[ARM] process: Add display of memory around registers when displaying regs.
[linux-3.10.git] / arch / arm / kernel / module.c
1 /*
2  *  linux/arch/arm/kernel/module.c
3  *
4  *  Copyright (C) 2002 Russell King.
5  *  Modified for nommu by Hyok S. Choi
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  *
11  * Module allocation method suggested by Andi Kleen.
12  */
13 #include <linux/module.h>
14 #include <linux/moduleloader.h>
15 #include <linux/kernel.h>
16 #include <linux/mm.h>
17 #include <linux/elf.h>
18 #include <linux/vmalloc.h>
19 #include <linux/fs.h>
20 #include <linux/string.h>
21 #include <linux/gfp.h>
22
23 #include <asm/pgtable.h>
24 #include <asm/sections.h>
25 #include <asm/smp_plat.h>
26 #include <asm/unwind.h>
27
28 #ifdef CONFIG_XIP_KERNEL
29 /*
30  * The XIP kernel text is mapped in the module area for modules and
31  * some other stuff to work without any indirect relocations.
32  * MODULES_VADDR is redefined here and not in asm/memory.h to avoid
33  * recompiling the whole kernel when CONFIG_XIP_KERNEL is turned on/off.
34  */
35 #undef MODULES_VADDR
36 #define MODULES_VADDR   (((unsigned long)_etext + ~PMD_MASK) & PMD_MASK)
37 #endif
38
39 #ifdef CONFIG_MMU
40 void *module_alloc(unsigned long size)
41 {
42         return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END,
43                                 GFP_KERNEL, PAGE_KERNEL_EXEC, -1,
44                                 __builtin_return_address(0));
45 }
46 #endif
47
48 int
49 apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex,
50                unsigned int relindex, struct module *module)
51 {
52         Elf32_Shdr *symsec = sechdrs + symindex;
53         Elf32_Shdr *relsec = sechdrs + relindex;
54         Elf32_Shdr *dstsec = sechdrs + relsec->sh_info;
55         Elf32_Rel *rel = (void *)relsec->sh_addr;
56         unsigned int i;
57
58         for (i = 0; i < relsec->sh_size / sizeof(Elf32_Rel); i++, rel++) {
59                 unsigned long loc;
60                 Elf32_Sym *sym;
61                 const char *symname;
62                 s32 offset;
63 #ifdef CONFIG_THUMB2_KERNEL
64                 u32 upper, lower, sign, j1, j2;
65 #endif
66
67                 offset = ELF32_R_SYM(rel->r_info);
68                 if (offset < 0 || offset > (symsec->sh_size / sizeof(Elf32_Sym))) {
69                         pr_err("%s: section %u reloc %u: bad relocation sym offset\n",
70                                 module->name, relindex, i);
71                         return -ENOEXEC;
72                 }
73
74                 sym = ((Elf32_Sym *)symsec->sh_addr) + offset;
75                 symname = strtab + sym->st_name;
76
77                 if (rel->r_offset < 0 || rel->r_offset > dstsec->sh_size - sizeof(u32)) {
78                         pr_err("%s: section %u reloc %u sym '%s': out of bounds relocation, offset %d size %u\n",
79                                module->name, relindex, i, symname,
80                                rel->r_offset, dstsec->sh_size);
81                         return -ENOEXEC;
82                 }
83
84                 loc = dstsec->sh_addr + rel->r_offset;
85
86                 switch (ELF32_R_TYPE(rel->r_info)) {
87                 case R_ARM_NONE:
88                         /* ignore */
89                         break;
90
91                 case R_ARM_ABS32:
92                         *(u32 *)loc += sym->st_value;
93                         break;
94
95                 case R_ARM_PC24:
96                 case R_ARM_CALL:
97                 case R_ARM_JUMP24:
98                         offset = (*(u32 *)loc & 0x00ffffff) << 2;
99                         if (offset & 0x02000000)
100                                 offset -= 0x04000000;
101
102                         offset += sym->st_value - loc;
103                         if (offset & 3 ||
104                             offset <= (s32)0xfe000000 ||
105                             offset >= (s32)0x02000000) {
106                                 pr_err("%s: section %u reloc %u sym '%s': relocation %u out of range (%#lx -> %#x)\n",
107                                        module->name, relindex, i, symname,
108                                        ELF32_R_TYPE(rel->r_info), loc,
109                                        sym->st_value);
110                                 return -ENOEXEC;
111                         }
112
113                         offset >>= 2;
114
115                         *(u32 *)loc &= 0xff000000;
116                         *(u32 *)loc |= offset & 0x00ffffff;
117                         break;
118
119                case R_ARM_V4BX:
120                        /* Preserve Rm and the condition code. Alter
121                         * other bits to re-code instruction as
122                         * MOV PC,Rm.
123                         */
124                        *(u32 *)loc &= 0xf000000f;
125                        *(u32 *)loc |= 0x01a0f000;
126                        break;
127
128                 case R_ARM_PREL31:
129                         offset = *(u32 *)loc + sym->st_value - loc;
130                         *(u32 *)loc = offset & 0x7fffffff;
131                         break;
132
133                 case R_ARM_MOVW_ABS_NC:
134                 case R_ARM_MOVT_ABS:
135                         offset = *(u32 *)loc;
136                         offset = ((offset & 0xf0000) >> 4) | (offset & 0xfff);
137                         offset = (offset ^ 0x8000) - 0x8000;
138
139                         offset += sym->st_value;
140                         if (ELF32_R_TYPE(rel->r_info) == R_ARM_MOVT_ABS)
141                                 offset >>= 16;
142
143                         *(u32 *)loc &= 0xfff0f000;
144                         *(u32 *)loc |= ((offset & 0xf000) << 4) |
145                                         (offset & 0x0fff);
146                         break;
147
148 #ifdef CONFIG_THUMB2_KERNEL
149                 case R_ARM_THM_CALL:
150                 case R_ARM_THM_JUMP24:
151                         upper = *(u16 *)loc;
152                         lower = *(u16 *)(loc + 2);
153
154                         /*
155                          * 25 bit signed address range (Thumb-2 BL and B.W
156                          * instructions):
157                          *   S:I1:I2:imm10:imm11:0
158                          * where:
159                          *   S     = upper[10]   = offset[24]
160                          *   I1    = ~(J1 ^ S)   = offset[23]
161                          *   I2    = ~(J2 ^ S)   = offset[22]
162                          *   imm10 = upper[9:0]  = offset[21:12]
163                          *   imm11 = lower[10:0] = offset[11:1]
164                          *   J1    = lower[13]
165                          *   J2    = lower[11]
166                          */
167                         sign = (upper >> 10) & 1;
168                         j1 = (lower >> 13) & 1;
169                         j2 = (lower >> 11) & 1;
170                         offset = (sign << 24) | ((~(j1 ^ sign) & 1) << 23) |
171                                 ((~(j2 ^ sign) & 1) << 22) |
172                                 ((upper & 0x03ff) << 12) |
173                                 ((lower & 0x07ff) << 1);
174                         if (offset & 0x01000000)
175                                 offset -= 0x02000000;
176                         offset += sym->st_value - loc;
177
178                         /*
179                          * For function symbols, only Thumb addresses are
180                          * allowed (no interworking).
181                          *
182                          * For non-function symbols, the destination
183                          * has no specific ARM/Thumb disposition, so
184                          * the branch is resolved under the assumption
185                          * that interworking is not required.
186                          */
187                         if ((ELF32_ST_TYPE(sym->st_info) == STT_FUNC &&
188                                 !(offset & 1)) ||
189                             offset <= (s32)0xff000000 ||
190                             offset >= (s32)0x01000000) {
191                                 pr_err("%s: section %u reloc %u sym '%s': relocation %u out of range (%#lx -> %#x)\n",
192                                        module->name, relindex, i, symname,
193                                        ELF32_R_TYPE(rel->r_info), loc,
194                                        sym->st_value);
195                                 return -ENOEXEC;
196                         }
197
198                         sign = (offset >> 24) & 1;
199                         j1 = sign ^ (~(offset >> 23) & 1);
200                         j2 = sign ^ (~(offset >> 22) & 1);
201                         *(u16 *)loc = (u16)((upper & 0xf800) | (sign << 10) |
202                                             ((offset >> 12) & 0x03ff));
203                         *(u16 *)(loc + 2) = (u16)((lower & 0xd000) |
204                                                   (j1 << 13) | (j2 << 11) |
205                                                   ((offset >> 1) & 0x07ff));
206                         break;
207
208                 case R_ARM_THM_MOVW_ABS_NC:
209                 case R_ARM_THM_MOVT_ABS:
210                         upper = *(u16 *)loc;
211                         lower = *(u16 *)(loc + 2);
212
213                         /*
214                          * MOVT/MOVW instructions encoding in Thumb-2:
215                          *
216                          * i    = upper[10]
217                          * imm4 = upper[3:0]
218                          * imm3 = lower[14:12]
219                          * imm8 = lower[7:0]
220                          *
221                          * imm16 = imm4:i:imm3:imm8
222                          */
223                         offset = ((upper & 0x000f) << 12) |
224                                 ((upper & 0x0400) << 1) |
225                                 ((lower & 0x7000) >> 4) | (lower & 0x00ff);
226                         offset = (offset ^ 0x8000) - 0x8000;
227                         offset += sym->st_value;
228
229                         if (ELF32_R_TYPE(rel->r_info) == R_ARM_THM_MOVT_ABS)
230                                 offset >>= 16;
231
232                         *(u16 *)loc = (u16)((upper & 0xfbf0) |
233                                             ((offset & 0xf000) >> 12) |
234                                             ((offset & 0x0800) >> 1));
235                         *(u16 *)(loc + 2) = (u16)((lower & 0x8f00) |
236                                                   ((offset & 0x0700) << 4) |
237                                                   (offset & 0x00ff));
238                         break;
239 #endif
240
241                 default:
242                         printk(KERN_ERR "%s: unknown relocation: %u\n",
243                                module->name, ELF32_R_TYPE(rel->r_info));
244                         return -ENOEXEC;
245                 }
246         }
247         return 0;
248 }
249
250 struct mod_unwind_map {
251         const Elf_Shdr *unw_sec;
252         const Elf_Shdr *txt_sec;
253 };
254
255 static const Elf_Shdr *find_mod_section(const Elf32_Ehdr *hdr,
256         const Elf_Shdr *sechdrs, const char *name)
257 {
258         const Elf_Shdr *s, *se;
259         const char *secstrs = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
260
261         for (s = sechdrs, se = sechdrs + hdr->e_shnum; s < se; s++)
262                 if (strcmp(name, secstrs + s->sh_name) == 0)
263                         return s;
264
265         return NULL;
266 }
267
268 extern void fixup_pv_table(const void *, unsigned long);
269 extern void fixup_smp(const void *, unsigned long);
270
271 int module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs,
272                     struct module *mod)
273 {
274         const Elf_Shdr *s = NULL;
275 #ifdef CONFIG_ARM_UNWIND
276         const char *secstrs = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
277         const Elf_Shdr *sechdrs_end = sechdrs + hdr->e_shnum;
278         struct mod_unwind_map maps[ARM_SEC_MAX];
279         int i;
280
281         memset(maps, 0, sizeof(maps));
282
283         for (s = sechdrs; s < sechdrs_end; s++) {
284                 const char *secname = secstrs + s->sh_name;
285
286                 if (!(s->sh_flags & SHF_ALLOC))
287                         continue;
288
289                 if (strcmp(".ARM.exidx.init.text", secname) == 0)
290                         maps[ARM_SEC_INIT].unw_sec = s;
291                 else if (strcmp(".ARM.exidx.devinit.text", secname) == 0)
292                         maps[ARM_SEC_DEVINIT].unw_sec = s;
293                 else if (strcmp(".ARM.exidx", secname) == 0)
294                         maps[ARM_SEC_CORE].unw_sec = s;
295                 else if (strcmp(".ARM.exidx.exit.text", secname) == 0)
296                         maps[ARM_SEC_EXIT].unw_sec = s;
297                 else if (strcmp(".ARM.exidx.devexit.text", secname) == 0)
298                         maps[ARM_SEC_DEVEXIT].unw_sec = s;
299                 else if (strcmp(".init.text", secname) == 0)
300                         maps[ARM_SEC_INIT].txt_sec = s;
301                 else if (strcmp(".devinit.text", secname) == 0)
302                         maps[ARM_SEC_DEVINIT].txt_sec = s;
303                 else if (strcmp(".text", secname) == 0)
304                         maps[ARM_SEC_CORE].txt_sec = s;
305                 else if (strcmp(".exit.text", secname) == 0)
306                         maps[ARM_SEC_EXIT].txt_sec = s;
307                 else if (strcmp(".devexit.text", secname) == 0)
308                         maps[ARM_SEC_DEVEXIT].txt_sec = s;
309         }
310
311         for (i = 0; i < ARM_SEC_MAX; i++)
312                 if (maps[i].unw_sec && maps[i].txt_sec)
313                         mod->arch.unwind[i] =
314                                 unwind_table_add(maps[i].unw_sec->sh_addr,
315                                                  maps[i].unw_sec->sh_size,
316                                                  maps[i].txt_sec->sh_addr,
317                                                  maps[i].txt_sec->sh_size);
318 #endif
319 #ifdef CONFIG_ARM_PATCH_PHYS_VIRT
320         s = find_mod_section(hdr, sechdrs, ".pv_table");
321         if (s)
322                 fixup_pv_table((void *)s->sh_addr, s->sh_size);
323 #endif
324         s = find_mod_section(hdr, sechdrs, ".alt.smp.init");
325         if (s && !is_smp())
326 #ifdef CONFIG_SMP_ON_UP
327                 fixup_smp((void *)s->sh_addr, s->sh_size);
328 #else
329                 return -EINVAL;
330 #endif
331         return 0;
332 }
333
334 void
335 module_arch_cleanup(struct module *mod)
336 {
337 #ifdef CONFIG_ARM_UNWIND
338         int i;
339
340         for (i = 0; i < ARM_SEC_MAX; i++)
341                 if (mod->arch.unwind[i])
342                         unwind_table_del(mod->arch.unwind[i]);
343 #endif
344 }