1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 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 #include "opt_cpu.h" 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/reg.h> 38 #include <sys/proc.h> 39 #include <sys/sysent.h> 40 #include <sys/imgact_elf.h> 41 #include <sys/syscall.h> 42 #include <sys/signalvar.h> 43 #include <sys/vnode.h> 44 45 #include <vm/vm.h> 46 #include <vm/pmap.h> 47 #include <vm/vm_param.h> 48 49 #include <machine/elf.h> 50 #include <machine/md_var.h> 51 #include <machine/npx.h> 52 53 struct sysentvec elf32_freebsd_sysvec = { 54 .sv_size = SYS_MAXSYSCALL, 55 .sv_table = sysent, 56 .sv_fixup = __elfN(freebsd_fixup), 57 .sv_sendsig = sendsig, 58 .sv_sigcode = sigcode, 59 .sv_szsigcode = &szsigcode, 60 .sv_name = "FreeBSD ELF32", 61 .sv_coredump = __elfN(coredump), 62 .sv_elf_core_osabi = ELFOSABI_FREEBSD, 63 .sv_elf_core_abi_vendor = FREEBSD_ABI_VENDOR, 64 .sv_elf_core_prepare_notes = __elfN(prepare_notes), 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_psstringssz = sizeof(struct ps_strings), 71 .sv_stackprot = VM_PROT_ALL, 72 .sv_copyout_auxargs = __elfN(freebsd_copyout_auxargs), 73 .sv_copyout_strings = exec_copyout_strings, 74 .sv_setregs = exec_setregs, 75 .sv_fixlimit = NULL, 76 .sv_maxssiz = NULL, 77 .sv_flags = SV_ABI_FREEBSD | SV_ASLR | SV_IA32 | SV_ILP32 | 78 SV_SHP | SV_TIMEKEEP | SV_RNG_SEED_VER | SV_SIGSYS, 79 .sv_set_syscall_retval = cpu_set_syscall_retval, 80 .sv_fetch_syscall_args = cpu_fetch_syscall_args, 81 .sv_syscallnames = syscallnames, 82 .sv_shared_page_base = SHAREDPAGE, 83 .sv_shared_page_len = PAGE_SIZE, 84 .sv_schedtail = NULL, 85 .sv_thread_detach = NULL, 86 .sv_trap = NULL, 87 .sv_onexec_old = exec_onexec_old, 88 .sv_onexit = exit_onexit, 89 .sv_set_fork_retval = x86_set_fork_retval, 90 .sv_regset_begin = SET_BEGIN(__elfN(regset)), 91 .sv_regset_end = SET_LIMIT(__elfN(regset)), 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 .interp_path = "/libexec/ld-elf.so.1", 100 .sysvec = &elf32_freebsd_sysvec, 101 .interp_newpath = NULL, 102 .brand_note = &elf32_freebsd_brandnote, 103 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 104 }; 105 106 SYSINIT(elf32, SI_SUB_EXEC, SI_ORDER_FIRST, 107 (sysinit_cfunc_t) elf32_insert_brand_entry, 108 &freebsd_brand_info); 109 110 static Elf32_Brandinfo freebsd_brand_oinfo = { 111 .brand = ELFOSABI_FREEBSD, 112 .machine = EM_386, 113 .compat_3_brand = "FreeBSD", 114 .interp_path = "/usr/libexec/ld-elf.so.1", 115 .sysvec = &elf32_freebsd_sysvec, 116 .interp_newpath = NULL, 117 .brand_note = &elf32_freebsd_brandnote, 118 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 119 }; 120 121 SYSINIT(oelf32, SI_SUB_EXEC, SI_ORDER_ANY, 122 (sysinit_cfunc_t) elf32_insert_brand_entry, 123 &freebsd_brand_oinfo); 124 125 static Elf32_Brandinfo kfreebsd_brand_info = { 126 .brand = ELFOSABI_FREEBSD, 127 .machine = EM_386, 128 .compat_3_brand = "FreeBSD", 129 .interp_path = "/lib/ld.so.1", 130 .sysvec = &elf32_freebsd_sysvec, 131 .interp_newpath = NULL, 132 .brand_note = &elf32_kfreebsd_brandnote, 133 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE_MANDATORY 134 }; 135 136 SYSINIT(kelf32, SI_SUB_EXEC, SI_ORDER_ANY, 137 (sysinit_cfunc_t) elf32_insert_brand_entry, 138 &kfreebsd_brand_info); 139 140 void 141 elf32_dump_thread(struct thread *td, void *dst, size_t *off) 142 { 143 void *buf; 144 size_t len; 145 146 len = 0; 147 if (use_xsave) { 148 if (dst != NULL) { 149 npxgetregs(td); 150 len += elf32_populate_note(NT_X86_XSTATE, 151 get_pcb_user_save_td(td), dst, 152 cpu_max_ext_state_size, &buf); 153 *(uint64_t *)((char *)buf + X86_XSTATE_XCR0_OFFSET) = 154 xsave_mask; 155 } else 156 len += elf32_populate_note(NT_X86_XSTATE, NULL, NULL, 157 cpu_max_ext_state_size, NULL); 158 } 159 *off = len; 160 } 161 162 bool 163 elf_is_ifunc_reloc(Elf_Size r_info) 164 { 165 166 return (ELF_R_TYPE(r_info) == R_386_IRELATIVE); 167 } 168 169 #define ERI_LOCAL 0x0001 170 171 /* Process one elf relocation with addend. */ 172 static int 173 elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data, 174 int type, elf_lookup_fn lookup, int flags) 175 { 176 Elf_Addr *where; 177 Elf_Addr addr; 178 Elf_Addr addend; 179 Elf_Word rtype, symidx; 180 const Elf_Rel *rel; 181 const Elf_Rela *rela; 182 int error; 183 184 switch (type) { 185 case ELF_RELOC_REL: 186 rel = (const Elf_Rel *)data; 187 where = (Elf_Addr *) (relocbase + rel->r_offset); 188 addend = *where; 189 rtype = ELF_R_TYPE(rel->r_info); 190 symidx = ELF_R_SYM(rel->r_info); 191 break; 192 case ELF_RELOC_RELA: 193 rela = (const Elf_Rela *)data; 194 where = (Elf_Addr *) (relocbase + rela->r_offset); 195 addend = rela->r_addend; 196 rtype = ELF_R_TYPE(rela->r_info); 197 symidx = ELF_R_SYM(rela->r_info); 198 break; 199 default: 200 panic("unknown reloc type %d\n", type); 201 } 202 203 if ((flags & ERI_LOCAL) != 0) { 204 if (rtype == R_386_RELATIVE) { /* A + B */ 205 addr = elf_relocaddr(lf, relocbase + addend); 206 if (*where != addr) 207 *where = addr; 208 } 209 return (0); 210 } 211 212 switch (rtype) { 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, " 240 "symbol index %d\n", symidx); 241 return (-1); 242 break; 243 244 case R_386_GLOB_DAT: /* S */ 245 case R_386_JMP_SLOT: /* S */ 246 error = lookup(lf, symidx, 1, &addr); 247 if (error != 0) 248 return (-1); 249 if (*where != addr) 250 *where = addr; 251 break; 252 253 case R_386_RELATIVE: 254 break; 255 256 case R_386_IRELATIVE: 257 addr = relocbase + addend; 258 addr = ((Elf_Addr (*)(void))addr)(); 259 if (*where != addr) 260 *where = addr; 261 break; 262 263 default: 264 printf("kldload: unexpected relocation type %d, " 265 "symbol index %d\n", rtype, symidx); 266 return (-1); 267 } 268 return(0); 269 } 270 271 int 272 elf_reloc(linker_file_t lf, Elf_Addr relocbase, const void *data, int type, 273 elf_lookup_fn lookup) 274 { 275 276 return (elf_reloc_internal(lf, relocbase, data, type, lookup, 0)); 277 } 278 279 int 280 elf_reloc_local(linker_file_t lf, Elf_Addr relocbase, const void *data, 281 int type, elf_lookup_fn lookup) 282 { 283 284 return (elf_reloc_internal(lf, relocbase, data, type, lookup, 285 ERI_LOCAL)); 286 } 287 288 int 289 elf_cpu_load_file(linker_file_t lf __unused) 290 { 291 292 return (0); 293 } 294 295 int 296 elf_cpu_unload_file(linker_file_t lf __unused) 297 { 298 299 return (0); 300 } 301 302 int 303 elf_cpu_parse_dynamic(caddr_t loadbase __unused, Elf_Dyn *dynamic __unused) 304 { 305 306 return (0); 307 } 308