diff options
Diffstat (limited to 'arch/ia64/kernel/module.c')
| -rw-r--r-- | arch/ia64/kernel/module.c | 957 |
1 files changed, 957 insertions, 0 deletions
diff --git a/arch/ia64/kernel/module.c b/arch/ia64/kernel/module.c new file mode 100644 index 000000000..2cba53c1d --- /dev/null +++ b/arch/ia64/kernel/module.c @@ -0,0 +1,957 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * IA-64-specific support for kernel module loader. + * + * Copyright (C) 2003 Hewlett-Packard Co + * David Mosberger-Tang <davidm@hpl.hp.com> + * + * 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 <linux/kernel.h> +#include <linux/sched.h> +#include <linux/elf.h> +#include <linux/moduleloader.h> +#include <linux/string.h> +#include <linux/vmalloc.h> + +#include <asm/patch.h> +#include <asm/unaligned.h> +#include <asm/sections.h> + +#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) != 1 && 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) != 1 && 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; + + 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->init_layout.base < mod->init_layout.size; +} + +static inline int +in_core (const struct module *mod, uint64_t addr) +{ + return addr - (uint64_t) mod->core_layout.base < mod->core_layout.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); + fallthrough; + 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->init_layout.base : mod->core_layout.base); + 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_layout.size > MAX_LTOFF) + /* + * This takes advantage of fact that SHF_ARCH_SMALL gets allocated + * at the end of the module. + */ + gp = mod->core_layout.size - MAX_LTOFF / 2; + else + gp = mod->core_layout.size / 2; + gp = (uint64_t) mod->core_layout.base + ((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) +{ + struct mod_arch_specific *mas = &mod->arch; + + DEBUGP("%s: init: entry=%p\n", __func__, mod->init); + if (mas->unwind) + register_unwind_table(mod); + + /* + * ".opd" was already relocated to the final destination. Store + * it's address for use in symbolizer. + */ + mas->opd_addr = (void *)mas->opd->sh_addr; + mas->opd_size = mas->opd->sh_size; + + /* + * Module relocation was already done at this point. Section + * headers are about to be deleted. Wipe out load-time context. + */ + mas->core_plt = NULL; + mas->init_plt = NULL; + mas->got = NULL; + mas->opd = NULL; + mas->unwind = NULL; + mas->gp = 0; + mas->next_got_entry = 0; + + return 0; +} + +void +module_arch_cleanup (struct module *mod) +{ + if (mod->arch.init_unw_table) { + unw_remove_unwind_table(mod->arch.init_unw_table); + mod->arch.init_unw_table = NULL; + } + if (mod->arch.core_unw_table) { + unw_remove_unwind_table(mod->arch.core_unw_table); + mod->arch.core_unw_table = NULL; + } +} + +void *dereference_module_function_descriptor(struct module *mod, void *ptr) +{ + struct mod_arch_specific *mas = &mod->arch; + + if (ptr < mas->opd_addr || ptr >= mas->opd_addr + mas->opd_size) + return ptr; + + return dereference_function_descriptor(ptr); +} |