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_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 ELF64", 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_LP64 | SV_SHP | 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 }; 87 INIT_SYSENTVEC(elf64_sysvec, &elf64_freebsd_sysvec); 88 89 void 90 amd64_lower_shared_page(struct sysentvec *sv) 91 { 92 if (hw_lower_amd64_sharedpage != 0) { 93 sv->sv_maxuser -= PAGE_SIZE; 94 sv->sv_shared_page_base -= PAGE_SIZE; 95 sv->sv_usrstack -= PAGE_SIZE; 96 sv->sv_psstrings -= PAGE_SIZE; 97 } 98 } 99 100 /* 101 * Do this fixup before INIT_SYSENTVEC (SI_ORDER_ANY) because the latter 102 * uses the value of sv_shared_page_base. 103 */ 104 SYSINIT(elf64_sysvec_fixup, SI_SUB_EXEC, SI_ORDER_FIRST, 105 (sysinit_cfunc_t) amd64_lower_shared_page, 106 &elf64_freebsd_sysvec); 107 108 static Elf64_Brandinfo freebsd_brand_info = { 109 .brand = ELFOSABI_FREEBSD, 110 .machine = EM_X86_64, 111 .compat_3_brand = "FreeBSD", 112 .emul_path = NULL, 113 .interp_path = "/libexec/ld-elf.so.1", 114 .sysvec = &elf64_freebsd_sysvec, 115 .interp_newpath = NULL, 116 .brand_note = &elf64_freebsd_brandnote, 117 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 118 }; 119 120 SYSINIT(elf64, SI_SUB_EXEC, SI_ORDER_FIRST, 121 (sysinit_cfunc_t) elf64_insert_brand_entry, 122 &freebsd_brand_info); 123 124 static Elf64_Brandinfo freebsd_brand_oinfo = { 125 .brand = ELFOSABI_FREEBSD, 126 .machine = EM_X86_64, 127 .compat_3_brand = "FreeBSD", 128 .emul_path = NULL, 129 .interp_path = "/usr/libexec/ld-elf.so.1", 130 .sysvec = &elf64_freebsd_sysvec, 131 .interp_newpath = NULL, 132 .brand_note = &elf64_freebsd_brandnote, 133 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 134 }; 135 136 SYSINIT(oelf64, SI_SUB_EXEC, SI_ORDER_ANY, 137 (sysinit_cfunc_t) elf64_insert_brand_entry, 138 &freebsd_brand_oinfo); 139 140 static Elf64_Brandinfo kfreebsd_brand_info = { 141 .brand = ELFOSABI_FREEBSD, 142 .machine = EM_X86_64, 143 .compat_3_brand = "FreeBSD", 144 .emul_path = NULL, 145 .interp_path = "/lib/ld-kfreebsd-x86-64.so.1", 146 .sysvec = &elf64_freebsd_sysvec, 147 .interp_newpath = NULL, 148 .brand_note = &elf64_kfreebsd_brandnote, 149 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE_MANDATORY 150 }; 151 152 SYSINIT(kelf64, SI_SUB_EXEC, SI_ORDER_ANY, 153 (sysinit_cfunc_t) elf64_insert_brand_entry, 154 &kfreebsd_brand_info); 155 156 void 157 elf64_dump_thread(struct thread *td, void *dst, size_t *off) 158 { 159 void *buf; 160 size_t len; 161 162 len = 0; 163 if (use_xsave) { 164 if (dst != NULL) { 165 fpugetregs(td); 166 len += elf64_populate_note(NT_X86_XSTATE, 167 get_pcb_user_save_td(td), dst, 168 cpu_max_ext_state_size, &buf); 169 *(uint64_t *)((char *)buf + X86_XSTATE_XCR0_OFFSET) = 170 xsave_mask; 171 } else 172 len += elf64_populate_note(NT_X86_XSTATE, NULL, NULL, 173 cpu_max_ext_state_size, NULL); 174 } 175 *off = len; 176 } 177 178 #define ERI_LOCAL 0x0001 179 #define ERI_ONLYIFUNC 0x0002 180 181 /* Process one elf relocation with addend. */ 182 static int 183 elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data, 184 int type, elf_lookup_fn lookup, int flags) 185 { 186 Elf64_Addr *where, val; 187 Elf32_Addr *where32, val32; 188 Elf_Addr addr; 189 Elf_Addr addend; 190 Elf_Size rtype, symidx; 191 const Elf_Rel *rel; 192 const Elf_Rela *rela; 193 int error; 194 195 switch (type) { 196 case ELF_RELOC_REL: 197 rel = (const Elf_Rel *)data; 198 where = (Elf_Addr *) (relocbase + rel->r_offset); 199 rtype = ELF_R_TYPE(rel->r_info); 200 symidx = ELF_R_SYM(rel->r_info); 201 /* Addend is 32 bit on 32 bit relocs */ 202 switch (rtype) { 203 case R_X86_64_PC32: 204 case R_X86_64_32S: 205 case R_X86_64_PLT32: 206 addend = *(Elf32_Addr *)where; 207 break; 208 default: 209 addend = *where; 210 break; 211 } 212 break; 213 case ELF_RELOC_RELA: 214 rela = (const Elf_Rela *)data; 215 where = (Elf_Addr *) (relocbase + rela->r_offset); 216 addend = rela->r_addend; 217 rtype = ELF_R_TYPE(rela->r_info); 218 symidx = ELF_R_SYM(rela->r_info); 219 break; 220 default: 221 panic("unknown reloc type %d\n", type); 222 } 223 224 if (((flags & ERI_ONLYIFUNC) == 0) ^ (rtype != R_X86_64_IRELATIVE)) 225 return (0); 226 227 switch (rtype) { 228 case R_X86_64_NONE: /* none */ 229 break; 230 231 case R_X86_64_64: /* S + A */ 232 error = lookup(lf, symidx, 1, &addr); 233 val = addr + addend; 234 if (error != 0) 235 return -1; 236 if (*where != val) 237 *where = val; 238 break; 239 240 case R_X86_64_PC32: /* S + A - P */ 241 case R_X86_64_PLT32: /* L + A - P, L is PLT location for 242 the symbol, which we treat as S */ 243 error = lookup(lf, symidx, 1, &addr); 244 where32 = (Elf32_Addr *)where; 245 val32 = (Elf32_Addr)(addr + addend - (Elf_Addr)where); 246 if (error != 0) 247 return -1; 248 if (*where32 != val32) 249 *where32 = val32; 250 break; 251 252 case R_X86_64_32S: /* S + A sign extend */ 253 error = lookup(lf, symidx, 1, &addr); 254 val32 = (Elf32_Addr)(addr + addend); 255 where32 = (Elf32_Addr *)where; 256 if (error != 0) 257 return -1; 258 if (*where32 != val32) 259 *where32 = val32; 260 break; 261 262 case R_X86_64_COPY: /* none */ 263 /* 264 * There shouldn't be copy relocations in kernel 265 * objects. 266 */ 267 printf("kldload: unexpected R_COPY relocation\n"); 268 return (-1); 269 break; 270 271 case R_X86_64_GLOB_DAT: /* S */ 272 case R_X86_64_JMP_SLOT: /* XXX need addend + offset */ 273 error = lookup(lf, symidx, 1, &addr); 274 if (error != 0) 275 return -1; 276 if (*where != addr) 277 *where = addr; 278 break; 279 280 case R_X86_64_RELATIVE: /* B + A */ 281 addr = relocbase + addend; 282 val = addr; 283 if (*where != val) 284 *where = val; 285 break; 286 287 case R_X86_64_IRELATIVE: 288 addr = relocbase + addend; 289 val = ((Elf64_Addr (*)(void))addr)(); 290 if (*where != val) 291 *where = val; 292 break; 293 294 default: 295 printf("kldload: unexpected relocation type %ld\n", 296 rtype); 297 return (-1); 298 } 299 return (0); 300 } 301 302 int 303 elf_reloc_ifunc(linker_file_t lf, Elf_Addr relocbase, const void *data, 304 int type, elf_lookup_fn lookup) 305 { 306 307 return (elf_reloc_internal(lf, relocbase, data, type, lookup, 308 ERI_ONLYIFUNC)); 309 } 310 311 int 312 elf_reloc(linker_file_t lf, Elf_Addr relocbase, const void *data, int type, 313 elf_lookup_fn lookup) 314 { 315 316 return (elf_reloc_internal(lf, relocbase, data, type, lookup, 0)); 317 } 318 319 int 320 elf_reloc_local(linker_file_t lf, Elf_Addr relocbase, const void *data, 321 int type, elf_lookup_fn lookup) 322 { 323 324 return (elf_reloc_internal(lf, relocbase, data, type, lookup, 325 ERI_LOCAL)); 326 } 327 328 int 329 elf_cpu_load_file(linker_file_t lf __unused) 330 { 331 332 return (0); 333 } 334 335 int 336 elf_cpu_unload_file(linker_file_t lf __unused) 337 { 338 339 return (0); 340 } 341