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/reg.h> 40 #include <sys/proc.h> 41 #include <sys/sysent.h> 42 #include <sys/imgact_elf.h> 43 #include <sys/syscall.h> 44 #include <sys/signalvar.h> 45 #include <sys/vnode.h> 46 47 #include <vm/vm.h> 48 #include <vm/pmap.h> 49 #include <vm/vm_param.h> 50 51 #include <machine/elf.h> 52 #include <machine/md_var.h> 53 #include <machine/npx.h> 54 55 struct sysentvec elf32_freebsd_sysvec = { 56 .sv_size = SYS_MAXSYSCALL, 57 .sv_table = sysent, 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_psstringssz = sizeof(struct ps_strings), 74 .sv_stackprot = VM_PROT_ALL, 75 .sv_copyout_auxargs = __elfN(freebsd_copyout_auxargs), 76 .sv_copyout_strings = exec_copyout_strings, 77 .sv_setregs = exec_setregs, 78 .sv_fixlimit = NULL, 79 .sv_maxssiz = NULL, 80 .sv_flags = SV_ABI_FREEBSD | SV_ASLR | SV_IA32 | SV_ILP32 | 81 SV_SHP | SV_TIMEKEEP | SV_RNG_SEED_VER, 82 .sv_set_syscall_retval = cpu_set_syscall_retval, 83 .sv_fetch_syscall_args = cpu_fetch_syscall_args, 84 .sv_syscallnames = syscallnames, 85 .sv_shared_page_base = SHAREDPAGE, 86 .sv_shared_page_len = PAGE_SIZE, 87 .sv_schedtail = NULL, 88 .sv_thread_detach = NULL, 89 .sv_trap = NULL, 90 .sv_onexec_old = exec_onexec_old, 91 .sv_onexit = exit_onexit, 92 .sv_set_fork_retval = x86_set_fork_retval, 93 .sv_regset_begin = SET_BEGIN(__elfN(regset)), 94 .sv_regset_end = SET_LIMIT(__elfN(regset)), 95 }; 96 INIT_SYSENTVEC(elf32_sysvec, &elf32_freebsd_sysvec); 97 98 static Elf32_Brandinfo freebsd_brand_info = { 99 .brand = ELFOSABI_FREEBSD, 100 .machine = EM_386, 101 .compat_3_brand = "FreeBSD", 102 .emul_path = NULL, 103 .interp_path = "/libexec/ld-elf.so.1", 104 .sysvec = &elf32_freebsd_sysvec, 105 .interp_newpath = NULL, 106 .brand_note = &elf32_freebsd_brandnote, 107 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 108 }; 109 110 SYSINIT(elf32, SI_SUB_EXEC, SI_ORDER_FIRST, 111 (sysinit_cfunc_t) elf32_insert_brand_entry, 112 &freebsd_brand_info); 113 114 static Elf32_Brandinfo freebsd_brand_oinfo = { 115 .brand = ELFOSABI_FREEBSD, 116 .machine = EM_386, 117 .compat_3_brand = "FreeBSD", 118 .emul_path = NULL, 119 .interp_path = "/usr/libexec/ld-elf.so.1", 120 .sysvec = &elf32_freebsd_sysvec, 121 .interp_newpath = NULL, 122 .brand_note = &elf32_freebsd_brandnote, 123 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 124 }; 125 126 SYSINIT(oelf32, SI_SUB_EXEC, SI_ORDER_ANY, 127 (sysinit_cfunc_t) elf32_insert_brand_entry, 128 &freebsd_brand_oinfo); 129 130 static Elf32_Brandinfo kfreebsd_brand_info = { 131 .brand = ELFOSABI_FREEBSD, 132 .machine = EM_386, 133 .compat_3_brand = "FreeBSD", 134 .emul_path = NULL, 135 .interp_path = "/lib/ld.so.1", 136 .sysvec = &elf32_freebsd_sysvec, 137 .interp_newpath = NULL, 138 .brand_note = &elf32_kfreebsd_brandnote, 139 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE_MANDATORY 140 }; 141 142 SYSINIT(kelf32, SI_SUB_EXEC, SI_ORDER_ANY, 143 (sysinit_cfunc_t) elf32_insert_brand_entry, 144 &kfreebsd_brand_info); 145 146 void 147 elf32_dump_thread(struct thread *td, void *dst, size_t *off) 148 { 149 void *buf; 150 size_t len; 151 152 len = 0; 153 if (use_xsave) { 154 if (dst != NULL) { 155 npxgetregs(td); 156 len += elf32_populate_note(NT_X86_XSTATE, 157 get_pcb_user_save_td(td), dst, 158 cpu_max_ext_state_size, &buf); 159 *(uint64_t *)((char *)buf + X86_XSTATE_XCR0_OFFSET) = 160 xsave_mask; 161 } else 162 len += elf32_populate_note(NT_X86_XSTATE, NULL, NULL, 163 cpu_max_ext_state_size, NULL); 164 } 165 *off = len; 166 } 167 168 bool 169 elf_is_ifunc_reloc(Elf_Size r_info) 170 { 171 172 return (ELF_R_TYPE(r_info) == R_386_IRELATIVE); 173 } 174 175 #define ERI_LOCAL 0x0001 176 177 /* Process one elf relocation with addend. */ 178 static int 179 elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data, 180 int type, elf_lookup_fn lookup, int flags) 181 { 182 Elf_Addr *where; 183 Elf_Addr addr; 184 Elf_Addr addend; 185 Elf_Word rtype, symidx; 186 const Elf_Rel *rel; 187 const Elf_Rela *rela; 188 int error; 189 190 switch (type) { 191 case ELF_RELOC_REL: 192 rel = (const Elf_Rel *)data; 193 where = (Elf_Addr *) (relocbase + rel->r_offset); 194 addend = *where; 195 rtype = ELF_R_TYPE(rel->r_info); 196 symidx = ELF_R_SYM(rel->r_info); 197 break; 198 case ELF_RELOC_RELA: 199 rela = (const Elf_Rela *)data; 200 where = (Elf_Addr *) (relocbase + rela->r_offset); 201 addend = rela->r_addend; 202 rtype = ELF_R_TYPE(rela->r_info); 203 symidx = ELF_R_SYM(rela->r_info); 204 break; 205 default: 206 panic("unknown reloc type %d\n", type); 207 } 208 209 if ((flags & ERI_LOCAL) != 0) { 210 if (rtype == R_386_RELATIVE) { /* A + B */ 211 addr = elf_relocaddr(lf, relocbase + addend); 212 if (*where != addr) 213 *where = addr; 214 } 215 return (0); 216 } 217 218 switch (rtype) { 219 case R_386_NONE: /* none */ 220 break; 221 222 case R_386_32: /* S + A */ 223 error = lookup(lf, symidx, 1, &addr); 224 if (error != 0) 225 return (-1); 226 addr += addend; 227 if (*where != addr) 228 *where = addr; 229 break; 230 231 case R_386_PC32: /* S + A - P */ 232 error = lookup(lf, symidx, 1, &addr); 233 if (error != 0) 234 return (-1); 235 addr += addend - (Elf_Addr)where; 236 if (*where != addr) 237 *where = addr; 238 break; 239 240 case R_386_COPY: /* none */ 241 /* 242 * There shouldn't be copy relocations in kernel 243 * objects. 244 */ 245 printf("kldload: unexpected R_COPY relocation, " 246 "symbol index %d\n", symidx); 247 return (-1); 248 break; 249 250 case R_386_GLOB_DAT: /* S */ 251 error = lookup(lf, symidx, 1, &addr); 252 if (error != 0) 253 return (-1); 254 if (*where != addr) 255 *where = addr; 256 break; 257 258 case R_386_RELATIVE: 259 break; 260 261 case R_386_IRELATIVE: 262 addr = relocbase + addend; 263 addr = ((Elf_Addr (*)(void))addr)(); 264 if (*where != addr) 265 *where = addr; 266 break; 267 268 default: 269 printf("kldload: unexpected relocation type %d, " 270 "symbol index %d\n", rtype, symidx); 271 return (-1); 272 } 273 return(0); 274 } 275 276 int 277 elf_reloc(linker_file_t lf, Elf_Addr relocbase, const void *data, int type, 278 elf_lookup_fn lookup) 279 { 280 281 return (elf_reloc_internal(lf, relocbase, data, type, lookup, 0)); 282 } 283 284 int 285 elf_reloc_local(linker_file_t lf, Elf_Addr relocbase, const void *data, 286 int type, elf_lookup_fn lookup) 287 { 288 289 return (elf_reloc_internal(lf, relocbase, data, type, lookup, 290 ERI_LOCAL)); 291 } 292 293 int 294 elf_cpu_load_file(linker_file_t lf __unused) 295 { 296 297 return (0); 298 } 299 300 int 301 elf_cpu_unload_file(linker_file_t lf __unused) 302 { 303 304 return (0); 305 } 306 307 int 308 elf_cpu_parse_dynamic(caddr_t loadbase __unused, Elf_Dyn *dynamic __unused) 309 { 310 311 return (0); 312 } 313