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  • only in /netgear-R7000-V1.0.7.12_1.2.5/components/opensource/linux/linux-2.6.36/arch/arm/kernel/
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/unwind.h>
26
27#ifdef CONFIG_XIP_KERNEL
28/*
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.
33 */
34#undef MODULES_VADDR
35#define MODULES_VADDR	(((unsigned long)_etext + ~PGDIR_MASK) & PGDIR_MASK)
36#endif
37
38#ifdef CONFIG_MMU
39void *module_alloc(unsigned long size)
40{
41	struct vm_struct *area;
42
43	size = PAGE_ALIGN(size);
44	if (!size)
45		return NULL;
46
47	area = __get_vm_area(size, VM_ALLOC, MODULES_VADDR, MODULES_END);
48	if (!area)
49		return NULL;
50
51	return __vmalloc_area(area, GFP_KERNEL, PAGE_KERNEL_EXEC);
52}
53#else /* CONFIG_MMU */
54void *module_alloc(unsigned long size)
55{
56	return size == 0 ? NULL : vmalloc(size);
57}
58#endif /* !CONFIG_MMU */
59
60void module_free(struct module *module, void *region)
61{
62	vfree(region);
63}
64
65int module_frob_arch_sections(Elf_Ehdr *hdr,
66			      Elf_Shdr *sechdrs,
67			      char *secstrings,
68			      struct module *mod)
69{
70#ifdef CONFIG_ARM_UNWIND
71	Elf_Shdr *s, *sechdrs_end = sechdrs + hdr->e_shnum;
72
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;
86	}
87#endif
88	return 0;
89}
90
91int
92apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex,
93	       unsigned int relindex, struct module *module)
94{
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;
99	unsigned int i;
100
101	for (i = 0; i < relsec->sh_size / sizeof(Elf32_Rel); i++, rel++) {
102		unsigned long loc;
103		Elf32_Sym *sym;
104		s32 offset;
105#ifdef CONFIG_THUMB2_KERNEL
106		u32 upper, lower, sign, j1, j2;
107#endif
108
109		offset = ELF32_R_SYM(rel->r_info);
110		if (offset < 0 || offset > (symsec->sh_size / sizeof(Elf32_Sym))) {
111			printk(KERN_ERR "%s: bad relocation, section %d reloc %d\n",
112				module->name, relindex, i);
113			return -ENOEXEC;
114		}
115
116		sym = ((Elf32_Sym *)symsec->sh_addr) + offset;
117
118		if (rel->r_offset < 0 || rel->r_offset > dstsec->sh_size - sizeof(u32)) {
119			printk(KERN_ERR "%s: out of bounds relocation, "
120				"section %d reloc %d offset %d size %d\n",
121				module->name, relindex, i, rel->r_offset,
122				dstsec->sh_size);
123			return -ENOEXEC;
124		}
125
126		loc = dstsec->sh_addr + rel->r_offset;
127
128		switch (ELF32_R_TYPE(rel->r_info)) {
129		case R_ARM_NONE:
130			/* ignore */
131			break;
132
133		case R_ARM_ABS32:
134			*(u32 *)loc += sym->st_value;
135			break;
136
137		case R_ARM_PC24:
138		case R_ARM_CALL:
139		case R_ARM_JUMP24:
140			offset = (*(u32 *)loc & 0x00ffffff) << 2;
141			if (offset & 0x02000000)
142				offset -= 0x04000000;
143
144			offset += sym->st_value - loc;
145			if (offset & 3 ||
146			    offset <= (s32)0xfe000000 ||
147			    offset >= (s32)0x02000000) {
148				printk(KERN_ERR
149				       "%s: relocation out of range, section "
150				       "%d reloc %d sym '%s'\n", module->name,
151				       relindex, i, strtab + sym->st_name);
152				return -ENOEXEC;
153			}
154
155			offset >>= 2;
156
157			*(u32 *)loc &= 0xff000000;
158			*(u32 *)loc |= offset & 0x00ffffff;
159			break;
160
161	       case R_ARM_V4BX:
162		       /* Preserve Rm and the condition code. Alter
163			* other bits to re-code instruction as
164			* MOV PC,Rm.
165			*/
166		       *(u32 *)loc &= 0xf000000f;
167		       *(u32 *)loc |= 0x01a0f000;
168		       break;
169
170		case R_ARM_PREL31:
171			offset = *(u32 *)loc + sym->st_value - loc;
172			*(u32 *)loc = offset & 0x7fffffff;
173			break;
174
175		case R_ARM_MOVW_ABS_NC:
176		case R_ARM_MOVT_ABS:
177			offset = *(u32 *)loc;
178			offset = ((offset & 0xf0000) >> 4) | (offset & 0xfff);
179			offset = (offset ^ 0x8000) - 0x8000;
180
181			offset += sym->st_value;
182			if (ELF32_R_TYPE(rel->r_info) == R_ARM_MOVT_ABS)
183				offset >>= 16;
184
185			*(u32 *)loc &= 0xfff0f000;
186			*(u32 *)loc |= ((offset & 0xf000) << 4) |
187					(offset & 0x0fff);
188			break;
189
190#ifdef CONFIG_THUMB2_KERNEL
191		case R_ARM_THM_CALL:
192		case R_ARM_THM_JUMP24:
193			upper = *(u16 *)loc;
194			lower = *(u16 *)(loc + 2);
195
196			/*
197			 * 25 bit signed address range (Thumb-2 BL and B.W
198			 * instructions):
199			 *   S:I1:I2:imm10:imm11:0
200			 * where:
201			 *   S     = upper[10]   = offset[24]
202			 *   I1    = ~(J1 ^ S)   = offset[23]
203			 *   I2    = ~(J2 ^ S)   = offset[22]
204			 *   imm10 = upper[9:0]  = offset[21:12]
205			 *   imm11 = lower[10:0] = offset[11:1]
206			 *   J1    = lower[13]
207			 *   J2    = lower[11]
208			 */
209			sign = (upper >> 10) & 1;
210			j1 = (lower >> 13) & 1;
211			j2 = (lower >> 11) & 1;
212			offset = (sign << 24) | ((~(j1 ^ sign) & 1) << 23) |
213				((~(j2 ^ sign) & 1) << 22) |
214				((upper & 0x03ff) << 12) |
215				((lower & 0x07ff) << 1);
216			if (offset & 0x01000000)
217				offset -= 0x02000000;
218			offset += sym->st_value - loc;
219
220			/* only Thumb addresses allowed (no interworking) */
221			if (!(offset & 1) ||
222			    offset <= (s32)0xff000000 ||
223			    offset >= (s32)0x01000000) {
224				printk(KERN_ERR
225				       "%s: relocation out of range, section "
226				       "%d reloc %d sym '%s'\n", module->name,
227				       relindex, i, strtab + sym->st_name);
228				return -ENOEXEC;
229			}
230
231			sign = (offset >> 24) & 1;
232			j1 = sign ^ (~(offset >> 23) & 1);
233			j2 = sign ^ (~(offset >> 22) & 1);
234			*(u16 *)loc = (u16)((upper & 0xf800) | (sign << 10) |
235					    ((offset >> 12) & 0x03ff));
236			*(u16 *)(loc + 2) = (u16)((lower & 0xd000) |
237						  (j1 << 13) | (j2 << 11) |
238						  ((offset >> 1) & 0x07ff));
239			break;
240
241		case R_ARM_THM_MOVW_ABS_NC:
242		case R_ARM_THM_MOVT_ABS:
243			upper = *(u16 *)loc;
244			lower = *(u16 *)(loc + 2);
245
246			/*
247			 * MOVT/MOVW instructions encoding in Thumb-2:
248			 *
249			 * i	= upper[10]
250			 * imm4	= upper[3:0]
251			 * imm3	= lower[14:12]
252			 * imm8	= lower[7:0]
253			 *
254			 * imm16 = imm4:i:imm3:imm8
255			 */
256			offset = ((upper & 0x000f) << 12) |
257				((upper & 0x0400) << 1) |
258				((lower & 0x7000) >> 4) | (lower & 0x00ff);
259			offset = (offset ^ 0x8000) - 0x8000;
260			offset += sym->st_value;
261
262			if (ELF32_R_TYPE(rel->r_info) == R_ARM_THM_MOVT_ABS)
263				offset >>= 16;
264
265			*(u16 *)loc = (u16)((upper & 0xfbf0) |
266					    ((offset & 0xf000) >> 12) |
267					    ((offset & 0x0800) >> 1));
268			*(u16 *)(loc + 2) = (u16)((lower & 0x8f00) |
269						  ((offset & 0x0700) << 4) |
270						  (offset & 0x00ff));
271			break;
272#endif
273
274		default:
275			printk(KERN_ERR "%s: unknown relocation: %u\n",
276			       module->name, ELF32_R_TYPE(rel->r_info));
277			return -ENOEXEC;
278		}
279	}
280	return 0;
281}
282
283int
284apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab,
285		   unsigned int symindex, unsigned int relsec, struct module *module)
286{
287	printk(KERN_ERR "module %s: ADD RELOCATION unsupported\n",
288	       module->name);
289	return -ENOEXEC;
290}
291
292#ifdef CONFIG_ARM_UNWIND
293static void register_unwind_tables(struct module *mod)
294{
295	if (mod->arch.unw_sec_init && mod->arch.sec_init_text)
296		mod->arch.unwind_init =
297			unwind_table_add(mod->arch.unw_sec_init->sh_addr,
298					 mod->arch.unw_sec_init->sh_size,
299					 mod->arch.sec_init_text->sh_addr,
300					 mod->arch.sec_init_text->sh_size);
301	if (mod->arch.unw_sec_devinit && mod->arch.sec_devinit_text)
302		mod->arch.unwind_devinit =
303			unwind_table_add(mod->arch.unw_sec_devinit->sh_addr,
304					 mod->arch.unw_sec_devinit->sh_size,
305					 mod->arch.sec_devinit_text->sh_addr,
306					 mod->arch.sec_devinit_text->sh_size);
307	if (mod->arch.unw_sec_core && mod->arch.sec_core_text)
308		mod->arch.unwind_core =
309			unwind_table_add(mod->arch.unw_sec_core->sh_addr,
310					 mod->arch.unw_sec_core->sh_size,
311					 mod->arch.sec_core_text->sh_addr,
312					 mod->arch.sec_core_text->sh_size);
313}
314
315static void unregister_unwind_tables(struct module *mod)
316{
317	unwind_table_del(mod->arch.unwind_init);
318	unwind_table_del(mod->arch.unwind_devinit);
319	unwind_table_del(mod->arch.unwind_core);
320}
321#else
322static inline void register_unwind_tables(struct module *mod) { }
323static inline void unregister_unwind_tables(struct module *mod) { }
324#endif
325
326int
327module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs,
328		struct module *module)
329{
330	register_unwind_tables(module);
331	return 0;
332}
333
334void
335module_arch_cleanup(struct module *mod)
336{
337	unregister_unwind_tables(mod);
338}
339