| // SPDX-License-Identifier: GPL-2.0+ |
| /* |
| * 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. |
| */ |
| #include <linux/module.h> |
| #include <linux/elf.h> |
| #include <linux/vmalloc.h> |
| #include <linux/fs.h> |
| #include <linux/string.h> |
| #include <linux/kernel.h> |
| #include <linux/moduleloader.h> |
| #include <linux/bug.h> |
| #include <asm/alternative.h> |
| |
| #if 0 |
| #define DEBUGP printk |
| #else |
| #define DEBUGP(fmt , ...) |
| #endif |
| |
| #define PLT_ENTRY_SIZE 20 |
| |
| void *module_alloc(unsigned long size) |
| { |
| if (PAGE_ALIGN(size) > MODULES_LEN) |
| return NULL; |
| return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END, |
| GFP_KERNEL, PAGE_KERNEL_EXEC, |
| 0, NUMA_NO_NODE, |
| __builtin_return_address(0)); |
| } |
| |
| void module_arch_freeing_init(struct module *mod) |
| { |
| if (is_livepatch_module(mod) && |
| mod->state == MODULE_STATE_LIVE) |
| return; |
| |
| vfree(mod->arch.syminfo); |
| mod->arch.syminfo = NULL; |
| } |
| |
| 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_layout.size = ALIGN(me->core_layout.size, 4); |
| me->arch.got_offset = me->core_layout.size; |
| me->core_layout.size += me->arch.got_size; |
| me->arch.plt_offset = me->core_layout.size; |
| me->core_layout.size += me->arch.plt_size; |
| return 0; |
| } |
| |
| static int apply_rela_bits(Elf_Addr loc, Elf_Addr val, |
| int sign, int bits, int shift) |
| { |
| unsigned long umax; |
| long min, max; |
| |
| if (val & ((1UL << shift) - 1)) |
| return -ENOEXEC; |
| if (sign) { |
| val = (Elf_Addr)(((long) val) >> shift); |
| min = -(1L << (bits - 1)); |
| max = (1L << (bits - 1)) - 1; |
| if ((long) val < min || (long) val > max) |
| return -ENOEXEC; |
| } else { |
| val >>= shift; |
| umax = ((1UL << (bits - 1)) << 1) - 1; |
| if ((unsigned long) val > umax) |
| return -ENOEXEC; |
| } |
| |
| if (bits == 8) |
| *(unsigned char *) loc = val; |
| else if (bits == 12) |
| *(unsigned short *) loc = (val & 0xfff) | |
| (*(unsigned short *) loc & 0xf000); |
| else if (bits == 16) |
| *(unsigned short *) loc = val; |
| else if (bits == 20) |
| *(unsigned int *) loc = (val & 0xfff) << 16 | |
| (val & 0xff000) >> 4 | |
| (*(unsigned int *) loc & 0xf00000ff); |
| else if (bits == 32) |
| *(unsigned int *) loc = val; |
| else if (bits == 64) |
| *(unsigned long *) loc = val; |
| return 0; |
| } |
| |
| static int apply_rela(Elf_Rela *rela, Elf_Addr base, Elf_Sym *symtab, |
| const char *strtab, struct module *me) |
| { |
| struct mod_arch_syminfo *info; |
| Elf_Addr loc, val; |
| int r_type, r_sym; |
| int rc = -ENOEXEC; |
| |
| /* 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_NONE: /* No relocation. */ |
| rc = 0; |
| break; |
| 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) |
| rc = apply_rela_bits(loc, val, 0, 8, 0); |
| else if (r_type == R_390_12) |
| rc = apply_rela_bits(loc, val, 0, 12, 0); |
| else if (r_type == R_390_16) |
| rc = apply_rela_bits(loc, val, 0, 16, 0); |
| else if (r_type == R_390_20) |
| rc = apply_rela_bits(loc, val, 1, 20, 0); |
| else if (r_type == R_390_32) |
| rc = apply_rela_bits(loc, val, 0, 32, 0); |
| else if (r_type == R_390_64) |
| rc = apply_rela_bits(loc, val, 0, 64, 0); |
| 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) |
| rc = apply_rela_bits(loc, val, 1, 16, 0); |
| else if (r_type == R_390_PC16DBL) |
| rc = apply_rela_bits(loc, val, 1, 16, 1); |
| else if (r_type == R_390_PC32DBL) |
| rc = apply_rela_bits(loc, val, 1, 32, 1); |
| else if (r_type == R_390_PC32) |
| rc = apply_rela_bits(loc, val, 1, 32, 0); |
| else if (r_type == R_390_PC64) |
| rc = apply_rela_bits(loc, val, 1, 64, 0); |
| 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->core_layout.base + 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) |
| rc = apply_rela_bits(loc, val, 0, 12, 0); |
| else if (r_type == R_390_GOT16 || |
| r_type == R_390_GOTPLT16) |
| rc = apply_rela_bits(loc, val, 0, 16, 0); |
| else if (r_type == R_390_GOT20 || |
| r_type == R_390_GOTPLT20) |
| rc = apply_rela_bits(loc, val, 1, 20, 0); |
| else if (r_type == R_390_GOT32 || |
| r_type == R_390_GOTPLT32) |
| rc = apply_rela_bits(loc, val, 0, 32, 0); |
| else if (r_type == R_390_GOT64 || |
| r_type == R_390_GOTPLT64) |
| rc = apply_rela_bits(loc, val, 0, 64, 0); |
| else if (r_type == R_390_GOTENT || |
| r_type == R_390_GOTPLTENT) { |
| val += (Elf_Addr) me->core_layout.base - loc; |
| rc = apply_rela_bits(loc, val, 1, 32, 1); |
| } |
| 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->core_layout.base + me->arch.plt_offset + |
| info->plt_offset; |
| 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; |
| 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->core_layout.base + |
| me->arch.plt_offset + |
| info->plt_offset; |
| val += rela->r_addend - loc; |
| } |
| if (r_type == R_390_PLT16DBL) |
| rc = apply_rela_bits(loc, val, 1, 16, 1); |
| else if (r_type == R_390_PLTOFF16) |
| rc = apply_rela_bits(loc, val, 0, 16, 0); |
| else if (r_type == R_390_PLT32DBL) |
| rc = apply_rela_bits(loc, val, 1, 32, 1); |
| else if (r_type == R_390_PLT32 || |
| r_type == R_390_PLTOFF32) |
| rc = apply_rela_bits(loc, val, 0, 32, 0); |
| else if (r_type == R_390_PLT64 || |
| r_type == R_390_PLTOFF64) |
| rc = apply_rela_bits(loc, val, 0, 64, 0); |
| 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->core_layout.base + me->arch.got_offset); |
| if (r_type == R_390_GOTOFF16) |
| rc = apply_rela_bits(loc, val, 0, 16, 0); |
| else if (r_type == R_390_GOTOFF32) |
| rc = apply_rela_bits(loc, val, 0, 32, 0); |
| else if (r_type == R_390_GOTOFF64) |
| rc = apply_rela_bits(loc, val, 0, 64, 0); |
| 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->core_layout.base + me->arch.got_offset + |
| rela->r_addend - loc; |
| if (r_type == R_390_GOTPC) |
| rc = apply_rela_bits(loc, val, 1, 32, 0); |
| else if (r_type == R_390_GOTPCDBL) |
| rc = apply_rela_bits(loc, val, 1, 32, 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. */ |
| return -ENOEXEC; |
| default: |
| printk(KERN_ERR "module %s: unknown relocation: %u\n", |
| me->name, r_type); |
| return -ENOEXEC; |
| } |
| if (rc) { |
| printk(KERN_ERR "module %s: relocation error for symbol %s " |
| "(r_type %i, value 0x%lx)\n", |
| me->name, strtab + symtab[r_sym].st_name, |
| r_type, (unsigned long) val); |
| return rc; |
| } |
| 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, strtab, me); |
| if (rc) |
| return rc; |
| } |
| return 0; |
| } |
| |
| int module_finalize(const Elf_Ehdr *hdr, |
| const Elf_Shdr *sechdrs, |
| struct module *me) |
| { |
| const Elf_Shdr *s; |
| char *secstrings; |
| |
| secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; |
| for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) { |
| if (!strcmp(".altinstructions", secstrings + s->sh_name)) { |
| /* patch .altinstructions */ |
| void *aseg = (void *)s->sh_addr; |
| |
| apply_alternatives(aseg, aseg + s->sh_size); |
| } |
| } |
| |
| jump_label_apply_nops(me); |
| return 0; |
| } |