1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 1994-1996 Søren Schmidt 5 * Copyright (c) 2018 Turing Robotic Industries Inc. 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 AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32 #include <sys/param.h> 33 #include <sys/systm.h> 34 #include <sys/cdefs.h> 35 #include <sys/elf.h> 36 #include <sys/exec.h> 37 #include <sys/imgact.h> 38 #include <sys/imgact_elf.h> 39 #include <sys/kernel.h> 40 #include <sys/lock.h> 41 #include <sys/module.h> 42 #include <sys/mutex.h> 43 #include <sys/proc.h> 44 #include <sys/signalvar.h> 45 #include <sys/sysctl.h> 46 #include <sys/sysent.h> 47 48 #include <vm/vm_param.h> 49 50 #include <arm64/linux/linux.h> 51 #include <arm64/linux/linux_proto.h> 52 #include <compat/linux/linux_dtrace.h> 53 #include <compat/linux/linux_emul.h> 54 #include <compat/linux/linux_futex.h> 55 #include <compat/linux/linux_ioctl.h> 56 #include <compat/linux/linux_mib.h> 57 #include <compat/linux/linux_misc.h> 58 #include <compat/linux/linux_vdso.h> 59 60 MODULE_VERSION(linux64elf, 1); 61 62 #if defined(DEBUG) 63 SYSCTL_PROC(_compat_linux, OID_AUTO, debug, CTLTYPE_STRING | CTLFLAG_RW, 0, 0, 64 linux_sysctl_debug, "A", "64-bit Linux debugging control"); 65 #endif 66 67 const char *linux_kplatform; 68 static int linux_szsigcode; 69 static vm_object_t linux_shared_page_obj; 70 static char *linux_shared_page_mapping; 71 extern char _binary_linux_locore_o_start; 72 extern char _binary_linux_locore_o_end; 73 74 extern struct sysent linux_sysent[LINUX_SYS_MAXSYSCALL]; 75 76 SET_DECLARE(linux_ioctl_handler_set, struct linux_ioctl_handler); 77 78 static register_t *linux_copyout_strings(struct image_params *imgp); 79 static int linux_elf_fixup(register_t **stack_base, 80 struct image_params *iparams); 81 static bool linux_trans_osrel(const Elf_Note *note, int32_t *osrel); 82 static void linux_vdso_install(const void *param); 83 static void linux_vdso_deinstall(const void *param); 84 static void linux_set_syscall_retval(struct thread *td, int error); 85 static int linux_fetch_syscall_args(struct thread *td); 86 static void linux_exec_setregs(struct thread *td, struct image_params *imgp, 87 u_long stack); 88 static int linux_vsyscall(struct thread *td); 89 90 /* DTrace init */ 91 LIN_SDT_PROVIDER_DECLARE(LINUX_DTRACE); 92 93 /* DTrace probes */ 94 LIN_SDT_PROBE_DEFINE2(sysvec, linux_translate_traps, todo, "int", "int"); 95 LIN_SDT_PROBE_DEFINE0(sysvec, linux_exec_setregs, todo); 96 LIN_SDT_PROBE_DEFINE0(sysvec, linux_elf_fixup, todo); 97 LIN_SDT_PROBE_DEFINE0(sysvec, linux_rt_sigreturn, todo); 98 LIN_SDT_PROBE_DEFINE0(sysvec, linux_rt_sendsig, todo); 99 LIN_SDT_PROBE_DEFINE0(sysvec, linux_vsyscall, todo); 100 LIN_SDT_PROBE_DEFINE0(sysvec, linux_vdso_install, todo); 101 LIN_SDT_PROBE_DEFINE0(sysvec, linux_vdso_deinstall, todo); 102 103 /* LINUXTODO: do we have traps to translate? */ 104 static int 105 linux_translate_traps(int signal, int trap_code) 106 { 107 108 LIN_SDT_PROBE2(sysvec, linux_translate_traps, todo, signal, trap_code); 109 return (signal); 110 } 111 112 LINUX_VDSO_SYM_CHAR(linux_platform); 113 114 static int 115 linux_fetch_syscall_args(struct thread *td) 116 { 117 struct proc *p; 118 struct syscall_args *sa; 119 register_t *ap; 120 121 p = td->td_proc; 122 ap = td->td_frame->tf_x; 123 sa = &td->td_sa; 124 125 sa->code = td->td_frame->tf_x[8]; 126 /* LINUXTODO: generic syscall? */ 127 if (p->p_sysent->sv_mask) 128 sa->code &= p->p_sysent->sv_mask; 129 if (sa->code >= p->p_sysent->sv_size) 130 sa->callp = &p->p_sysent->sv_table[0]; 131 else 132 sa->callp = &p->p_sysent->sv_table[sa->code]; 133 134 sa->narg = sa->callp->sy_narg; 135 if (sa->narg > 8) 136 panic("ARM64TODO: Could we have more than 8 args?"); 137 memcpy(sa->args, ap, 8 * sizeof(register_t)); 138 139 td->td_retval[0] = 0; 140 return (0); 141 } 142 143 static void 144 linux_set_syscall_retval(struct thread *td, int error) 145 { 146 147 td->td_retval[1] = td->td_frame->tf_x[1]; 148 cpu_set_syscall_retval(td, error); 149 } 150 151 static int 152 linux_elf_fixup(register_t **stack_base, struct image_params *imgp) 153 { 154 Elf_Auxargs *args; 155 Elf_Auxinfo *argarray, *pos; 156 Elf_Addr *auxbase, *base; 157 struct ps_strings *arginfo; 158 struct proc *p; 159 int error, issetugid; 160 161 LIN_SDT_PROBE0(sysvec, linux_elf_fixup, todo); 162 p = imgp->proc; 163 arginfo = (struct ps_strings *)p->p_sysent->sv_psstrings; 164 165 KASSERT(curthread->td_proc == imgp->proc, 166 ("unsafe linux_elf_fixup(), should be curproc")); 167 base = (Elf64_Addr *)*stack_base; 168 args = (Elf64_Auxargs *)imgp->auxargs; 169 /* Auxargs after argc, and NULL-terminated argv and envv lists. */ 170 auxbase = base + 1 + imgp->args->argc + 1 + imgp->args->envc + 1; 171 argarray = pos = malloc(LINUX_AT_COUNT * sizeof(*pos), M_TEMP, 172 M_WAITOK | M_ZERO); 173 174 issetugid = p->p_flag & P_SUGID ? 1 : 0; 175 AUXARGS_ENTRY(pos, LINUX_AT_SYSINFO_EHDR, 176 imgp->proc->p_sysent->sv_shared_page_base); 177 #if 0 /* LINUXTODO: implement arm64 LINUX_AT_HWCAP */ 178 AUXARGS_ENTRY(pos, LINUX_AT_HWCAP, cpu_feature); 179 #endif 180 AUXARGS_ENTRY(pos, LINUX_AT_CLKTCK, stclohz); 181 AUXARGS_ENTRY(pos, AT_PHDR, args->phdr); 182 AUXARGS_ENTRY(pos, AT_PHENT, args->phent); 183 AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum); 184 AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz); 185 AUXARGS_ENTRY(pos, AT_BASE, args->base); 186 AUXARGS_ENTRY(pos, AT_FLAGS, args->flags); 187 AUXARGS_ENTRY(pos, AT_ENTRY, args->entry); 188 AUXARGS_ENTRY(pos, AT_UID, imgp->proc->p_ucred->cr_ruid); 189 AUXARGS_ENTRY(pos, AT_EUID, imgp->proc->p_ucred->cr_svuid); 190 AUXARGS_ENTRY(pos, AT_GID, imgp->proc->p_ucred->cr_rgid); 191 AUXARGS_ENTRY(pos, AT_EGID, imgp->proc->p_ucred->cr_svgid); 192 AUXARGS_ENTRY(pos, LINUX_AT_SECURE, issetugid); 193 #if 0 /* LINUXTODO: implement arm64 LINUX_AT_PLATFORM */ 194 AUXARGS_ENTRY(pos, LINUX_AT_PLATFORM, PTROUT(linux_platform)); 195 #endif 196 AUXARGS_ENTRY(pos, LINUX_AT_RANDOM, imgp->canary); 197 if (imgp->execpathp != 0) 198 AUXARGS_ENTRY(pos, LINUX_AT_EXECFN, imgp->execpathp); 199 if (args->execfd != -1) 200 AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd); 201 AUXARGS_ENTRY(pos, AT_NULL, 0); 202 free(imgp->auxargs, M_TEMP); 203 imgp->auxargs = NULL; 204 KASSERT(pos - argarray <= LINUX_AT_COUNT, ("Too many auxargs")); 205 206 error = copyout(argarray, auxbase, sizeof(*argarray) * LINUX_AT_COUNT); 207 free(argarray, M_TEMP); 208 if (error != 0) 209 return (error); 210 211 return (0); 212 } 213 214 /* 215 * Copy strings out to the new process address space, constructing new arg 216 * and env vector tables. Return a pointer to the base so that it can be used 217 * as the initial stack pointer. 218 * LINUXTODO: deduplicate against other linuxulator archs 219 */ 220 static register_t * 221 linux_copyout_strings(struct image_params *imgp) 222 { 223 char **vectp; 224 char *stringp, *destp; 225 register_t *stack_base; 226 struct ps_strings *arginfo; 227 char canary[LINUX_AT_RANDOM_LEN]; 228 size_t execpath_len; 229 struct proc *p; 230 int argc, envc; 231 232 /* Calculate string base and vector table pointers. */ 233 if (imgp->execpath != NULL && imgp->auxargs != NULL) 234 execpath_len = strlen(imgp->execpath) + 1; 235 else 236 execpath_len = 0; 237 238 p = imgp->proc; 239 arginfo = (struct ps_strings *)p->p_sysent->sv_psstrings; 240 destp = (caddr_t)arginfo - SPARE_USRSPACE - 241 roundup(sizeof(canary), sizeof(char *)) - 242 roundup(execpath_len, sizeof(char *)) - 243 roundup(ARG_MAX - imgp->args->stringspace, sizeof(char *)); 244 245 if (execpath_len != 0) { 246 imgp->execpathp = (uintptr_t)arginfo - execpath_len; 247 copyout(imgp->execpath, (void *)imgp->execpathp, execpath_len); 248 } 249 250 /* Prepare the canary for SSP. */ 251 arc4rand(canary, sizeof(canary), 0); 252 imgp->canary = (uintptr_t)arginfo - 253 roundup(execpath_len, sizeof(char *)) - 254 roundup(sizeof(canary), sizeof(char *)); 255 copyout(canary, (void *)imgp->canary, sizeof(canary)); 256 257 vectp = (char **)destp; 258 if (imgp->auxargs) { 259 /* 260 * Allocate room on the stack for the ELF auxargs 261 * array. It has up to LINUX_AT_COUNT entries. 262 */ 263 vectp -= howmany(LINUX_AT_COUNT * sizeof(Elf64_Auxinfo), 264 sizeof(*vectp)); 265 } 266 267 /* 268 * Allocate room for argc and the argv[] and env vectors including the 269 * terminating NULL pointers. 270 */ 271 vectp -= 1 + imgp->args->argc + 1 + imgp->args->envc + 1; 272 vectp = (char **)STACKALIGN(vectp); 273 274 /* vectp also becomes our initial stack base. */ 275 stack_base = (register_t *)vectp; 276 277 stringp = imgp->args->begin_argv; 278 argc = imgp->args->argc; 279 envc = imgp->args->envc; 280 281 /* Copy out strings - arguments and environment. */ 282 copyout(stringp, destp, ARG_MAX - imgp->args->stringspace); 283 284 /* Fill in "ps_strings" struct for ps, w, etc. */ 285 suword(&arginfo->ps_argvstr, (long)(intptr_t)vectp); 286 suword(&arginfo->ps_nargvstr, argc); 287 288 suword(vectp++, argc); 289 /* Fill in argument portion of vector table. */ 290 for (; argc > 0; --argc) { 291 suword(vectp++, (long)(intptr_t)destp); 292 while (*stringp++ != 0) 293 destp++; 294 destp++; 295 } 296 297 /* A null vector table pointer separates the argp's from the envp's. */ 298 suword(vectp++, 0); 299 300 suword(&arginfo->ps_envstr, (long)(intptr_t)vectp); 301 suword(&arginfo->ps_nenvstr, envc); 302 303 /* Fill in environment portion of vector table. */ 304 for (; envc > 0; --envc) { 305 suword(vectp++, (long)(intptr_t)destp); 306 while (*stringp++ != 0) 307 destp++; 308 destp++; 309 } 310 311 /* The end of the vector table is a null pointer. */ 312 suword(vectp, 0); 313 return (stack_base); 314 } 315 316 /* 317 * Reset registers to default values on exec. 318 */ 319 static void 320 linux_exec_setregs(struct thread *td, struct image_params *imgp, u_long stack) 321 { 322 struct trapframe *regs = td->td_frame; 323 324 /* LINUXTODO: validate */ 325 LIN_SDT_PROBE0(sysvec, linux_exec_setregs, todo); 326 327 memset(regs, 0, sizeof(*regs)); 328 /* glibc start.S registers function pointer in x0 with atexit. */ 329 regs->tf_sp = stack; 330 #if 0 /* LINUXTODO: See if this is used. */ 331 regs->tf_lr = imgp->entry_addr; 332 #else 333 regs->tf_lr = 0xffffffffffffffff; 334 #endif 335 regs->tf_elr = imgp->entry_addr; 336 } 337 338 int 339 linux_rt_sigreturn(struct thread *td, struct linux_rt_sigreturn_args *args) 340 { 341 342 /* LINUXTODO: implement */ 343 LIN_SDT_PROBE0(sysvec, linux_rt_sigreturn, todo); 344 return (EDOOFUS); 345 } 346 347 static void 348 linux_rt_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask) 349 { 350 351 /* LINUXTODO: implement */ 352 LIN_SDT_PROBE0(sysvec, linux_rt_sendsig, todo); 353 } 354 355 static int 356 linux_vsyscall(struct thread *td) 357 { 358 359 /* LINUXTODO: implement */ 360 LIN_SDT_PROBE0(sysvec, linux_vsyscall, todo); 361 return (EDOOFUS); 362 } 363 364 struct sysentvec elf_linux_sysvec = { 365 .sv_size = LINUX_SYS_MAXSYSCALL, 366 .sv_table = linux_sysent, 367 .sv_mask = 0, 368 .sv_errsize = ELAST + 1, 369 .sv_errtbl = linux_errtbl, 370 .sv_transtrap = linux_translate_traps, 371 .sv_fixup = linux_elf_fixup, 372 .sv_sendsig = linux_rt_sendsig, 373 .sv_sigcode = &_binary_linux_locore_o_start, 374 .sv_szsigcode = &linux_szsigcode, 375 .sv_name = "Linux ELF64", 376 .sv_coredump = elf64_coredump, 377 .sv_imgact_try = linux_exec_imgact_try, 378 .sv_minsigstksz = LINUX_MINSIGSTKSZ, 379 .sv_pagesize = PAGE_SIZE, 380 .sv_minuser = VM_MIN_ADDRESS, 381 .sv_maxuser = VM_MAXUSER_ADDRESS, 382 .sv_usrstack = USRSTACK, 383 .sv_psstrings = PS_STRINGS, /* XXX */ 384 .sv_stackprot = VM_PROT_ALL, /* XXX */ 385 .sv_copyout_strings = linux_copyout_strings, 386 .sv_setregs = linux_exec_setregs, 387 .sv_fixlimit = NULL, 388 .sv_maxssiz = NULL, 389 .sv_flags = SV_ABI_LINUX | SV_LP64 | SV_SHP, 390 .sv_set_syscall_retval = linux_set_syscall_retval, 391 .sv_fetch_syscall_args = linux_fetch_syscall_args, 392 .sv_syscallnames = NULL, 393 .sv_shared_page_base = SHAREDPAGE, 394 .sv_shared_page_len = PAGE_SIZE, 395 .sv_schedtail = linux_schedtail, 396 .sv_thread_detach = linux_thread_detach, 397 .sv_trap = linux_vsyscall, 398 }; 399 400 static void 401 linux_vdso_install(const void *param) 402 { 403 404 linux_szsigcode = (&_binary_linux_locore_o_end - 405 &_binary_linux_locore_o_start); 406 407 if (linux_szsigcode > elf_linux_sysvec.sv_shared_page_len) 408 panic("invalid Linux VDSO size\n"); 409 410 __elfN(linux_vdso_fixup)(&elf_linux_sysvec); 411 412 linux_shared_page_obj = __elfN(linux_shared_page_init) 413 (&linux_shared_page_mapping); 414 415 __elfN(linux_vdso_reloc)(&elf_linux_sysvec); 416 417 memcpy(linux_shared_page_mapping, elf_linux_sysvec.sv_sigcode, 418 linux_szsigcode); 419 elf_linux_sysvec.sv_shared_page_obj = linux_shared_page_obj; 420 421 printf("LINUXTODO: %s: fix linux_kplatform\n", __func__); 422 #if 0 423 linux_kplatform = linux_shared_page_mapping + 424 (linux_platform - (caddr_t)elf_linux_sysvec.sv_shared_page_base); 425 #else 426 linux_kplatform = "arm64"; 427 #endif 428 } 429 SYSINIT(elf_linux_vdso_init, SI_SUB_EXEC, SI_ORDER_ANY, 430 linux_vdso_install, NULL); 431 432 static void 433 linux_vdso_deinstall(const void *param) 434 { 435 436 LIN_SDT_PROBE0(sysvec, linux_vdso_deinstall, todo); 437 __elfN(linux_shared_page_fini)(linux_shared_page_obj); 438 } 439 SYSUNINIT(elf_linux_vdso_uninit, SI_SUB_EXEC, SI_ORDER_FIRST, 440 linux_vdso_deinstall, NULL); 441 442 static char GNU_ABI_VENDOR[] = "GNU"; 443 static int GNU_ABI_LINUX = 0; 444 445 /* LINUXTODO: deduplicate */ 446 static bool 447 linux_trans_osrel(const Elf_Note *note, int32_t *osrel) 448 { 449 const Elf32_Word *desc; 450 uintptr_t p; 451 452 p = (uintptr_t)(note + 1); 453 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 454 455 desc = (const Elf32_Word *)p; 456 if (desc[0] != GNU_ABI_LINUX) 457 return (false); 458 459 *osrel = LINUX_KERNVER(desc[1], desc[2], desc[3]); 460 return (true); 461 } 462 463 static Elf_Brandnote linux64_brandnote = { 464 .hdr.n_namesz = sizeof(GNU_ABI_VENDOR), 465 .hdr.n_descsz = 16, 466 .hdr.n_type = 1, 467 .vendor = GNU_ABI_VENDOR, 468 .flags = BN_TRANSLATE_OSREL, 469 .trans_osrel = linux_trans_osrel 470 }; 471 472 static Elf64_Brandinfo linux_glibc2brand = { 473 .brand = ELFOSABI_LINUX, 474 .machine = EM_AARCH64, 475 .compat_3_brand = "Linux", 476 .emul_path = "/compat/linux", 477 .interp_path = "/lib64/ld-linux-x86-64.so.2", 478 .sysvec = &elf_linux_sysvec, 479 .interp_newpath = NULL, 480 .brand_note = &linux64_brandnote, 481 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 482 }; 483 484 Elf64_Brandinfo *linux_brandlist[] = { 485 &linux_glibc2brand, 486 NULL 487 }; 488 489 static int 490 linux64_elf_modevent(module_t mod, int type, void *data) 491 { 492 Elf64_Brandinfo **brandinfo; 493 struct linux_ioctl_handler**lihp; 494 int error; 495 496 error = 0; 497 switch(type) { 498 case MOD_LOAD: 499 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL; 500 ++brandinfo) 501 if (elf64_insert_brand_entry(*brandinfo) < 0) 502 error = EINVAL; 503 if (error == 0) { 504 SET_FOREACH(lihp, linux_ioctl_handler_set) 505 linux_ioctl_register_handler(*lihp); 506 LIST_INIT(&futex_list); 507 mtx_init(&futex_mtx, "ftllk64", NULL, MTX_DEF); 508 stclohz = (stathz ? stathz : hz); 509 if (bootverbose) 510 printf("Linux arm64 ELF exec handler installed\n"); 511 } 512 break; 513 case MOD_UNLOAD: 514 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL; 515 ++brandinfo) 516 if (elf64_brand_inuse(*brandinfo)) 517 error = EBUSY; 518 if (error == 0) { 519 for (brandinfo = &linux_brandlist[0]; 520 *brandinfo != NULL; ++brandinfo) 521 if (elf64_remove_brand_entry(*brandinfo) < 0) 522 error = EINVAL; 523 } 524 if (error == 0) { 525 SET_FOREACH(lihp, linux_ioctl_handler_set) 526 linux_ioctl_unregister_handler(*lihp); 527 mtx_destroy(&futex_mtx); 528 if (bootverbose) 529 printf("Linux ELF exec handler removed\n"); 530 } else 531 printf("Could not deinstall ELF interpreter entry\n"); 532 break; 533 default: 534 return (EOPNOTSUPP); 535 } 536 return (error); 537 } 538 539 static moduledata_t linux64_elf_mod = { 540 "linux64elf", 541 linux64_elf_modevent, 542 0 543 }; 544 545 DECLARE_MODULE_TIED(linux64elf, linux64_elf_mod, SI_SUB_EXEC, SI_ORDER_ANY); 546 MODULE_DEPEND(linux64elf, linux_common, 1, 1, 1); 547 FEATURE(linux64, "AArch64 Linux 64bit support"); 548