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_strings = exec_copyout_strings, 72 .sv_setregs = exec_setregs, 73 .sv_fixlimit = NULL, 74 .sv_maxssiz = NULL, 75 .sv_flags = SV_ABI_FREEBSD | SV_ASLR | SV_LP64 | SV_SHP | 76 SV_TIMEKEEP, 77 .sv_set_syscall_retval = cpu_set_syscall_retval, 78 .sv_fetch_syscall_args = cpu_fetch_syscall_args, 79 .sv_syscallnames = syscallnames, 80 .sv_shared_page_base = SHAREDPAGE, 81 .sv_shared_page_len = PAGE_SIZE, 82 .sv_schedtail = NULL, 83 .sv_thread_detach = NULL, 84 .sv_trap = NULL, 85 }; 86 INIT_SYSENTVEC(elf64_sysvec, &elf64_freebsd_sysvec); 87 88 void 89 amd64_lower_shared_page(struct sysentvec *sv) 90 { 91 if (hw_lower_amd64_sharedpage != 0) { 92 sv->sv_maxuser -= PAGE_SIZE; 93 sv->sv_shared_page_base -= PAGE_SIZE; 94 sv->sv_usrstack -= PAGE_SIZE; 95 sv->sv_psstrings -= PAGE_SIZE; 96 } 97 } 98 99 /* 100 * Do this fixup before INIT_SYSENTVEC (SI_ORDER_ANY) because the latter 101 * uses the value of sv_shared_page_base. 102 */ 103 SYSINIT(elf64_sysvec_fixup, SI_SUB_EXEC, SI_ORDER_FIRST, 104 (sysinit_cfunc_t) amd64_lower_shared_page, 105 &elf64_freebsd_sysvec); 106 107 static Elf64_Brandinfo freebsd_brand_info = { 108 .brand = ELFOSABI_FREEBSD, 109 .machine = EM_X86_64, 110 .compat_3_brand = "FreeBSD", 111 .emul_path = NULL, 112 .interp_path = "/libexec/ld-elf.so.1", 113 .sysvec = &elf64_freebsd_sysvec, 114 .interp_newpath = NULL, 115 .brand_note = &elf64_freebsd_brandnote, 116 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 117 }; 118 119 SYSINIT(elf64, SI_SUB_EXEC, SI_ORDER_FIRST, 120 (sysinit_cfunc_t) elf64_insert_brand_entry, 121 &freebsd_brand_info); 122 123 static Elf64_Brandinfo freebsd_brand_oinfo = { 124 .brand = ELFOSABI_FREEBSD, 125 .machine = EM_X86_64, 126 .compat_3_brand = "FreeBSD", 127 .emul_path = NULL, 128 .interp_path = "/usr/libexec/ld-elf.so.1", 129 .sysvec = &elf64_freebsd_sysvec, 130 .interp_newpath = NULL, 131 .brand_note = &elf64_freebsd_brandnote, 132 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 133 }; 134 135 SYSINIT(oelf64, SI_SUB_EXEC, SI_ORDER_ANY, 136 (sysinit_cfunc_t) elf64_insert_brand_entry, 137 &freebsd_brand_oinfo); 138 139 static Elf64_Brandinfo kfreebsd_brand_info = { 140 .brand = ELFOSABI_FREEBSD, 141 .machine = EM_X86_64, 142 .compat_3_brand = "FreeBSD", 143 .emul_path = NULL, 144 .interp_path = "/lib/ld-kfreebsd-x86-64.so.1", 145 .sysvec = &elf64_freebsd_sysvec, 146 .interp_newpath = NULL, 147 .brand_note = &elf64_kfreebsd_brandnote, 148 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE_MANDATORY 149 }; 150 151 SYSINIT(kelf64, SI_SUB_EXEC, SI_ORDER_ANY, 152 (sysinit_cfunc_t) elf64_insert_brand_entry, 153 &kfreebsd_brand_info); 154 155 void 156 elf64_dump_thread(struct thread *td, void *dst, size_t *off) 157 { 158 void *buf; 159 size_t len; 160 161 len = 0; 162 if (use_xsave) { 163 if (dst != NULL) { 164 fpugetregs(td); 165 len += elf64_populate_note(NT_X86_XSTATE, 166 get_pcb_user_save_td(td), dst, 167 cpu_max_ext_state_size, &buf); 168 *(uint64_t *)((char *)buf + X86_XSTATE_XCR0_OFFSET) = 169 xsave_mask; 170 } else 171 len += elf64_populate_note(NT_X86_XSTATE, NULL, NULL, 172 cpu_max_ext_state_size, NULL); 173 } 174 *off = len; 175 } 176 177 bool 178 elf_is_ifunc_reloc(Elf_Size r_info) 179 { 180 181 return (ELF_R_TYPE(r_info) == R_X86_64_IRELATIVE); 182 } 183 184 /* Process one elf relocation with addend. */ 185 static int 186 elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data, 187 int type, elf_lookup_fn lookup) 188 { 189 Elf64_Addr *where, val; 190 Elf32_Addr *where32, val32; 191 Elf_Addr addr; 192 Elf_Addr addend; 193 Elf_Size rtype, symidx; 194 const Elf_Rel *rel; 195 const Elf_Rela *rela; 196 int error; 197 198 switch (type) { 199 case ELF_RELOC_REL: 200 rel = (const Elf_Rel *)data; 201 where = (Elf_Addr *) (relocbase + rel->r_offset); 202 rtype = ELF_R_TYPE(rel->r_info); 203 symidx = ELF_R_SYM(rel->r_info); 204 /* Addend is 32 bit on 32 bit relocs */ 205 switch (rtype) { 206 case R_X86_64_PC32: 207 case R_X86_64_32S: 208 case R_X86_64_PLT32: 209 addend = *(Elf32_Addr *)where; 210 break; 211 default: 212 addend = *where; 213 break; 214 } 215 break; 216 case ELF_RELOC_RELA: 217 rela = (const Elf_Rela *)data; 218 where = (Elf_Addr *) (relocbase + rela->r_offset); 219 addend = rela->r_addend; 220 rtype = ELF_R_TYPE(rela->r_info); 221 symidx = ELF_R_SYM(rela->r_info); 222 break; 223 default: 224 panic("unknown reloc type %d\n", type); 225 } 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(linker_file_t lf, Elf_Addr relocbase, const void *data, int type, 304 elf_lookup_fn lookup) 305 { 306 307 return (elf_reloc_internal(lf, relocbase, data, type, lookup)); 308 } 309 310 int 311 elf_reloc_local(linker_file_t lf, Elf_Addr relocbase, const void *data, 312 int type, elf_lookup_fn lookup) 313 { 314 315 return (elf_reloc_internal(lf, relocbase, data, type, lookup)); 316 } 317 318 int 319 elf_cpu_load_file(linker_file_t lf __unused) 320 { 321 322 return (0); 323 } 324 325 int 326 elf_cpu_unload_file(linker_file_t lf __unused) 327 { 328 329 return (0); 330 } 331