elf_machdep.c revision 338867
1/*- 2 * Copyright 1996-1998 John D. Polstra. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24 */ 25 26#include <sys/cdefs.h> 27__FBSDID("$FreeBSD: stable/11/sys/i386/i386/elf_machdep.c 338867 2018-09-21 20:40:37Z markj $"); 28 29#include "opt_cpu.h" 30 31#include <sys/param.h> 32#include <sys/kernel.h> 33#include <sys/systm.h> 34#include <sys/exec.h> 35#include <sys/imgact.h> 36#include <sys/linker.h> 37#include <sys/proc.h> 38#include <sys/sysent.h> 39#include <sys/imgact_elf.h> 40#include <sys/syscall.h> 41#include <sys/signalvar.h> 42#include <sys/vnode.h> 43 44#include <vm/vm.h> 45#include <vm/pmap.h> 46#include <vm/vm_param.h> 47 48#include <machine/elf.h> 49#include <machine/md_var.h> 50#include <machine/npx.h> 51 52struct sysentvec elf32_freebsd_sysvec = { 53 .sv_size = SYS_MAXSYSCALL, 54 .sv_table = sysent, 55 .sv_mask = 0, 56 .sv_errsize = 0, 57 .sv_errtbl = NULL, 58 .sv_transtrap = NULL, 59 .sv_fixup = __elfN(freebsd_fixup), 60 .sv_sendsig = sendsig, 61 .sv_sigcode = sigcode, 62 .sv_szsigcode = &szsigcode, 63 .sv_name = "FreeBSD ELF32", 64 .sv_coredump = __elfN(coredump), 65 .sv_imgact_try = NULL, 66 .sv_minsigstksz = MINSIGSTKSZ, 67 .sv_pagesize = PAGE_SIZE, 68 .sv_minuser = VM_MIN_ADDRESS, 69 .sv_maxuser = VM_MAXUSER_ADDRESS, 70 .sv_usrstack = USRSTACK, 71 .sv_psstrings = PS_STRINGS, 72 .sv_stackprot = VM_PROT_ALL, 73 .sv_copyout_strings = exec_copyout_strings, 74 .sv_setregs = exec_setregs, 75 .sv_fixlimit = NULL, 76 .sv_maxssiz = NULL, 77 .sv_flags = SV_ABI_FREEBSD | SV_IA32 | SV_ILP32 | SV_SHP | 78 SV_TIMEKEEP, 79 .sv_set_syscall_retval = cpu_set_syscall_retval, 80 .sv_fetch_syscall_args = cpu_fetch_syscall_args, 81 .sv_syscallnames = syscallnames, 82 .sv_shared_page_base = SHAREDPAGE, 83 .sv_shared_page_len = PAGE_SIZE, 84 .sv_schedtail = NULL, 85 .sv_thread_detach = NULL, 86 .sv_trap = NULL, 87}; 88INIT_SYSENTVEC(elf32_sysvec, &elf32_freebsd_sysvec); 89 90static Elf32_Brandinfo freebsd_brand_info = { 91 .brand = ELFOSABI_FREEBSD, 92 .machine = EM_386, 93 .compat_3_brand = "FreeBSD", 94 .emul_path = NULL, 95 .interp_path = "/libexec/ld-elf.so.1", 96 .sysvec = &elf32_freebsd_sysvec, 97 .interp_newpath = NULL, 98 .brand_note = &elf32_freebsd_brandnote, 99 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 100}; 101 102SYSINIT(elf32, SI_SUB_EXEC, SI_ORDER_FIRST, 103 (sysinit_cfunc_t) elf32_insert_brand_entry, 104 &freebsd_brand_info); 105 106static Elf32_Brandinfo freebsd_brand_oinfo = { 107 .brand = ELFOSABI_FREEBSD, 108 .machine = EM_386, 109 .compat_3_brand = "FreeBSD", 110 .emul_path = NULL, 111 .interp_path = "/usr/libexec/ld-elf.so.1", 112 .sysvec = &elf32_freebsd_sysvec, 113 .interp_newpath = NULL, 114 .brand_note = &elf32_freebsd_brandnote, 115 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 116}; 117 118SYSINIT(oelf32, SI_SUB_EXEC, SI_ORDER_ANY, 119 (sysinit_cfunc_t) elf32_insert_brand_entry, 120 &freebsd_brand_oinfo); 121 122static Elf32_Brandinfo kfreebsd_brand_info = { 123 .brand = ELFOSABI_FREEBSD, 124 .machine = EM_386, 125 .compat_3_brand = "FreeBSD", 126 .emul_path = NULL, 127 .interp_path = "/lib/ld.so.1", 128 .sysvec = &elf32_freebsd_sysvec, 129 .interp_newpath = NULL, 130 .brand_note = &elf32_kfreebsd_brandnote, 131 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE_MANDATORY 132}; 133 134SYSINIT(kelf32, SI_SUB_EXEC, SI_ORDER_ANY, 135 (sysinit_cfunc_t) elf32_insert_brand_entry, 136 &kfreebsd_brand_info); 137 138 139void 140elf32_dump_thread(struct thread *td, void *dst, size_t *off) 141{ 142 void *buf; 143 size_t len; 144 145 len = 0; 146 if (use_xsave) { 147 if (dst != NULL) { 148 npxgetregs(td); 149 len += elf32_populate_note(NT_X86_XSTATE, 150 get_pcb_user_save_td(td), dst, 151 cpu_max_ext_state_size, &buf); 152 *(uint64_t *)((char *)buf + X86_XSTATE_XCR0_OFFSET) = 153 xsave_mask; 154 } else 155 len += elf32_populate_note(NT_X86_XSTATE, NULL, NULL, 156 cpu_max_ext_state_size, NULL); 157 } 158 *off = len; 159} 160 161bool 162elf_is_ifunc_reloc(Elf_Size r_info) 163{ 164 165 return (ELF_R_TYPE(r_info) == R_386_IRELATIVE); 166} 167 168#define ERI_LOCAL 0x0001 169 170/* Process one elf relocation with addend. */ 171static int 172elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data, 173 int type, elf_lookup_fn lookup, int flags) 174{ 175 Elf_Addr *where; 176 Elf_Addr addr; 177 Elf_Addr addend; 178 Elf_Word rtype, symidx; 179 const Elf_Rel *rel; 180 const Elf_Rela *rela; 181 int error; 182 183 switch (type) { 184 case ELF_RELOC_REL: 185 rel = (const Elf_Rel *)data; 186 where = (Elf_Addr *) (relocbase + rel->r_offset); 187 addend = *where; 188 rtype = ELF_R_TYPE(rel->r_info); 189 symidx = ELF_R_SYM(rel->r_info); 190 break; 191 case ELF_RELOC_RELA: 192 rela = (const Elf_Rela *)data; 193 where = (Elf_Addr *) (relocbase + rela->r_offset); 194 addend = rela->r_addend; 195 rtype = ELF_R_TYPE(rela->r_info); 196 symidx = ELF_R_SYM(rela->r_info); 197 break; 198 default: 199 panic("unknown reloc type %d\n", type); 200 } 201 202 if ((flags & ERI_LOCAL) != 0) { 203 if (rtype == R_386_RELATIVE) { /* A + B */ 204 addr = elf_relocaddr(lf, relocbase + addend); 205 if (*where != addr) 206 *where = addr; 207 } 208 return (0); 209 } 210 211 switch (rtype) { 212 213 case R_386_NONE: /* none */ 214 break; 215 216 case R_386_32: /* S + A */ 217 error = lookup(lf, symidx, 1, &addr); 218 if (error != 0) 219 return -1; 220 addr += addend; 221 if (*where != addr) 222 *where = addr; 223 break; 224 225 case R_386_PC32: /* S + A - P */ 226 error = lookup(lf, symidx, 1, &addr); 227 if (error != 0) 228 return -1; 229 addr += addend - (Elf_Addr)where; 230 if (*where != addr) 231 *where = addr; 232 break; 233 234 case R_386_COPY: /* none */ 235 /* 236 * There shouldn't be copy relocations in kernel 237 * objects. 238 */ 239 printf("kldload: unexpected R_COPY relocation\n"); 240 return -1; 241 break; 242 243 case R_386_GLOB_DAT: /* S */ 244 error = lookup(lf, symidx, 1, &addr); 245 if (error != 0) 246 return -1; 247 if (*where != addr) 248 *where = addr; 249 break; 250 251 case R_386_RELATIVE: 252 break; 253 254 case R_386_IRELATIVE: 255 addr = relocbase + addend; 256 addr = ((Elf_Addr (*)(void))addr)(); 257 if (*where != addr) 258 *where = addr; 259 break; 260 default: 261 printf("kldload: unexpected relocation type %d\n", 262 rtype); 263 return -1; 264 } 265 return(0); 266} 267 268int 269elf_reloc(linker_file_t lf, Elf_Addr relocbase, const void *data, int type, 270 elf_lookup_fn lookup) 271{ 272 273 return (elf_reloc_internal(lf, relocbase, data, type, lookup, 0)); 274} 275 276int 277elf_reloc_local(linker_file_t lf, Elf_Addr relocbase, const void *data, 278 int type, elf_lookup_fn lookup) 279{ 280 281 return (elf_reloc_internal(lf, relocbase, data, type, lookup, 282 ERI_LOCAL)); 283} 284 285int 286elf_cpu_load_file(linker_file_t lf __unused) 287{ 288 289 return (0); 290} 291 292int 293elf_cpu_unload_file(linker_file_t lf __unused) 294{ 295 296 return (0); 297} 298