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#include <linux/bug.h> 25 26#define DEBUGP(fmt...) 27 28void *module_alloc(unsigned long size) 29{ 30 if (size == 0) 31 return NULL; 32 return vmalloc_exec(size); 33} 34 35 36/* Free memory returned from module_alloc */ 37void module_free(struct module *mod, void *module_region) 38{ 39 vfree(module_region); 40} 41 42/* We don't need anything special. */ 43int module_frob_arch_sections(Elf_Ehdr *hdr, 44 Elf_Shdr *sechdrs, 45 char *secstrings, 46 struct module *mod) 47{ 48 return 0; 49} 50 51int apply_relocate(Elf32_Shdr *sechdrs, 52 const char *strtab, 53 unsigned int symindex, 54 unsigned int relsec, 55 struct module *me) 56{ 57 unsigned int i; 58 Elf32_Rel *rel = (void *)sechdrs[relsec].sh_addr; 59 Elf32_Sym *sym; 60 uint32_t *location; 61 62 DEBUGP("Applying relocate section %u to %u\n", relsec, 63 sechdrs[relsec].sh_info); 64 for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) { 65 /* This is where to make the change */ 66 location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr 67 + rel[i].r_offset; 68 /* This is the symbol it is referring to. Note that all 69 undefined symbols have been resolved. */ 70 sym = (Elf32_Sym *)sechdrs[symindex].sh_addr 71 + ELF32_R_SYM(rel[i].r_info); 72 73 switch (ELF32_R_TYPE(rel[i].r_info)) { 74 case R_386_32: 75 /* We add the value into the location given */ 76 *location += sym->st_value; 77 break; 78 case R_386_PC32: 79 /* Add the value, subtract its postition */ 80 *location += sym->st_value - (uint32_t)location; 81 break; 82 default: 83 printk(KERN_ERR "module %s: Unknown relocation: %u\n", 84 me->name, ELF32_R_TYPE(rel[i].r_info)); 85 return -ENOEXEC; 86 } 87 } 88 return 0; 89} 90 91int apply_relocate_add(Elf32_Shdr *sechdrs, 92 const char *strtab, 93 unsigned int symindex, 94 unsigned int relsec, 95 struct module *me) 96{ 97 printk(KERN_ERR "module %s: ADD RELOCATION unsupported\n", 98 me->name); 99 return -ENOEXEC; 100} 101 102int module_finalize(const Elf_Ehdr *hdr, 103 const Elf_Shdr *sechdrs, 104 struct module *me) 105{ 106 const Elf_Shdr *s, *text = NULL, *alt = NULL, *locks = NULL, 107 *para = NULL; 108 char *secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; 109 110 for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) { 111 if (!strcmp(".text", secstrings + s->sh_name)) 112 text = s; 113 if (!strcmp(".altinstructions", secstrings + s->sh_name)) 114 alt = s; 115 if (!strcmp(".smp_locks", secstrings + s->sh_name)) 116 locks= s; 117 if (!strcmp(".parainstructions", secstrings + s->sh_name)) 118 para = s; 119 } 120 121 if (alt) { 122 /* patch .altinstructions */ 123 void *aseg = (void *)alt->sh_addr; 124 apply_alternatives(aseg, aseg + alt->sh_size); 125 } 126 if (locks && text) { 127 void *lseg = (void *)locks->sh_addr; 128 void *tseg = (void *)text->sh_addr; 129 alternatives_smp_module_add(me, me->name, 130 lseg, lseg + locks->sh_size, 131 tseg, tseg + text->sh_size); 132 } 133 134 if (para) { 135 void *pseg = (void *)para->sh_addr; 136 apply_paravirt(pseg, pseg + para->sh_size); 137 } 138 139 return module_bug_finalize(hdr, sechdrs, me); 140} 141 142void module_arch_cleanup(struct module *mod) 143{ 144 alternatives_smp_module_del(mod); 145 module_bug_cleanup(mod); 146} 147