/* * Kernel module help for s390. * * S390 version * Copyright IBM Corp. 2002, 2003 * Author(s): Arnd Bergmann (arndb@de.ibm.com) * Martin Schwidefsky (schwidefsky@de.ibm.com) * * based on i386 version * Copyright (C) 2001 Rusty Russell. * * 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 #include #include #include #include #include #include #include #if 0 #define DEBUGP printk #else #define DEBUGP(fmt , ...) #endif #ifndef CONFIG_64BIT #define PLT_ENTRY_SIZE 12 #else /* CONFIG_64BIT */ #define PLT_ENTRY_SIZE 20 #endif /* CONFIG_64BIT */ /* Free memory returned from module_alloc */ void module_free(struct module *mod, void *module_region) { if (mod) { vfree(mod->arch.syminfo); mod->arch.syminfo = NULL; } vfree(module_region); } static void check_rela(Elf_Rela *rela, struct module *me) { struct mod_arch_syminfo *info; info = me->arch.syminfo + ELF_R_SYM (rela->r_info); switch (ELF_R_TYPE (rela->r_info)) { case R_390_GOT12: /* 12 bit GOT offset. */ case R_390_GOT16: /* 16 bit GOT offset. */ case R_390_GOT20: /* 20 bit GOT offset. */ case R_390_GOT32: /* 32 bit GOT offset. */ case R_390_GOT64: /* 64 bit GOT offset. */ case R_390_GOTENT: /* 32 bit PC rel. to GOT entry shifted by 1. */ case R_390_GOTPLT12: /* 12 bit offset to jump slot. */ case R_390_GOTPLT16: /* 16 bit offset to jump slot. */ case R_390_GOTPLT20: /* 20 bit offset to jump slot. */ case R_390_GOTPLT32: /* 32 bit offset to jump slot. */ case R_390_GOTPLT64: /* 64 bit offset to jump slot. */ case R_390_GOTPLTENT: /* 32 bit rel. offset to jump slot >> 1. */ if (info->got_offset == -1UL) { info->got_offset = me->arch.got_size; me->arch.got_size += sizeof(void*); } break; case R_390_PLT16DBL: /* 16 bit PC rel. PLT shifted by 1. */ case R_390_PLT32DBL: /* 32 bit PC rel. PLT shifted by 1. */ case R_390_PLT32: /* 32 bit PC relative PLT address. */ case R_390_PLT64: /* 64 bit PC relative PLT address. */ case R_390_PLTOFF16: /* 16 bit offset from GOT to PLT. */ case R_390_PLTOFF32: /* 32 bit offset from GOT to PLT. */ case R_390_PLTOFF64: /* 16 bit offset from GOT to PLT. */ if (info->plt_offset == -1UL) { info->plt_offset = me->arch.plt_size; me->arch.plt_size += PLT_ENTRY_SIZE; } break; case R_390_COPY: case R_390_GLOB_DAT: case R_390_JMP_SLOT: case R_390_RELATIVE: /* Only needed if we want to support loading of modules linked with -shared. */ break; } } /* * Account for GOT and PLT relocations. We can't add sections for * got and plt but we can increase the core module size. */ int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs, char *secstrings, struct module *me) { Elf_Shdr *symtab; Elf_Sym *symbols; Elf_Rela *rela; char *strings; int nrela, i, j; /* Find symbol table and string table. */ symtab = NULL; for (i = 0; i < hdr->e_shnum; i++) switch (sechdrs[i].sh_type) { case SHT_SYMTAB: symtab = sechdrs + i; break; } if (!symtab) { printk(KERN_ERR "module %s: no symbol table\n", me->name); return -ENOEXEC; } /* Allocate one syminfo structure per symbol. */ me->arch.nsyms = symtab->sh_size / sizeof(Elf_Sym); me->arch.syminfo = vmalloc(me->arch.nsyms * sizeof(struct mod_arch_syminfo)); if (!me->arch.syminfo) return -ENOMEM; symbols = (void *) hdr + symtab->sh_offset; strings = (void *) hdr + sechdrs[symtab->sh_link].sh_offset; for (i = 0; i < me->arch.nsyms; i++) { if (symbols[i].st_shndx == SHN_UNDEF && strcmp(strings + symbols[i].st_name, "_GLOBAL_OFFSET_TABLE_") == 0) /* "Define" it as absolute. */ symbols[i].st_shndx = SHN_ABS; me->arch.syminfo[i].got_offset = -1UL; me->arch.syminfo[i].plt_offset = -1UL; me->arch.syminfo[i].got_initialized = 0; me->arch.syminfo[i].plt_initialized = 0; } /* Search for got/plt relocations. */ me->arch.got_size = me->arch.plt_size = 0; for (i = 0; i < hdr->e_shnum; i++) { if (sechdrs[i].sh_type != SHT_RELA) continue; nrela = sechdrs[i].sh_size / sizeof(Elf_Rela); rela = (void *) hdr + sechdrs[i].sh_offset; for (j = 0; j < nrela; j++) check_rela(rela + j, me); } /* Increase core size by size of got & plt and set start offsets for got and plt. */ me->core_size = ALIGN(me->core_size, 4); me->arch.got_offset = me->core_size; me->core_size += me->arch.got_size; me->arch.plt_offset = me->core_size; me->core_size += me->arch.plt_size; return 0; } static int apply_rela(Elf_Rela *rela, Elf_Addr base, Elf_Sym *symtab, struct module *me) { struct mod_arch_syminfo *info; Elf_Addr loc, val; int r_type, r_sym; /* This is where to make the change */ loc = base + rela->r_offset; /* This is the symbol it is referring to. Note that all undefined symbols have been resolved. */ r_sym = ELF_R_SYM(rela->r_info); r_type = ELF_R_TYPE(rela->r_info); info = me->arch.syminfo + r_sym; val = symtab[r_sym].st_value; switch (r_type) { case R_390_8: /* Direct 8 bit. */ case R_390_12: /* Direct 12 bit. */ case R_390_16: /* Direct 16 bit. */ case R_390_20: /* Direct 20 bit. */ case R_390_32: /* Direct 32 bit. */ case R_390_64: /* Direct 64 bit. */ val += rela->r_addend; if (r_type == R_390_8) *(unsigned char *) loc = val; else if (r_type == R_390_12) *(unsigned short *) loc = (val & 0xfff) | (*(unsigned short *) loc & 0xf000); else if (r_type == R_390_16) *(unsigned short *) loc = val; else if (r_type == R_390_20) *(unsigned int *) loc = (*(unsigned int *) loc & 0xf00000ff) | (val & 0xfff) << 16 | (val & 0xff000) >> 4; else if (r_type == R_390_32) *(unsigned int *) loc = val; else if (r_type == R_390_64) *(unsigned long *) loc = val; break; case R_390_PC16: /* PC relative 16 bit. */ case R_390_PC16DBL: /* PC relative 16 bit shifted by 1. */ case R_390_PC32DBL: /* PC relative 32 bit shifted by 1. */ case R_390_PC32: /* PC relative 32 bit. */ case R_390_PC64: /* PC relative 64 bit. */ val += rela->r_addend - loc; if (r_type == R_390_PC16) *(unsigned short *) loc = val; else if (r_type == R_390_PC16DBL) *(unsigned short *) loc = val >> 1; else if (r_type == R_390_PC32DBL) *(unsigned int *) loc = val >> 1; else if (r_type == R_390_PC32) *(unsigned int *) loc = val; else if (r_type == R_390_PC64) *(unsigned long *) loc = val; break; case R_390_GOT12: /* 12 bit GOT offset. */ case R_390_GOT16: /* 16 bit GOT offset. */ case R_390_GOT20: /* 20 bit GOT offset. */ case R_390_GOT32: /* 32 bit GOT offset. */ case R_390_GOT64: /* 64 bit GOT offset. */ case R_390_GOTENT: /* 32 bit PC rel. to GOT entry shifted by 1. */ case R_390_GOTPLT12: /* 12 bit offset to jump slot. */ case R_390_GOTPLT20: /* 20 bit offset to jump slot. */ case R_390_GOTPLT16: /* 16 bit offset to jump slot. */ case R_390_GOTPLT32: /* 32 bit offset to jump slot. */ case R_390_GOTPLT64: /* 64 bit offset to jump slot. */ case R_390_GOTPLTENT: /* 32 bit rel. offset to jump slot >> 1. */ if (info->got_initialized == 0) { Elf_Addr *gotent; gotent = me->module_core + me->arch.got_offset + info->got_offset; *gotent = val; info->got_initialized = 1; } val = info->got_offset + rela->r_addend; if (r_type == R_390_GOT12 || r_type == R_390_GOTPLT12) *(unsigned short *) loc = (val & 0xfff) | (*(unsigned short *) loc & 0xf000); else if (r_type == R_390_GOT16 || r_type == R_390_GOTPLT16) *(unsigned short *) loc = val; else if (r_type == R_390_GOT20 || r_type == R_390_GOTPLT20) *(unsigned int *) loc = (*(unsigned int *) loc & 0xf00000ff) | (val & 0xfff) << 16 | (val & 0xff000) >> 4; else if (r_type == R_390_GOT32 || r_type == R_390_GOTPLT32) *(unsigned int *) loc = val; else if (r_type == R_390_GOTENT || r_type == R_390_GOTPLTENT) *(unsigned int *) loc = (val + (Elf_Addr) me->module_core - loc) >> 1; else if (r_type == R_390_GOT64 || r_type == R_390_GOTPLT64) *(unsigned long *) loc = val; break; case R_390_PLT16DBL: /* 16 bit PC rel. PLT shifted by 1. */ case R_390_PLT32DBL: /* 32 bit PC rel. PLT shifted by 1. */ case R_390_PLT32: /* 32 bit PC relative PLT address. */ case R_390_PLT64: /* 64 bit PC relative PLT address. */ case R_390_PLTOFF16: /* 16 bit offset from GOT to PLT. */ case R_390_PLTOFF32: /* 32 bit offset from GOT to PLT. */ case R_390_PLTOFF64: /* 16 bit offset from GOT to PLT. */ if (info->plt_initialized == 0) { unsigned int *ip; ip = me->module_core + me->arch.plt_offset + info->plt_offset; #ifndef CONFIG_64BIT ip[0] = 0x0d105810; /* basr 1,0; l 1,6(1); br 1 */ ip[1] = 0x100607f1; ip[2] = val; #else /* CONFIG_64BIT */ ip[0] = 0x0d10e310; /* basr 1,0; lg 1,10(1); br 1 */ ip[1] = 0x100a0004; ip[2] = 0x07f10000; ip[3] = (unsigned int) (val >> 32); ip[4] = (unsigned int) val; #endif /* CONFIG_64BIT */ info->plt_initialized = 1; } if (r_type == R_390_PLTOFF16 || r_type == R_390_PLTOFF32 || r_type == R_390_PLTOFF64) val = me->arch.plt_offset - me->arch.got_offset + info->plt_offset + rela->r_addend; else { if (!((r_type == R_390_PLT16DBL && val - loc + 0xffffUL < 0x1ffffeUL) || (r_type == R_390_PLT32DBL && val - loc + 0xffffffffULL < 0x1fffffffeULL))) val = (Elf_Addr) me->module_core + me->arch.plt_offset + info->plt_offset; val += rela->r_addend - loc; } if (r_type == R_390_PLT16DBL) *(unsigned short *) loc = val >> 1; else if (r_type == R_390_PLTOFF16) *(unsigned short *) loc = val; else if (r_type == R_390_PLT32DBL) *(unsigned int *) loc = val >> 1; else if (r_type == R_390_PLT32 || r_type == R_390_PLTOFF32) *(unsigned int *) loc = val; else if (r_type == R_390_PLT64 || r_type == R_390_PLTOFF64) *(unsigned long *) loc = val; break; case R_390_GOTOFF16: /* 16 bit offset to GOT. */ case R_390_GOTOFF32: /* 32 bit offset to GOT. */ case R_390_GOTOFF64: /* 64 bit offset to GOT. */ val = val + rela->r_addend - ((Elf_Addr) me->module_core + me->arch.got_offset); if (r_type == R_390_GOTOFF16) *(unsigned short *) loc = val; else if (r_type == R_390_GOTOFF32) *(unsigned int *) loc = val; else if (r_type == R_390_GOTOFF64) *(unsigned long *) loc = val; break; case R_390_GOTPC: /* 32 bit PC relative offset to GOT. */ case R_390_GOTPCDBL: /* 32 bit PC rel. off. to GOT shifted by 1. */ val = (Elf_Addr) me->module_core + me->arch.got_offset + rela->r_addend - loc; if (r_type == R_390_GOTPC) *(unsigned int *) loc = val; else if (r_type == R_390_GOTPCDBL) *(unsigned int *) loc = val >> 1; break; case R_390_COPY: case R_390_GLOB_DAT: /* Create GOT entry. */ case R_390_JMP_SLOT: /* Create PLT entry. */ case R_390_RELATIVE: /* Adjust by program base. */ /* Only needed if we want to support loading of modules linked with -shared. */ break; default: printk(KERN_ERR "module %s: Unknown relocation: %u\n", me->name, r_type); return -ENOEXEC; } return 0; } int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab, unsigned int symindex, unsigned int relsec, struct module *me) { Elf_Addr base; Elf_Sym *symtab; Elf_Rela *rela; unsigned long i, n; int rc; DEBUGP("Applying relocate section %u to %u\n", relsec, sechdrs[relsec].sh_info); base = sechdrs[sechdrs[relsec].sh_info].sh_addr; symtab = (Elf_Sym *) sechdrs[symindex].sh_addr; rela = (Elf_Rela *) sechdrs[relsec].sh_addr; n = sechdrs[relsec].sh_size / sizeof(Elf_Rela); for (i = 0; i < n; i++, rela++) { rc = apply_rela(rela, base, symtab, me); if (rc) return rc; } return 0; } int module_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs, struct module *me) { vfree(me->arch.syminfo); me->arch.syminfo = NULL; return 0; }