diff options
Diffstat (limited to 'arch/x86/kernel/module.c')
| -rw-r--r-- | arch/x86/kernel/module.c | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/arch/x86/kernel/module.c b/arch/x86/kernel/module.c index 1ea42d083494..b92fbcf48609 100644 --- a/arch/x86/kernel/module.c +++ b/arch/x86/kernel/module.c @@ -34,6 +34,32 @@ #define DEBUGP(fmt...) #endif +#if defined(CONFIG_UML) || defined(CONFIG_X86_32) +void *module_alloc(unsigned long size) +{ + if (size == 0) + return NULL; + return vmalloc_exec(size); +} +#else /*X86_64*/ +void *module_alloc(unsigned long size) +{ + struct vm_struct *area; + + if (!size) + return NULL; + size = PAGE_ALIGN(size); + if (size > MODULES_LEN) + return NULL; + + area = __get_vm_area(size, VM_ALLOC, MODULES_VADDR, MODULES_END); + if (!area) + return NULL; + + return __vmalloc_area(area, GFP_KERNEL, PAGE_KERNEL_EXEC); +} +#endif + /* Free memory returned from module_alloc */ void module_free(struct module *mod, void *module_region) { @@ -51,6 +77,140 @@ int module_frob_arch_sections(Elf_Ehdr *hdr, return 0; } +#ifdef CONFIG_X86_32 +int apply_relocate(Elf32_Shdr *sechdrs, + const char *strtab, + unsigned int symindex, + unsigned int relsec, + struct module *me) +{ + unsigned int i; + Elf32_Rel *rel = (void *)sechdrs[relsec].sh_addr; + Elf32_Sym *sym; + uint32_t *location; + + DEBUGP("Applying relocate section %u to %u\n", relsec, + sechdrs[relsec].sh_info); + for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) { + /* This is where to make the change */ + location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr + + rel[i].r_offset; + /* This is the symbol it is referring to. Note that all + undefined symbols have been resolved. */ + sym = (Elf32_Sym *)sechdrs[symindex].sh_addr + + ELF32_R_SYM(rel[i].r_info); + + switch (ELF32_R_TYPE(rel[i].r_info)) { + case R_386_32: + /* We add the value into the location given */ + *location += sym->st_value; + break; + case R_386_PC32: + /* Add the value, subtract its postition */ + *location += sym->st_value - (uint32_t)location; + break; + default: + printk(KERN_ERR "module %s: Unknown relocation: %u\n", + me->name, ELF32_R_TYPE(rel[i].r_info)); + return -ENOEXEC; + } + } + return 0; +} + +int apply_relocate_add(Elf32_Shdr *sechdrs, + const char *strtab, + unsigned int symindex, + unsigned int relsec, + struct module *me) +{ + printk(KERN_ERR "module %s: ADD RELOCATION unsupported\n", + me->name); + return -ENOEXEC; +} +#else /*X86_64*/ +int apply_relocate_add(Elf64_Shdr *sechdrs, + const char *strtab, + unsigned int symindex, + unsigned int relsec, + struct module *me) +{ + unsigned int i; + Elf64_Rela *rel = (void *)sechdrs[relsec].sh_addr; + Elf64_Sym *sym; + void *loc; + u64 val; + + DEBUGP("Applying relocate section %u to %u\n", relsec, + sechdrs[relsec].sh_info); + for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) { + /* This is where to make the change */ + loc = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr + + rel[i].r_offset; + + /* This is the symbol it is referring to. Note that all + undefined symbols have been resolved. */ + sym = (Elf64_Sym *)sechdrs[symindex].sh_addr + + ELF64_R_SYM(rel[i].r_info); + + DEBUGP("type %d st_value %Lx r_addend %Lx loc %Lx\n", + (int)ELF64_R_TYPE(rel[i].r_info), + sym->st_value, rel[i].r_addend, (u64)loc); + + val = sym->st_value + rel[i].r_addend; + + switch (ELF64_R_TYPE(rel[i].r_info)) { + case R_X86_64_NONE: + break; + case R_X86_64_64: + *(u64 *)loc = val; + break; + case R_X86_64_32: + *(u32 *)loc = val; + if (val != *(u32 *)loc) + goto overflow; + break; + case R_X86_64_32S: + *(s32 *)loc = val; + if ((s64)val != *(s32 *)loc) + goto overflow; + break; + case R_X86_64_PC32: + val -= (u64)loc; + *(u32 *)loc = val; +#if 0 + if ((s64)val != *(s32 *)loc) + goto overflow; +#endif + break; + default: + printk(KERN_ERR "module %s: Unknown rela relocation: %llu\n", + me->name, ELF64_R_TYPE(rel[i].r_info)); + return -ENOEXEC; + } + } + return 0; + +overflow: + printk(KERN_ERR "overflow in relocation type %d val %Lx\n", + (int)ELF64_R_TYPE(rel[i].r_info), val); + printk(KERN_ERR "`%s' likely not compiled with -mcmodel=kernel\n", + me->name); + return -ENOEXEC; +} + +int apply_relocate(Elf_Shdr *sechdrs, + const char *strtab, + unsigned int symindex, + unsigned int relsec, + struct module *me) +{ + printk(KERN_ERR "non add relocation not supported\n"); + return -ENOSYS; +} + +#endif + int module_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs, struct module *me) |