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-rw-r--r--arch/alpha/kernel/module.c311
1 files changed, 311 insertions, 0 deletions
diff --git a/arch/alpha/kernel/module.c b/arch/alpha/kernel/module.c
new file mode 100644
index 000000000000..fc271e316a38
--- /dev/null
+++ b/arch/alpha/kernel/module.c
@@ -0,0 +1,311 @@
1/* Kernel module help for Alpha.
2 Copyright (C) 2002 Richard Henderson.
3
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2 of the License, or
7 (at your option) any later version.
8
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
13
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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#include <linux/slab.h>
25
26#if 0
27#define DEBUGP printk
28#else
29#define DEBUGP(fmt...)
30#endif
31
32void *
33module_alloc(unsigned long size)
34{
35 if (size == 0)
36 return NULL;
37 return vmalloc(size);
38}
39
40void
41module_free(struct module *mod, void *module_region)
42{
43 vfree(module_region);
44}
45
46/* Allocate the GOT at the end of the core sections. */
47
48struct got_entry {
49 struct got_entry *next;
50 Elf64_Addr r_offset;
51 int got_offset;
52};
53
54static inline void
55process_reloc_for_got(Elf64_Rela *rela,
56 struct got_entry *chains, Elf64_Xword *poffset)
57{
58 unsigned long r_sym = ELF64_R_SYM (rela->r_info);
59 unsigned long r_type = ELF64_R_TYPE (rela->r_info);
60 Elf64_Addr r_offset = rela->r_offset;
61 struct got_entry *g;
62
63 if (r_type != R_ALPHA_LITERAL)
64 return;
65
66 for (g = chains + r_sym; g ; g = g->next)
67 if (g->r_offset == r_offset) {
68 if (g->got_offset == 0) {
69 g->got_offset = *poffset;
70 *poffset += 8;
71 }
72 goto found_entry;
73 }
74
75 g = kmalloc (sizeof (*g), GFP_KERNEL);
76 g->next = chains[r_sym].next;
77 g->r_offset = r_offset;
78 g->got_offset = *poffset;
79 *poffset += 8;
80 chains[r_sym].next = g;
81
82 found_entry:
83 /* Trick: most of the ELF64_R_TYPE field is unused. There are
84 42 valid relocation types, and a 32-bit field. Co-opt the
85 bits above 256 to store the got offset for this reloc. */
86 rela->r_info |= g->got_offset << 8;
87}
88
89int
90module_frob_arch_sections(Elf64_Ehdr *hdr, Elf64_Shdr *sechdrs,
91 char *secstrings, struct module *me)
92{
93 struct got_entry *chains;
94 Elf64_Rela *rela;
95 Elf64_Shdr *esechdrs, *symtab, *s, *got;
96 unsigned long nsyms, nrela, i;
97
98 esechdrs = sechdrs + hdr->e_shnum;
99 symtab = got = NULL;
100
101 /* Find out how large the symbol table is. Allocate one got_entry
102 head per symbol. Normally this will be enough, but not always.
103 We'll chain different offsets for the symbol down each head. */
104 for (s = sechdrs; s < esechdrs; ++s)
105 if (s->sh_type == SHT_SYMTAB)
106 symtab = s;
107 else if (!strcmp(".got", secstrings + s->sh_name)) {
108 got = s;
109 me->arch.gotsecindex = s - sechdrs;
110 }
111
112 if (!symtab) {
113 printk(KERN_ERR "module %s: no symbol table\n", me->name);
114 return -ENOEXEC;
115 }
116 if (!got) {
117 printk(KERN_ERR "module %s: no got section\n", me->name);
118 return -ENOEXEC;
119 }
120
121 nsyms = symtab->sh_size / sizeof(Elf64_Sym);
122 chains = kmalloc(nsyms * sizeof(struct got_entry), GFP_KERNEL);
123 memset(chains, 0, nsyms * sizeof(struct got_entry));
124
125 got->sh_size = 0;
126 got->sh_addralign = 8;
127 got->sh_type = SHT_NOBITS;
128
129 /* Examine all LITERAL relocations to find out what GOT entries
130 are required. This sizes the GOT section as well. */
131 for (s = sechdrs; s < esechdrs; ++s)
132 if (s->sh_type == SHT_RELA) {
133 nrela = s->sh_size / sizeof(Elf64_Rela);
134 rela = (void *)hdr + s->sh_offset;
135 for (i = 0; i < nrela; ++i)
136 process_reloc_for_got(rela+i, chains,
137 &got->sh_size);
138 }
139
140 /* Free the memory we allocated. */
141 for (i = 0; i < nsyms; ++i) {
142 struct got_entry *g, *n;
143 for (g = chains[i].next; g ; g = n) {
144 n = g->next;
145 kfree(g);
146 }
147 }
148 kfree(chains);
149
150 return 0;
151}
152
153int
154apply_relocate(Elf64_Shdr *sechdrs, const char *strtab, unsigned int symindex,
155 unsigned int relsec, struct module *me)
156{
157 printk(KERN_ERR "module %s: REL relocation unsupported\n", me->name);
158 return -ENOEXEC;
159}
160
161int
162apply_relocate_add(Elf64_Shdr *sechdrs, const char *strtab,
163 unsigned int symindex, unsigned int relsec,
164 struct module *me)
165{
166 Elf64_Rela *rela = (void *)sechdrs[relsec].sh_addr;
167 unsigned long i, n = sechdrs[relsec].sh_size / sizeof(*rela);
168 Elf64_Sym *symtab, *sym;
169 void *base, *location;
170 unsigned long got, gp;
171
172 DEBUGP("Applying relocate section %u to %u\n", relsec,
173 sechdrs[relsec].sh_info);
174
175 base = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr;
176 symtab = (Elf64_Sym *)sechdrs[symindex].sh_addr;
177
178 /* The small sections were sorted to the end of the segment.
179 The following should definitely cover them. */
180 gp = (u64)me->module_core + me->core_size - 0x8000;
181 got = sechdrs[me->arch.gotsecindex].sh_addr;
182
183 for (i = 0; i < n; i++) {
184 unsigned long r_sym = ELF64_R_SYM (rela[i].r_info);
185 unsigned long r_type = ELF64_R_TYPE (rela[i].r_info);
186 unsigned long r_got_offset = r_type >> 8;
187 unsigned long value, hi, lo;
188 r_type &= 0xff;
189
190 /* This is where to make the change. */
191 location = base + rela[i].r_offset;
192
193 /* This is the symbol it is referring to. Note that all
194 unresolved symbols have been resolved. */
195 sym = symtab + r_sym;
196 value = sym->st_value + rela[i].r_addend;
197
198 switch (r_type) {
199 case R_ALPHA_NONE:
200 break;
201 case R_ALPHA_REFQUAD:
202 /* BUG() can produce misaligned relocations. */
203 ((u32 *)location)[0] = value;
204 ((u32 *)location)[1] = value >> 32;
205 break;
206 case R_ALPHA_GPREL32:
207 value -= gp;
208 if ((int)value != value)
209 goto reloc_overflow;
210 *(u32 *)location = value;
211 break;
212 case R_ALPHA_LITERAL:
213 hi = got + r_got_offset;
214 lo = hi - gp;
215 if ((short)lo != lo)
216 goto reloc_overflow;
217 *(u16 *)location = lo;
218 *(u64 *)hi = value;
219 break;
220 case R_ALPHA_LITUSE:
221 break;
222 case R_ALPHA_GPDISP:
223 value = gp - (u64)location;
224 lo = (short)value;
225 hi = (int)(value - lo);
226 if (hi + lo != value)
227 goto reloc_overflow;
228 *(u16 *)location = hi >> 16;
229 *(u16 *)(location + rela[i].r_addend) = lo;
230 break;
231 case R_ALPHA_BRSGP:
232 /* BRSGP is only allowed to bind to local symbols.
233 If the section is undef, this means that the
234 value was resolved from somewhere else. */
235 if (sym->st_shndx == SHN_UNDEF)
236 goto reloc_overflow;
237 if ((sym->st_other & STO_ALPHA_STD_GPLOAD) ==
238 STO_ALPHA_STD_GPLOAD)
239 /* Omit the prologue. */
240 value += 8;
241 /* FALLTHRU */
242 case R_ALPHA_BRADDR:
243 value -= (u64)location + 4;
244 if (value & 3)
245 goto reloc_overflow;
246 value = (long)value >> 2;
247 if (value + (1<<21) >= 1<<22)
248 goto reloc_overflow;
249 value &= 0x1fffff;
250 value |= *(u32 *)location & ~0x1fffff;
251 *(u32 *)location = value;
252 break;
253 case R_ALPHA_HINT:
254 break;
255 case R_ALPHA_SREL32:
256 value -= (u64)location;
257 if ((int)value != value)
258 goto reloc_overflow;
259 *(u32 *)location = value;
260 break;
261 case R_ALPHA_SREL64:
262 value -= (u64)location;
263 *(u64 *)location = value;
264 break;
265 case R_ALPHA_GPRELHIGH:
266 value = (long)(value - gp + 0x8000) >> 16;
267 if ((short) value != value)
268 goto reloc_overflow;
269 *(u16 *)location = value;
270 break;
271 case R_ALPHA_GPRELLOW:
272 value -= gp;
273 *(u16 *)location = value;
274 break;
275 case R_ALPHA_GPREL16:
276 value -= gp;
277 if ((short) value != value)
278 goto reloc_overflow;
279 *(u16 *)location = value;
280 break;
281 default:
282 printk(KERN_ERR "module %s: Unknown relocation: %lu\n",
283 me->name, r_type);
284 return -ENOEXEC;
285 reloc_overflow:
286 if (ELF64_ST_TYPE (sym->st_info) == STT_SECTION)
287 printk(KERN_ERR
288 "module %s: Relocation overflow vs section %d\n",
289 me->name, sym->st_shndx);
290 else
291 printk(KERN_ERR
292 "module %s: Relocation overflow vs %s\n",
293 me->name, strtab + sym->st_name);
294 return -ENOEXEC;
295 }
296 }
297
298 return 0;
299}
300
301int
302module_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs,
303 struct module *me)
304{
305 return 0;
306}
307
308void
309module_arch_cleanup(struct module *mod)
310{
311}
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