2 * linux/arch/arm/kernel/module.c
4 * Copyright (C) 2002 Russell King.
5 * Modified for nommu by Hyok S. Choi
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.
11 * Module allocation method suggested by Andi Kleen.
13 #include <linux/module.h>
14 #include <linux/moduleloader.h>
15 #include <linux/kernel.h>
17 #include <linux/elf.h>
18 #include <linux/vmalloc.h>
20 #include <linux/string.h>
21 #include <linux/gfp.h>
23 #include <asm/pgtable.h>
24 #include <asm/sections.h>
25 #include <asm/unwind.h>
27 #ifdef CONFIG_XIP_KERNEL
29 * The XIP kernel text is mapped in the module area for modules and
30 * some other stuff to work without any indirect relocations.
31 * MODULES_VADDR is redefined here and not in asm/memory.h to avoid
32 * recompiling the whole kernel when CONFIG_XIP_KERNEL is turned on/off.
35 #define MODULES_VADDR (((unsigned long)_etext + ~PGDIR_MASK) & PGDIR_MASK)
39 void *module_alloc(unsigned long size)
41 struct vm_struct *area;
43 size = PAGE_ALIGN(size);
47 area = __get_vm_area(size, VM_ALLOC, MODULES_VADDR, MODULES_END);
51 return __vmalloc_area(area, GFP_KERNEL, PAGE_KERNEL_EXEC);
53 #else /* CONFIG_MMU */
54 void *module_alloc(unsigned long size)
56 return size == 0 ? NULL : vmalloc(size);
58 #endif /* !CONFIG_MMU */
60 void module_free(struct module *module, void *region)
65 int module_frob_arch_sections(Elf_Ehdr *hdr,
74 apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex,
75 unsigned int relindex, struct module *module)
77 Elf32_Shdr *symsec = sechdrs + symindex;
78 Elf32_Shdr *relsec = sechdrs + relindex;
79 Elf32_Shdr *dstsec = sechdrs + relsec->sh_info;
80 Elf32_Rel *rel = (void *)relsec->sh_addr;
83 for (i = 0; i < relsec->sh_size / sizeof(Elf32_Rel); i++, rel++) {
87 #ifdef CONFIG_THUMB2_KERNEL
88 u32 upper, lower, sign, j1, j2;
91 offset = ELF32_R_SYM(rel->r_info);
92 if (offset < 0 || offset > (symsec->sh_size / sizeof(Elf32_Sym))) {
93 printk(KERN_ERR "%s: bad relocation, section %d reloc %d\n",
94 module->name, relindex, i);
98 sym = ((Elf32_Sym *)symsec->sh_addr) + offset;
100 if (rel->r_offset < 0 || rel->r_offset > dstsec->sh_size - sizeof(u32)) {
101 printk(KERN_ERR "%s: out of bounds relocation, "
102 "section %d reloc %d offset %d size %d\n",
103 module->name, relindex, i, rel->r_offset,
108 loc = dstsec->sh_addr + rel->r_offset;
110 switch (ELF32_R_TYPE(rel->r_info)) {
116 *(u32 *)loc += sym->st_value;
122 offset = (*(u32 *)loc & 0x00ffffff) << 2;
123 if (offset & 0x02000000)
124 offset -= 0x04000000;
126 offset += sym->st_value - loc;
128 offset <= (s32)0xfe000000 ||
129 offset >= (s32)0x02000000) {
131 "%s: relocation out of range, section "
132 "%d reloc %d sym '%s'\n", module->name,
133 relindex, i, strtab + sym->st_name);
139 *(u32 *)loc &= 0xff000000;
140 *(u32 *)loc |= offset & 0x00ffffff;
144 /* Preserve Rm and the condition code. Alter
145 * other bits to re-code instruction as
148 *(u32 *)loc &= 0xf000000f;
149 *(u32 *)loc |= 0x01a0f000;
153 offset = *(u32 *)loc + sym->st_value - loc;
154 *(u32 *)loc = offset & 0x7fffffff;
157 case R_ARM_MOVW_ABS_NC:
159 offset = *(u32 *)loc;
160 offset = ((offset & 0xf0000) >> 4) | (offset & 0xfff);
161 offset = (offset ^ 0x8000) - 0x8000;
163 offset += sym->st_value;
164 if (ELF32_R_TYPE(rel->r_info) == R_ARM_MOVT_ABS)
167 *(u32 *)loc &= 0xfff0f000;
168 *(u32 *)loc |= ((offset & 0xf000) << 4) |
172 #ifdef CONFIG_THUMB2_KERNEL
174 case R_ARM_THM_JUMP24:
176 lower = *(u16 *)(loc + 2);
179 * 25 bit signed address range (Thumb-2 BL and B.W
181 * S:I1:I2:imm10:imm11:0
183 * S = upper[10] = offset[24]
184 * I1 = ~(J1 ^ S) = offset[23]
185 * I2 = ~(J2 ^ S) = offset[22]
186 * imm10 = upper[9:0] = offset[21:12]
187 * imm11 = lower[10:0] = offset[11:1]
191 sign = (upper >> 10) & 1;
192 j1 = (lower >> 13) & 1;
193 j2 = (lower >> 11) & 1;
194 offset = (sign << 24) | ((~(j1 ^ sign) & 1) << 23) |
195 ((~(j2 ^ sign) & 1) << 22) |
196 ((upper & 0x03ff) << 12) |
197 ((lower & 0x07ff) << 1);
198 if (offset & 0x01000000)
199 offset -= 0x02000000;
200 offset += sym->st_value - loc;
202 /* only Thumb addresses allowed (no interworking) */
204 offset <= (s32)0xff000000 ||
205 offset >= (s32)0x01000000) {
207 "%s: relocation out of range, section "
208 "%d reloc %d sym '%s'\n", module->name,
209 relindex, i, strtab + sym->st_name);
213 sign = (offset >> 24) & 1;
214 j1 = sign ^ (~(offset >> 23) & 1);
215 j2 = sign ^ (~(offset >> 22) & 1);
216 *(u16 *)loc = (u16)((upper & 0xf800) | (sign << 10) |
217 ((offset >> 12) & 0x03ff));
218 *(u16 *)(loc + 2) = (u16)((lower & 0xd000) |
219 (j1 << 13) | (j2 << 11) |
220 ((offset >> 1) & 0x07ff));
223 case R_ARM_THM_MOVW_ABS_NC:
224 case R_ARM_THM_MOVT_ABS:
226 lower = *(u16 *)(loc + 2);
229 * MOVT/MOVW instructions encoding in Thumb-2:
233 * imm3 = lower[14:12]
236 * imm16 = imm4:i:imm3:imm8
238 offset = ((upper & 0x000f) << 12) |
239 ((upper & 0x0400) << 1) |
240 ((lower & 0x7000) >> 4) | (lower & 0x00ff);
241 offset = (offset ^ 0x8000) - 0x8000;
242 offset += sym->st_value;
244 if (ELF32_R_TYPE(rel->r_info) == R_ARM_THM_MOVT_ABS)
247 *(u16 *)loc = (u16)((upper & 0xfbf0) |
248 ((offset & 0xf000) >> 12) |
249 ((offset & 0x0800) >> 1));
250 *(u16 *)(loc + 2) = (u16)((lower & 0x8f00) |
251 ((offset & 0x0700) << 4) |
257 printk(KERN_ERR "%s: unknown relocation: %u\n",
258 module->name, ELF32_R_TYPE(rel->r_info));
266 apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab,
267 unsigned int symindex, unsigned int relsec, struct module *module)
269 printk(KERN_ERR "module %s: ADD RELOCATION unsupported\n",
274 struct mod_unwind_map {
275 const Elf_Shdr *unw_sec;
276 const Elf_Shdr *txt_sec;
279 int module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs,
282 #ifdef CONFIG_ARM_UNWIND
283 const char *secstrs = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
284 const Elf_Shdr *s, *sechdrs_end = sechdrs + hdr->e_shnum;
285 struct mod_unwind_map maps[ARM_SEC_MAX];
288 memset(maps, 0, sizeof(maps));
290 for (s = sechdrs; s < sechdrs_end; s++) {
291 const char *secname = secstrs + s->sh_name;
293 if (!(s->sh_flags & SHF_ALLOC))
296 if (strcmp(".ARM.exidx.init.text", secname) == 0)
297 maps[ARM_SEC_INIT].unw_sec = s;
298 else if (strcmp(".ARM.exidx.devinit.text", secname) == 0)
299 maps[ARM_SEC_DEVINIT].unw_sec = s;
300 else if (strcmp(".ARM.exidx", secname) == 0)
301 maps[ARM_SEC_CORE].unw_sec = s;
302 else if (strcmp(".ARM.exidx.exit.text", secname) == 0)
303 maps[ARM_SEC_EXIT].unw_sec = s;
304 else if (strcmp(".ARM.exidx.devexit.text", secname) == 0)
305 maps[ARM_SEC_DEVEXIT].unw_sec = s;
306 else if (strcmp(".init.text", secname) == 0)
307 maps[ARM_SEC_INIT].txt_sec = s;
308 else if (strcmp(".devinit.text", secname) == 0)
309 maps[ARM_SEC_DEVINIT].txt_sec = s;
310 else if (strcmp(".text", secname) == 0)
311 maps[ARM_SEC_CORE].txt_sec = s;
312 else if (strcmp(".exit.text", secname) == 0)
313 maps[ARM_SEC_EXIT].txt_sec = s;
314 else if (strcmp(".devexit.text", secname) == 0)
315 maps[ARM_SEC_DEVEXIT].txt_sec = s;
318 for (i = 0; i < ARM_SEC_MAX; i++)
319 if (maps[i].unw_sec && maps[i].txt_sec)
320 mod->arch.unwind[i] =
321 unwind_table_add(maps[i].unw_sec->sh_addr,
322 maps[i].unw_sec->sh_size,
323 maps[i].txt_sec->sh_addr,
324 maps[i].txt_sec->sh_size);
330 module_arch_cleanup(struct module *mod)
332 #ifdef CONFIG_ARM_UNWIND
335 for (i = 0; i < ARM_SEC_MAX; i++)
336 if (mod->arch.unwind[i])
337 unwind_table_del(mod->arch.unwind[i]);