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Linux 4.11-rc5
[linux/fpc-iii.git] / arch / s390 / kernel / module.c
blob1a27f307a92079e79ead66c5e50e4f54e992530c
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 #define PLT_ENTRY_SIZE 20
42
43 void *module_alloc(unsigned long size)
44 {
45 if (PAGE_ALIGN(size) > MODULES_LEN)
46 return NULL;
47 return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END,
48 GFP_KERNEL, PAGE_KERNEL_EXEC,
49 0, NUMA_NO_NODE,
50 __builtin_return_address(0));
51 }
52
53 void module_arch_freeing_init(struct module *mod)
54 {
55 if (is_livepatch_module(mod) &&
56 mod->state == MODULE_STATE_LIVE)
57 return;
58
59 vfree(mod->arch.syminfo);
60 mod->arch.syminfo = NULL;
61 }
62
63 static void check_rela(Elf_Rela *rela, struct module *me)
64 {
65 struct mod_arch_syminfo *info;
66
67 info = me->arch.syminfo + ELF_R_SYM (rela->r_info);
68 switch (ELF_R_TYPE (rela->r_info)) {
69 case R_390_GOT12: /* 12 bit GOT offset. */
70 case R_390_GOT16: /* 16 bit GOT offset. */
71 case R_390_GOT20: /* 20 bit GOT offset. */
72 case R_390_GOT32: /* 32 bit GOT offset. */
73 case R_390_GOT64: /* 64 bit GOT offset. */
74 case R_390_GOTENT: /* 32 bit PC rel. to GOT entry shifted by 1. */
75 case R_390_GOTPLT12: /* 12 bit offset to jump slot. */
76 case R_390_GOTPLT16: /* 16 bit offset to jump slot. */
77 case R_390_GOTPLT20: /* 20 bit offset to jump slot. */
78 case R_390_GOTPLT32: /* 32 bit offset to jump slot. */
79 case R_390_GOTPLT64: /* 64 bit offset to jump slot. */
80 case R_390_GOTPLTENT: /* 32 bit rel. offset to jump slot >> 1. */
81 if (info->got_offset == -1UL) {
82 info->got_offset = me->arch.got_size;
83 me->arch.got_size += sizeof(void*);
84 }
85 break;
86 case R_390_PLT16DBL: /* 16 bit PC rel. PLT shifted by 1. */
87 case R_390_PLT32DBL: /* 32 bit PC rel. PLT shifted by 1. */
88 case R_390_PLT32: /* 32 bit PC relative PLT address. */
89 case R_390_PLT64: /* 64 bit PC relative PLT address. */
90 case R_390_PLTOFF16: /* 16 bit offset from GOT to PLT. */
91 case R_390_PLTOFF32: /* 32 bit offset from GOT to PLT. */
92 case R_390_PLTOFF64: /* 16 bit offset from GOT to PLT. */
93 if (info->plt_offset == -1UL) {
94 info->plt_offset = me->arch.plt_size;
95 me->arch.plt_size += PLT_ENTRY_SIZE;
96 }
97 break;
98 case R_390_COPY:
99 case R_390_GLOB_DAT:
100 case R_390_JMP_SLOT:
101 case R_390_RELATIVE:
102 /* Only needed if we want to support loading of
103 modules linked with -shared. */
104 break;
105 }
106 }
107
108 /*
109 * Account for GOT and PLT relocations. We can't add sections for
110 * got and plt but we can increase the core module size.
111 */
112 int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
113 char *secstrings, struct module *me)
114 {
115 Elf_Shdr *symtab;
116 Elf_Sym *symbols;
117 Elf_Rela *rela;
118 char *strings;
119 int nrela, i, j;
120
121 /* Find symbol table and string table. */
122 symtab = NULL;
123 for (i = 0; i < hdr->e_shnum; i++)
124 switch (sechdrs[i].sh_type) {
125 case SHT_SYMTAB:
126 symtab = sechdrs + i;
127 break;
128 }
129 if (!symtab) {
130 printk(KERN_ERR "module %s: no symbol table\n", me->name);
131 return -ENOEXEC;
132 }
133
134 /* Allocate one syminfo structure per symbol. */
135 me->arch.nsyms = symtab->sh_size / sizeof(Elf_Sym);
136 me->arch.syminfo = vmalloc(me->arch.nsyms *
137 sizeof(struct mod_arch_syminfo));
138 if (!me->arch.syminfo)
139 return -ENOMEM;
140 symbols = (void *) hdr + symtab->sh_offset;
141 strings = (void *) hdr + sechdrs[symtab->sh_link].sh_offset;
142 for (i = 0; i < me->arch.nsyms; i++) {
143 if (symbols[i].st_shndx == SHN_UNDEF &&
144 strcmp(strings + symbols[i].st_name,
145 "_GLOBAL_OFFSET_TABLE_") == 0)
146 /* "Define" it as absolute. */
147 symbols[i].st_shndx = SHN_ABS;
148 me->arch.syminfo[i].got_offset = -1UL;
149 me->arch.syminfo[i].plt_offset = -1UL;
150 me->arch.syminfo[i].got_initialized = 0;
151 me->arch.syminfo[i].plt_initialized = 0;
152 }
153
154 /* Search for got/plt relocations. */
155 me->arch.got_size = me->arch.plt_size = 0;
156 for (i = 0; i < hdr->e_shnum; i++) {
157 if (sechdrs[i].sh_type != SHT_RELA)
158 continue;
159 nrela = sechdrs[i].sh_size / sizeof(Elf_Rela);
160 rela = (void *) hdr + sechdrs[i].sh_offset;
161 for (j = 0; j < nrela; j++)
162 check_rela(rela + j, me);
163 }
164
165 /* Increase core size by size of got & plt and set start
166 offsets for got and plt. */
167 me->core_layout.size = ALIGN(me->core_layout.size, 4);
168 me->arch.got_offset = me->core_layout.size;
169 me->core_layout.size += me->arch.got_size;
170 me->arch.plt_offset = me->core_layout.size;
171 me->core_layout.size += me->arch.plt_size;
172 return 0;
173 }
174
175 static int apply_rela_bits(Elf_Addr loc, Elf_Addr val,
176 int sign, int bits, int shift)
177 {
178 unsigned long umax;
179 long min, max;
180
181 if (val & ((1UL << shift) - 1))
182 return -ENOEXEC;
183 if (sign) {
184 val = (Elf_Addr)(((long) val) >> shift);
185 min = -(1L << (bits - 1));
186 max = (1L << (bits - 1)) - 1;
187 if ((long) val < min || (long) val > max)
188 return -ENOEXEC;
189 } else {
190 val >>= shift;
191 umax = ((1UL << (bits - 1)) << 1) - 1;
192 if ((unsigned long) val > umax)
193 return -ENOEXEC;
194 }
195
196 if (bits == 8)
197 *(unsigned char *) loc = val;
198 else if (bits == 12)
199 *(unsigned short *) loc = (val & 0xfff) |
200 (*(unsigned short *) loc & 0xf000);
201 else if (bits == 16)
202 *(unsigned short *) loc = val;
203 else if (bits == 20)
204 *(unsigned int *) loc = (val & 0xfff) << 16 |
205 (val & 0xff000) >> 4 |
206 (*(unsigned int *) loc & 0xf00000ff);
207 else if (bits == 32)
208 *(unsigned int *) loc = val;
209 else if (bits == 64)
210 *(unsigned long *) loc = val;
211 return 0;
212 }
213
214 static int apply_rela(Elf_Rela *rela, Elf_Addr base, Elf_Sym *symtab,
215 const char *strtab, struct module *me)
216 {
217 struct mod_arch_syminfo *info;
218 Elf_Addr loc, val;
219 int r_type, r_sym;
220 int rc = -ENOEXEC;
221
222 /* This is where to make the change */
223 loc = base + rela->r_offset;
224 /* This is the symbol it is referring to. Note that all
225 undefined symbols have been resolved. */
226 r_sym = ELF_R_SYM(rela->r_info);
227 r_type = ELF_R_TYPE(rela->r_info);
228 info = me->arch.syminfo + r_sym;
229 val = symtab[r_sym].st_value;
230
231 switch (r_type) {
232 case R_390_NONE: /* No relocation. */
233 rc = 0;
234 break;
235 case R_390_8: /* Direct 8 bit. */
236 case R_390_12: /* Direct 12 bit. */
237 case R_390_16: /* Direct 16 bit. */
238 case R_390_20: /* Direct 20 bit. */
239 case R_390_32: /* Direct 32 bit. */
240 case R_390_64: /* Direct 64 bit. */
241 val += rela->r_addend;
242 if (r_type == R_390_8)
243 rc = apply_rela_bits(loc, val, 0, 8, 0);
244 else if (r_type == R_390_12)
245 rc = apply_rela_bits(loc, val, 0, 12, 0);
246 else if (r_type == R_390_16)
247 rc = apply_rela_bits(loc, val, 0, 16, 0);
248 else if (r_type == R_390_20)
249 rc = apply_rela_bits(loc, val, 1, 20, 0);
250 else if (r_type == R_390_32)
251 rc = apply_rela_bits(loc, val, 0, 32, 0);
252 else if (r_type == R_390_64)
253 rc = apply_rela_bits(loc, val, 0, 64, 0);
254 break;
255 case R_390_PC16: /* PC relative 16 bit. */
256 case R_390_PC16DBL: /* PC relative 16 bit shifted by 1. */
257 case R_390_PC32DBL: /* PC relative 32 bit shifted by 1. */
258 case R_390_PC32: /* PC relative 32 bit. */
259 case R_390_PC64: /* PC relative 64 bit. */
260 val += rela->r_addend - loc;
261 if (r_type == R_390_PC16)
262 rc = apply_rela_bits(loc, val, 1, 16, 0);
263 else if (r_type == R_390_PC16DBL)
264 rc = apply_rela_bits(loc, val, 1, 16, 1);
265 else if (r_type == R_390_PC32DBL)
266 rc = apply_rela_bits(loc, val, 1, 32, 1);
267 else if (r_type == R_390_PC32)
268 rc = apply_rela_bits(loc, val, 1, 32, 0);
269 else if (r_type == R_390_PC64)
270 rc = apply_rela_bits(loc, val, 1, 64, 0);
271 break;
272 case R_390_GOT12: /* 12 bit GOT offset. */
273 case R_390_GOT16: /* 16 bit GOT offset. */
274 case R_390_GOT20: /* 20 bit GOT offset. */
275 case R_390_GOT32: /* 32 bit GOT offset. */
276 case R_390_GOT64: /* 64 bit GOT offset. */
277 case R_390_GOTENT: /* 32 bit PC rel. to GOT entry shifted by 1. */
278 case R_390_GOTPLT12: /* 12 bit offset to jump slot. */
279 case R_390_GOTPLT20: /* 20 bit offset to jump slot. */
280 case R_390_GOTPLT16: /* 16 bit offset to jump slot. */
281 case R_390_GOTPLT32: /* 32 bit offset to jump slot. */
282 case R_390_GOTPLT64: /* 64 bit offset to jump slot. */
283 case R_390_GOTPLTENT: /* 32 bit rel. offset to jump slot >> 1. */
284 if (info->got_initialized == 0) {
285 Elf_Addr *gotent;
286
287 gotent = me->core_layout.base + me->arch.got_offset +
288 info->got_offset;
289 *gotent = val;
290 info->got_initialized = 1;
291 }
292 val = info->got_offset + rela->r_addend;
293 if (r_type == R_390_GOT12 ||
294 r_type == R_390_GOTPLT12)
295 rc = apply_rela_bits(loc, val, 0, 12, 0);
296 else if (r_type == R_390_GOT16 ||
297 r_type == R_390_GOTPLT16)
298 rc = apply_rela_bits(loc, val, 0, 16, 0);
299 else if (r_type == R_390_GOT20 ||
300 r_type == R_390_GOTPLT20)
301 rc = apply_rela_bits(loc, val, 1, 20, 0);
302 else if (r_type == R_390_GOT32 ||
303 r_type == R_390_GOTPLT32)
304 rc = apply_rela_bits(loc, val, 0, 32, 0);
305 else if (r_type == R_390_GOT64 ||
306 r_type == R_390_GOTPLT64)
307 rc = apply_rela_bits(loc, val, 0, 64, 0);
308 else if (r_type == R_390_GOTENT ||
309 r_type == R_390_GOTPLTENT) {
310 val += (Elf_Addr) me->core_layout.base - loc;
311 rc = apply_rela_bits(loc, val, 1, 32, 1);
312 }
313 break;
314 case R_390_PLT16DBL: /* 16 bit PC rel. PLT shifted by 1. */
315 case R_390_PLT32DBL: /* 32 bit PC rel. PLT shifted by 1. */
316 case R_390_PLT32: /* 32 bit PC relative PLT address. */
317 case R_390_PLT64: /* 64 bit PC relative PLT address. */
318 case R_390_PLTOFF16: /* 16 bit offset from GOT to PLT. */
319 case R_390_PLTOFF32: /* 32 bit offset from GOT to PLT. */
320 case R_390_PLTOFF64: /* 16 bit offset from GOT to PLT. */
321 if (info->plt_initialized == 0) {
322 unsigned int *ip;
323 ip = me->core_layout.base + me->arch.plt_offset +
324 info->plt_offset;
325 ip[0] = 0x0d10e310; /* basr 1,0; lg 1,10(1); br 1 */
326 ip[1] = 0x100a0004;
327 ip[2] = 0x07f10000;
328 ip[3] = (unsigned int) (val >> 32);
329 ip[4] = (unsigned int) val;
330 info->plt_initialized = 1;
331 }
332 if (r_type == R_390_PLTOFF16 ||
333 r_type == R_390_PLTOFF32 ||
334 r_type == R_390_PLTOFF64)
335 val = me->arch.plt_offset - me->arch.got_offset +
336 info->plt_offset + rela->r_addend;
337 else {
338 if (!((r_type == R_390_PLT16DBL &&
339 val - loc + 0xffffUL < 0x1ffffeUL) ||
340 (r_type == R_390_PLT32DBL &&
341 val - loc + 0xffffffffULL < 0x1fffffffeULL)))
342 val = (Elf_Addr) me->core_layout.base +
343 me->arch.plt_offset +
344 info->plt_offset;
345 val += rela->r_addend - loc;
346 }
347 if (r_type == R_390_PLT16DBL)
348 rc = apply_rela_bits(loc, val, 1, 16, 1);
349 else if (r_type == R_390_PLTOFF16)
350 rc = apply_rela_bits(loc, val, 0, 16, 0);
351 else if (r_type == R_390_PLT32DBL)
352 rc = apply_rela_bits(loc, val, 1, 32, 1);
353 else if (r_type == R_390_PLT32 ||
354 r_type == R_390_PLTOFF32)
355 rc = apply_rela_bits(loc, val, 0, 32, 0);
356 else if (r_type == R_390_PLT64 ||
357 r_type == R_390_PLTOFF64)
358 rc = apply_rela_bits(loc, val, 0, 64, 0);
359 break;
360 case R_390_GOTOFF16: /* 16 bit offset to GOT. */
361 case R_390_GOTOFF32: /* 32 bit offset to GOT. */
362 case R_390_GOTOFF64: /* 64 bit offset to GOT. */
363 val = val + rela->r_addend -
364 ((Elf_Addr) me->core_layout.base + me->arch.got_offset);
365 if (r_type == R_390_GOTOFF16)
366 rc = apply_rela_bits(loc, val, 0, 16, 0);
367 else if (r_type == R_390_GOTOFF32)
368 rc = apply_rela_bits(loc, val, 0, 32, 0);
369 else if (r_type == R_390_GOTOFF64)
370 rc = apply_rela_bits(loc, val, 0, 64, 0);
371 break;
372 case R_390_GOTPC: /* 32 bit PC relative offset to GOT. */
373 case R_390_GOTPCDBL: /* 32 bit PC rel. off. to GOT shifted by 1. */
374 val = (Elf_Addr) me->core_layout.base + me->arch.got_offset +
375 rela->r_addend - loc;
376 if (r_type == R_390_GOTPC)
377 rc = apply_rela_bits(loc, val, 1, 32, 0);
378 else if (r_type == R_390_GOTPCDBL)
379 rc = apply_rela_bits(loc, val, 1, 32, 1);
380 break;
381 case R_390_COPY:
382 case R_390_GLOB_DAT: /* Create GOT entry. */
383 case R_390_JMP_SLOT: /* Create PLT entry. */
384 case R_390_RELATIVE: /* Adjust by program base. */
385 /* Only needed if we want to support loading of
386 modules linked with -shared. */
387 return -ENOEXEC;
388 default:
389 printk(KERN_ERR "module %s: unknown relocation: %u\n",
390 me->name, r_type);
391 return -ENOEXEC;
392 }
393 if (rc) {
394 printk(KERN_ERR "module %s: relocation error for symbol %s "
395 "(r_type %i, value 0x%lx)\n",
396 me->name, strtab + symtab[r_sym].st_name,
397 r_type, (unsigned long) val);
398 return rc;
399 }
400 return 0;
401 }
402
403 int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
404 unsigned int symindex, unsigned int relsec,
405 struct module *me)
406 {
407 Elf_Addr base;
408 Elf_Sym *symtab;
409 Elf_Rela *rela;
410 unsigned long i, n;
411 int rc;
412
413 DEBUGP("Applying relocate section %u to %u\n",
414 relsec, sechdrs[relsec].sh_info);
415 base = sechdrs[sechdrs[relsec].sh_info].sh_addr;
416 symtab = (Elf_Sym *) sechdrs[symindex].sh_addr;
417 rela = (Elf_Rela *) sechdrs[relsec].sh_addr;
418 n = sechdrs[relsec].sh_size / sizeof(Elf_Rela);
419
420 for (i = 0; i < n; i++, rela++) {
421 rc = apply_rela(rela, base, symtab, strtab, me);
422 if (rc)
423 return rc;
424 }
425 return 0;
426 }
427
428 int module_finalize(const Elf_Ehdr *hdr,
429 const Elf_Shdr *sechdrs,
430 struct module *me)
431 {
432 jump_label_apply_nops(me);
433 return 0;
434 }
Linux with added FPC-III support