/* Kernel module help for x86-64 Copyright (C) 2001 Rusty Russell. Copyright (C) 2002,2003 Andi Kleen, SuSE Labs. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include <linux/moduleloader.h> #include <linux/elf.h> #include <linux/vmalloc.h> #include <linux/fs.h> #include <linux/string.h> #include <linux/kernel.h> #include <linux/slab.h> #include <linux/bug.h> #include <asm/system.h> #include <asm/page.h> #include <asm/pgtable.h> #define DEBUGP(fmt...) #ifndef CONFIG_UML void module_free(struct module *mod, void *module_region) { vfree(module_region); /* FIXME: If module_region == mod->init_region, trim exception table entries. */ } 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 /* We don't need anything special. */ int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs, char *secstrings, struct module *mod) { return 0; } 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: %Lu\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("non add relocation not supported\n"); return -ENOSYS; } int module_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs, struct module *me) { const Elf_Shdr *s, *text = NULL, *alt = NULL, *locks = NULL; char *secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) { if (!strcmp(".text", secstrings + s->sh_name)) text = s; if (!strcmp(".altinstructions", secstrings + s->sh_name)) alt = s; if (!strcmp(".smp_locks", secstrings + s->sh_name)) locks= s; } if (alt) { /* patch .altinstructions */ void *aseg = (void *)alt->sh_addr; apply_alternatives(aseg, aseg + alt->sh_size); } if (locks && text) { void *lseg = (void *)locks->sh_addr; void *tseg = (void *)text->sh_addr; alternatives_smp_module_add(me, me->name, lseg, lseg + locks->sh_size, tseg, tseg + text->sh_size); } return module_bug_finalize(hdr, sechdrs, me); } void module_arch_cleanup(struct module *mod) { alternatives_smp_module_del(mod); module_bug_cleanup(mod); }