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/arch/i386/kernel/module.c

https://bitbucket.org/evzijst/gittest
C | 129 lines | 89 code | 13 blank | 27 comment | 6 complexity | 69bd0f581a821184fdbe7ac26f74fe5c MD5 | raw file
  1/*  Kernel module help for i386.
  2    Copyright (C) 2001 Rusty Russell.
  3
  4    This program is free software; you can redistribute it and/or modify
  5    it under the terms of the GNU General Public License as published by
  6    the Free Software Foundation; either version 2 of the License, or
  7    (at your option) any later version.
  8
  9    This program is distributed in the hope that it will be useful,
 10    but WITHOUT ANY WARRANTY; without even the implied warranty of
 11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 12    GNU General Public License for more details.
 13
 14    You should have received a copy of the GNU General Public License
 15    along with this program; if not, write to the Free Software
 16    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 17*/
 18#include <linux/moduleloader.h>
 19#include <linux/elf.h>
 20#include <linux/vmalloc.h>
 21#include <linux/fs.h>
 22#include <linux/string.h>
 23#include <linux/kernel.h>
 24
 25#if 0
 26#define DEBUGP printk
 27#else
 28#define DEBUGP(fmt...)
 29#endif
 30
 31void *module_alloc(unsigned long size)
 32{
 33	if (size == 0)
 34		return NULL;
 35	return vmalloc_exec(size);
 36}
 37
 38
 39/* Free memory returned from module_alloc */
 40void module_free(struct module *mod, void *module_region)
 41{
 42	vfree(module_region);
 43	/* FIXME: If module_region == mod->init_region, trim exception
 44           table entries. */
 45}
 46
 47/* We don't need anything special. */
 48int module_frob_arch_sections(Elf_Ehdr *hdr,
 49			      Elf_Shdr *sechdrs,
 50			      char *secstrings,
 51			      struct module *mod)
 52{
 53	return 0;
 54}
 55
 56int apply_relocate(Elf32_Shdr *sechdrs,
 57		   const char *strtab,
 58		   unsigned int symindex,
 59		   unsigned int relsec,
 60		   struct module *me)
 61{
 62	unsigned int i;
 63	Elf32_Rel *rel = (void *)sechdrs[relsec].sh_addr;
 64	Elf32_Sym *sym;
 65	uint32_t *location;
 66
 67	DEBUGP("Applying relocate section %u to %u\n", relsec,
 68	       sechdrs[relsec].sh_info);
 69	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
 70		/* This is where to make the change */
 71		location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
 72			+ rel[i].r_offset;
 73		/* This is the symbol it is referring to.  Note that all
 74		   undefined symbols have been resolved.  */
 75		sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
 76			+ ELF32_R_SYM(rel[i].r_info);
 77
 78		switch (ELF32_R_TYPE(rel[i].r_info)) {
 79		case R_386_32:
 80			/* We add the value into the location given */
 81			*location += sym->st_value;
 82			break;
 83		case R_386_PC32:
 84			/* Add the value, subtract its postition */
 85			*location += sym->st_value - (uint32_t)location;
 86			break;
 87		default:
 88			printk(KERN_ERR "module %s: Unknown relocation: %u\n",
 89			       me->name, ELF32_R_TYPE(rel[i].r_info));
 90			return -ENOEXEC;
 91		}
 92	}
 93	return 0;
 94}
 95
 96int apply_relocate_add(Elf32_Shdr *sechdrs,
 97		       const char *strtab,
 98		       unsigned int symindex,
 99		       unsigned int relsec,
100		       struct module *me)
101{
102	printk(KERN_ERR "module %s: ADD RELOCATION unsupported\n",
103	       me->name);
104	return -ENOEXEC;
105}
106
107extern void apply_alternatives(void *start, void *end); 
108
109int module_finalize(const Elf_Ehdr *hdr,
110		    const Elf_Shdr *sechdrs,
111		    struct module *me)
112{
113	const Elf_Shdr *s;
114	char *secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
115
116	/* look for .altinstructions to patch */ 
117	for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) { 
118		void *seg; 		
119		if (strcmp(".altinstructions", secstrings + s->sh_name))
120			continue;
121		seg = (void *)s->sh_addr; 
122		apply_alternatives(seg, seg + s->sh_size); 
123	} 	
124	return 0;
125}
126
127void module_arch_cleanup(struct module *mod)
128{
129}