1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright 1996-1998 John D. Polstra. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 #include <sys/cdefs.h> 29 __FBSDID("$FreeBSD$"); 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/fpu.h> 50 #include <machine/md_var.h> 51 52 struct sysentvec elf64_freebsd_sysvec = { 53 .sv_size = SYS_MAXSYSCALL, 54 .sv_table = sysent, 55 .sv_errsize = 0, 56 .sv_errtbl = NULL, 57 .sv_transtrap = NULL, 58 .sv_fixup = __elfN(freebsd_fixup), 59 .sv_sendsig = sendsig, 60 .sv_sigcode = sigcode, 61 .sv_szsigcode = &szsigcode, 62 .sv_name = "FreeBSD ELF64", 63 .sv_coredump = __elfN(coredump), 64 .sv_imgact_try = NULL, 65 .sv_minsigstksz = MINSIGSTKSZ, 66 .sv_minuser = VM_MIN_ADDRESS, 67 .sv_maxuser = VM_MAXUSER_ADDRESS, 68 .sv_usrstack = USRSTACK, 69 .sv_psstrings = PS_STRINGS, 70 .sv_stackprot = VM_PROT_ALL, 71 .sv_copyout_auxargs = __elfN(freebsd_copyout_auxargs), 72 .sv_copyout_strings = exec_copyout_strings, 73 .sv_setregs = exec_setregs, 74 .sv_fixlimit = NULL, 75 .sv_maxssiz = NULL, 76 .sv_flags = SV_ABI_FREEBSD | SV_ASLR | SV_LP64 | SV_SHP | 77 SV_TIMEKEEP, 78 .sv_set_syscall_retval = cpu_set_syscall_retval, 79 .sv_fetch_syscall_args = cpu_fetch_syscall_args, 80 .sv_syscallnames = syscallnames, 81 .sv_shared_page_base = SHAREDPAGE, 82 .sv_shared_page_len = PAGE_SIZE, 83 .sv_schedtail = NULL, 84 .sv_thread_detach = NULL, 85 .sv_trap = NULL, 86 .sv_stackgap = elf64_stackgap, 87 }; 88 INIT_SYSENTVEC(elf64_sysvec, &elf64_freebsd_sysvec); 89 90 void 91 amd64_lower_shared_page(struct sysentvec *sv) 92 { 93 if (hw_lower_amd64_sharedpage != 0) { 94 sv->sv_maxuser -= PAGE_SIZE; 95 sv->sv_shared_page_base -= PAGE_SIZE; 96 sv->sv_usrstack -= PAGE_SIZE; 97 sv->sv_psstrings -= PAGE_SIZE; 98 } 99 } 100 101 /* 102 * Do this fixup before INIT_SYSENTVEC (SI_ORDER_ANY) because the latter 103 * uses the value of sv_shared_page_base. 104 */ 105 SYSINIT(elf64_sysvec_fixup, SI_SUB_EXEC, SI_ORDER_FIRST, 106 (sysinit_cfunc_t) amd64_lower_shared_page, 107 &elf64_freebsd_sysvec); 108 109 static Elf64_Brandinfo freebsd_brand_info = { 110 .brand = ELFOSABI_FREEBSD, 111 .machine = EM_X86_64, 112 .compat_3_brand = "FreeBSD", 113 .emul_path = NULL, 114 .interp_path = "/libexec/ld-elf.so.1", 115 .sysvec = &elf64_freebsd_sysvec, 116 .interp_newpath = NULL, 117 .brand_note = &elf64_freebsd_brandnote, 118 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 119 }; 120 121 SYSINIT(elf64, SI_SUB_EXEC, SI_ORDER_FIRST, 122 (sysinit_cfunc_t) elf64_insert_brand_entry, 123 &freebsd_brand_info); 124 125 static Elf64_Brandinfo freebsd_brand_oinfo = { 126 .brand = ELFOSABI_FREEBSD, 127 .machine = EM_X86_64, 128 .compat_3_brand = "FreeBSD", 129 .emul_path = NULL, 130 .interp_path = "/usr/libexec/ld-elf.so.1", 131 .sysvec = &elf64_freebsd_sysvec, 132 .interp_newpath = NULL, 133 .brand_note = &elf64_freebsd_brandnote, 134 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 135 }; 136 137 SYSINIT(oelf64, SI_SUB_EXEC, SI_ORDER_ANY, 138 (sysinit_cfunc_t) elf64_insert_brand_entry, 139 &freebsd_brand_oinfo); 140 141 static Elf64_Brandinfo kfreebsd_brand_info = { 142 .brand = ELFOSABI_FREEBSD, 143 .machine = EM_X86_64, 144 .compat_3_brand = "FreeBSD", 145 .emul_path = NULL, 146 .interp_path = "/lib/ld-kfreebsd-x86-64.so.1", 147 .sysvec = &elf64_freebsd_sysvec, 148 .interp_newpath = NULL, 149 .brand_note = &elf64_kfreebsd_brandnote, 150 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE_MANDATORY 151 }; 152 153 SYSINIT(kelf64, SI_SUB_EXEC, SI_ORDER_ANY, 154 (sysinit_cfunc_t) elf64_insert_brand_entry, 155 &kfreebsd_brand_info); 156 157 void 158 elf64_dump_thread(struct thread *td, void *dst, size_t *off) 159 { 160 void *buf; 161 size_t len; 162 163 len = 0; 164 if (use_xsave) { 165 if (dst != NULL) { 166 fpugetregs(td); 167 len += elf64_populate_note(NT_X86_XSTATE, 168 get_pcb_user_save_td(td), dst, 169 cpu_max_ext_state_size, &buf); 170 *(uint64_t *)((char *)buf + X86_XSTATE_XCR0_OFFSET) = 171 xsave_mask; 172 } else 173 len += elf64_populate_note(NT_X86_XSTATE, NULL, NULL, 174 cpu_max_ext_state_size, NULL); 175 } 176 *off = len; 177 } 178 179 bool 180 elf_is_ifunc_reloc(Elf_Size r_info) 181 { 182 183 return (ELF_R_TYPE(r_info) == R_X86_64_IRELATIVE); 184 } 185 186 /* Process one elf relocation with addend. */ 187 static int 188 elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data, 189 int type, bool late_ifunc, elf_lookup_fn lookup) 190 { 191 Elf64_Addr *where, val; 192 Elf32_Addr *where32, val32; 193 Elf_Addr addr; 194 Elf_Addr addend; 195 Elf_Size rtype, symidx; 196 const Elf_Rel *rel; 197 const Elf_Rela *rela; 198 int error; 199 200 switch (type) { 201 case ELF_RELOC_REL: 202 rel = (const Elf_Rel *)data; 203 where = (Elf_Addr *) (relocbase + rel->r_offset); 204 rtype = ELF_R_TYPE(rel->r_info); 205 symidx = ELF_R_SYM(rel->r_info); 206 /* Addend is 32 bit on 32 bit relocs */ 207 switch (rtype) { 208 case R_X86_64_PC32: 209 case R_X86_64_32S: 210 case R_X86_64_PLT32: 211 addend = *(Elf32_Addr *)where; 212 break; 213 default: 214 addend = *where; 215 break; 216 } 217 break; 218 case ELF_RELOC_RELA: 219 rela = (const Elf_Rela *)data; 220 where = (Elf_Addr *) (relocbase + rela->r_offset); 221 addend = rela->r_addend; 222 rtype = ELF_R_TYPE(rela->r_info); 223 symidx = ELF_R_SYM(rela->r_info); 224 break; 225 default: 226 panic("unknown reloc type %d\n", type); 227 } 228 229 if (late_ifunc) { 230 KASSERT(type == ELF_RELOC_RELA, 231 ("Only RELA ifunc relocations are supported")); 232 if (rtype != R_X86_64_IRELATIVE) 233 return (0); 234 } 235 236 switch (rtype) { 237 case R_X86_64_NONE: /* none */ 238 break; 239 240 case R_X86_64_64: /* S + A */ 241 error = lookup(lf, symidx, 1, &addr); 242 val = addr + addend; 243 if (error != 0) 244 return -1; 245 if (*where != val) 246 *where = val; 247 break; 248 249 case R_X86_64_PC32: /* S + A - P */ 250 case R_X86_64_PLT32: /* L + A - P, L is PLT location for 251 the symbol, which we treat as S */ 252 error = lookup(lf, symidx, 1, &addr); 253 where32 = (Elf32_Addr *)where; 254 val32 = (Elf32_Addr)(addr + addend - (Elf_Addr)where); 255 if (error != 0) 256 return -1; 257 if (*where32 != val32) 258 *where32 = val32; 259 break; 260 261 case R_X86_64_32S: /* S + A sign extend */ 262 error = lookup(lf, symidx, 1, &addr); 263 val32 = (Elf32_Addr)(addr + addend); 264 where32 = (Elf32_Addr *)where; 265 if (error != 0) 266 return -1; 267 if (*where32 != val32) 268 *where32 = val32; 269 break; 270 271 case R_X86_64_COPY: /* none */ 272 /* 273 * There shouldn't be copy relocations in kernel 274 * objects. 275 */ 276 printf("kldload: unexpected R_COPY relocation\n"); 277 return (-1); 278 279 case R_X86_64_GLOB_DAT: /* S */ 280 case R_X86_64_JMP_SLOT: /* XXX need addend + offset */ 281 error = lookup(lf, symidx, 1, &addr); 282 if (error != 0) 283 return -1; 284 if (*where != addr) 285 *where = addr; 286 break; 287 288 case R_X86_64_RELATIVE: /* B + A */ 289 addr = elf_relocaddr(lf, relocbase + addend); 290 val = addr; 291 if (*where != val) 292 *where = val; 293 break; 294 295 case R_X86_64_IRELATIVE: 296 addr = relocbase + addend; 297 val = ((Elf64_Addr (*)(void))addr)(); 298 if (*where != val) 299 *where = val; 300 break; 301 302 default: 303 printf("kldload: unexpected relocation type %ld\n", 304 rtype); 305 return (-1); 306 } 307 return (0); 308 } 309 310 int 311 elf_reloc(linker_file_t lf, Elf_Addr relocbase, const void *data, int type, 312 elf_lookup_fn lookup) 313 { 314 315 return (elf_reloc_internal(lf, relocbase, data, type, false, lookup)); 316 } 317 318 int 319 elf_reloc_local(linker_file_t lf, Elf_Addr relocbase, const void *data, 320 int type, elf_lookup_fn lookup) 321 { 322 323 return (elf_reloc_internal(lf, relocbase, data, type, false, lookup)); 324 } 325 326 int 327 elf_reloc_late(linker_file_t lf, Elf_Addr relocbase, const void *data, 328 int type, elf_lookup_fn lookup) 329 { 330 331 return (elf_reloc_internal(lf, relocbase, data, type, true, lookup)); 332 } 333 334 int 335 elf_cpu_load_file(linker_file_t lf __unused) 336 { 337 338 return (0); 339 } 340 341 int 342 elf_cpu_unload_file(linker_file_t lf __unused) 343 { 344 345 return (0); 346 } 347 348 int 349 elf_cpu_parse_dynamic(caddr_t loadbase __unused, Elf_Dyn *dynamic __unused) 350 { 351 352 return (0); 353 } 354