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_errsize = 0, 58 .sv_errtbl = NULL, 59 .sv_transtrap = NULL, 60 .sv_fixup = __elfN(freebsd_fixup), 61 .sv_sendsig = sendsig, 62 .sv_sigcode = sigcode, 63 .sv_szsigcode = &szsigcode, 64 .sv_name = "FreeBSD ELF32", 65 .sv_coredump = __elfN(coredump), 66 .sv_imgact_try = NULL, 67 .sv_minsigstksz = MINSIGSTKSZ, 68 .sv_pagesize = PAGE_SIZE, 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_strings = exec_copyout_strings, 75 .sv_setregs = exec_setregs, 76 .sv_fixlimit = NULL, 77 .sv_maxssiz = NULL, 78 .sv_flags = SV_ABI_FREEBSD | SV_ASLR | SV_IA32 | SV_ILP32 | 79 SV_SHP | SV_TIMEKEEP, 80 .sv_set_syscall_retval = cpu_set_syscall_retval, 81 .sv_fetch_syscall_args = cpu_fetch_syscall_args, 82 .sv_syscallnames = syscallnames, 83 .sv_shared_page_base = SHAREDPAGE, 84 .sv_shared_page_len = PAGE_SIZE, 85 .sv_schedtail = NULL, 86 .sv_thread_detach = NULL, 87 .sv_trap = NULL, 88 }; 89 INIT_SYSENTVEC(elf32_sysvec, &elf32_freebsd_sysvec); 90 91 static Elf32_Brandinfo freebsd_brand_info = { 92 .brand = ELFOSABI_FREEBSD, 93 .machine = EM_386, 94 .compat_3_brand = "FreeBSD", 95 .emul_path = NULL, 96 .interp_path = "/libexec/ld-elf.so.1", 97 .sysvec = &elf32_freebsd_sysvec, 98 .interp_newpath = NULL, 99 .brand_note = &elf32_freebsd_brandnote, 100 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 101 }; 102 103 SYSINIT(elf32, SI_SUB_EXEC, SI_ORDER_FIRST, 104 (sysinit_cfunc_t) elf32_insert_brand_entry, 105 &freebsd_brand_info); 106 107 static Elf32_Brandinfo freebsd_brand_oinfo = { 108 .brand = ELFOSABI_FREEBSD, 109 .machine = EM_386, 110 .compat_3_brand = "FreeBSD", 111 .emul_path = NULL, 112 .interp_path = "/usr/libexec/ld-elf.so.1", 113 .sysvec = &elf32_freebsd_sysvec, 114 .interp_newpath = NULL, 115 .brand_note = &elf32_freebsd_brandnote, 116 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 117 }; 118 119 SYSINIT(oelf32, SI_SUB_EXEC, SI_ORDER_ANY, 120 (sysinit_cfunc_t) elf32_insert_brand_entry, 121 &freebsd_brand_oinfo); 122 123 static Elf32_Brandinfo kfreebsd_brand_info = { 124 .brand = ELFOSABI_FREEBSD, 125 .machine = EM_386, 126 .compat_3_brand = "FreeBSD", 127 .emul_path = NULL, 128 .interp_path = "/lib/ld.so.1", 129 .sysvec = &elf32_freebsd_sysvec, 130 .interp_newpath = NULL, 131 .brand_note = &elf32_kfreebsd_brandnote, 132 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE_MANDATORY 133 }; 134 135 SYSINIT(kelf32, SI_SUB_EXEC, SI_ORDER_ANY, 136 (sysinit_cfunc_t) elf32_insert_brand_entry, 137 &kfreebsd_brand_info); 138 139 void 140 elf32_dump_thread(struct thread *td, void *dst, size_t *off) 141 { 142 void *buf; 143 size_t len; 144 145 len = 0; 146 if (use_xsave) { 147 if (dst != NULL) { 148 npxgetregs(td); 149 len += elf32_populate_note(NT_X86_XSTATE, 150 get_pcb_user_save_td(td), dst, 151 cpu_max_ext_state_size, &buf); 152 *(uint64_t *)((char *)buf + X86_XSTATE_XCR0_OFFSET) = 153 xsave_mask; 154 } else 155 len += elf32_populate_note(NT_X86_XSTATE, NULL, NULL, 156 cpu_max_ext_state_size, NULL); 157 } 158 *off = len; 159 } 160 161 bool 162 elf_is_ifunc_reloc(Elf_Size r_info) 163 { 164 165 return (ELF_R_TYPE(r_info) == R_386_IRELATIVE); 166 } 167 168 #define ERI_LOCAL 0x0001 169 170 /* Process one elf relocation with addend. */ 171 static int 172 elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data, 173 int type, elf_lookup_fn lookup, int flags) 174 { 175 Elf_Addr *where; 176 Elf_Addr addr; 177 Elf_Addr addend; 178 Elf_Word rtype, symidx; 179 const Elf_Rel *rel; 180 const Elf_Rela *rela; 181 int error; 182 183 switch (type) { 184 case ELF_RELOC_REL: 185 rel = (const Elf_Rel *)data; 186 where = (Elf_Addr *) (relocbase + rel->r_offset); 187 addend = *where; 188 rtype = ELF_R_TYPE(rel->r_info); 189 symidx = ELF_R_SYM(rel->r_info); 190 break; 191 case ELF_RELOC_RELA: 192 rela = (const Elf_Rela *)data; 193 where = (Elf_Addr *) (relocbase + rela->r_offset); 194 addend = rela->r_addend; 195 rtype = ELF_R_TYPE(rela->r_info); 196 symidx = ELF_R_SYM(rela->r_info); 197 break; 198 default: 199 panic("unknown reloc type %d\n", type); 200 } 201 202 if ((flags & ERI_LOCAL) != 0) { 203 if (rtype == R_386_RELATIVE) { /* A + B */ 204 addr = elf_relocaddr(lf, relocbase + addend); 205 if (*where != addr) 206 *where = addr; 207 } 208 return (0); 209 } 210 211 switch (rtype) { 212 213 case R_386_NONE: /* none */ 214 break; 215 216 case R_386_32: /* S + A */ 217 error = lookup(lf, symidx, 1, &addr); 218 if (error != 0) 219 return -1; 220 addr += addend; 221 if (*where != addr) 222 *where = addr; 223 break; 224 225 case R_386_PC32: /* S + A - P */ 226 error = lookup(lf, symidx, 1, &addr); 227 if (error != 0) 228 return -1; 229 addr += addend - (Elf_Addr)where; 230 if (*where != addr) 231 *where = addr; 232 break; 233 234 case R_386_COPY: /* none */ 235 /* 236 * There shouldn't be copy relocations in kernel 237 * objects. 238 */ 239 printf("kldload: unexpected R_COPY relocation\n"); 240 return -1; 241 break; 242 243 case R_386_GLOB_DAT: /* S */ 244 error = lookup(lf, symidx, 1, &addr); 245 if (error != 0) 246 return -1; 247 if (*where != addr) 248 *where = addr; 249 break; 250 251 case R_386_RELATIVE: 252 break; 253 254 case R_386_IRELATIVE: 255 addr = relocbase + addend; 256 addr = ((Elf_Addr (*)(void))addr)(); 257 if (*where != addr) 258 *where = addr; 259 break; 260 default: 261 printf("kldload: unexpected relocation type %d\n", 262 rtype); 263 return -1; 264 } 265 return(0); 266 } 267 268 int 269 elf_reloc(linker_file_t lf, Elf_Addr relocbase, const void *data, int type, 270 elf_lookup_fn lookup) 271 { 272 273 return (elf_reloc_internal(lf, relocbase, data, type, lookup, 0)); 274 } 275 276 int 277 elf_reloc_local(linker_file_t lf, Elf_Addr relocbase, const void *data, 278 int type, elf_lookup_fn lookup) 279 { 280 281 return (elf_reloc_internal(lf, relocbase, data, type, lookup, 282 ERI_LOCAL)); 283 } 284 285 int 286 elf_cpu_load_file(linker_file_t lf __unused) 287 { 288 289 return (0); 290 } 291 292 int 293 elf_cpu_unload_file(linker_file_t lf __unused) 294 { 295 296 return (0); 297 } 298