hwrng: core - Don't use a stack buffer in add_early_randomness()
[linux/fpc-iii.git] / arch / s390 / kernel / module.c
blobfbc07891f9e7534abd8c150a49cb1539610dc232
1 /*
2 * Kernel module help for s390.
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)
9 * based on i386 version
10 * Copyright (C) 2001 Rusty Russell.
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.
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.
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
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>
35 #if 0
36 #define DEBUGP printk
37 #else
38 #define DEBUGP(fmt , ...)
39 #endif
41 #define PLT_ENTRY_SIZE 20
43 void *module_alloc(unsigned long size)
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, 0, NUMA_NO_NODE,
49 __builtin_return_address(0));
52 void module_arch_freeing_init(struct module *mod)
54 if (is_livepatch_module(mod) &&
55 mod->state == MODULE_STATE_LIVE)
56 return;
58 vfree(mod->arch.syminfo);
59 mod->arch.syminfo = NULL;
62 static void check_rela(Elf_Rela *rela, struct module *me)
64 struct mod_arch_syminfo *info;
66 info = me->arch.syminfo + ELF_R_SYM (rela->r_info);
67 switch (ELF_R_TYPE (rela->r_info)) {
68 case R_390_GOT12: /* 12 bit GOT offset. */
69 case R_390_GOT16: /* 16 bit GOT offset. */
70 case R_390_GOT20: /* 20 bit GOT offset. */
71 case R_390_GOT32: /* 32 bit GOT offset. */
72 case R_390_GOT64: /* 64 bit GOT offset. */
73 case R_390_GOTENT: /* 32 bit PC rel. to GOT entry shifted by 1. */
74 case R_390_GOTPLT12: /* 12 bit offset to jump slot. */
75 case R_390_GOTPLT16: /* 16 bit offset to jump slot. */
76 case R_390_GOTPLT20: /* 20 bit offset to jump slot. */
77 case R_390_GOTPLT32: /* 32 bit offset to jump slot. */
78 case R_390_GOTPLT64: /* 64 bit offset to jump slot. */
79 case R_390_GOTPLTENT: /* 32 bit rel. offset to jump slot >> 1. */
80 if (info->got_offset == -1UL) {
81 info->got_offset = me->arch.got_size;
82 me->arch.got_size += sizeof(void*);
84 break;
85 case R_390_PLT16DBL: /* 16 bit PC rel. PLT shifted by 1. */
86 case R_390_PLT32DBL: /* 32 bit PC rel. PLT shifted by 1. */
87 case R_390_PLT32: /* 32 bit PC relative PLT address. */
88 case R_390_PLT64: /* 64 bit PC relative PLT address. */
89 case R_390_PLTOFF16: /* 16 bit offset from GOT to PLT. */
90 case R_390_PLTOFF32: /* 32 bit offset from GOT to PLT. */
91 case R_390_PLTOFF64: /* 16 bit offset from GOT to PLT. */
92 if (info->plt_offset == -1UL) {
93 info->plt_offset = me->arch.plt_size;
94 me->arch.plt_size += PLT_ENTRY_SIZE;
96 break;
97 case R_390_COPY:
98 case R_390_GLOB_DAT:
99 case R_390_JMP_SLOT:
100 case R_390_RELATIVE:
101 /* Only needed if we want to support loading of
102 modules linked with -shared. */
103 break;
108 * Account for GOT and PLT relocations. We can't add sections for
109 * got and plt but we can increase the core module size.
111 int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
112 char *secstrings, struct module *me)
114 Elf_Shdr *symtab;
115 Elf_Sym *symbols;
116 Elf_Rela *rela;
117 char *strings;
118 int nrela, i, j;
120 /* Find symbol table and string table. */
121 symtab = NULL;
122 for (i = 0; i < hdr->e_shnum; i++)
123 switch (sechdrs[i].sh_type) {
124 case SHT_SYMTAB:
125 symtab = sechdrs + i;
126 break;
128 if (!symtab) {
129 printk(KERN_ERR "module %s: no symbol table\n", me->name);
130 return -ENOEXEC;
133 /* Allocate one syminfo structure per symbol. */
134 me->arch.nsyms = symtab->sh_size / sizeof(Elf_Sym);
135 me->arch.syminfo = vmalloc(me->arch.nsyms *
136 sizeof(struct mod_arch_syminfo));
137 if (!me->arch.syminfo)
138 return -ENOMEM;
139 symbols = (void *) hdr + symtab->sh_offset;
140 strings = (void *) hdr + sechdrs[symtab->sh_link].sh_offset;
141 for (i = 0; i < me->arch.nsyms; i++) {
142 if (symbols[i].st_shndx == SHN_UNDEF &&
143 strcmp(strings + symbols[i].st_name,
144 "_GLOBAL_OFFSET_TABLE_") == 0)
145 /* "Define" it as absolute. */
146 symbols[i].st_shndx = SHN_ABS;
147 me->arch.syminfo[i].got_offset = -1UL;
148 me->arch.syminfo[i].plt_offset = -1UL;
149 me->arch.syminfo[i].got_initialized = 0;
150 me->arch.syminfo[i].plt_initialized = 0;
153 /* Search for got/plt relocations. */
154 me->arch.got_size = me->arch.plt_size = 0;
155 for (i = 0; i < hdr->e_shnum; i++) {
156 if (sechdrs[i].sh_type != SHT_RELA)
157 continue;
158 nrela = sechdrs[i].sh_size / sizeof(Elf_Rela);
159 rela = (void *) hdr + sechdrs[i].sh_offset;
160 for (j = 0; j < nrela; j++)
161 check_rela(rela + j, me);
164 /* Increase core size by size of got & plt and set start
165 offsets for got and plt. */
166 me->core_layout.size = ALIGN(me->core_layout.size, 4);
167 me->arch.got_offset = me->core_layout.size;
168 me->core_layout.size += me->arch.got_size;
169 me->arch.plt_offset = me->core_layout.size;
170 me->core_layout.size += me->arch.plt_size;
171 return 0;
174 static int apply_rela_bits(Elf_Addr loc, Elf_Addr val,
175 int sign, int bits, int shift)
177 unsigned long umax;
178 long min, max;
180 if (val & ((1UL << shift) - 1))
181 return -ENOEXEC;
182 if (sign) {
183 val = (Elf_Addr)(((long) val) >> shift);
184 min = -(1L << (bits - 1));
185 max = (1L << (bits - 1)) - 1;
186 if ((long) val < min || (long) val > max)
187 return -ENOEXEC;
188 } else {
189 val >>= shift;
190 umax = ((1UL << (bits - 1)) << 1) - 1;
191 if ((unsigned long) val > umax)
192 return -ENOEXEC;
195 if (bits == 8)
196 *(unsigned char *) loc = val;
197 else if (bits == 12)
198 *(unsigned short *) loc = (val & 0xfff) |
199 (*(unsigned short *) loc & 0xf000);
200 else if (bits == 16)
201 *(unsigned short *) loc = val;
202 else if (bits == 20)
203 *(unsigned int *) loc = (val & 0xfff) << 16 |
204 (val & 0xff000) >> 4 |
205 (*(unsigned int *) loc & 0xf00000ff);
206 else if (bits == 32)
207 *(unsigned int *) loc = val;
208 else if (bits == 64)
209 *(unsigned long *) loc = val;
210 return 0;
213 static int apply_rela(Elf_Rela *rela, Elf_Addr base, Elf_Sym *symtab,
214 const char *strtab, struct module *me)
216 struct mod_arch_syminfo *info;
217 Elf_Addr loc, val;
218 int r_type, r_sym;
219 int rc = -ENOEXEC;
221 /* This is where to make the change */
222 loc = base + rela->r_offset;
223 /* This is the symbol it is referring to. Note that all
224 undefined symbols have been resolved. */
225 r_sym = ELF_R_SYM(rela->r_info);
226 r_type = ELF_R_TYPE(rela->r_info);
227 info = me->arch.syminfo + r_sym;
228 val = symtab[r_sym].st_value;
230 switch (r_type) {
231 case R_390_NONE: /* No relocation. */
232 rc = 0;
233 break;
234 case R_390_8: /* Direct 8 bit. */
235 case R_390_12: /* Direct 12 bit. */
236 case R_390_16: /* Direct 16 bit. */
237 case R_390_20: /* Direct 20 bit. */
238 case R_390_32: /* Direct 32 bit. */
239 case R_390_64: /* Direct 64 bit. */
240 val += rela->r_addend;
241 if (r_type == R_390_8)
242 rc = apply_rela_bits(loc, val, 0, 8, 0);
243 else if (r_type == R_390_12)
244 rc = apply_rela_bits(loc, val, 0, 12, 0);
245 else if (r_type == R_390_16)
246 rc = apply_rela_bits(loc, val, 0, 16, 0);
247 else if (r_type == R_390_20)
248 rc = apply_rela_bits(loc, val, 1, 20, 0);
249 else if (r_type == R_390_32)
250 rc = apply_rela_bits(loc, val, 0, 32, 0);
251 else if (r_type == R_390_64)
252 rc = apply_rela_bits(loc, val, 0, 64, 0);
253 break;
254 case R_390_PC16: /* PC relative 16 bit. */
255 case R_390_PC16DBL: /* PC relative 16 bit shifted by 1. */
256 case R_390_PC32DBL: /* PC relative 32 bit shifted by 1. */
257 case R_390_PC32: /* PC relative 32 bit. */
258 case R_390_PC64: /* PC relative 64 bit. */
259 val += rela->r_addend - loc;
260 if (r_type == R_390_PC16)
261 rc = apply_rela_bits(loc, val, 1, 16, 0);
262 else if (r_type == R_390_PC16DBL)
263 rc = apply_rela_bits(loc, val, 1, 16, 1);
264 else if (r_type == R_390_PC32DBL)
265 rc = apply_rela_bits(loc, val, 1, 32, 1);
266 else if (r_type == R_390_PC32)
267 rc = apply_rela_bits(loc, val, 1, 32, 0);
268 else if (r_type == R_390_PC64)
269 rc = apply_rela_bits(loc, val, 1, 64, 0);
270 break;
271 case R_390_GOT12: /* 12 bit GOT offset. */
272 case R_390_GOT16: /* 16 bit GOT offset. */
273 case R_390_GOT20: /* 20 bit GOT offset. */
274 case R_390_GOT32: /* 32 bit GOT offset. */
275 case R_390_GOT64: /* 64 bit GOT offset. */
276 case R_390_GOTENT: /* 32 bit PC rel. to GOT entry shifted by 1. */
277 case R_390_GOTPLT12: /* 12 bit offset to jump slot. */
278 case R_390_GOTPLT20: /* 20 bit offset to jump slot. */
279 case R_390_GOTPLT16: /* 16 bit offset to jump slot. */
280 case R_390_GOTPLT32: /* 32 bit offset to jump slot. */
281 case R_390_GOTPLT64: /* 64 bit offset to jump slot. */
282 case R_390_GOTPLTENT: /* 32 bit rel. offset to jump slot >> 1. */
283 if (info->got_initialized == 0) {
284 Elf_Addr *gotent;
286 gotent = me->core_layout.base + me->arch.got_offset +
287 info->got_offset;
288 *gotent = val;
289 info->got_initialized = 1;
291 val = info->got_offset + rela->r_addend;
292 if (r_type == R_390_GOT12 ||
293 r_type == R_390_GOTPLT12)
294 rc = apply_rela_bits(loc, val, 0, 12, 0);
295 else if (r_type == R_390_GOT16 ||
296 r_type == R_390_GOTPLT16)
297 rc = apply_rela_bits(loc, val, 0, 16, 0);
298 else if (r_type == R_390_GOT20 ||
299 r_type == R_390_GOTPLT20)
300 rc = apply_rela_bits(loc, val, 1, 20, 0);
301 else if (r_type == R_390_GOT32 ||
302 r_type == R_390_GOTPLT32)
303 rc = apply_rela_bits(loc, val, 0, 32, 0);
304 else if (r_type == R_390_GOT64 ||
305 r_type == R_390_GOTPLT64)
306 rc = apply_rela_bits(loc, val, 0, 64, 0);
307 else if (r_type == R_390_GOTENT ||
308 r_type == R_390_GOTPLTENT) {
309 val += (Elf_Addr) me->core_layout.base - loc;
310 rc = apply_rela_bits(loc, val, 1, 32, 1);
312 break;
313 case R_390_PLT16DBL: /* 16 bit PC rel. PLT shifted by 1. */
314 case R_390_PLT32DBL: /* 32 bit PC rel. PLT shifted by 1. */
315 case R_390_PLT32: /* 32 bit PC relative PLT address. */
316 case R_390_PLT64: /* 64 bit PC relative PLT address. */
317 case R_390_PLTOFF16: /* 16 bit offset from GOT to PLT. */
318 case R_390_PLTOFF32: /* 32 bit offset from GOT to PLT. */
319 case R_390_PLTOFF64: /* 16 bit offset from GOT to PLT. */
320 if (info->plt_initialized == 0) {
321 unsigned int *ip;
322 ip = me->core_layout.base + me->arch.plt_offset +
323 info->plt_offset;
324 ip[0] = 0x0d10e310; /* basr 1,0; lg 1,10(1); br 1 */
325 ip[1] = 0x100a0004;
326 ip[2] = 0x07f10000;
327 ip[3] = (unsigned int) (val >> 32);
328 ip[4] = (unsigned int) val;
329 info->plt_initialized = 1;
331 if (r_type == R_390_PLTOFF16 ||
332 r_type == R_390_PLTOFF32 ||
333 r_type == R_390_PLTOFF64)
334 val = me->arch.plt_offset - me->arch.got_offset +
335 info->plt_offset + rela->r_addend;
336 else {
337 if (!((r_type == R_390_PLT16DBL &&
338 val - loc + 0xffffUL < 0x1ffffeUL) ||
339 (r_type == R_390_PLT32DBL &&
340 val - loc + 0xffffffffULL < 0x1fffffffeULL)))
341 val = (Elf_Addr) me->core_layout.base +
342 me->arch.plt_offset +
343 info->plt_offset;
344 val += rela->r_addend - loc;
346 if (r_type == R_390_PLT16DBL)
347 rc = apply_rela_bits(loc, val, 1, 16, 1);
348 else if (r_type == R_390_PLTOFF16)
349 rc = apply_rela_bits(loc, val, 0, 16, 0);
350 else if (r_type == R_390_PLT32DBL)
351 rc = apply_rela_bits(loc, val, 1, 32, 1);
352 else if (r_type == R_390_PLT32 ||
353 r_type == R_390_PLTOFF32)
354 rc = apply_rela_bits(loc, val, 0, 32, 0);
355 else if (r_type == R_390_PLT64 ||
356 r_type == R_390_PLTOFF64)
357 rc = apply_rela_bits(loc, val, 0, 64, 0);
358 break;
359 case R_390_GOTOFF16: /* 16 bit offset to GOT. */
360 case R_390_GOTOFF32: /* 32 bit offset to GOT. */
361 case R_390_GOTOFF64: /* 64 bit offset to GOT. */
362 val = val + rela->r_addend -
363 ((Elf_Addr) me->core_layout.base + me->arch.got_offset);
364 if (r_type == R_390_GOTOFF16)
365 rc = apply_rela_bits(loc, val, 0, 16, 0);
366 else if (r_type == R_390_GOTOFF32)
367 rc = apply_rela_bits(loc, val, 0, 32, 0);
368 else if (r_type == R_390_GOTOFF64)
369 rc = apply_rela_bits(loc, val, 0, 64, 0);
370 break;
371 case R_390_GOTPC: /* 32 bit PC relative offset to GOT. */
372 case R_390_GOTPCDBL: /* 32 bit PC rel. off. to GOT shifted by 1. */
373 val = (Elf_Addr) me->core_layout.base + me->arch.got_offset +
374 rela->r_addend - loc;
375 if (r_type == R_390_GOTPC)
376 rc = apply_rela_bits(loc, val, 1, 32, 0);
377 else if (r_type == R_390_GOTPCDBL)
378 rc = apply_rela_bits(loc, val, 1, 32, 1);
379 break;
380 case R_390_COPY:
381 case R_390_GLOB_DAT: /* Create GOT entry. */
382 case R_390_JMP_SLOT: /* Create PLT entry. */
383 case R_390_RELATIVE: /* Adjust by program base. */
384 /* Only needed if we want to support loading of
385 modules linked with -shared. */
386 return -ENOEXEC;
387 default:
388 printk(KERN_ERR "module %s: unknown relocation: %u\n",
389 me->name, r_type);
390 return -ENOEXEC;
392 if (rc) {
393 printk(KERN_ERR "module %s: relocation error for symbol %s "
394 "(r_type %i, value 0x%lx)\n",
395 me->name, strtab + symtab[r_sym].st_name,
396 r_type, (unsigned long) val);
397 return rc;
399 return 0;
402 int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
403 unsigned int symindex, unsigned int relsec,
404 struct module *me)
406 Elf_Addr base;
407 Elf_Sym *symtab;
408 Elf_Rela *rela;
409 unsigned long i, n;
410 int rc;
412 DEBUGP("Applying relocate section %u to %u\n",
413 relsec, sechdrs[relsec].sh_info);
414 base = sechdrs[sechdrs[relsec].sh_info].sh_addr;
415 symtab = (Elf_Sym *) sechdrs[symindex].sh_addr;
416 rela = (Elf_Rela *) sechdrs[relsec].sh_addr;
417 n = sechdrs[relsec].sh_size / sizeof(Elf_Rela);
419 for (i = 0; i < n; i++, rela++) {
420 rc = apply_rela(rela, base, symtab, strtab, me);
421 if (rc)
422 return rc;
424 return 0;
427 int module_finalize(const Elf_Ehdr *hdr,
428 const Elf_Shdr *sechdrs,
429 struct module *me)
431 jump_label_apply_nops(me);
432 return 0;