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 "opt_cpu.h" 32 33 #include <sys/param.h> 34 #include <sys/kernel.h> 35 #include <sys/systm.h> 36 #include <sys/exec.h> 37 #include <sys/imgact.h> 38 #include <sys/linker.h> 39 #include <sys/proc.h> 40 #include <sys/sysent.h> 41 #include <sys/imgact_elf.h> 42 #include <sys/syscall.h> 43 #include <sys/signalvar.h> 44 #include <sys/vnode.h> 45 46 #include <vm/vm.h> 47 #include <vm/pmap.h> 48 #include <vm/vm_param.h> 49 50 #include <machine/elf.h> 51 #include <machine/md_var.h> 52 #include <machine/npx.h> 53 54 struct sysentvec elf32_freebsd_sysvec = { 55 .sv_size = SYS_MAXSYSCALL, 56 .sv_table = sysent, 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 ELF32", 63 .sv_coredump = __elfN(coredump), 64 .sv_elf_core_osabi = ELFOSABI_FREEBSD, 65 .sv_elf_core_abi_vendor = FREEBSD_ABI_VENDOR, 66 .sv_elf_core_prepare_notes = __elfN(prepare_notes), 67 .sv_imgact_try = NULL, 68 .sv_minsigstksz = MINSIGSTKSZ, 69 .sv_minuser = VM_MIN_ADDRESS, 70 .sv_maxuser = VM_MAXUSER_ADDRESS, 71 .sv_usrstack = USRSTACK, 72 .sv_psstrings = PS_STRINGS, 73 .sv_stackprot = VM_PROT_ALL, 74 .sv_copyout_auxargs = __elfN(freebsd_copyout_auxargs), 75 .sv_copyout_strings = exec_copyout_strings, 76 .sv_setregs = exec_setregs, 77 .sv_fixlimit = NULL, 78 .sv_maxssiz = NULL, 79 .sv_flags = SV_ABI_FREEBSD | SV_ASLR | SV_IA32 | SV_ILP32 | 80 SV_SHP | SV_TIMEKEEP | SV_RNG_SEED_VER, 81 .sv_set_syscall_retval = cpu_set_syscall_retval, 82 .sv_fetch_syscall_args = cpu_fetch_syscall_args, 83 .sv_syscallnames = syscallnames, 84 .sv_shared_page_base = SHAREDPAGE, 85 .sv_shared_page_len = PAGE_SIZE, 86 .sv_schedtail = NULL, 87 .sv_thread_detach = NULL, 88 .sv_trap = NULL, 89 .sv_onexec_old = exec_onexec_old, 90 .sv_onexit = exit_onexit, 91 .sv_set_fork_retval = x86_set_fork_retval, 92 }; 93 INIT_SYSENTVEC(elf32_sysvec, &elf32_freebsd_sysvec); 94 95 static Elf32_Brandinfo freebsd_brand_info = { 96 .brand = ELFOSABI_FREEBSD, 97 .machine = EM_386, 98 .compat_3_brand = "FreeBSD", 99 .emul_path = NULL, 100 .interp_path = "/libexec/ld-elf.so.1", 101 .sysvec = &elf32_freebsd_sysvec, 102 .interp_newpath = NULL, 103 .brand_note = &elf32_freebsd_brandnote, 104 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 105 }; 106 107 SYSINIT(elf32, SI_SUB_EXEC, SI_ORDER_FIRST, 108 (sysinit_cfunc_t) elf32_insert_brand_entry, 109 &freebsd_brand_info); 110 111 static Elf32_Brandinfo freebsd_brand_oinfo = { 112 .brand = ELFOSABI_FREEBSD, 113 .machine = EM_386, 114 .compat_3_brand = "FreeBSD", 115 .emul_path = NULL, 116 .interp_path = "/usr/libexec/ld-elf.so.1", 117 .sysvec = &elf32_freebsd_sysvec, 118 .interp_newpath = NULL, 119 .brand_note = &elf32_freebsd_brandnote, 120 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 121 }; 122 123 SYSINIT(oelf32, SI_SUB_EXEC, SI_ORDER_ANY, 124 (sysinit_cfunc_t) elf32_insert_brand_entry, 125 &freebsd_brand_oinfo); 126 127 static Elf32_Brandinfo kfreebsd_brand_info = { 128 .brand = ELFOSABI_FREEBSD, 129 .machine = EM_386, 130 .compat_3_brand = "FreeBSD", 131 .emul_path = NULL, 132 .interp_path = "/lib/ld.so.1", 133 .sysvec = &elf32_freebsd_sysvec, 134 .interp_newpath = NULL, 135 .brand_note = &elf32_kfreebsd_brandnote, 136 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE_MANDATORY 137 }; 138 139 SYSINIT(kelf32, SI_SUB_EXEC, SI_ORDER_ANY, 140 (sysinit_cfunc_t) elf32_insert_brand_entry, 141 &kfreebsd_brand_info); 142 143 void 144 elf32_dump_thread(struct thread *td, void *dst, size_t *off) 145 { 146 void *buf; 147 size_t len; 148 149 len = 0; 150 if (use_xsave) { 151 if (dst != NULL) { 152 npxgetregs(td); 153 len += elf32_populate_note(NT_X86_XSTATE, 154 get_pcb_user_save_td(td), dst, 155 cpu_max_ext_state_size, &buf); 156 *(uint64_t *)((char *)buf + X86_XSTATE_XCR0_OFFSET) = 157 xsave_mask; 158 } else 159 len += elf32_populate_note(NT_X86_XSTATE, NULL, NULL, 160 cpu_max_ext_state_size, NULL); 161 } 162 *off = len; 163 } 164 165 bool 166 elf_is_ifunc_reloc(Elf_Size r_info) 167 { 168 169 return (ELF_R_TYPE(r_info) == R_386_IRELATIVE); 170 } 171 172 #define ERI_LOCAL 0x0001 173 174 /* Process one elf relocation with addend. */ 175 static int 176 elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data, 177 int type, elf_lookup_fn lookup, int flags) 178 { 179 Elf_Addr *where; 180 Elf_Addr addr; 181 Elf_Addr addend; 182 Elf_Word rtype, symidx; 183 const Elf_Rel *rel; 184 const Elf_Rela *rela; 185 int error; 186 187 switch (type) { 188 case ELF_RELOC_REL: 189 rel = (const Elf_Rel *)data; 190 where = (Elf_Addr *) (relocbase + rel->r_offset); 191 addend = *where; 192 rtype = ELF_R_TYPE(rel->r_info); 193 symidx = ELF_R_SYM(rel->r_info); 194 break; 195 case ELF_RELOC_RELA: 196 rela = (const Elf_Rela *)data; 197 where = (Elf_Addr *) (relocbase + rela->r_offset); 198 addend = rela->r_addend; 199 rtype = ELF_R_TYPE(rela->r_info); 200 symidx = ELF_R_SYM(rela->r_info); 201 break; 202 default: 203 panic("unknown reloc type %d\n", type); 204 } 205 206 if ((flags & ERI_LOCAL) != 0) { 207 if (rtype == R_386_RELATIVE) { /* A + B */ 208 addr = elf_relocaddr(lf, relocbase + addend); 209 if (*where != addr) 210 *where = addr; 211 } 212 return (0); 213 } 214 215 switch (rtype) { 216 case R_386_NONE: /* none */ 217 break; 218 219 case R_386_32: /* S + A */ 220 error = lookup(lf, symidx, 1, &addr); 221 if (error != 0) 222 return (-1); 223 addr += addend; 224 if (*where != addr) 225 *where = addr; 226 break; 227 228 case R_386_PC32: /* S + A - P */ 229 error = lookup(lf, symidx, 1, &addr); 230 if (error != 0) 231 return (-1); 232 addr += addend - (Elf_Addr)where; 233 if (*where != addr) 234 *where = addr; 235 break; 236 237 case R_386_COPY: /* none */ 238 /* 239 * There shouldn't be copy relocations in kernel 240 * objects. 241 */ 242 printf("kldload: unexpected R_COPY relocation, " 243 "symbol index %d\n", symidx); 244 return (-1); 245 break; 246 247 case R_386_GLOB_DAT: /* S */ 248 error = lookup(lf, symidx, 1, &addr); 249 if (error != 0) 250 return (-1); 251 if (*where != addr) 252 *where = addr; 253 break; 254 255 case R_386_RELATIVE: 256 break; 257 258 case R_386_IRELATIVE: 259 addr = relocbase + addend; 260 addr = ((Elf_Addr (*)(void))addr)(); 261 if (*where != addr) 262 *where = addr; 263 break; 264 265 default: 266 printf("kldload: unexpected relocation type %d, " 267 "symbol index %d\n", rtype, symidx); 268 return (-1); 269 } 270 return(0); 271 } 272 273 int 274 elf_reloc(linker_file_t lf, Elf_Addr relocbase, const void *data, int type, 275 elf_lookup_fn lookup) 276 { 277 278 return (elf_reloc_internal(lf, relocbase, data, type, lookup, 0)); 279 } 280 281 int 282 elf_reloc_local(linker_file_t lf, Elf_Addr relocbase, const void *data, 283 int type, elf_lookup_fn lookup) 284 { 285 286 return (elf_reloc_internal(lf, relocbase, data, type, lookup, 287 ERI_LOCAL)); 288 } 289 290 int 291 elf_cpu_load_file(linker_file_t lf __unused) 292 { 293 294 return (0); 295 } 296 297 int 298 elf_cpu_unload_file(linker_file_t lf __unused) 299 { 300 301 return (0); 302 } 303 304 int 305 elf_cpu_parse_dynamic(caddr_t loadbase __unused, Elf_Dyn *dynamic __unused) 306 { 307 308 return (0); 309 } 310