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,
70 #ifdef CONFIG_ARM_UNWIND
71 Elf_Shdr *s, *sechdrs_end = sechdrs + hdr->e_shnum;
73 for (s = sechdrs; s < sechdrs_end; s++) {
74 if (strcmp(".ARM.exidx.init.text", secstrings + s->sh_name) == 0)
75 mod->arch.unw_sec_init = s;
76 else if (strcmp(".ARM.exidx.devinit.text", secstrings + s->sh_name) == 0)
77 mod->arch.unw_sec_devinit = s;
78 else if (strcmp(".ARM.exidx", secstrings + s->sh_name) == 0)
79 mod->arch.unw_sec_core = s;
80 else if (strcmp(".init.text", secstrings + s->sh_name) == 0)
81 mod->arch.sec_init_text = s;
82 else if (strcmp(".devinit.text", secstrings + s->sh_name) == 0)
83 mod->arch.sec_devinit_text = s;
84 else if (strcmp(".text", secstrings + s->sh_name) == 0)
85 mod->arch.sec_core_text = s;
92 apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex,
93 unsigned int relindex, struct module *module)
95 Elf32_Shdr *symsec = sechdrs + symindex;
96 Elf32_Shdr *relsec = sechdrs + relindex;
97 Elf32_Shdr *dstsec = sechdrs + relsec->sh_info;
98 Elf32_Rel *rel = (void *)relsec->sh_addr;
101 for (i = 0; i < relsec->sh_size / sizeof(Elf32_Rel); i++, rel++) {
105 u32 upper, lower, sign, j1, j2;
107 offset = ELF32_R_SYM(rel->r_info);
108 if (offset < 0 || offset > (symsec->sh_size / sizeof(Elf32_Sym))) {
109 printk(KERN_ERR "%s: bad relocation, section %d reloc %d\n",
110 module->name, relindex, i);
114 sym = ((Elf32_Sym *)symsec->sh_addr) + offset;
116 if (rel->r_offset < 0 || rel->r_offset > dstsec->sh_size - sizeof(u32)) {
117 printk(KERN_ERR "%s: out of bounds relocation, "
118 "section %d reloc %d offset %d size %d\n",
119 module->name, relindex, i, rel->r_offset,
124 loc = dstsec->sh_addr + rel->r_offset;
126 switch (ELF32_R_TYPE(rel->r_info)) {
132 *(u32 *)loc += sym->st_value;
138 offset = (*(u32 *)loc & 0x00ffffff) << 2;
139 if (offset & 0x02000000)
140 offset -= 0x04000000;
142 offset += sym->st_value - loc;
144 offset <= (s32)0xfe000000 ||
145 offset >= (s32)0x02000000) {
147 "%s: relocation out of range, section "
148 "%d reloc %d sym '%s'\n", module->name,
149 relindex, i, strtab + sym->st_name);
155 *(u32 *)loc &= 0xff000000;
156 *(u32 *)loc |= offset & 0x00ffffff;
160 /* Preserve Rm and the condition code. Alter
161 * other bits to re-code instruction as
164 *(u32 *)loc &= 0xf000000f;
165 *(u32 *)loc |= 0x01a0f000;
169 offset = *(u32 *)loc + sym->st_value - loc;
170 *(u32 *)loc = offset & 0x7fffffff;
173 case R_ARM_MOVW_ABS_NC:
175 offset = *(u32 *)loc;
176 offset = ((offset & 0xf0000) >> 4) | (offset & 0xfff);
177 offset = (offset ^ 0x8000) - 0x8000;
179 offset += sym->st_value;
180 if (ELF32_R_TYPE(rel->r_info) == R_ARM_MOVT_ABS)
183 *(u32 *)loc &= 0xfff0f000;
184 *(u32 *)loc |= ((offset & 0xf000) << 4) |
189 case R_ARM_THM_JUMP24:
191 lower = *(u16 *)(loc + 2);
194 * 25 bit signed address range (Thumb-2 BL and B.W
196 * S:I1:I2:imm10:imm11:0
198 * S = upper[10] = offset[24]
199 * I1 = ~(J1 ^ S) = offset[23]
200 * I2 = ~(J2 ^ S) = offset[22]
201 * imm10 = upper[9:0] = offset[21:12]
202 * imm11 = lower[10:0] = offset[11:1]
206 sign = (upper >> 10) & 1;
207 j1 = (lower >> 13) & 1;
208 j2 = (lower >> 11) & 1;
209 offset = (sign << 24) | ((~(j1 ^ sign) & 1) << 23) |
210 ((~(j2 ^ sign) & 1) << 22) |
211 ((upper & 0x03ff) << 12) |
212 ((lower & 0x07ff) << 1);
213 if (offset & 0x01000000)
214 offset -= 0x02000000;
215 offset += sym->st_value - loc;
217 /* only Thumb addresses allowed (no interworking) */
219 offset <= (s32)0xff000000 ||
220 offset >= (s32)0x01000000) {
222 "%s: relocation out of range, section "
223 "%d reloc %d sym '%s'\n", module->name,
224 relindex, i, strtab + sym->st_name);
228 sign = (offset >> 24) & 1;
229 j1 = sign ^ (~(offset >> 23) & 1);
230 j2 = sign ^ (~(offset >> 22) & 1);
231 *(u16 *)loc = (u16)((upper & 0xf800) | (sign << 10) |
232 ((offset >> 12) & 0x03ff));
233 *(u16 *)(loc + 2) = (u16)((lower & 0xd000) |
234 (j1 << 13) | (j2 << 11) |
235 ((offset >> 1) & 0x07ff));
237 lower = *(u16 *)(loc + 2);
241 printk(KERN_ERR "%s: unknown relocation: %u\n",
242 module->name, ELF32_R_TYPE(rel->r_info));
250 apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab,
251 unsigned int symindex, unsigned int relsec, struct module *module)
253 printk(KERN_ERR "module %s: ADD RELOCATION unsupported\n",
258 #ifdef CONFIG_ARM_UNWIND
259 static void register_unwind_tables(struct module *mod)
261 if (mod->arch.unw_sec_init && mod->arch.sec_init_text)
262 mod->arch.unwind_init =
263 unwind_table_add(mod->arch.unw_sec_init->sh_addr,
264 mod->arch.unw_sec_init->sh_size,
265 mod->arch.sec_init_text->sh_addr,
266 mod->arch.sec_init_text->sh_size);
267 if (mod->arch.unw_sec_devinit && mod->arch.sec_devinit_text)
268 mod->arch.unwind_devinit =
269 unwind_table_add(mod->arch.unw_sec_devinit->sh_addr,
270 mod->arch.unw_sec_devinit->sh_size,
271 mod->arch.sec_devinit_text->sh_addr,
272 mod->arch.sec_devinit_text->sh_size);
273 if (mod->arch.unw_sec_core && mod->arch.sec_core_text)
274 mod->arch.unwind_core =
275 unwind_table_add(mod->arch.unw_sec_core->sh_addr,
276 mod->arch.unw_sec_core->sh_size,
277 mod->arch.sec_core_text->sh_addr,
278 mod->arch.sec_core_text->sh_size);
281 static void unregister_unwind_tables(struct module *mod)
283 unwind_table_del(mod->arch.unwind_init);
284 unwind_table_del(mod->arch.unwind_devinit);
285 unwind_table_del(mod->arch.unwind_core);
288 static inline void register_unwind_tables(struct module *mod) { }
289 static inline void unregister_unwind_tables(struct module *mod) { }
293 module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs,
294 struct module *module)
296 register_unwind_tables(module);
301 module_arch_cleanup(struct module *mod)
303 unregister_unwind_tables(mod);