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_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_IA32 | SV_ILP32 | 77 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(elf32_sysvec, &elf32_freebsd_sysvec); 88 89 static Elf32_Brandinfo freebsd_brand_info = { 90 .brand = ELFOSABI_FREEBSD, 91 .machine = EM_386, 92 .compat_3_brand = "FreeBSD", 93 .emul_path = NULL, 94 .interp_path = "/libexec/ld-elf.so.1", 95 .sysvec = &elf32_freebsd_sysvec, 96 .interp_newpath = NULL, 97 .brand_note = &elf32_freebsd_brandnote, 98 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 99 }; 100 101 SYSINIT(elf32, SI_SUB_EXEC, SI_ORDER_FIRST, 102 (sysinit_cfunc_t) elf32_insert_brand_entry, 103 &freebsd_brand_info); 104 105 static Elf32_Brandinfo freebsd_brand_oinfo = { 106 .brand = ELFOSABI_FREEBSD, 107 .machine = EM_386, 108 .compat_3_brand = "FreeBSD", 109 .emul_path = NULL, 110 .interp_path = "/usr/libexec/ld-elf.so.1", 111 .sysvec = &elf32_freebsd_sysvec, 112 .interp_newpath = NULL, 113 .brand_note = &elf32_freebsd_brandnote, 114 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 115 }; 116 117 SYSINIT(oelf32, SI_SUB_EXEC, SI_ORDER_ANY, 118 (sysinit_cfunc_t) elf32_insert_brand_entry, 119 &freebsd_brand_oinfo); 120 121 static Elf32_Brandinfo kfreebsd_brand_info = { 122 .brand = ELFOSABI_FREEBSD, 123 .machine = EM_386, 124 .compat_3_brand = "FreeBSD", 125 .emul_path = NULL, 126 .interp_path = "/lib/ld.so.1", 127 .sysvec = &elf32_freebsd_sysvec, 128 .interp_newpath = NULL, 129 .brand_note = &elf32_kfreebsd_brandnote, 130 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE_MANDATORY 131 }; 132 133 SYSINIT(kelf32, SI_SUB_EXEC, SI_ORDER_ANY, 134 (sysinit_cfunc_t) elf32_insert_brand_entry, 135 &kfreebsd_brand_info); 136 137 void 138 elf32_dump_thread(struct thread *td, void *dst, size_t *off) 139 { 140 void *buf; 141 size_t len; 142 143 len = 0; 144 if (use_xsave) { 145 if (dst != NULL) { 146 npxgetregs(td); 147 len += elf32_populate_note(NT_X86_XSTATE, 148 get_pcb_user_save_td(td), dst, 149 cpu_max_ext_state_size, &buf); 150 *(uint64_t *)((char *)buf + X86_XSTATE_XCR0_OFFSET) = 151 xsave_mask; 152 } else 153 len += elf32_populate_note(NT_X86_XSTATE, NULL, NULL, 154 cpu_max_ext_state_size, NULL); 155 } 156 *off = len; 157 } 158 159 bool 160 elf_is_ifunc_reloc(Elf_Size r_info) 161 { 162 163 return (ELF_R_TYPE(r_info) == R_386_IRELATIVE); 164 } 165 166 #define ERI_LOCAL 0x0001 167 168 /* Process one elf relocation with addend. */ 169 static int 170 elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data, 171 int type, elf_lookup_fn lookup, int flags) 172 { 173 Elf_Addr *where; 174 Elf_Addr addr; 175 Elf_Addr addend; 176 Elf_Word rtype, symidx; 177 const Elf_Rel *rel; 178 const Elf_Rela *rela; 179 int error; 180 181 switch (type) { 182 case ELF_RELOC_REL: 183 rel = (const Elf_Rel *)data; 184 where = (Elf_Addr *) (relocbase + rel->r_offset); 185 addend = *where; 186 rtype = ELF_R_TYPE(rel->r_info); 187 symidx = ELF_R_SYM(rel->r_info); 188 break; 189 case ELF_RELOC_RELA: 190 rela = (const Elf_Rela *)data; 191 where = (Elf_Addr *) (relocbase + rela->r_offset); 192 addend = rela->r_addend; 193 rtype = ELF_R_TYPE(rela->r_info); 194 symidx = ELF_R_SYM(rela->r_info); 195 break; 196 default: 197 panic("unknown reloc type %d\n", type); 198 } 199 200 if ((flags & ERI_LOCAL) != 0) { 201 if (rtype == R_386_RELATIVE) { /* A + B */ 202 addr = elf_relocaddr(lf, relocbase + addend); 203 if (*where != addr) 204 *where = addr; 205 } 206 return (0); 207 } 208 209 switch (rtype) { 210 case R_386_NONE: /* none */ 211 break; 212 213 case R_386_32: /* S + A */ 214 error = lookup(lf, symidx, 1, &addr); 215 if (error != 0) 216 return -1; 217 addr += addend; 218 if (*where != addr) 219 *where = addr; 220 break; 221 222 case R_386_PC32: /* S + A - P */ 223 error = lookup(lf, symidx, 1, &addr); 224 if (error != 0) 225 return -1; 226 addr += addend - (Elf_Addr)where; 227 if (*where != addr) 228 *where = addr; 229 break; 230 231 case R_386_COPY: /* none */ 232 /* 233 * There shouldn't be copy relocations in kernel 234 * objects. 235 */ 236 printf("kldload: unexpected R_COPY relocation\n"); 237 return -1; 238 break; 239 240 case R_386_GLOB_DAT: /* S */ 241 error = lookup(lf, symidx, 1, &addr); 242 if (error != 0) 243 return -1; 244 if (*where != addr) 245 *where = addr; 246 break; 247 248 case R_386_RELATIVE: 249 break; 250 251 case R_386_IRELATIVE: 252 addr = relocbase + addend; 253 addr = ((Elf_Addr (*)(void))addr)(); 254 if (*where != addr) 255 *where = addr; 256 break; 257 default: 258 printf("kldload: unexpected relocation type %d\n", 259 rtype); 260 return -1; 261 } 262 return(0); 263 } 264 265 int 266 elf_reloc(linker_file_t lf, Elf_Addr relocbase, const void *data, int type, 267 elf_lookup_fn lookup) 268 { 269 270 return (elf_reloc_internal(lf, relocbase, data, type, lookup, 0)); 271 } 272 273 int 274 elf_reloc_local(linker_file_t lf, Elf_Addr relocbase, const void *data, 275 int type, elf_lookup_fn lookup) 276 { 277 278 return (elf_reloc_internal(lf, relocbase, data, type, lookup, 279 ERI_LOCAL)); 280 } 281 282 int 283 elf_cpu_load_file(linker_file_t lf __unused) 284 { 285 286 return (0); 287 } 288 289 int 290 elf_cpu_unload_file(linker_file_t lf __unused) 291 { 292 293 return (0); 294 } 295 296 int 297 elf_cpu_parse_dynamic(caddr_t loadbase __unused, Elf_Dyn *dynamic __unused) 298 { 299 300 return (0); 301 } 302