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1da177e4 LT |
1 | /* |
2 | * arch/s390/kernel/module.c - Kernel module help for s390. | |
3 | * | |
4 | * S390 version | |
5 | * Copyright (C) 2002, 2003 IBM Deutschland Entwicklung GmbH, | |
6 | * IBM Corporation | |
7 | * Author(s): Arnd Bergmann (arndb@de.ibm.com) | |
8 | * Martin Schwidefsky (schwidefsky@de.ibm.com) | |
9 | * | |
10 | * based on i386 version | |
11 | * Copyright (C) 2001 Rusty Russell. | |
12 | * | |
13 | * This program is free software; you can redistribute it and/or modify | |
14 | * it under the terms of the GNU General Public License as published by | |
15 | * the Free Software Foundation; either version 2 of the License, or | |
16 | * (at your option) any later version. | |
17 | * | |
18 | * This program is distributed in the hope that it will be useful, | |
19 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
20 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
21 | * GNU General Public License for more details. | |
22 | * | |
23 | * You should have received a copy of the GNU General Public License | |
24 | * along with this program; if not, write to the Free Software | |
25 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
26 | */ | |
27 | #include <linux/module.h> | |
28 | #include <linux/elf.h> | |
29 | #include <linux/vmalloc.h> | |
30 | #include <linux/fs.h> | |
31 | #include <linux/string.h> | |
32 | #include <linux/kernel.h> | |
2b67fc46 | 33 | #include <linux/moduleloader.h> |
c0007f1a | 34 | #include <linux/bug.h> |
1da177e4 LT |
35 | |
36 | #if 0 | |
37 | #define DEBUGP printk | |
38 | #else | |
39 | #define DEBUGP(fmt , ...) | |
40 | #endif | |
41 | ||
347a8dc3 | 42 | #ifndef CONFIG_64BIT |
1da177e4 | 43 | #define PLT_ENTRY_SIZE 12 |
347a8dc3 | 44 | #else /* CONFIG_64BIT */ |
1da177e4 | 45 | #define PLT_ENTRY_SIZE 20 |
347a8dc3 | 46 | #endif /* CONFIG_64BIT */ |
1da177e4 | 47 | |
1da177e4 LT |
48 | /* Free memory returned from module_alloc */ |
49 | void module_free(struct module *mod, void *module_region) | |
50 | { | |
3164a3cb HB |
51 | if (mod) { |
52 | vfree(mod->arch.syminfo); | |
53 | mod->arch.syminfo = NULL; | |
54 | } | |
1da177e4 | 55 | vfree(module_region); |
1da177e4 LT |
56 | } |
57 | ||
4d284cac | 58 | static void |
1da177e4 LT |
59 | check_rela(Elf_Rela *rela, struct module *me) |
60 | { | |
61 | struct mod_arch_syminfo *info; | |
62 | ||
63 | info = me->arch.syminfo + ELF_R_SYM (rela->r_info); | |
64 | switch (ELF_R_TYPE (rela->r_info)) { | |
65 | case R_390_GOT12: /* 12 bit GOT offset. */ | |
66 | case R_390_GOT16: /* 16 bit GOT offset. */ | |
67 | case R_390_GOT20: /* 20 bit GOT offset. */ | |
68 | case R_390_GOT32: /* 32 bit GOT offset. */ | |
69 | case R_390_GOT64: /* 64 bit GOT offset. */ | |
70 | case R_390_GOTENT: /* 32 bit PC rel. to GOT entry shifted by 1. */ | |
71 | case R_390_GOTPLT12: /* 12 bit offset to jump slot. */ | |
72 | case R_390_GOTPLT16: /* 16 bit offset to jump slot. */ | |
73 | case R_390_GOTPLT20: /* 20 bit offset to jump slot. */ | |
74 | case R_390_GOTPLT32: /* 32 bit offset to jump slot. */ | |
75 | case R_390_GOTPLT64: /* 64 bit offset to jump slot. */ | |
76 | case R_390_GOTPLTENT: /* 32 bit rel. offset to jump slot >> 1. */ | |
77 | if (info->got_offset == -1UL) { | |
78 | info->got_offset = me->arch.got_size; | |
79 | me->arch.got_size += sizeof(void*); | |
80 | } | |
81 | break; | |
82 | case R_390_PLT16DBL: /* 16 bit PC rel. PLT shifted by 1. */ | |
83 | case R_390_PLT32DBL: /* 32 bit PC rel. PLT shifted by 1. */ | |
84 | case R_390_PLT32: /* 32 bit PC relative PLT address. */ | |
85 | case R_390_PLT64: /* 64 bit PC relative PLT address. */ | |
86 | case R_390_PLTOFF16: /* 16 bit offset from GOT to PLT. */ | |
87 | case R_390_PLTOFF32: /* 32 bit offset from GOT to PLT. */ | |
88 | case R_390_PLTOFF64: /* 16 bit offset from GOT to PLT. */ | |
89 | if (info->plt_offset == -1UL) { | |
90 | info->plt_offset = me->arch.plt_size; | |
91 | me->arch.plt_size += PLT_ENTRY_SIZE; | |
92 | } | |
93 | break; | |
94 | case R_390_COPY: | |
95 | case R_390_GLOB_DAT: | |
96 | case R_390_JMP_SLOT: | |
97 | case R_390_RELATIVE: | |
98 | /* Only needed if we want to support loading of | |
99 | modules linked with -shared. */ | |
100 | break; | |
101 | } | |
102 | } | |
103 | ||
104 | /* | |
105 | * Account for GOT and PLT relocations. We can't add sections for | |
106 | * got and plt but we can increase the core module size. | |
107 | */ | |
108 | int | |
109 | module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs, | |
110 | char *secstrings, struct module *me) | |
111 | { | |
112 | Elf_Shdr *symtab; | |
113 | Elf_Sym *symbols; | |
114 | Elf_Rela *rela; | |
115 | char *strings; | |
116 | int nrela, i, j; | |
117 | ||
118 | /* Find symbol table and string table. */ | |
d2c993d8 | 119 | symtab = NULL; |
1da177e4 LT |
120 | for (i = 0; i < hdr->e_shnum; i++) |
121 | switch (sechdrs[i].sh_type) { | |
122 | case SHT_SYMTAB: | |
123 | symtab = sechdrs + i; | |
124 | break; | |
125 | } | |
126 | if (!symtab) { | |
127 | printk(KERN_ERR "module %s: no symbol table\n", me->name); | |
128 | return -ENOEXEC; | |
129 | } | |
130 | ||
131 | /* Allocate one syminfo structure per symbol. */ | |
132 | me->arch.nsyms = symtab->sh_size / sizeof(Elf_Sym); | |
133 | me->arch.syminfo = vmalloc(me->arch.nsyms * | |
134 | sizeof(struct mod_arch_syminfo)); | |
135 | if (!me->arch.syminfo) | |
136 | return -ENOMEM; | |
137 | symbols = (void *) hdr + symtab->sh_offset; | |
138 | strings = (void *) hdr + sechdrs[symtab->sh_link].sh_offset; | |
139 | for (i = 0; i < me->arch.nsyms; i++) { | |
140 | if (symbols[i].st_shndx == SHN_UNDEF && | |
141 | strcmp(strings + symbols[i].st_name, | |
142 | "_GLOBAL_OFFSET_TABLE_") == 0) | |
143 | /* "Define" it as absolute. */ | |
144 | symbols[i].st_shndx = SHN_ABS; | |
145 | me->arch.syminfo[i].got_offset = -1UL; | |
146 | me->arch.syminfo[i].plt_offset = -1UL; | |
147 | me->arch.syminfo[i].got_initialized = 0; | |
148 | me->arch.syminfo[i].plt_initialized = 0; | |
149 | } | |
150 | ||
151 | /* Search for got/plt relocations. */ | |
152 | me->arch.got_size = me->arch.plt_size = 0; | |
153 | for (i = 0; i < hdr->e_shnum; i++) { | |
154 | if (sechdrs[i].sh_type != SHT_RELA) | |
155 | continue; | |
156 | nrela = sechdrs[i].sh_size / sizeof(Elf_Rela); | |
157 | rela = (void *) hdr + sechdrs[i].sh_offset; | |
158 | for (j = 0; j < nrela; j++) | |
159 | check_rela(rela + j, me); | |
160 | } | |
161 | ||
162 | /* Increase core size by size of got & plt and set start | |
163 | offsets for got and plt. */ | |
164 | me->core_size = ALIGN(me->core_size, 4); | |
165 | me->arch.got_offset = me->core_size; | |
166 | me->core_size += me->arch.got_size; | |
167 | me->arch.plt_offset = me->core_size; | |
168 | me->core_size += me->arch.plt_size; | |
169 | return 0; | |
170 | } | |
171 | ||
4d284cac | 172 | static int |
1da177e4 LT |
173 | apply_rela(Elf_Rela *rela, Elf_Addr base, Elf_Sym *symtab, |
174 | struct module *me) | |
175 | { | |
176 | struct mod_arch_syminfo *info; | |
177 | Elf_Addr loc, val; | |
178 | int r_type, r_sym; | |
179 | ||
180 | /* This is where to make the change */ | |
181 | loc = base + rela->r_offset; | |
182 | /* This is the symbol it is referring to. Note that all | |
183 | undefined symbols have been resolved. */ | |
184 | r_sym = ELF_R_SYM(rela->r_info); | |
185 | r_type = ELF_R_TYPE(rela->r_info); | |
186 | info = me->arch.syminfo + r_sym; | |
187 | val = symtab[r_sym].st_value; | |
188 | ||
189 | switch (r_type) { | |
190 | case R_390_8: /* Direct 8 bit. */ | |
191 | case R_390_12: /* Direct 12 bit. */ | |
192 | case R_390_16: /* Direct 16 bit. */ | |
193 | case R_390_20: /* Direct 20 bit. */ | |
194 | case R_390_32: /* Direct 32 bit. */ | |
195 | case R_390_64: /* Direct 64 bit. */ | |
196 | val += rela->r_addend; | |
197 | if (r_type == R_390_8) | |
198 | *(unsigned char *) loc = val; | |
199 | else if (r_type == R_390_12) | |
200 | *(unsigned short *) loc = (val & 0xfff) | | |
201 | (*(unsigned short *) loc & 0xf000); | |
202 | else if (r_type == R_390_16) | |
203 | *(unsigned short *) loc = val; | |
204 | else if (r_type == R_390_20) | |
205 | *(unsigned int *) loc = | |
206 | (*(unsigned int *) loc & 0xf00000ff) | | |
207 | (val & 0xfff) << 16 | (val & 0xff000) >> 4; | |
208 | else if (r_type == R_390_32) | |
209 | *(unsigned int *) loc = val; | |
210 | else if (r_type == R_390_64) | |
211 | *(unsigned long *) loc = val; | |
212 | break; | |
213 | case R_390_PC16: /* PC relative 16 bit. */ | |
214 | case R_390_PC16DBL: /* PC relative 16 bit shifted by 1. */ | |
215 | case R_390_PC32DBL: /* PC relative 32 bit shifted by 1. */ | |
216 | case R_390_PC32: /* PC relative 32 bit. */ | |
217 | case R_390_PC64: /* PC relative 64 bit. */ | |
218 | val += rela->r_addend - loc; | |
219 | if (r_type == R_390_PC16) | |
220 | *(unsigned short *) loc = val; | |
221 | else if (r_type == R_390_PC16DBL) | |
222 | *(unsigned short *) loc = val >> 1; | |
223 | else if (r_type == R_390_PC32DBL) | |
224 | *(unsigned int *) loc = val >> 1; | |
225 | else if (r_type == R_390_PC32) | |
226 | *(unsigned int *) loc = val; | |
227 | else if (r_type == R_390_PC64) | |
228 | *(unsigned long *) loc = val; | |
229 | break; | |
230 | case R_390_GOT12: /* 12 bit GOT offset. */ | |
231 | case R_390_GOT16: /* 16 bit GOT offset. */ | |
232 | case R_390_GOT20: /* 20 bit GOT offset. */ | |
233 | case R_390_GOT32: /* 32 bit GOT offset. */ | |
234 | case R_390_GOT64: /* 64 bit GOT offset. */ | |
235 | case R_390_GOTENT: /* 32 bit PC rel. to GOT entry shifted by 1. */ | |
236 | case R_390_GOTPLT12: /* 12 bit offset to jump slot. */ | |
237 | case R_390_GOTPLT20: /* 20 bit offset to jump slot. */ | |
238 | case R_390_GOTPLT16: /* 16 bit offset to jump slot. */ | |
239 | case R_390_GOTPLT32: /* 32 bit offset to jump slot. */ | |
240 | case R_390_GOTPLT64: /* 64 bit offset to jump slot. */ | |
241 | case R_390_GOTPLTENT: /* 32 bit rel. offset to jump slot >> 1. */ | |
242 | if (info->got_initialized == 0) { | |
243 | Elf_Addr *gotent; | |
244 | ||
245 | gotent = me->module_core + me->arch.got_offset + | |
246 | info->got_offset; | |
247 | *gotent = val; | |
248 | info->got_initialized = 1; | |
249 | } | |
250 | val = info->got_offset + rela->r_addend; | |
251 | if (r_type == R_390_GOT12 || | |
252 | r_type == R_390_GOTPLT12) | |
253 | *(unsigned short *) loc = (val & 0xfff) | | |
254 | (*(unsigned short *) loc & 0xf000); | |
255 | else if (r_type == R_390_GOT16 || | |
256 | r_type == R_390_GOTPLT16) | |
257 | *(unsigned short *) loc = val; | |
258 | else if (r_type == R_390_GOT20 || | |
259 | r_type == R_390_GOTPLT20) | |
260 | *(unsigned int *) loc = | |
261 | (*(unsigned int *) loc & 0xf00000ff) | | |
262 | (val & 0xfff) << 16 | (val & 0xff000) >> 4; | |
263 | else if (r_type == R_390_GOT32 || | |
264 | r_type == R_390_GOTPLT32) | |
265 | *(unsigned int *) loc = val; | |
266 | else if (r_type == R_390_GOTENT || | |
267 | r_type == R_390_GOTPLTENT) | |
268 | *(unsigned int *) loc = | |
269 | (val + (Elf_Addr) me->module_core - loc) >> 1; | |
270 | else if (r_type == R_390_GOT64 || | |
271 | r_type == R_390_GOTPLT64) | |
272 | *(unsigned long *) loc = val; | |
273 | break; | |
274 | case R_390_PLT16DBL: /* 16 bit PC rel. PLT shifted by 1. */ | |
275 | case R_390_PLT32DBL: /* 32 bit PC rel. PLT shifted by 1. */ | |
276 | case R_390_PLT32: /* 32 bit PC relative PLT address. */ | |
277 | case R_390_PLT64: /* 64 bit PC relative PLT address. */ | |
278 | case R_390_PLTOFF16: /* 16 bit offset from GOT to PLT. */ | |
279 | case R_390_PLTOFF32: /* 32 bit offset from GOT to PLT. */ | |
280 | case R_390_PLTOFF64: /* 16 bit offset from GOT to PLT. */ | |
281 | if (info->plt_initialized == 0) { | |
282 | unsigned int *ip; | |
283 | ip = me->module_core + me->arch.plt_offset + | |
284 | info->plt_offset; | |
347a8dc3 | 285 | #ifndef CONFIG_64BIT |
1da177e4 LT |
286 | ip[0] = 0x0d105810; /* basr 1,0; l 1,6(1); br 1 */ |
287 | ip[1] = 0x100607f1; | |
288 | ip[2] = val; | |
347a8dc3 | 289 | #else /* CONFIG_64BIT */ |
1da177e4 LT |
290 | ip[0] = 0x0d10e310; /* basr 1,0; lg 1,10(1); br 1 */ |
291 | ip[1] = 0x100a0004; | |
292 | ip[2] = 0x07f10000; | |
293 | ip[3] = (unsigned int) (val >> 32); | |
294 | ip[4] = (unsigned int) val; | |
347a8dc3 | 295 | #endif /* CONFIG_64BIT */ |
1da177e4 LT |
296 | info->plt_initialized = 1; |
297 | } | |
298 | if (r_type == R_390_PLTOFF16 || | |
504665a9 MS |
299 | r_type == R_390_PLTOFF32 || |
300 | r_type == R_390_PLTOFF64) | |
1da177e4 LT |
301 | val = me->arch.plt_offset - me->arch.got_offset + |
302 | info->plt_offset + rela->r_addend; | |
504665a9 MS |
303 | else { |
304 | if (!((r_type == R_390_PLT16DBL && | |
305 | val - loc + 0xffffUL < 0x1ffffeUL) || | |
306 | (r_type == R_390_PLT32DBL && | |
307 | val - loc + 0xffffffffULL < 0x1fffffffeULL))) | |
308 | val = (Elf_Addr) me->module_core + | |
309 | me->arch.plt_offset + | |
310 | info->plt_offset; | |
311 | val += rela->r_addend - loc; | |
312 | } | |
1da177e4 LT |
313 | if (r_type == R_390_PLT16DBL) |
314 | *(unsigned short *) loc = val >> 1; | |
315 | else if (r_type == R_390_PLTOFF16) | |
316 | *(unsigned short *) loc = val; | |
317 | else if (r_type == R_390_PLT32DBL) | |
318 | *(unsigned int *) loc = val >> 1; | |
319 | else if (r_type == R_390_PLT32 || | |
320 | r_type == R_390_PLTOFF32) | |
321 | *(unsigned int *) loc = val; | |
322 | else if (r_type == R_390_PLT64 || | |
323 | r_type == R_390_PLTOFF64) | |
324 | *(unsigned long *) loc = val; | |
325 | break; | |
326 | case R_390_GOTOFF16: /* 16 bit offset to GOT. */ | |
327 | case R_390_GOTOFF32: /* 32 bit offset to GOT. */ | |
328 | case R_390_GOTOFF64: /* 64 bit offset to GOT. */ | |
329 | val = val + rela->r_addend - | |
330 | ((Elf_Addr) me->module_core + me->arch.got_offset); | |
331 | if (r_type == R_390_GOTOFF16) | |
332 | *(unsigned short *) loc = val; | |
333 | else if (r_type == R_390_GOTOFF32) | |
334 | *(unsigned int *) loc = val; | |
335 | else if (r_type == R_390_GOTOFF64) | |
336 | *(unsigned long *) loc = val; | |
337 | break; | |
338 | case R_390_GOTPC: /* 32 bit PC relative offset to GOT. */ | |
339 | case R_390_GOTPCDBL: /* 32 bit PC rel. off. to GOT shifted by 1. */ | |
340 | val = (Elf_Addr) me->module_core + me->arch.got_offset + | |
341 | rela->r_addend - loc; | |
342 | if (r_type == R_390_GOTPC) | |
343 | *(unsigned int *) loc = val; | |
344 | else if (r_type == R_390_GOTPCDBL) | |
345 | *(unsigned int *) loc = val >> 1; | |
346 | break; | |
347 | case R_390_COPY: | |
348 | case R_390_GLOB_DAT: /* Create GOT entry. */ | |
349 | case R_390_JMP_SLOT: /* Create PLT entry. */ | |
350 | case R_390_RELATIVE: /* Adjust by program base. */ | |
351 | /* Only needed if we want to support loading of | |
352 | modules linked with -shared. */ | |
353 | break; | |
354 | default: | |
355 | printk(KERN_ERR "module %s: Unknown relocation: %u\n", | |
356 | me->name, r_type); | |
357 | return -ENOEXEC; | |
358 | } | |
359 | return 0; | |
360 | } | |
361 | ||
362 | int | |
363 | apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab, | |
364 | unsigned int symindex, unsigned int relsec, | |
365 | struct module *me) | |
366 | { | |
367 | Elf_Addr base; | |
368 | Elf_Sym *symtab; | |
369 | Elf_Rela *rela; | |
370 | unsigned long i, n; | |
371 | int rc; | |
372 | ||
373 | DEBUGP("Applying relocate section %u to %u\n", | |
374 | relsec, sechdrs[relsec].sh_info); | |
375 | base = sechdrs[sechdrs[relsec].sh_info].sh_addr; | |
376 | symtab = (Elf_Sym *) sechdrs[symindex].sh_addr; | |
377 | rela = (Elf_Rela *) sechdrs[relsec].sh_addr; | |
378 | n = sechdrs[relsec].sh_size / sizeof(Elf_Rela); | |
379 | ||
380 | for (i = 0; i < n; i++, rela++) { | |
381 | rc = apply_rela(rela, base, symtab, me); | |
382 | if (rc) | |
383 | return rc; | |
384 | } | |
385 | return 0; | |
386 | } | |
387 | ||
388 | int module_finalize(const Elf_Ehdr *hdr, | |
389 | const Elf_Shdr *sechdrs, | |
390 | struct module *me) | |
391 | { | |
392 | vfree(me->arch.syminfo); | |
6a03f5f0 | 393 | me->arch.syminfo = NULL; |
5336377d | 394 | return 0; |
1da177e4 | 395 | } |