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_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*);
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
;
101 /* Only needed if we want to support loading of
102 modules linked with -shared. */
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.
112 module_frob_arch_sections(Elf_Ehdr
*hdr
, Elf_Shdr
*sechdrs
,
113 char *secstrings
, struct module
*me
)
121 /* Find symbol table and string table. */
123 for (i
= 0; i
< hdr
->e_shnum
; i
++)
124 switch (sechdrs
[i
].sh_type
) {
126 symtab
= sechdrs
+ i
;
130 printk(KERN_ERR
"module %s: no symbol table\n", me
->name
);
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
)
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;
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
)
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
);
165 /* Increase core size by size of got & plt and set start
166 offsets for got and plt. */
167 me
->core_size
= ALIGN(me
->core_size
, 4);
168 me
->arch
.got_offset
= me
->core_size
;
169 me
->core_size
+= me
->arch
.got_size
;
170 me
->arch
.plt_offset
= me
->core_size
;
171 me
->core_size
+= me
->arch
.plt_size
;
176 apply_relocate(Elf_Shdr
*sechdrs
, const char *strtab
, unsigned int symindex
,
177 unsigned int relsec
, struct module
*me
)
179 printk(KERN_ERR
"module %s: RELOCATION unsupported\n",
185 apply_rela(Elf_Rela
*rela
, Elf_Addr base
, Elf_Sym
*symtab
,
188 struct mod_arch_syminfo
*info
;
192 /* This is where to make the change */
193 loc
= base
+ rela
->r_offset
;
194 /* This is the symbol it is referring to. Note that all
195 undefined symbols have been resolved. */
196 r_sym
= ELF_R_SYM(rela
->r_info
);
197 r_type
= ELF_R_TYPE(rela
->r_info
);
198 info
= me
->arch
.syminfo
+ r_sym
;
199 val
= symtab
[r_sym
].st_value
;
202 case R_390_8
: /* Direct 8 bit. */
203 case R_390_12
: /* Direct 12 bit. */
204 case R_390_16
: /* Direct 16 bit. */
205 case R_390_20
: /* Direct 20 bit. */
206 case R_390_32
: /* Direct 32 bit. */
207 case R_390_64
: /* Direct 64 bit. */
208 val
+= rela
->r_addend
;
209 if (r_type
== R_390_8
)
210 *(unsigned char *) loc
= val
;
211 else if (r_type
== R_390_12
)
212 *(unsigned short *) loc
= (val
& 0xfff) |
213 (*(unsigned short *) loc
& 0xf000);
214 else if (r_type
== R_390_16
)
215 *(unsigned short *) loc
= val
;
216 else if (r_type
== R_390_20
)
217 *(unsigned int *) loc
=
218 (*(unsigned int *) loc
& 0xf00000ff) |
219 (val
& 0xfff) << 16 | (val
& 0xff000) >> 4;
220 else if (r_type
== R_390_32
)
221 *(unsigned int *) loc
= val
;
222 else if (r_type
== R_390_64
)
223 *(unsigned long *) loc
= val
;
225 case R_390_PC16
: /* PC relative 16 bit. */
226 case R_390_PC16DBL
: /* PC relative 16 bit shifted by 1. */
227 case R_390_PC32DBL
: /* PC relative 32 bit shifted by 1. */
228 case R_390_PC32
: /* PC relative 32 bit. */
229 case R_390_PC64
: /* PC relative 64 bit. */
230 val
+= rela
->r_addend
- loc
;
231 if (r_type
== R_390_PC16
)
232 *(unsigned short *) loc
= val
;
233 else if (r_type
== R_390_PC16DBL
)
234 *(unsigned short *) loc
= val
>> 1;
235 else if (r_type
== R_390_PC32DBL
)
236 *(unsigned int *) loc
= val
>> 1;
237 else if (r_type
== R_390_PC32
)
238 *(unsigned int *) loc
= val
;
239 else if (r_type
== R_390_PC64
)
240 *(unsigned long *) loc
= val
;
242 case R_390_GOT12
: /* 12 bit GOT offset. */
243 case R_390_GOT16
: /* 16 bit GOT offset. */
244 case R_390_GOT20
: /* 20 bit GOT offset. */
245 case R_390_GOT32
: /* 32 bit GOT offset. */
246 case R_390_GOT64
: /* 64 bit GOT offset. */
247 case R_390_GOTENT
: /* 32 bit PC rel. to GOT entry shifted by 1. */
248 case R_390_GOTPLT12
: /* 12 bit offset to jump slot. */
249 case R_390_GOTPLT20
: /* 20 bit offset to jump slot. */
250 case R_390_GOTPLT16
: /* 16 bit offset to jump slot. */
251 case R_390_GOTPLT32
: /* 32 bit offset to jump slot. */
252 case R_390_GOTPLT64
: /* 64 bit offset to jump slot. */
253 case R_390_GOTPLTENT
: /* 32 bit rel. offset to jump slot >> 1. */
254 if (info
->got_initialized
== 0) {
257 gotent
= me
->module_core
+ me
->arch
.got_offset
+
260 info
->got_initialized
= 1;
262 val
= info
->got_offset
+ rela
->r_addend
;
263 if (r_type
== R_390_GOT12
||
264 r_type
== R_390_GOTPLT12
)
265 *(unsigned short *) loc
= (val
& 0xfff) |
266 (*(unsigned short *) loc
& 0xf000);
267 else if (r_type
== R_390_GOT16
||
268 r_type
== R_390_GOTPLT16
)
269 *(unsigned short *) loc
= val
;
270 else if (r_type
== R_390_GOT20
||
271 r_type
== R_390_GOTPLT20
)
272 *(unsigned int *) loc
=
273 (*(unsigned int *) loc
& 0xf00000ff) |
274 (val
& 0xfff) << 16 | (val
& 0xff000) >> 4;
275 else if (r_type
== R_390_GOT32
||
276 r_type
== R_390_GOTPLT32
)
277 *(unsigned int *) loc
= val
;
278 else if (r_type
== R_390_GOTENT
||
279 r_type
== R_390_GOTPLTENT
)
280 *(unsigned int *) loc
=
281 (val
+ (Elf_Addr
) me
->module_core
- loc
) >> 1;
282 else if (r_type
== R_390_GOT64
||
283 r_type
== R_390_GOTPLT64
)
284 *(unsigned long *) loc
= val
;
286 case R_390_PLT16DBL
: /* 16 bit PC rel. PLT shifted by 1. */
287 case R_390_PLT32DBL
: /* 32 bit PC rel. PLT shifted by 1. */
288 case R_390_PLT32
: /* 32 bit PC relative PLT address. */
289 case R_390_PLT64
: /* 64 bit PC relative PLT address. */
290 case R_390_PLTOFF16
: /* 16 bit offset from GOT to PLT. */
291 case R_390_PLTOFF32
: /* 32 bit offset from GOT to PLT. */
292 case R_390_PLTOFF64
: /* 16 bit offset from GOT to PLT. */
293 if (info
->plt_initialized
== 0) {
295 ip
= me
->module_core
+ me
->arch
.plt_offset
+
297 #ifndef CONFIG_ARCH_S390X
298 ip
[0] = 0x0d105810; /* basr 1,0; l 1,6(1); br 1 */
301 #else /* CONFIG_ARCH_S390X */
302 ip
[0] = 0x0d10e310; /* basr 1,0; lg 1,10(1); br 1 */
305 ip
[3] = (unsigned int) (val
>> 32);
306 ip
[4] = (unsigned int) val
;
307 #endif /* CONFIG_ARCH_S390X */
308 info
->plt_initialized
= 1;
310 if (r_type
== R_390_PLTOFF16
||
311 r_type
== R_390_PLTOFF32
312 || r_type
== R_390_PLTOFF64
314 val
= me
->arch
.plt_offset
- me
->arch
.got_offset
+
315 info
->plt_offset
+ rela
->r_addend
;
317 val
= (Elf_Addr
) me
->module_core
+
318 me
->arch
.plt_offset
+ info
->plt_offset
+
319 rela
->r_addend
- loc
;
320 if (r_type
== R_390_PLT16DBL
)
321 *(unsigned short *) loc
= val
>> 1;
322 else if (r_type
== R_390_PLTOFF16
)
323 *(unsigned short *) loc
= val
;
324 else if (r_type
== R_390_PLT32DBL
)
325 *(unsigned int *) loc
= val
>> 1;
326 else if (r_type
== R_390_PLT32
||
327 r_type
== R_390_PLTOFF32
)
328 *(unsigned int *) loc
= val
;
329 else if (r_type
== R_390_PLT64
||
330 r_type
== R_390_PLTOFF64
)
331 *(unsigned long *) loc
= val
;
333 case R_390_GOTOFF16
: /* 16 bit offset to GOT. */
334 case R_390_GOTOFF32
: /* 32 bit offset to GOT. */
335 case R_390_GOTOFF64
: /* 64 bit offset to GOT. */
336 val
= val
+ rela
->r_addend
-
337 ((Elf_Addr
) me
->module_core
+ me
->arch
.got_offset
);
338 if (r_type
== R_390_GOTOFF16
)
339 *(unsigned short *) loc
= val
;
340 else if (r_type
== R_390_GOTOFF32
)
341 *(unsigned int *) loc
= val
;
342 else if (r_type
== R_390_GOTOFF64
)
343 *(unsigned long *) loc
= val
;
345 case R_390_GOTPC
: /* 32 bit PC relative offset to GOT. */
346 case R_390_GOTPCDBL
: /* 32 bit PC rel. off. to GOT shifted by 1. */
347 val
= (Elf_Addr
) me
->module_core
+ me
->arch
.got_offset
+
348 rela
->r_addend
- loc
;
349 if (r_type
== R_390_GOTPC
)
350 *(unsigned int *) loc
= val
;
351 else if (r_type
== R_390_GOTPCDBL
)
352 *(unsigned int *) loc
= val
>> 1;
355 case R_390_GLOB_DAT
: /* Create GOT entry. */
356 case R_390_JMP_SLOT
: /* Create PLT entry. */
357 case R_390_RELATIVE
: /* Adjust by program base. */
358 /* Only needed if we want to support loading of
359 modules linked with -shared. */
362 printk(KERN_ERR
"module %s: Unknown relocation: %u\n",
370 apply_relocate_add(Elf_Shdr
*sechdrs
, const char *strtab
,
371 unsigned int symindex
, unsigned int relsec
,
380 DEBUGP("Applying relocate section %u to %u\n",
381 relsec
, sechdrs
[relsec
].sh_info
);
382 base
= sechdrs
[sechdrs
[relsec
].sh_info
].sh_addr
;
383 symtab
= (Elf_Sym
*) sechdrs
[symindex
].sh_addr
;
384 rela
= (Elf_Rela
*) sechdrs
[relsec
].sh_addr
;
385 n
= sechdrs
[relsec
].sh_size
/ sizeof(Elf_Rela
);
387 for (i
= 0; i
< n
; i
++, rela
++) {
388 rc
= apply_rela(rela
, base
, symtab
, me
);
395 int module_finalize(const Elf_Ehdr
*hdr
,
396 const Elf_Shdr
*sechdrs
,
399 vfree(me
->arch
.syminfo
);
403 void module_arch_cleanup(struct module
*mod
)