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