module: cleanup FIXME comments about trimming exception table entries.
[linux-2.6.git] / arch / m32r / kernel / module.c
1 /*  Kernel module help for M32R.
2
3     This program is free software; you can redistribute it and/or modify
4     it under the terms of the GNU General Public License as published by
5     the Free Software Foundation; either version 2 of the License, or
6     (at your option) any later version.
7
8     This program is distributed in the hope that it will be useful,
9     but WITHOUT ANY WARRANTY; without even the implied warranty of
10     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11     GNU General Public License for more details.
12
13     You should have received a copy of the GNU General Public License
14     along with this program; if not, write to the Free Software
15     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
16 */
17
18 #include <linux/moduleloader.h>
19 #include <linux/elf.h>
20 #include <linux/vmalloc.h>
21 #include <linux/fs.h>
22 #include <linux/string.h>
23 #include <linux/kernel.h>
24
25 #if 0
26 #define DEBUGP printk
27 #else
28 #define DEBUGP(fmt...)
29 #endif
30
31 void *module_alloc(unsigned long size)
32 {
33         if (size == 0)
34                 return NULL;
35 #ifdef CONFIG_MMU
36         return vmalloc_exec(size);
37 #else
38         return vmalloc(size);
39 #endif
40 }
41
42
43 /* Free memory returned from module_alloc */
44 void module_free(struct module *mod, void *module_region)
45 {
46         vfree(module_region);
47 }
48
49 /* We don't need anything special. */
50 int module_frob_arch_sections(Elf_Ehdr *hdr,
51                               Elf_Shdr *sechdrs,
52                               char *secstrings,
53                               struct module *mod)
54 {
55         return 0;
56 }
57
58 #define COPY_UNALIGNED_WORD(sw, tw, align) \
59 { \
60         void *__s = &(sw), *__t = &(tw); \
61         unsigned short *__s2 = __s, *__t2 =__t; \
62         unsigned char *__s1 = __s, *__t1 =__t; \
63         switch ((align)) \
64         { \
65         case 0: \
66                 *(unsigned long *) __t = *(unsigned long *) __s; \
67                 break; \
68         case 2: \
69                 *__t2++ = *__s2++; \
70                 *__t2 = *__s2; \
71                 break; \
72         default: \
73                 *__t1++ = *__s1++; \
74                 *__t1++ = *__s1++; \
75                 *__t1++ = *__s1++; \
76                 *__t1 = *__s1; \
77                 break; \
78         } \
79 }
80
81 #define COPY_UNALIGNED_HWORD(sw, tw, align) \
82   { \
83     void *__s = &(sw), *__t = &(tw); \
84     unsigned short *__s2 = __s, *__t2 =__t; \
85     unsigned char *__s1 = __s, *__t1 =__t; \
86     switch ((align)) \
87     { \
88     case 0: \
89       *__t2 = *__s2; \
90       break; \
91     default: \
92       *__t1++ = *__s1++; \
93       *__t1 = *__s1; \
94       break; \
95     } \
96   }
97
98 int apply_relocate_add(Elf32_Shdr *sechdrs,
99                    const char *strtab,
100                    unsigned int symindex,
101                    unsigned int relsec,
102                    struct module *me)
103 {
104         unsigned int i;
105         Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr;
106         Elf32_Sym *sym;
107         Elf32_Addr relocation;
108         uint32_t *location;
109         uint32_t value;
110         unsigned short *hlocation;
111         unsigned short hvalue;
112         int svalue;
113         int align;
114
115         DEBUGP("Applying relocate section %u to %u\n", relsec,
116                sechdrs[relsec].sh_info);
117         for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
118                 /* This is where to make the change */
119                 location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
120                         + rel[i].r_offset;
121                 /* This is the symbol it is referring to.  Note that all
122                    undefined symbols have been resolved.  */
123                 sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
124                         + ELF32_R_SYM(rel[i].r_info);
125                 relocation = sym->st_value + rel[i].r_addend;
126                 align = (int)location & 3;
127
128                 switch (ELF32_R_TYPE(rel[i].r_info)) {
129                 case R_M32R_32_RELA:
130                         COPY_UNALIGNED_WORD (*location, value, align);
131                         value += relocation;
132                         COPY_UNALIGNED_WORD (value, *location, align);
133                         break;
134                 case R_M32R_HI16_ULO_RELA:
135                         COPY_UNALIGNED_WORD (*location, value, align);
136                         relocation = (relocation >>16) & 0xffff;
137                         /* RELA must has 0 at relocation field. */
138                         value += relocation;
139                         COPY_UNALIGNED_WORD (value, *location, align);
140                         break;
141                 case R_M32R_HI16_SLO_RELA:
142                         COPY_UNALIGNED_WORD (*location, value, align);
143                         if (relocation & 0x8000) relocation += 0x10000;
144                         relocation = (relocation >>16) & 0xffff;
145                         /* RELA must has 0 at relocation field. */
146                         value += relocation;
147                         COPY_UNALIGNED_WORD (value, *location, align);
148                         break;
149                 case R_M32R_16_RELA:
150                         hlocation = (unsigned short *)location;
151                         relocation = relocation & 0xffff;
152                         /* RELA must has 0 at relocation field. */
153                         hvalue = relocation;
154                         COPY_UNALIGNED_WORD (hvalue, *hlocation, align);
155                         break;
156                 case R_M32R_SDA16_RELA:
157                 case R_M32R_LO16_RELA:
158                         COPY_UNALIGNED_WORD (*location, value, align);
159                         relocation = relocation & 0xffff;
160                         /* RELA must has 0 at relocation field. */
161                         value += relocation;
162                         COPY_UNALIGNED_WORD (value, *location, align);
163                         break;
164                 case R_M32R_24_RELA:
165                         COPY_UNALIGNED_WORD (*location, value, align);
166                         relocation = relocation & 0xffffff;
167                         /* RELA must has 0 at relocation field. */
168                         value += relocation;
169                         COPY_UNALIGNED_WORD (value, *location, align);
170                         break;
171                 case R_M32R_18_PCREL_RELA:
172                         relocation = (relocation - (Elf32_Addr) location);
173                         if (relocation < -0x20000 || 0x1fffc < relocation)
174                                 {
175                                         printk(KERN_ERR "module %s: relocation overflow: %u\n",
176                                         me->name, relocation);
177                                         return -ENOEXEC;
178                                 }
179                         COPY_UNALIGNED_WORD (*location, value, align);
180                         if (value & 0xffff)
181                                 {
182                                         /* RELA must has 0 at relocation field. */
183                                         printk(KERN_ERR "module %s: illegal relocation field: %u\n",
184                                         me->name, value);
185                                         return -ENOEXEC;
186                                 }
187                         relocation = (relocation >> 2) & 0xffff;
188                         value += relocation;
189                         COPY_UNALIGNED_WORD (value, *location, align);
190                         break;
191                 case R_M32R_10_PCREL_RELA:
192                         hlocation = (unsigned short *)location;
193                         relocation = (relocation - (Elf32_Addr) location);
194                         COPY_UNALIGNED_HWORD (*hlocation, hvalue, align);
195                         svalue = (int)hvalue;
196                         svalue = (signed char)svalue << 2;
197                         relocation += svalue;
198                         relocation = (relocation >> 2) & 0xff;
199                         hvalue = hvalue & 0xff00;
200                         hvalue += relocation;
201                         COPY_UNALIGNED_HWORD (hvalue, *hlocation, align);
202                         break;
203                 case R_M32R_26_PCREL_RELA:
204                         relocation = (relocation - (Elf32_Addr) location);
205                         if (relocation < -0x2000000 || 0x1fffffc < relocation)
206                                 {
207                                         printk(KERN_ERR "module %s: relocation overflow: %u\n",
208                                         me->name, relocation);
209                                         return -ENOEXEC;
210                                 }
211                         COPY_UNALIGNED_WORD (*location, value, align);
212                         if (value & 0xffffff)
213                                 {
214                                         /* RELA must has 0 at relocation field. */
215                                         printk(KERN_ERR "module %s: illegal relocation field: %u\n",
216                                         me->name, value);
217                                         return -ENOEXEC;
218                                 }
219                         relocation = (relocation >> 2) & 0xffffff;
220                         value += relocation;
221                         COPY_UNALIGNED_WORD (value, *location, align);
222                         break;
223                 default:
224                         printk(KERN_ERR "module %s: Unknown relocation: %u\n",
225                                me->name, ELF32_R_TYPE(rel[i].r_info));
226                         return -ENOEXEC;
227                 }
228         }
229         return 0;
230 }
231
232 int apply_relocate(Elf32_Shdr *sechdrs,
233                        const char *strtab,
234                        unsigned int symindex,
235                        unsigned int relsec,
236                        struct module *me)
237 {
238 #if 0
239         printk(KERN_ERR "module %s: REL RELOCATION unsupported\n",
240                me->name);
241         return -ENOEXEC;
242 #endif
243         return 0;
244
245 }
246
247 int module_finalize(const Elf_Ehdr *hdr,
248                     const Elf_Shdr *sechdrs,
249                     struct module *me)
250 {
251         return 0;
252 }
253
254 void module_arch_cleanup(struct module *mod)
255 {
256 }