2 * arch/s390/kernel/module.c - Kernel module help for s390.
5 * Copyright (C) 2002, 2003 IBM Deutschland Entwicklung GmbH,
7 * Author(s): Arnd Bergmann (arndb@de.ibm.com)
8 * Martin Schwidefsky (schwidefsky@de.ibm.com)
10 * based on i386 version
11 * Copyright (C) 2001 Rusty Russell.
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.
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.
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
27 #include <linux/module.h>
28 #include <linux/elf.h>
29 #include <linux/vmalloc.h>
31 #include <linux/string.h>
32 #include <linux/kernel.h>
37 #define DEBUGP(fmt , ...)
40 #ifndef CONFIG_ARCH_S390X
41 #define PLT_ENTRY_SIZE 12
42 #else /* CONFIG_ARCH_S390X */
43 #define PLT_ENTRY_SIZE 20
44 #endif /* CONFIG_ARCH_S390X */
46 void *module_alloc(unsigned long size)
53 /* Free memory returned from module_alloc */
54 void module_free(struct module *mod, void *module_region)
57 /* FIXME: If module_region == mod->init_region, trim exception
62 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_GOT32: /* 32 bit GOT offset. */
71 case R_390_GOT64: /* 64 bit GOT offset. */
72 case R_390_GOTENT: /* 32 bit PC rel. to GOT entry shifted by 1. */
73 case R_390_GOTPLT12: /* 12 bit offset to jump slot. */
74 case R_390_GOTPLT16: /* 16 bit offset to jump slot. */
75 case R_390_GOTPLT32: /* 32 bit offset to jump slot. */
76 case R_390_GOTPLT64: /* 64 bit offset to jump slot. */
77 case R_390_GOTPLTENT: /* 32 bit rel. offset to jump slot >> 1. */
78 if (info->got_offset == -1UL) {
79 info->got_offset = me->arch.got_size;
80 me->arch.got_size += sizeof(void*);
83 case R_390_PLT16DBL: /* 16 bit PC rel. PLT shifted by 1. */
84 case R_390_PLT32DBL: /* 32 bit PC rel. PLT shifted by 1. */
85 case R_390_PLT32: /* 32 bit PC relative PLT address. */
86 case R_390_PLT64: /* 64 bit PC relative PLT address. */
87 case R_390_PLTOFF16: /* 16 bit offset from GOT to PLT. */
88 case R_390_PLTOFF32: /* 32 bit offset from GOT to PLT. */
89 case R_390_PLTOFF64: /* 16 bit offset from GOT to PLT. */
90 if (info->plt_offset == -1UL) {
91 info->plt_offset = me->arch.plt_size;
92 me->arch.plt_size += PLT_ENTRY_SIZE;
99 /* Only needed if we want to support loading of
100 modules linked with -shared. */
106 * Account for GOT and PLT relocations. We can't add sections for
107 * got and plt but we can increase the core module size.
110 module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
111 char *secstrings, struct module *me)
119 /* Find symbol table and string table. */
121 for (i = 0; i < hdr->e_shnum; i++)
122 switch (sechdrs[i].sh_type) {
124 symtab = sechdrs + i;
128 printk(KERN_ERR "module %s: no symbol table\n", me->name);
132 /* Allocate one syminfo structure per symbol. */
133 me->arch.nsyms = symtab->sh_size / sizeof(Elf_Sym);
134 me->arch.syminfo = kmalloc(me->arch.nsyms *
135 sizeof(struct mod_arch_syminfo),
137 if (!me->arch.syminfo)
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)
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_size = ALIGN(me->core_size, 4);
167 me->arch.got_offset = me->core_size;
168 me->core_size += me->arch.got_size;
169 me->arch.plt_offset = me->core_size;
170 me->core_size += me->arch.plt_size;
175 apply_relocate(Elf_Shdr *sechdrs, const char *strtab, unsigned int symindex,
176 unsigned int relsec, struct module *me)
178 printk(KERN_ERR "module %s: RELOCATION unsupported\n",
184 apply_rela(Elf_Rela *rela, Elf_Addr base, Elf_Sym *symtab,
187 struct mod_arch_syminfo *info;
191 /* This is where to make the change */
192 loc = base + rela->r_offset;
193 /* This is the symbol it is referring to. Note that all
194 undefined symbols have been resolved. */
195 r_sym = ELF_R_SYM(rela->r_info);
196 r_type = ELF_R_TYPE(rela->r_info);
197 info = me->arch.syminfo + r_sym;
198 val = symtab[r_sym].st_value;
201 case R_390_8: /* Direct 8 bit. */
202 case R_390_12: /* Direct 12 bit. */
203 case R_390_16: /* Direct 16 bit. */
204 case R_390_32: /* Direct 32 bit. */
205 case R_390_64: /* Direct 64 bit. */
206 val += rela->r_addend;
207 if (r_type == R_390_8)
208 *(unsigned char *) loc = val;
209 else if (r_type == R_390_12)
210 *(unsigned short *) loc = (val & 0xfff) |
211 (*(unsigned short *) loc & 0xf000);
212 else if (r_type == R_390_16)
213 *(unsigned short *) loc = val;
214 else if (r_type == R_390_32)
215 *(unsigned int *) loc = val;
216 else if (r_type == R_390_64)
217 *(unsigned long *) loc = val;
219 case R_390_PC16: /* PC relative 16 bit. */
220 case R_390_PC16DBL: /* PC relative 16 bit shifted by 1. */
221 case R_390_PC32DBL: /* PC relative 32 bit shifted by 1. */
222 case R_390_PC32: /* PC relative 32 bit. */
223 case R_390_PC64: /* PC relative 64 bit. */
224 val += rela->r_addend - loc;
225 if (r_type == R_390_PC16)
226 *(unsigned short *) loc = val;
227 else if (r_type == R_390_PC16DBL)
228 *(unsigned short *) loc = val >> 1;
229 else if (r_type == R_390_PC32DBL)
230 *(unsigned int *) loc = val >> 1;
231 else if (r_type == R_390_PC32)
232 *(unsigned int *) loc = val;
233 else if (r_type == R_390_PC64)
234 *(unsigned long *) loc = val;
236 case R_390_GOT12: /* 12 bit GOT offset. */
237 case R_390_GOT16: /* 16 bit GOT offset. */
238 case R_390_GOT32: /* 32 bit GOT offset. */
239 case R_390_GOT64: /* 64 bit GOT offset. */
240 case R_390_GOTENT: /* 32 bit PC rel. to GOT entry shifted by 1. */
241 case R_390_GOTPLT12: /* 12 bit offset to jump slot. */
242 case R_390_GOTPLT16: /* 16 bit offset to jump slot. */
243 case R_390_GOTPLT32: /* 32 bit offset to jump slot. */
244 case R_390_GOTPLT64: /* 64 bit offset to jump slot. */
245 case R_390_GOTPLTENT: /* 32 bit rel. offset to jump slot >> 1. */
246 if (info->got_initialized == 0) {
249 gotent = me->module_core + me->arch.got_offset +
252 info->got_initialized = 1;
254 val = info->got_offset + rela->r_addend;
255 if (r_type == R_390_GOT12 ||
256 r_type == R_390_GOTPLT12)
257 *(unsigned short *) loc = (val & 0xfff) |
258 (*(unsigned short *) loc & 0xf000);
259 else if (r_type == R_390_GOT16 ||
260 r_type == R_390_GOTPLT16)
261 *(unsigned short *) loc = val;
262 else if (r_type == R_390_GOT32 ||
263 r_type == R_390_GOTPLT32)
264 *(unsigned int *) loc = val;
265 else if (r_type == R_390_GOTENT ||
266 r_type == R_390_GOTPLTENT)
267 *(unsigned int *) loc = val >> 1;
268 else if (r_type == R_390_GOT64 ||
269 r_type == R_390_GOTPLT64)
270 *(unsigned long *) loc = val;
272 case R_390_PLT16DBL: /* 16 bit PC rel. PLT shifted by 1. */
273 case R_390_PLT32DBL: /* 32 bit PC rel. PLT shifted by 1. */
274 case R_390_PLT32: /* 32 bit PC relative PLT address. */
275 case R_390_PLT64: /* 64 bit PC relative PLT address. */
276 case R_390_PLTOFF16: /* 16 bit offset from GOT to PLT. */
277 case R_390_PLTOFF32: /* 32 bit offset from GOT to PLT. */
278 case R_390_PLTOFF64: /* 16 bit offset from GOT to PLT. */
279 if (info->plt_initialized == 0) {
281 ip = me->module_core + me->arch.plt_offset +
283 #ifndef CONFIG_ARCH_S390X
284 ip[0] = 0x0d105810; /* basr 1,0; l 1,6(1); br 1 */
287 #else /* CONFIG_ARCH_S390X */
288 ip[0] = 0x0d10e310; /* basr 1,0; lg 1,10(1); br 1 */
291 ip[3] = (unsigned int) (val >> 32);
292 ip[4] = (unsigned int) val;
293 #endif /* CONFIG_ARCH_S390X */
294 info->plt_initialized = 1;
296 if (r_type == R_390_PLTOFF16 ||
297 r_type == R_390_PLTOFF32
298 || r_type == R_390_PLTOFF64
300 val = me->arch.plt_offset - me->arch.got_offset +
301 info->plt_offset + rela->r_addend;
303 val = (Elf_Addr) me->module_core +
304 me->arch.plt_offset + info->plt_offset +
305 rela->r_addend - loc;
306 if (r_type == R_390_PLT16DBL)
307 *(unsigned short *) loc = val >> 1;
308 else if (r_type == R_390_PLTOFF16)
309 *(unsigned short *) loc = val;
310 else if (r_type == R_390_PLT32DBL)
311 *(unsigned int *) loc = val >> 1;
312 else if (r_type == R_390_PLT32 ||
313 r_type == R_390_PLTOFF32)
314 *(unsigned int *) loc = val;
315 else if (r_type == R_390_PLT64 ||
316 r_type == R_390_PLTOFF64)
317 *(unsigned long *) loc = val;
319 case R_390_GOTOFF16: /* 16 bit offset to GOT. */
320 case R_390_GOTOFF32: /* 32 bit offset to GOT. */
321 case R_390_GOTOFF64: /* 64 bit offset to GOT. */
322 val = val + rela->r_addend -
323 ((Elf_Addr) me->module_core + me->arch.got_offset);
324 if (r_type == R_390_GOTOFF16)
325 *(unsigned short *) loc = val;
326 else if (r_type == R_390_GOTOFF32)
327 *(unsigned int *) loc = val;
328 else if (r_type == R_390_GOTOFF64)
329 *(unsigned long *) loc = val;
331 case R_390_GOTPC: /* 32 bit PC relative offset to GOT. */
332 case R_390_GOTPCDBL: /* 32 bit PC rel. off. to GOT shifted by 1. */
333 val = (Elf_Addr) me->module_core + me->arch.got_offset +
334 rela->r_addend - loc;
335 if (r_type == R_390_GOTPC)
336 *(unsigned int *) loc = val;
337 else if (r_type == R_390_GOTPCDBL)
338 *(unsigned int *) loc = val >> 1;
341 case R_390_GLOB_DAT: /* Create GOT entry. */
342 case R_390_JMP_SLOT: /* Create PLT entry. */
343 case R_390_RELATIVE: /* Adjust by program base. */
344 /* Only needed if we want to support loading of
345 modules linked with -shared. */
348 printk(KERN_ERR "module %s: Unknown relocation: %u\n",
356 apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
357 unsigned int symindex, unsigned int relsec,
366 DEBUGP("Applying relocate section %u to %u\n",
367 relsec, sechdrs[relsec].sh_info);
368 base = sechdrs[sechdrs[relsec].sh_info].sh_addr;
369 symtab = (Elf_Sym *) sechdrs[symindex].sh_addr;
370 rela = (Elf_Rela *) sechdrs[relsec].sh_addr;
371 n = sechdrs[relsec].sh_size / sizeof(Elf_Rela);
373 for (i = 0; i < n; i++, rela++) {
374 rc = apply_rela(rela, base, symtab, me);
381 int module_finalize(const Elf_Ehdr *hdr,
382 const Elf_Shdr *sechdrs,
385 if (me->arch.syminfo)
386 kfree(me->arch.syminfo);