc;
357 }
358 if (r_type == R_390_PLT16DBL)
359 rc = apply_rela_bits(loc, val, 1, 16, 1);
360 else if (r_type == R_390_PLTOFF16)
361 rc = apply_rela_bits(loc, val, 0, 16, 0);
362 else if (r_type == R_390_PLT32DBL)
363 rc = apply_rela_bits(loc, val, 1, 32, 1);
364 else if (r_type == R_390_PLT32 ||
365 r_type == R_390_PLTOFF32)
366 rc = apply_rela_bits(loc, val, 0, 32, 0);
367 else if (r_type == R_390_PLT64 ||
368 r_type == R_390_PLTOFF64)
369 rc = apply_rela_bits(loc, val, 0, 64, 0);
370 break;
371 case R_390_GOTOFF16: /* 16 bit offset to GOT. */
372 case R_390_GOTOFF32: /* 32 bit offset to GOT. */
373 case R_390_GOTOFF64: /* 64 bit offset to GOT. */
374 val = val + rela->r_addend -
375 ((Elf_Addr) me->module_core + me->arch.got_offset);
376 if (r_type == R_390_GOTOFF16)
377 rc = apply_rela_bits(loc, val, 0, 16, 0);
378 else if (r_type == R_390_GOTOFF32)
379 rc = apply_rela_bits(loc, val, 0, 32, 0);
380 else if (r_type == R_390_GOTOFF64)
381 rc = apply_rela_bits(loc, val, 0, 64, 0);
382 break;
383 case R_390_GOTPC: /* 32 bit PC relative offset to GOT. */
384 case R_390_GOTPCDBL: /* 32 bit PC rel. off. to GOT shifted by 1. */
385 val = (Elf_Addr) me->module_core + me->arch.got_offset +
386 rela->r_addend - loc;
387 if (r_type == R_390_GOTPC)
388 rc = apply_rela_bits(loc, val, 1, 32, 0);
389 else if (r_type == R_390_GOTPCDBL)
390 rc = apply_rela_bits(loc, val, 1, 32, 1);
391 break;
392 case R_390_COPY:
393 case R_390_GLOB_DAT: /* Create GOT entry. */
394 case R_390_JMP_SLOT: /* Create PLT entry. */
395 case R_390_RELATIVE: /* Adjust by program base. */
396 /* Only needed if we want to support loading of
397 modules linked with -shared. */
398 return -ENOEXEC;
399 default:
400 printk(KERN_ERR "module %s: unknown relocation: %u\n",
401 me->name, r_type);
402 return -ENOEXEC;
403 }
404 if (rc) {
405 printk(KERN_ERR "module %s: relocation error for symbol %s "
406 "(r_type %i, value 0x%lx)\n",
407 me->name, strtab + symtab[r_sym].st_name,
408 r_type, (unsigned long) val);
409 return rc;
410 }
411 return 0;
412 }
413
414 int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
415 unsigned int symindex, unsigned int relsec,
416 struct module *me)
417 {
418 Elf_Addr base;
419 Elf_Sym *symtab;
420 Elf_Rela *rela;
421 unsigned long i, n;
422 int rc;
423
424 DEBUGP("Applying relocate section %u to %u\n",
425 relsec, sechdrs[relsec].sh_info);
426 base = sechdrs[sechdrs[relsec].sh_info].sh_addr;
427 symtab = (Elf_Sym *) sechdrs[symindex].sh_addr;
428 rela = (Elf_Rela *) sechdrs[relsec].sh_addr;
429 n = sechdrs[relsec].sh_size / sizeof(Elf_Rela);
430
431 for (i = 0; i < n; i++, rela++) {
432 rc = apply_rela(rela, base, symtab, strtab, me);
433 if (rc)
434 return rc;
435 }
436 return 0;
437 }
438
439 int module_finalize(const Elf_Ehdr *hdr,
440 const Elf_Shdr *sechdrs,
441 struct module *me)
442 {
443 vfree(me->arch.syminfo);
444 me->arch.syminfo = NULL;
445 return 0;
446 }
Linux with added FPC-III support