/* * IA-64-specific support for kernel module loader. * * Copyright (C) 2003 Hewlett-Packard Co * David Mosberger-Tang * * Loosely based on patch by Rusty Russell. */ /* relocs tested so far: DIR64LSB FPTR64LSB GPREL22 LDXMOV LDXMOV LTOFF22 LTOFF22X LTOFF22X LTOFF_FPTR22 PCREL21B (for br.call only; br.cond is not supported out of modules!) PCREL60B (for brl.cond only; brl.call is not supported for modules!) PCREL64LSB SECREL32LSB SEGREL64LSB */ #include #include #include #include #include #include #include #include #define ARCH_MODULE_DEBUG 0 #if ARCH_MODULE_DEBUG # define DEBUGP printk # define inline #else # define DEBUGP(fmt , a...) #endif #ifdef CONFIG_ITANIUM # define USE_BRL 0 #else # define USE_BRL 1 #endif #define MAX_LTOFF ((uint64_t) (1 << 22)) /* max. allowable linkage-table offset */ /* Define some relocation helper macros/types: */ #define FORMAT_SHIFT 0 #define FORMAT_BITS 3 #define FORMAT_MASK ((1 << FORMAT_BITS) - 1) #define VALUE_SHIFT 3 #define VALUE_BITS 5 #define VALUE_MASK ((1 << VALUE_BITS) - 1) enum reloc_target_format { /* direct encoded formats: */ RF_NONE = 0, RF_INSN14 = 1, RF_INSN22 = 2, RF_INSN64 = 3, RF_32MSB = 4, RF_32LSB = 5, RF_64MSB = 6, RF_64LSB = 7, /* formats that cannot be directly decoded: */ RF_INSN60, RF_INSN21B, /* imm21 form 1 */ RF_INSN21M, /* imm21 form 2 */ RF_INSN21F /* imm21 form 3 */ }; enum reloc_value_formula { RV_DIRECT = 4, /* S + A */ RV_GPREL = 5, /* @gprel(S + A) */ RV_LTREL = 6, /* @ltoff(S + A) */ RV_PLTREL = 7, /* @pltoff(S + A) */ RV_FPTR = 8, /* @fptr(S + A) */ RV_PCREL = 9, /* S + A - P */ RV_LTREL_FPTR = 10, /* @ltoff(@fptr(S + A)) */ RV_SEGREL = 11, /* @segrel(S + A) */ RV_SECREL = 12, /* @secrel(S + A) */ RV_BDREL = 13, /* BD + A */ RV_LTV = 14, /* S + A (like RV_DIRECT, except frozen at static link-time) */ RV_PCREL2 = 15, /* S + A - P */ RV_SPECIAL = 16, /* various (see below) */ RV_RSVD17 = 17, RV_TPREL = 18, /* @tprel(S + A) */ RV_LTREL_TPREL = 19, /* @ltoff(@tprel(S + A)) */ RV_DTPMOD = 20, /* @dtpmod(S + A) */ RV_LTREL_DTPMOD = 21, /* @ltoff(@dtpmod(S + A)) */ RV_DTPREL = 22, /* @dtprel(S + A) */ RV_LTREL_DTPREL = 23, /* @ltoff(@dtprel(S + A)) */ RV_RSVD24 = 24, RV_RSVD25 = 25, RV_RSVD26 = 26, RV_RSVD27 = 27 /* 28-31 reserved for implementation-specific purposes. */ }; #define N(reloc) [R_IA64_##reloc] = #reloc static const char *reloc_name[256] = { N(NONE), N(IMM14), N(IMM22), N(IMM64), N(DIR32MSB), N(DIR32LSB), N(DIR64MSB), N(DIR64LSB), N(GPREL22), N(GPREL64I), N(GPREL32MSB), N(GPREL32LSB), N(GPREL64MSB), N(GPREL64LSB), N(LTOFF22), N(LTOFF64I), N(PLTOFF22), N(PLTOFF64I), N(PLTOFF64MSB), N(PLTOFF64LSB), N(FPTR64I), N(FPTR32MSB), N(FPTR32LSB), N(FPTR64MSB), N(FPTR64LSB), N(PCREL60B), N(PCREL21B), N(PCREL21M), N(PCREL21F), N(PCREL32MSB), N(PCREL32LSB), N(PCREL64MSB), N(PCREL64LSB), N(LTOFF_FPTR22), N(LTOFF_FPTR64I), N(LTOFF_FPTR32MSB), N(LTOFF_FPTR32LSB), N(LTOFF_FPTR64MSB), N(LTOFF_FPTR64LSB), N(SEGREL32MSB), N(SEGREL32LSB), N(SEGREL64MSB), N(SEGREL64LSB), N(SECREL32MSB), N(SECREL32LSB), N(SECREL64MSB), N(SECREL64LSB), N(REL32MSB), N(REL32LSB), N(REL64MSB), N(REL64LSB), N(LTV32MSB), N(LTV32LSB), N(LTV64MSB), N(LTV64LSB), N(PCREL21BI), N(PCREL22), N(PCREL64I), N(IPLTMSB), N(IPLTLSB), N(COPY), N(LTOFF22X), N(LDXMOV), N(TPREL14), N(TPREL22), N(TPREL64I), N(TPREL64MSB), N(TPREL64LSB), N(LTOFF_TPREL22), N(DTPMOD64MSB), N(DTPMOD64LSB), N(LTOFF_DTPMOD22), N(DTPREL14), N(DTPREL22), N(DTPREL64I), N(DTPREL32MSB), N(DTPREL32LSB), N(DTPREL64MSB), N(DTPREL64LSB), N(LTOFF_DTPREL22) }; #undef N /* Opaque struct for insns, to protect against derefs. */ struct insn; static inline uint64_t bundle (const struct insn *insn) { return (uint64_t) insn & ~0xfUL; } static inline int slot (const struct insn *insn) { return (uint64_t) insn & 0x3; } static int apply_imm64 (struct module *mod, struct insn *insn, uint64_t val) { if (slot(insn) != 2) { printk(KERN_ERR "%s: invalid slot number %d for IMM64\n", mod->name, slot(insn)); return 0; } ia64_patch_imm64((u64) insn, val); return 1; } static int apply_imm60 (struct module *mod, struct insn *insn, uint64_t val) { if (slot(insn) != 2) { printk(KERN_ERR "%s: invalid slot number %d for IMM60\n", mod->name, slot(insn)); return 0; } if (val + ((uint64_t) 1 << 59) >= (1UL << 60)) { printk(KERN_ERR "%s: value %ld out of IMM60 range\n", mod->name, (long) val); return 0; } ia64_patch_imm60((u64) insn, val); return 1; } static int apply_imm22 (struct module *mod, struct insn *insn, uint64_t val) { if (val + (1 << 21) >= (1 << 22)) { printk(KERN_ERR "%s: value %li out of IMM22 range\n", mod->name, (long)val); return 0; } ia64_patch((u64) insn, 0x01fffcfe000UL, ( ((val & 0x200000UL) << 15) /* bit 21 -> 36 */ | ((val & 0x1f0000UL) << 6) /* bit 16 -> 22 */ | ((val & 0x00ff80UL) << 20) /* bit 7 -> 27 */ | ((val & 0x00007fUL) << 13) /* bit 0 -> 13 */)); return 1; } static int apply_imm21b (struct module *mod, struct insn *insn, uint64_t val) { if (val + (1 << 20) >= (1 << 21)) { printk(KERN_ERR "%s: value %li out of IMM21b range\n", mod->name, (long)val); return 0; } ia64_patch((u64) insn, 0x11ffffe000UL, ( ((val & 0x100000UL) << 16) /* bit 20 -> 36 */ | ((val & 0x0fffffUL) << 13) /* bit 0 -> 13 */)); return 1; } #if USE_BRL struct plt_entry { /* Three instruction bundles in PLT. */ unsigned char bundle[2][16]; }; static const struct plt_entry ia64_plt_template = { { { 0x04, 0x00, 0x00, 0x00, 0x01, 0x00, /* [MLX] nop.m 0 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x20, /* movl gp=TARGET_GP */ 0x00, 0x00, 0x00, 0x60 }, { 0x05, 0x00, 0x00, 0x00, 0x01, 0x00, /* [MLX] nop.m 0 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* brl.many gp=TARGET_GP */ 0x08, 0x00, 0x00, 0xc0 } } }; static int patch_plt (struct module *mod, struct plt_entry *plt, long target_ip, unsigned long target_gp) { if (apply_imm64(mod, (struct insn *) (plt->bundle[0] + 2), target_gp) && apply_imm60(mod, (struct insn *) (plt->bundle[1] + 2), (target_ip - (int64_t) plt->bundle[1]) / 16)) return 1; return 0; } unsigned long plt_target (struct plt_entry *plt) { uint64_t b0, b1, *b = (uint64_t *) plt->bundle[1]; long off; b0 = b[0]; b1 = b[1]; off = ( ((b1 & 0x00fffff000000000UL) >> 36) /* imm20b -> bit 0 */ | ((b0 >> 48) << 20) | ((b1 & 0x7fffffUL) << 36) /* imm39 -> bit 20 */ | ((b1 & 0x0800000000000000UL) << 0)); /* i -> bit 59 */ return (long) plt->bundle[1] + 16*off; } #else /* !USE_BRL */ struct plt_entry { /* Three instruction bundles in PLT. */ unsigned char bundle[3][16]; }; static const struct plt_entry ia64_plt_template = { { { 0x05, 0x00, 0x00, 0x00, 0x01, 0x00, /* [MLX] nop.m 0 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* movl r16=TARGET_IP */ 0x02, 0x00, 0x00, 0x60 }, { 0x04, 0x00, 0x00, 0x00, 0x01, 0x00, /* [MLX] nop.m 0 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x20, /* movl gp=TARGET_GP */ 0x00, 0x00, 0x00, 0x60 }, { 0x11, 0x00, 0x00, 0x00, 0x01, 0x00, /* [MIB] nop.m 0 */ 0x60, 0x80, 0x04, 0x80, 0x03, 0x00, /* mov b6=r16 */ 0x60, 0x00, 0x80, 0x00 /* br.few b6 */ } } }; static int patch_plt (struct module *mod, struct plt_entry *plt, long target_ip, unsigned long target_gp) { if (apply_imm64(mod, (struct insn *) (plt->bundle[0] + 2), target_ip) && apply_imm64(mod, (struct insn *) (plt->bundle[1] + 2), target_gp)) return 1; return 0; } unsigned long plt_target (struct plt_entry *plt) { uint64_t b0, b1, *b = (uint64_t *) plt->bundle[0]; b0 = b[0]; b1 = b[1]; return ( ((b1 & 0x000007f000000000) >> 36) /* imm7b -> bit 0 */ | ((b1 & 0x07fc000000000000) >> 43) /* imm9d -> bit 7 */ | ((b1 & 0x0003e00000000000) >> 29) /* imm5c -> bit 16 */ | ((b1 & 0x0000100000000000) >> 23) /* ic -> bit 21 */ | ((b0 >> 46) << 22) | ((b1 & 0x7fffff) << 40) /* imm41 -> bit 22 */ | ((b1 & 0x0800000000000000) << 4)); /* i -> bit 63 */ } #endif /* !USE_BRL */ void module_arch_freeing_init (struct module *mod) { if (mod->arch.init_unw_table) { unw_remove_unwind_table(mod->arch.init_unw_table); mod->arch.init_unw_table = NULL; } } /* Have we already seen one of these relocations? */ /* FIXME: we could look in other sections, too --RR */ static int duplicate_reloc (const Elf64_Rela *rela, unsigned int num) { unsigned int i; for (i = 0; i < num; i++) { if (rela[i].r_info == rela[num].r_info && rela[i].r_addend == rela[num].r_addend) return 1; } return 0; } /* Count how many GOT entries we may need */ static unsigned int count_gots (const Elf64_Rela *rela, unsigned int num) { unsigned int i, ret = 0; /* Sure, this is order(n^2), but it's usually short, and not time critical */ for (i = 0; i < num; i++) { switch (ELF64_R_TYPE(rela[i].r_info)) { case R_IA64_LTOFF22: case R_IA64_LTOFF22X: case R_IA64_LTOFF64I: case R_IA64_LTOFF_FPTR22: case R_IA64_LTOFF_FPTR64I: case R_IA64_LTOFF_FPTR32MSB: case R_IA64_LTOFF_FPTR32LSB: case R_IA64_LTOFF_FPTR64MSB: case R_IA64_LTOFF_FPTR64LSB: if (!duplicate_reloc(rela, i)) ret++; break; } } return ret; } /* Count how many PLT entries we may need */ static unsigned int count_plts (const Elf64_Rela *rela, unsigned int num) { unsigned int i, ret = 0; /* Sure, this is order(n^2), but it's usually short, and not time critical */ for (i = 0; i < num; i++) { switch (ELF64_R_TYPE(rela[i].r_info)) { case R_IA64_PCREL21B: case R_IA64_PLTOFF22: case R_IA64_PLTOFF64I: case R_IA64_PLTOFF64MSB: case R_IA64_PLTOFF64LSB: case R_IA64_IPLTMSB: case R_IA64_IPLTLSB: if (!duplicate_reloc(rela, i)) ret++; break; } } return ret; } /* We need to create an function-descriptors for any internal function which is referenced. */ static unsigned int count_fdescs (const Elf64_Rela *rela, unsigned int num) { unsigned int i, ret = 0; /* Sure, this is order(n^2), but it's usually short, and not time critical. */ for (i = 0; i < num; i++) { switch (ELF64_R_TYPE(rela[i].r_info)) { case R_IA64_FPTR64I: case R_IA64_FPTR32LSB: case R_IA64_FPTR32MSB: case R_IA64_FPTR64LSB: case R_IA64_FPTR64MSB: case R_IA64_LTOFF_FPTR22: case R_IA64_LTOFF_FPTR32LSB: case R_IA64_LTOFF_FPTR32MSB: case R_IA64_LTOFF_FPTR64I: case R_IA64_LTOFF_FPTR64LSB: case R_IA64_LTOFF_FPTR64MSB: case R_IA64_IPLTMSB: case R_IA64_IPLTLSB: /* * Jumps to static functions sometimes go straight to their * offset. Of course, that may not be possible if the jump is * from init -> core or vice. versa, so we need to generate an * FDESC (and PLT etc) for that. */ case R_IA64_PCREL21B: if (!duplicate_reloc(rela, i)) ret++; break; } } return ret; } int module_frob_arch_sections (Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, char *secstrings, struct module *mod) { unsigned long core_plts = 0, init_plts = 0, gots = 0, fdescs = 0; Elf64_Shdr *s, *sechdrs_end = sechdrs + ehdr->e_shnum; /* * To store the PLTs and function-descriptors, we expand the .text section for * core module-code and the .init.text section for initialization code. */ for (s = sechdrs; s < sechdrs_end; ++s) if (strcmp(".core.plt", secstrings + s->sh_name) == 0) mod->arch.core_plt = s; else if (strcmp(".init.plt", secstrings + s->sh_name) == 0) mod->arch.init_plt = s; else if (strcmp(".got", secstrings + s->sh_name) == 0) mod->arch.got = s; else if (strcmp(".opd", secstrings + s->sh_name) == 0) mod->arch.opd = s; else if (strcmp(".IA_64.unwind", secstrings + s->sh_name) == 0) mod->arch.unwind = s; #ifdef CONFIG_PARAVIRT else if (strcmp(".paravirt_bundles", secstrings + s->sh_name) == 0) mod->arch.paravirt_bundles = s; else if (strcmp(".paravirt_insts", secstrings + s->sh_name) == 0) mod->arch.paravirt_insts = s; #endif if (!mod->arch.core_plt || !mod->arch.init_plt || !mod->arch.got || !mod->arch.opd) { printk(KERN_ERR "%s: sections missing\n", mod->name); return -ENOEXEC; } /* GOT and PLTs can occur in any relocated section... */ for (s = sechdrs + 1; s < sechdrs_end; ++s) { const Elf64_Rela *rels = (void *)ehdr + s->sh_offset; unsigned long numrels = s->sh_size/sizeof(Elf64_Rela); if (s->sh_type != SHT_RELA) continue; gots += count_gots(rels, numrels); fdescs += count_fdescs(rels, numrels); if (strstr(secstrings + s->sh_name, ".init")) init_plts += count_plts(rels, numrels); else core_plts += count_plts(rels, numrels); } mod->arch.core_plt->sh_type = SHT_NOBITS; mod->arch.core_plt->sh_flags = SHF_EXECINSTR | SHF_ALLOC; mod->arch.core_plt->sh_addralign = 16; mod->arch.core_plt->sh_size = core_plts * sizeof(struct plt_entry); mod->arch.init_plt->sh_type = SHT_NOBITS; mod->arch.init_plt->sh_flags = SHF_EXECINSTR | SHF_ALLOC; mod->arch.init_plt->sh_addralign = 16; mod->arch.init_plt->sh_size = init_plts * sizeof(struct plt_entry); mod->arch.got->sh_type = SHT_NOBITS; mod->arch.got->sh_flags = ARCH_SHF_SMALL | SHF_ALLOC; mod->arch.got->sh_addralign = 8; mod->arch.got->sh_size = gots * sizeof(struct got_entry); mod->arch.opd->sh_type = SHT_NOBITS; mod->arch.opd->sh_flags = SHF_ALLOC; mod->arch.opd->sh_addralign = 8; mod->arch.opd->sh_size = fdescs * sizeof(struct fdesc); DEBUGP("%s: core.plt=%lx, init.plt=%lx, got=%lx, fdesc=%lx\n", __func__, mod->arch.core_plt->sh_size, mod->arch.init_plt->sh_size, mod->arch.got->sh_size, mod->arch.opd->sh_size); return 0; } static inline int in_init (const struct module *mod, uint64_t addr) { return addr - (uint64_t) mod->module_init < mod->init_size; } static inline int in_core (const struct module *mod, uint64_t addr) { return addr - (uint64_t) mod->module_core < mod->core_size; } static inline int is_internal (const struct module *mod, uint64_t value) { return in_init(mod, value) || in_core(mod, value); } /* * Get gp-relative offset for the linkage-table entry of VALUE. */ static uint64_t get_ltoff (struct module *mod, uint64_t value, int *okp) { struct got_entry *got, *e; if (!*okp) return 0; got = (void *) mod->arch.got->sh_addr; for (e = got; e < got + mod->arch.next_got_entry; ++e) if (e->val == value) goto found; /* Not enough GOT entries? */ BUG_ON(e >= (struct got_entry *) (mod->arch.got->sh_addr + mod->arch.got->sh_size)); e->val = value; ++mod->arch.next_got_entry; found: return (uint64_t) e - mod->arch.gp; } static inline int gp_addressable (struct module *mod, uint64_t value) { return value - mod->arch.gp + MAX_LTOFF/2 < MAX_LTOFF; } /* Get PC-relative PLT entry for this value. Returns 0 on failure. */ static uint64_t get_plt (struct module *mod, const struct insn *insn, uint64_t value, int *okp) { struct plt_entry *plt, *plt_end; uint64_t target_ip, target_gp; if (!*okp) return 0; if (in_init(mod, (uint64_t) insn)) { plt = (void *) mod->arch.init_plt->sh_addr; plt_end = (void *) plt + mod->arch.init_plt->sh_size; } else { plt = (void *) mod->arch.core_plt->sh_addr; plt_end = (void *) plt + mod->arch.core_plt->sh_size; } /* "value" is a pointer to a function-descriptor; fetch the target ip/gp from it: */ target_ip = ((uint64_t *) value)[0]; target_gp = ((uint64_t *) value)[1]; /* Look for existing PLT entry. */ while (plt->bundle[0][0]) { if (plt_target(plt) == target_ip) goto found; if (++plt >= plt_end) BUG(); } *plt = ia64_plt_template; if (!patch_plt(mod, plt, target_ip, target_gp)) { *okp = 0; return 0; } #if ARCH_MODULE_DEBUG if (plt_target(plt) != target_ip) { printk("%s: mistargeted PLT: wanted %lx, got %lx\n", __func__, target_ip, plt_target(plt)); *okp = 0; return 0; } #endif found: return (uint64_t) plt; } /* Get function descriptor for VALUE. */ static uint64_t get_fdesc (struct module *mod, uint64_t value, int *okp) { struct fdesc *fdesc = (void *) mod->arch.opd->sh_addr; if (!*okp) return 0; if (!value) { printk(KERN_ERR "%s: fdesc for zero requested!\n", mod->name); return 0; } if (!is_internal(mod, value)) /* * If it's not a module-local entry-point, "value" already points to a * function-descriptor. */ return value; /* Look for existing function descriptor. */ while (fdesc->ip) { if (fdesc->ip == value) return (uint64_t)fdesc; if ((uint64_t) ++fdesc >= mod->arch.opd->sh_addr + mod->arch.opd->sh_size) BUG(); } /* Create new one */ fdesc->ip = value; fdesc->gp = mod->arch.gp; return (uint64_t) fdesc; } static inline int do_reloc (struct module *mod, uint8_t r_type, Elf64_Sym *sym, uint64_t addend, Elf64_Shdr *sec, void *location) { enum reloc_target_format format = (r_type >> FORMAT_SHIFT) & FORMAT_MASK; enum reloc_value_formula formula = (r_type >> VALUE_SHIFT) & VALUE_MASK; uint64_t val; int ok = 1; val = sym->st_value + addend; switch (formula) { case RV_SEGREL: /* segment base is arbitrarily chosen to be 0 for kernel modules */ case RV_DIRECT: break; case RV_GPREL: val -= mod->arch.gp; break; case RV_LTREL: val = get_ltoff(mod, val, &ok); break; case RV_PLTREL: val = get_plt(mod, location, val, &ok); break; case RV_FPTR: val = get_fdesc(mod, val, &ok); break; case RV_SECREL: val -= sec->sh_addr; break; case RV_LTREL_FPTR: val = get_ltoff(mod, get_fdesc(mod, val, &ok), &ok); break; case RV_PCREL: switch (r_type) { case R_IA64_PCREL21B: if ((in_init(mod, val) && in_core(mod, (uint64_t)location)) || (in_core(mod, val) && in_init(mod, (uint64_t)location))) { /* * Init section may have been allocated far away from core, * if the branch won't reach, then allocate a plt for it. */ uint64_t delta = ((int64_t)val - (int64_t)location) / 16; if (delta + (1 << 20) >= (1 << 21)) { val = get_fdesc(mod, val, &ok); val = get_plt(mod, location, val, &ok); } } else if (!is_internal(mod, val)) val = get_plt(mod, location, val, &ok); /* FALL THROUGH */ default: val -= bundle(location); break; case R_IA64_PCREL32MSB: case R_IA64_PCREL32LSB: case R_IA64_PCREL64MSB: case R_IA64_PCREL64LSB: val -= (uint64_t) location; break; } switch (r_type) { case R_IA64_PCREL60B: format = RF_INSN60; break; case R_IA64_PCREL21B: format = RF_INSN21B; break; case R_IA64_PCREL21M: format = RF_INSN21M; break; case R_IA64_PCREL21F: format = RF_INSN21F; break; default: break; } break; case RV_BDREL: val -= (uint64_t) (in_init(mod, val) ? mod->module_init : mod->module_core); break; case RV_LTV: /* can link-time value relocs happen here? */ BUG(); break; case RV_PCREL2: if (r_type == R_IA64_PCREL21BI) { if (!is_internal(mod, val)) { printk(KERN_ERR "%s: %s reloc against " "non-local symbol (%lx)\n", __func__, reloc_name[r_type], (unsigned long)val); return -ENOEXEC; } format = RF_INSN21B; } val -= bundle(location); break; case RV_SPECIAL: switch (r_type) { case R_IA64_IPLTMSB: case R_IA64_IPLTLSB: val = get_fdesc(mod, get_plt(mod, location, val, &ok), &ok); format = RF_64LSB; if (r_type == R_IA64_IPLTMSB) format = RF_64MSB; break; case R_IA64_SUB: val = addend - sym->st_value; format = RF_INSN64; break; case R_IA64_LTOFF22X: if (gp_addressable(mod, val)) val -= mod->arch.gp; else val = get_ltoff(mod, val, &ok); format = RF_INSN22; break; case R_IA64_LDXMOV: if (gp_addressable(mod, val)) { /* turn "ld8" into "mov": */ DEBUGP("%s: patching ld8 at %p to mov\n", __func__, location); ia64_patch((u64) location, 0x1fff80fe000UL, 0x10000000000UL); } return 0; default: if (reloc_name[r_type]) printk(KERN_ERR "%s: special reloc %s not supported", mod->name, reloc_name[r_type]); else printk(KERN_ERR "%s: unknown special reloc %x\n", mod->name, r_type); return -ENOEXEC; } break; case RV_TPREL: case RV_LTREL_TPREL: case RV_DTPMOD: case RV_LTREL_DTPMOD: case RV_DTPREL: case RV_LTREL_DTPREL: printk(KERN_ERR "%s: %s reloc not supported\n", mod->name, reloc_name[r_type] ? reloc_name[r_type] : "?"); return -ENOEXEC; default: printk(KERN_ERR "%s: unknown reloc %x\n", mod->name, r_type); return -ENOEXEC; } if (!ok) return -ENOEXEC; DEBUGP("%s: [%p]<-%016lx = %s(%lx)\n", __func__, location, val, reloc_name[r_type] ? reloc_name[r_type] : "?", sym->st_value + addend); switch (format) { case RF_INSN21B: ok = apply_imm21b(mod, location, (int64_t) val / 16); break; case RF_INSN22: ok = apply_imm22(mod, location, val); break; case RF_INSN64: ok = apply_imm64(mod, location, val); break; case RF_INSN60: ok = apply_imm60(mod, location, (int64_t) val / 16); break; case RF_32LSB: put_unaligned(val, (uint32_t *) location); break; case RF_64LSB: put_unaligned(val, (uint64_t *) location); break; case RF_32MSB: /* ia64 Linux is little-endian... */ case RF_64MSB: /* ia64 Linux is little-endian... */ case RF_INSN14: /* must be within-module, i.e., resolved by "ld -r" */ case RF_INSN21M: /* must be within-module, i.e., resolved by "ld -r" */ case RF_INSN21F: /* must be within-module, i.e., resolved by "ld -r" */ printk(KERN_ERR "%s: format %u needed by %s reloc is not supported\n", mod->name, format, reloc_name[r_type] ? reloc_name[r_type] : "?"); return -ENOEXEC; default: printk(KERN_ERR "%s: relocation %s resulted in unknown format %u\n", mod->name, reloc_name[r_type] ? reloc_name[r_type] : "?", format); return -ENOEXEC; } return ok ? 0 : -ENOEXEC; } int apply_relocate_add (Elf64_Shdr *sechdrs, const char *strtab, unsigned int symindex, unsigned int relsec, struct module *mod) { unsigned int i, n = sechdrs[relsec].sh_size / sizeof(Elf64_Rela); Elf64_Rela *rela = (void *) sechdrs[relsec].sh_addr; Elf64_Shdr *target_sec; int ret; DEBUGP("%s: applying section %u (%u relocs) to %u\n", __func__, relsec, n, sechdrs[relsec].sh_info); target_sec = sechdrs + sechdrs[relsec].sh_info; if (target_sec->sh_entsize == ~0UL) /* * If target section wasn't allocated, we don't need to relocate it. * Happens, e.g., for debug sections. */ return 0; if (!mod->arch.gp) { /* * XXX Should have an arch-hook for running this after final section * addresses have been selected... */ uint64_t gp; if (mod->core_size > MAX_LTOFF) /* * This takes advantage of fact that SHF_ARCH_SMALL gets allocated * at the end of the module. */ gp = mod->core_size - MAX_LTOFF / 2; else gp = mod->core_size / 2; gp = (uint64_t) mod->module_core + ((gp + 7) & -8); mod->arch.gp = gp; DEBUGP("%s: placing gp at 0x%lx\n", __func__, gp); } for (i = 0; i < n; i++) { ret = do_reloc(mod, ELF64_R_TYPE(rela[i].r_info), ((Elf64_Sym *) sechdrs[symindex].sh_addr + ELF64_R_SYM(rela[i].r_info)), rela[i].r_addend, target_sec, (void *) target_sec->sh_addr + rela[i].r_offset); if (ret < 0) return ret; } return 0; } /* * Modules contain a single unwind table which covers both the core and the init text * sections but since the two are not contiguous, we need to split this table up such that * we can register (and unregister) each "segment" separately. Fortunately, this sounds * more complicated than it really is. */ static void register_unwind_table (struct module *mod) { struct unw_table_entry *start = (void *) mod->arch.unwind->sh_addr; struct unw_table_entry *end = start + mod->arch.unwind->sh_size / sizeof (*start); struct unw_table_entry tmp, *e1, *e2, *core, *init; unsigned long num_init = 0, num_core = 0; /* First, count how many init and core unwind-table entries there are. */ for (e1 = start; e1 < end; ++e1) if (in_init(mod, e1->start_offset)) ++num_init; else ++num_core; /* * Second, sort the table such that all unwind-table entries for the init and core * text sections are nicely separated. We do this with a stupid bubble sort * (unwind tables don't get ridiculously huge). */ for (e1 = start; e1 < end; ++e1) { for (e2 = e1 + 1; e2 < end; ++e2) { if (e2->start_offset < e1->start_offset) { tmp = *e1; *e1 = *e2; *e2 = tmp; } } } /* * Third, locate the init and core segments in the unwind table: */ if (in_init(mod, start->start_offset)) { init = start; core = start + num_init; } else { core = start; init = start + num_core; } DEBUGP("%s: name=%s, gp=%lx, num_init=%lu, num_core=%lu\n", __func__, mod->name, mod->arch.gp, num_init, num_core); /* * Fourth, register both tables (if not empty). */ if (num_core > 0) { mod->arch.core_unw_table = unw_add_unwind_table(mod->name, 0, mod->arch.gp, core, core + num_core); DEBUGP("%s: core: handle=%p [%p-%p)\n", __func__, mod->arch.core_unw_table, core, core + num_core); } if (num_init > 0) { mod->arch.init_unw_table = unw_add_unwind_table(mod->name, 0, mod->arch.gp, init, init + num_init); DEBUGP("%s: init: handle=%p [%p-%p)\n", __func__, mod->arch.init_unw_table, init, init + num_init); } } int module_finalize (const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs, struct module *mod) { DEBUGP("%s: init: entry=%p\n", __func__, mod->init); if (mod->arch.unwind) register_unwind_table(mod); #ifdef CONFIG_PARAVIRT if (mod->arch.paravirt_bundles) { struct paravirt_patch_site_bundle *start = (struct paravirt_patch_site_bundle *) mod->arch.paravirt_bundles->sh_addr; struct paravirt_patch_site_bundle *end = (struct paravirt_patch_site_bundle *) (mod->arch.paravirt_bundles->sh_addr + mod->arch.paravirt_bundles->sh_size); paravirt_patch_apply_bundle(start, end); } if (mod->arch.paravirt_insts) { struct paravirt_patch_site_inst *start = (struct paravirt_patch_site_inst *) mod->arch.paravirt_insts->sh_addr; struct paravirt_patch_site_inst *end = (struct paravirt_patch_site_inst *) (mod->arch.paravirt_insts->sh_addr + mod->arch.paravirt_insts->sh_size); paravirt_patch_apply_inst(start, end); } #endif return 0; } void module_arch_cleanup (struct module *mod) { if (mod->arch.init_unw_table) unw_remove_unwind_table(mod->arch.init_unw_table); if (mod->arch.core_unw_table) unw_remove_unwind_table(mod->arch.core_unw_table); }