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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/arch/arm/kernel/module.c
3 *
4 * Copyright (C) 2002 Russell King.
Hyok S. Choi6a570b22006-09-26 17:37:07 +09005 * Modified for nommu by Hyok S. Choi
Linus Torvalds1da177e2005-04-16 15:20:36 -07006 *
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 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070013#include <linux/module.h>
Russell Kingf339ab32005-10-28 14:29:43 +010014#include <linux/moduleloader.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#include <linux/kernel.h>
Andrea Righi27ac7922008-07-23 21:28:13 -070016#include <linux/mm.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070017#include <linux/elf.h>
18#include <linux/vmalloc.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070019#include <linux/fs.h>
20#include <linux/string.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090021#include <linux/gfp.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070022
23#include <asm/pgtable.h>
Russell King37efe642008-12-01 11:53:07 +000024#include <asm/sections.h>
Russell King4a9cb362011-02-10 15:25:18 +000025#include <asm/smp_plat.h>
Catalin Marinas2e1926e2009-02-11 13:09:54 +010026#include <asm/unwind.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070027
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.
Russell Kingab4f2ee2008-11-06 17:11:07 +000032 * MODULES_VADDR is redefined here and not in asm/memory.h to avoid
Linus Torvalds1da177e2005-04-16 15:20:36 -070033 * recompiling the whole kernel when CONFIG_XIP_KERNEL is turned on/off.
34 */
Russell Kingab4f2ee2008-11-06 17:11:07 +000035#undef MODULES_VADDR
Russell King37efe642008-12-01 11:53:07 +000036#define MODULES_VADDR (((unsigned long)_etext + ~PGDIR_MASK) & PGDIR_MASK)
Linus Torvalds1da177e2005-04-16 15:20:36 -070037#endif
38
Hyok S. Choi6a570b22006-09-26 17:37:07 +090039#ifdef CONFIG_MMU
Linus Torvalds1da177e2005-04-16 15:20:36 -070040void *module_alloc(unsigned long size)
41{
David Rientjesd0a21262011-01-13 15:46:02 -080042 return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END,
43 GFP_KERNEL, PAGE_KERNEL_EXEC, -1,
44 __builtin_return_address(0));
Linus Torvalds1da177e2005-04-16 15:20:36 -070045}
Jonas Bonn66574cc2011-06-30 21:22:12 +020046#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070047
48int
49apply_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;
Russell King68e6fad2011-01-11 19:57:14 +000061 const char *symname;
Linus Torvalds1da177e2005-04-16 15:20:36 -070062 s32 offset;
Catalin Marinasb7493152010-06-21 15:11:38 +010063#ifdef CONFIG_THUMB2_KERNEL
Catalin Marinasadca6dc2009-07-24 12:32:59 +010064 u32 upper, lower, sign, j1, j2;
Catalin Marinasb7493152010-06-21 15:11:38 +010065#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070066
67 offset = ELF32_R_SYM(rel->r_info);
68 if (offset < 0 || offset > (symsec->sh_size / sizeof(Elf32_Sym))) {
Russell King68e6fad2011-01-11 19:57:14 +000069 pr_err("%s: section %u reloc %u: bad relocation sym offset\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -070070 module->name, relindex, i);
71 return -ENOEXEC;
72 }
73
74 sym = ((Elf32_Sym *)symsec->sh_addr) + offset;
Russell King68e6fad2011-01-11 19:57:14 +000075 symname = strtab + sym->st_name;
Linus Torvalds1da177e2005-04-16 15:20:36 -070076
77 if (rel->r_offset < 0 || rel->r_offset > dstsec->sh_size - sizeof(u32)) {
Russell King68e6fad2011-01-11 19:57:14 +000078 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);
Linus Torvalds1da177e2005-04-16 15:20:36 -070081 return -ENOEXEC;
82 }
83
84 loc = dstsec->sh_addr + rel->r_offset;
85
86 switch (ELF32_R_TYPE(rel->r_info)) {
Catalin Marinas2e1926e2009-02-11 13:09:54 +010087 case R_ARM_NONE:
88 /* ignore */
89 break;
90
Linus Torvalds1da177e2005-04-16 15:20:36 -070091 case R_ARM_ABS32:
92 *(u32 *)loc += sym->st_value;
93 break;
94
95 case R_ARM_PC24:
Daniel Jacobowitzc2e26112005-12-14 22:04:22 +000096 case R_ARM_CALL:
97 case R_ARM_JUMP24:
Linus Torvalds1da177e2005-04-16 15:20:36 -070098 offset = (*(u32 *)loc & 0x00ffffff) << 2;
99 if (offset & 0x02000000)
100 offset -= 0x04000000;
101
102 offset += sym->st_value - loc;
103 if (offset & 3 ||
Kevin Weltonc5f12502007-05-08 22:05:25 +0100104 offset <= (s32)0xfe000000 ||
105 offset >= (s32)0x02000000) {
Russell King68e6fad2011-01-11 19:57:14 +0000106 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);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110 return -ENOEXEC;
111 }
112
113 offset >>= 2;
114
115 *(u32 *)loc &= 0xff000000;
116 *(u32 *)loc |= offset & 0x00ffffff;
117 break;
118
Daniel Silverstone4731f8b2009-03-20 11:11:43 +0100119 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
Catalin Marinas2e1926e2009-02-11 13:09:54 +0100128 case R_ARM_PREL31:
129 offset = *(u32 *)loc + sym->st_value - loc;
130 *(u32 *)loc = offset & 0x7fffffff;
131 break;
132
Paul Gortmakerae51e602009-05-07 16:18:40 +0100133 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
Catalin Marinasb7493152010-06-21 15:11:38 +0100148#ifdef CONFIG_THUMB2_KERNEL
Catalin Marinasadca6dc2009-07-24 12:32:59 +0100149 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
Dave Martin9a003182011-06-16 12:09:37 +0100178 /*
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)) ||
Catalin Marinasadca6dc2009-07-24 12:32:59 +0100189 offset <= (s32)0xff000000 ||
190 offset >= (s32)0x01000000) {
Russell King68e6fad2011-01-11 19:57:14 +0000191 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);
Catalin Marinasadca6dc2009-07-24 12:32:59 +0100195 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));
Catalin Marinasadca6dc2009-07-24 12:32:59 +0100206 break;
207
Catalin Marinas8dd47742010-06-21 15:10:37 +0100208 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;
Catalin Marinasb7493152010-06-21 15:11:38 +0100239#endif
Catalin Marinas8dd47742010-06-21 15:10:37 +0100240
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241 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
Russell King89313602010-11-12 13:02:46 +0000250struct mod_unwind_map {
251 const Elf_Shdr *unw_sec;
252 const Elf_Shdr *txt_sec;
253};
254
Russell King4a9cb362011-02-10 15:25:18 +0000255static 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
Russell Kingdc21af92011-01-04 19:09:43 +0000268extern void fixup_pv_table(const void *, unsigned long);
Russell King4a9cb362011-02-10 15:25:18 +0000269extern void fixup_smp(const void *, unsigned long);
270
Russell King89313602010-11-12 13:02:46 +0000271int module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs,
272 struct module *mod)
273{
Russell Kingdc21af92011-01-04 19:09:43 +0000274 const Elf_Shdr *s = NULL;
Catalin Marinas2e1926e2009-02-11 13:09:54 +0100275#ifdef CONFIG_ARM_UNWIND
Russell King89313602010-11-12 13:02:46 +0000276 const char *secstrs = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
Russell King4a9cb362011-02-10 15:25:18 +0000277 const Elf_Shdr *sechdrs_end = sechdrs + hdr->e_shnum;
Russell King89313602010-11-12 13:02:46 +0000278 struct mod_unwind_map maps[ARM_SEC_MAX];
Phil Carmodye5f77722010-08-19 15:16:37 +0100279 int i;
Russell King89313602010-11-12 13:02:46 +0000280
281 memset(maps, 0, sizeof(maps));
282
283 for (s = sechdrs; s < sechdrs_end; s++) {
284 const char *secname = secstrs + s->sh_name;
285
Russell King50005a82010-11-12 13:04:16 +0000286 if (!(s->sh_flags & SHF_ALLOC))
287 continue;
288
Russell King89313602010-11-12 13:02:46 +0000289 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;
Phil Carmodye5f77722010-08-19 15:16:37 +0100309 }
Catalin Marinas2e1926e2009-02-11 13:09:54 +0100310
Russell King89313602010-11-12 13:02:46 +0000311 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);
Catalin Marinas2e1926e2009-02-11 13:09:54 +0100318#endif
Russell Kingdc21af92011-01-04 19:09:43 +0000319#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
Russell King4a9cb362011-02-10 15:25:18 +0000324 s = find_mod_section(hdr, sechdrs, ".alt.smp.init");
325 if (s && !is_smp())
326 fixup_smp((void *)s->sh_addr, s->sh_size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700327 return 0;
328}
329
330void
331module_arch_cleanup(struct module *mod)
332{
Russell King89313602010-11-12 13:02:46 +0000333#ifdef CONFIG_ARM_UNWIND
334 int i;
335
336 for (i = 0; i < ARM_SEC_MAX; i++)
337 if (mod->arch.unwind[i])
338 unwind_table_del(mod->arch.unwind[i]);
339#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340}