1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 2004 Tim J. Robbins 5 * Copyright (c) 2003 Peter Wemm 6 * Copyright (c) 2002 Doug Rabson 7 * Copyright (c) 1998-1999 Andrew Gallatin 8 * Copyright (c) 1994-1996 Søren Schmidt 9 * All rights reserved. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer 16 * in this position and unchanged. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. The name of the author may not be used to endorse or promote products 21 * derived from this software without specific prior written permission 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 24 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 25 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 26 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 27 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 28 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 29 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 30 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 31 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 32 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 33 */ 34 35 #ifndef COMPAT_FREEBSD32 36 #error "Unable to compile Linux-emulator due to missing COMPAT_FREEBSD32 option!" 37 #endif 38 39 #define __ELF_WORD_SIZE 32 40 41 #include <sys/param.h> 42 #include <sys/exec.h> 43 #include <sys/imgact.h> 44 #include <sys/imgact_elf.h> 45 #include <sys/kernel.h> 46 #include <sys/lock.h> 47 #include <sys/module.h> 48 #include <sys/mutex.h> 49 #include <sys/proc.h> 50 #include <sys/stddef.h> 51 #include <sys/syscallsubr.h> 52 #include <sys/sysctl.h> 53 #include <sys/sysent.h> 54 55 #include <vm/pmap.h> 56 #include <vm/vm.h> 57 #include <vm/vm_map.h> 58 #include <vm/vm_param.h> 59 60 #include <machine/md_var.h> 61 #include <machine/trap.h> 62 63 #include <x86/linux/linux_x86.h> 64 #include <amd64/linux/linux_emul_md.h> 65 #include <amd64/linux32/linux.h> 66 #include <amd64/linux32/linux32_proto.h> 67 #include <compat/linux/linux_elf.h> 68 #include <compat/linux/linux_emul.h> 69 #include <compat/linux/linux_fork.h> 70 #include <compat/linux/linux_ioctl.h> 71 #include <compat/linux/linux_mib.h> 72 #include <compat/linux/linux_misc.h> 73 #include <compat/linux/linux_signal.h> 74 #include <compat/linux/linux_util.h> 75 #include <compat/linux/linux_vdso.h> 76 77 #include <x86/linux/linux_x86_sigframe.h> 78 79 MODULE_VERSION(linux, 1); 80 81 #define LINUX32_MAXUSER ((1ul << 32) - PAGE_SIZE) 82 #define LINUX32_VDSOPAGE_SIZE PAGE_SIZE * 2 83 #define LINUX32_VDSOPAGE (LINUX32_MAXUSER - LINUX32_VDSOPAGE_SIZE) 84 #define LINUX32_SHAREDPAGE (LINUX32_VDSOPAGE - PAGE_SIZE) 85 /* 86 * PAGE_SIZE - the size 87 * of the native SHAREDPAGE 88 */ 89 #define LINUX32_USRSTACK LINUX32_SHAREDPAGE 90 91 static int linux_szsigcode; 92 static vm_object_t linux_vdso_obj; 93 static char *linux_vdso_mapping; 94 extern char _binary_linux32_vdso_so_o_start; 95 extern char _binary_linux32_vdso_so_o_end; 96 static vm_offset_t linux_vdso_base; 97 98 extern struct sysent linux32_sysent[LINUX32_SYS_MAXSYSCALL]; 99 extern const char *linux32_syscallnames[]; 100 101 SET_DECLARE(linux_ioctl_handler_set, struct linux_ioctl_handler); 102 103 static int linux_copyout_strings(struct image_params *imgp, 104 uintptr_t *stack_base); 105 static void linux_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask); 106 static void linux_exec_setregs(struct thread *td, 107 struct image_params *imgp, uintptr_t stack); 108 static void linux_exec_sysvec_init(void *param); 109 static int linux_on_exec_vmspace(struct proc *p, 110 struct image_params *imgp); 111 static void linux32_fixlimit(struct rlimit *rl, int which); 112 static void linux_vdso_install(const void *param); 113 static void linux_vdso_deinstall(const void *param); 114 static void linux_vdso_reloc(char *mapping, Elf_Addr offset); 115 static void linux32_set_fork_retval(struct thread *td); 116 static void linux32_set_syscall_retval(struct thread *td, int error); 117 118 struct linux32_ps_strings { 119 u_int32_t ps_argvstr; /* first of 0 or more argument strings */ 120 u_int ps_nargvstr; /* the number of argument strings */ 121 u_int32_t ps_envstr; /* first of 0 or more environment strings */ 122 u_int ps_nenvstr; /* the number of environment strings */ 123 }; 124 #define LINUX32_PS_STRINGS (LINUX32_USRSTACK - \ 125 sizeof(struct linux32_ps_strings)) 126 127 LINUX_VDSO_SYM_INTPTR(__kernel_vsyscall); 128 LINUX_VDSO_SYM_INTPTR(linux32_vdso_sigcode); 129 LINUX_VDSO_SYM_INTPTR(linux32_vdso_rt_sigcode); 130 LINUX_VDSO_SYM_INTPTR(kern_timekeep_base); 131 LINUX_VDSO_SYM_INTPTR(kern_tsc_selector); 132 LINUX_VDSO_SYM_INTPTR(kern_cpu_selector); 133 LINUX_VDSO_SYM_CHAR(linux_platform); 134 135 void 136 linux32_arch_copyout_auxargs(struct image_params *imgp, Elf_Auxinfo **pos) 137 { 138 139 AUXARGS_ENTRY((*pos), LINUX_AT_SYSINFO, __kernel_vsyscall); 140 AUXARGS_ENTRY((*pos), LINUX_AT_SYSINFO_EHDR, linux_vdso_base); 141 AUXARGS_ENTRY((*pos), LINUX_AT_HWCAP, cpu_feature); 142 AUXARGS_ENTRY((*pos), LINUX_AT_HWCAP2, linux_x86_elf_hwcap2()); 143 AUXARGS_ENTRY((*pos), LINUX_AT_PLATFORM, PTROUT(linux_platform)); 144 } 145 146 static void 147 linux_rt_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask) 148 { 149 struct thread *td = curthread; 150 struct proc *p = td->td_proc; 151 struct sigacts *psp; 152 struct trapframe *regs; 153 struct l_rt_sigframe *fp, frame; 154 int oonstack; 155 int sig; 156 int code; 157 158 sig = linux_translate_traps(ksi->ksi_signo, ksi->ksi_trapno); 159 code = ksi->ksi_code; 160 PROC_LOCK_ASSERT(p, MA_OWNED); 161 psp = p->p_sigacts; 162 mtx_assert(&psp->ps_mtx, MA_OWNED); 163 regs = td->td_frame; 164 oonstack = sigonstack(regs->tf_rsp); 165 166 /* Allocate space for the signal handler context. */ 167 if ((td->td_pflags & TDP_ALTSTACK) && !oonstack && 168 SIGISMEMBER(psp->ps_sigonstack, sig)) { 169 fp = (struct l_rt_sigframe *)((uintptr_t)td->td_sigstk.ss_sp + 170 td->td_sigstk.ss_size - sizeof(struct l_rt_sigframe)); 171 } else 172 fp = (struct l_rt_sigframe *)regs->tf_rsp - 1; 173 mtx_unlock(&psp->ps_mtx); 174 175 /* Build the argument list for the signal handler. */ 176 sig = bsd_to_linux_signal(sig); 177 178 bzero(&frame, sizeof(frame)); 179 180 frame.sf_sig = sig; 181 frame.sf_siginfo = PTROUT(&fp->sf_si); 182 frame.sf_ucontext = PTROUT(&fp->sf_uc); 183 184 /* Fill in POSIX parts. */ 185 siginfo_to_lsiginfo(&ksi->ksi_info, &frame.sf_si, sig); 186 187 /* 188 * Build the signal context to be used by sigreturn and libgcc unwind. 189 */ 190 frame.sf_uc.uc_stack.ss_sp = PTROUT(td->td_sigstk.ss_sp); 191 frame.sf_uc.uc_stack.ss_size = td->td_sigstk.ss_size; 192 frame.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK) 193 ? ((oonstack) ? LINUX_SS_ONSTACK : 0) : LINUX_SS_DISABLE; 194 PROC_UNLOCK(p); 195 196 bsd_to_linux_sigset(mask, &frame.sf_uc.uc_sigmask); 197 198 frame.sf_uc.uc_mcontext.sc_mask = frame.sf_uc.uc_sigmask.__mask; 199 frame.sf_uc.uc_mcontext.sc_edi = regs->tf_rdi; 200 frame.sf_uc.uc_mcontext.sc_esi = regs->tf_rsi; 201 frame.sf_uc.uc_mcontext.sc_ebp = regs->tf_rbp; 202 frame.sf_uc.uc_mcontext.sc_ebx = regs->tf_rbx; 203 frame.sf_uc.uc_mcontext.sc_esp = regs->tf_rsp; 204 frame.sf_uc.uc_mcontext.sc_edx = regs->tf_rdx; 205 frame.sf_uc.uc_mcontext.sc_ecx = regs->tf_rcx; 206 frame.sf_uc.uc_mcontext.sc_eax = regs->tf_rax; 207 frame.sf_uc.uc_mcontext.sc_eip = regs->tf_rip; 208 frame.sf_uc.uc_mcontext.sc_cs = regs->tf_cs; 209 frame.sf_uc.uc_mcontext.sc_gs = regs->tf_gs; 210 frame.sf_uc.uc_mcontext.sc_fs = regs->tf_fs; 211 frame.sf_uc.uc_mcontext.sc_es = regs->tf_es; 212 frame.sf_uc.uc_mcontext.sc_ds = regs->tf_ds; 213 frame.sf_uc.uc_mcontext.sc_eflags = regs->tf_rflags; 214 frame.sf_uc.uc_mcontext.sc_esp_at_signal = regs->tf_rsp; 215 frame.sf_uc.uc_mcontext.sc_ss = regs->tf_ss; 216 frame.sf_uc.uc_mcontext.sc_err = regs->tf_err; 217 frame.sf_uc.uc_mcontext.sc_cr2 = (u_int32_t)(uintptr_t)ksi->ksi_addr; 218 frame.sf_uc.uc_mcontext.sc_trapno = bsd_to_linux_trapcode(code); 219 220 if (copyout(&frame, fp, sizeof(frame)) != 0) { 221 /* 222 * Process has trashed its stack; give it an illegal 223 * instruction to halt it in its tracks. 224 */ 225 PROC_LOCK(p); 226 sigexit(td, SIGILL); 227 } 228 229 /* Build context to run handler in. */ 230 regs->tf_rsp = PTROUT(fp); 231 regs->tf_rip = linux32_vdso_rt_sigcode; 232 regs->tf_rdi = PTROUT(catcher); 233 regs->tf_rflags &= ~(PSL_T | PSL_D); 234 regs->tf_cs = _ucode32sel; 235 regs->tf_ss = _udatasel; 236 regs->tf_ds = _udatasel; 237 regs->tf_es = _udatasel; 238 regs->tf_fs = _ufssel; 239 regs->tf_gs = _ugssel; 240 regs->tf_flags = TF_HASSEGS; 241 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 242 PROC_LOCK(p); 243 mtx_lock(&psp->ps_mtx); 244 } 245 246 /* 247 * Send an interrupt to process. 248 * 249 * Stack is set up to allow sigcode stored 250 * in u. to call routine, followed by kcall 251 * to sigreturn routine below. After sigreturn 252 * resets the signal mask, the stack, and the 253 * frame pointer, it returns to the user 254 * specified pc, psl. 255 */ 256 static void 257 linux_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask) 258 { 259 struct thread *td = curthread; 260 struct proc *p = td->td_proc; 261 struct sigacts *psp; 262 struct trapframe *regs; 263 struct l_sigframe *fp, frame; 264 l_sigset_t lmask; 265 int oonstack; 266 int sig, code; 267 268 sig = linux_translate_traps(ksi->ksi_signo, ksi->ksi_trapno); 269 code = ksi->ksi_code; 270 PROC_LOCK_ASSERT(p, MA_OWNED); 271 psp = p->p_sigacts; 272 mtx_assert(&psp->ps_mtx, MA_OWNED); 273 if (SIGISMEMBER(psp->ps_siginfo, sig)) { 274 /* Signal handler installed with SA_SIGINFO. */ 275 linux_rt_sendsig(catcher, ksi, mask); 276 return; 277 } 278 279 regs = td->td_frame; 280 oonstack = sigonstack(regs->tf_rsp); 281 282 /* Allocate space for the signal handler context. */ 283 if ((td->td_pflags & TDP_ALTSTACK) && !oonstack && 284 SIGISMEMBER(psp->ps_sigonstack, sig)) { 285 fp = (struct l_sigframe *)((uintptr_t)td->td_sigstk.ss_sp + 286 td->td_sigstk.ss_size - sizeof(struct l_sigframe)); 287 } else 288 fp = (struct l_sigframe *)regs->tf_rsp - 1; 289 mtx_unlock(&psp->ps_mtx); 290 PROC_UNLOCK(p); 291 292 /* Build the argument list for the signal handler. */ 293 sig = bsd_to_linux_signal(sig); 294 295 bzero(&frame, sizeof(frame)); 296 297 frame.sf_sig = sig; 298 frame.sf_sigmask = *mask; 299 bsd_to_linux_sigset(mask, &lmask); 300 301 /* Build the signal context to be used by sigreturn. */ 302 frame.sf_sc.sc_mask = lmask.__mask; 303 frame.sf_sc.sc_gs = regs->tf_gs; 304 frame.sf_sc.sc_fs = regs->tf_fs; 305 frame.sf_sc.sc_es = regs->tf_es; 306 frame.sf_sc.sc_ds = regs->tf_ds; 307 frame.sf_sc.sc_edi = regs->tf_rdi; 308 frame.sf_sc.sc_esi = regs->tf_rsi; 309 frame.sf_sc.sc_ebp = regs->tf_rbp; 310 frame.sf_sc.sc_ebx = regs->tf_rbx; 311 frame.sf_sc.sc_esp = regs->tf_rsp; 312 frame.sf_sc.sc_edx = regs->tf_rdx; 313 frame.sf_sc.sc_ecx = regs->tf_rcx; 314 frame.sf_sc.sc_eax = regs->tf_rax; 315 frame.sf_sc.sc_eip = regs->tf_rip; 316 frame.sf_sc.sc_cs = regs->tf_cs; 317 frame.sf_sc.sc_eflags = regs->tf_rflags; 318 frame.sf_sc.sc_esp_at_signal = regs->tf_rsp; 319 frame.sf_sc.sc_ss = regs->tf_ss; 320 frame.sf_sc.sc_err = regs->tf_err; 321 frame.sf_sc.sc_cr2 = (u_int32_t)(uintptr_t)ksi->ksi_addr; 322 frame.sf_sc.sc_trapno = bsd_to_linux_trapcode(code); 323 324 if (copyout(&frame, fp, sizeof(frame)) != 0) { 325 /* 326 * Process has trashed its stack; give it an illegal 327 * instruction to halt it in its tracks. 328 */ 329 PROC_LOCK(p); 330 sigexit(td, SIGILL); 331 } 332 333 /* Build context to run handler in. */ 334 regs->tf_rsp = PTROUT(fp); 335 regs->tf_rip = linux32_vdso_sigcode; 336 regs->tf_rdi = PTROUT(catcher); 337 regs->tf_rflags &= ~(PSL_T | PSL_D); 338 regs->tf_cs = _ucode32sel; 339 regs->tf_ss = _udatasel; 340 regs->tf_ds = _udatasel; 341 regs->tf_es = _udatasel; 342 regs->tf_fs = _ufssel; 343 regs->tf_gs = _ugssel; 344 regs->tf_flags = TF_HASSEGS; 345 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 346 PROC_LOCK(p); 347 mtx_lock(&psp->ps_mtx); 348 } 349 350 /* 351 * System call to cleanup state after a signal 352 * has been taken. Reset signal mask and 353 * stack state from context left by sendsig (above). 354 * Return to previous pc and psl as specified by 355 * context left by sendsig. Check carefully to 356 * make sure that the user has not modified the 357 * psl to gain improper privileges or to cause 358 * a machine fault. 359 */ 360 int 361 linux_sigreturn(struct thread *td, struct linux_sigreturn_args *args) 362 { 363 struct l_sigframe frame; 364 struct trapframe *regs; 365 int eflags; 366 ksiginfo_t ksi; 367 368 regs = td->td_frame; 369 370 /* 371 * The trampoline code hands us the sigframe. 372 * It is unsafe to keep track of it ourselves, in the event that a 373 * program jumps out of a signal handler. 374 */ 375 if (copyin(args->sfp, &frame, sizeof(frame)) != 0) 376 return (EFAULT); 377 378 /* Check for security violations. */ 379 eflags = frame.sf_sc.sc_eflags; 380 if (!EFL_SECURE(eflags, regs->tf_rflags)) 381 return(EINVAL); 382 383 /* 384 * Don't allow users to load a valid privileged %cs. Let the 385 * hardware check for invalid selectors, excess privilege in 386 * other selectors, invalid %eip's and invalid %esp's. 387 */ 388 if (!CS_SECURE(frame.sf_sc.sc_cs)) { 389 ksiginfo_init_trap(&ksi); 390 ksi.ksi_signo = SIGBUS; 391 ksi.ksi_code = BUS_OBJERR; 392 ksi.ksi_trapno = T_PROTFLT; 393 ksi.ksi_addr = (void *)regs->tf_rip; 394 trapsignal(td, &ksi); 395 return(EINVAL); 396 } 397 398 kern_sigprocmask(td, SIG_SETMASK, &frame.sf_sigmask, NULL, 0); 399 400 /* Restore signal context. */ 401 regs->tf_rdi = frame.sf_sc.sc_edi; 402 regs->tf_rsi = frame.sf_sc.sc_esi; 403 regs->tf_rbp = frame.sf_sc.sc_ebp; 404 regs->tf_rbx = frame.sf_sc.sc_ebx; 405 regs->tf_rdx = frame.sf_sc.sc_edx; 406 regs->tf_rcx = frame.sf_sc.sc_ecx; 407 regs->tf_rax = frame.sf_sc.sc_eax; 408 regs->tf_rip = frame.sf_sc.sc_eip; 409 regs->tf_cs = frame.sf_sc.sc_cs; 410 regs->tf_ds = frame.sf_sc.sc_ds; 411 regs->tf_es = frame.sf_sc.sc_es; 412 regs->tf_fs = frame.sf_sc.sc_fs; 413 regs->tf_gs = frame.sf_sc.sc_gs; 414 regs->tf_rflags = eflags; 415 regs->tf_rsp = frame.sf_sc.sc_esp_at_signal; 416 regs->tf_ss = frame.sf_sc.sc_ss; 417 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 418 419 return (EJUSTRETURN); 420 } 421 422 /* 423 * System call to cleanup state after a signal 424 * has been taken. Reset signal mask and 425 * stack state from context left by rt_sendsig (above). 426 * Return to previous pc and psl as specified by 427 * context left by sendsig. Check carefully to 428 * make sure that the user has not modified the 429 * psl to gain improper privileges or to cause 430 * a machine fault. 431 */ 432 int 433 linux_rt_sigreturn(struct thread *td, struct linux_rt_sigreturn_args *args) 434 { 435 struct l_ucontext uc; 436 struct l_sigcontext *context; 437 sigset_t bmask; 438 l_stack_t *lss; 439 stack_t ss; 440 struct trapframe *regs; 441 int eflags; 442 ksiginfo_t ksi; 443 444 regs = td->td_frame; 445 446 /* 447 * The trampoline code hands us the ucontext. 448 * It is unsafe to keep track of it ourselves, in the event that a 449 * program jumps out of a signal handler. 450 */ 451 if (copyin(args->ucp, &uc, sizeof(uc)) != 0) 452 return (EFAULT); 453 454 context = &uc.uc_mcontext; 455 456 /* Check for security violations. */ 457 eflags = context->sc_eflags; 458 if (!EFL_SECURE(eflags, regs->tf_rflags)) 459 return(EINVAL); 460 461 /* 462 * Don't allow users to load a valid privileged %cs. Let the 463 * hardware check for invalid selectors, excess privilege in 464 * other selectors, invalid %eip's and invalid %esp's. 465 */ 466 if (!CS_SECURE(context->sc_cs)) { 467 ksiginfo_init_trap(&ksi); 468 ksi.ksi_signo = SIGBUS; 469 ksi.ksi_code = BUS_OBJERR; 470 ksi.ksi_trapno = T_PROTFLT; 471 ksi.ksi_addr = (void *)regs->tf_rip; 472 trapsignal(td, &ksi); 473 return(EINVAL); 474 } 475 476 linux_to_bsd_sigset(&uc.uc_sigmask, &bmask); 477 kern_sigprocmask(td, SIG_SETMASK, &bmask, NULL, 0); 478 479 /* 480 * Restore signal context 481 */ 482 regs->tf_gs = context->sc_gs; 483 regs->tf_fs = context->sc_fs; 484 regs->tf_es = context->sc_es; 485 regs->tf_ds = context->sc_ds; 486 regs->tf_rdi = context->sc_edi; 487 regs->tf_rsi = context->sc_esi; 488 regs->tf_rbp = context->sc_ebp; 489 regs->tf_rbx = context->sc_ebx; 490 regs->tf_rdx = context->sc_edx; 491 regs->tf_rcx = context->sc_ecx; 492 regs->tf_rax = context->sc_eax; 493 regs->tf_rip = context->sc_eip; 494 regs->tf_cs = context->sc_cs; 495 regs->tf_rflags = eflags; 496 regs->tf_rsp = context->sc_esp_at_signal; 497 regs->tf_ss = context->sc_ss; 498 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 499 500 /* 501 * call sigaltstack & ignore results.. 502 */ 503 lss = &uc.uc_stack; 504 ss.ss_sp = PTRIN(lss->ss_sp); 505 ss.ss_size = lss->ss_size; 506 ss.ss_flags = linux_to_bsd_sigaltstack(lss->ss_flags); 507 508 (void)kern_sigaltstack(td, &ss, NULL); 509 510 return (EJUSTRETURN); 511 } 512 513 static int 514 linux32_fetch_syscall_args(struct thread *td) 515 { 516 struct proc *p; 517 struct trapframe *frame; 518 struct syscall_args *sa; 519 520 p = td->td_proc; 521 frame = td->td_frame; 522 sa = &td->td_sa; 523 524 sa->args[0] = frame->tf_rbx; 525 sa->args[1] = frame->tf_rcx; 526 sa->args[2] = frame->tf_rdx; 527 sa->args[3] = frame->tf_rsi; 528 sa->args[4] = frame->tf_rdi; 529 sa->args[5] = frame->tf_rbp; 530 sa->code = frame->tf_rax; 531 sa->original_code = sa->code; 532 533 if (sa->code >= p->p_sysent->sv_size) 534 /* nosys */ 535 sa->callp = &nosys_sysent; 536 else 537 sa->callp = &p->p_sysent->sv_table[sa->code]; 538 539 td->td_retval[0] = 0; 540 td->td_retval[1] = frame->tf_rdx; 541 542 return (0); 543 } 544 545 static void 546 linux32_set_syscall_retval(struct thread *td, int error) 547 { 548 struct trapframe *frame = td->td_frame; 549 550 cpu_set_syscall_retval(td, error); 551 552 if (__predict_false(error != 0)) { 553 if (error != ERESTART && error != EJUSTRETURN) 554 frame->tf_rax = bsd_to_linux_errno(error); 555 } 556 } 557 558 static void 559 linux32_set_fork_retval(struct thread *td) 560 { 561 struct trapframe *frame = td->td_frame; 562 563 frame->tf_rax = 0; 564 } 565 566 /* 567 * Clear registers on exec 568 * XXX copied from ia32_signal.c. 569 */ 570 static void 571 linux_exec_setregs(struct thread *td, struct image_params *imgp, 572 uintptr_t stack) 573 { 574 struct trapframe *regs = td->td_frame; 575 struct pcb *pcb = td->td_pcb; 576 register_t saved_rflags; 577 578 regs = td->td_frame; 579 pcb = td->td_pcb; 580 581 if (td->td_proc->p_md.md_ldt != NULL) 582 user_ldt_free(td); 583 584 /* Do full restore on return so that we can change to a different %cs */ 585 set_pcb_flags(pcb, PCB_32BIT | PCB_FULL_IRET); 586 clear_pcb_flags(pcb, PCB_TLSBASE); 587 588 critical_enter(); 589 wrmsr(MSR_FSBASE, 0); 590 wrmsr(MSR_KGSBASE, 0); /* User value while we're in the kernel */ 591 pcb->pcb_fsbase = 0; 592 pcb->pcb_gsbase = 0; 593 critical_exit(); 594 pcb->pcb_initial_fpucw = __LINUX_NPXCW__; 595 596 saved_rflags = regs->tf_rflags & PSL_T; 597 bzero((char *)regs, sizeof(struct trapframe)); 598 regs->tf_rip = imgp->entry_addr; 599 regs->tf_rsp = stack; 600 regs->tf_rflags = PSL_USER | saved_rflags; 601 regs->tf_gs = _ugssel; 602 regs->tf_fs = _ufssel; 603 regs->tf_es = _udatasel; 604 regs->tf_ds = _udatasel; 605 regs->tf_ss = _udatasel; 606 regs->tf_flags = TF_HASSEGS; 607 regs->tf_cs = _ucode32sel; 608 regs->tf_rbx = (register_t)imgp->ps_strings; 609 610 x86_clear_dbregs(pcb); 611 612 fpstate_drop(td); 613 614 /* Linux processes start with PKRU denying unallocated keys. */ 615 linux_pkru_exec_init(td); 616 } 617 618 /* 619 * XXX copied from ia32_sysvec.c. 620 */ 621 static int 622 linux_copyout_strings(struct image_params *imgp, uintptr_t *stack_base) 623 { 624 int argc, envc, error; 625 u_int32_t *vectp; 626 char *stringp; 627 uintptr_t destp, ustringp; 628 struct linux32_ps_strings *arginfo; 629 char canary[LINUX_AT_RANDOM_LEN]; 630 size_t execpath_len; 631 632 arginfo = (struct linux32_ps_strings *)PROC_PS_STRINGS(imgp->proc); 633 destp = (uintptr_t)arginfo; 634 635 if (imgp->execpath != NULL && imgp->auxargs != NULL) { 636 execpath_len = strlen(imgp->execpath) + 1; 637 destp -= execpath_len; 638 destp = rounddown2(destp, sizeof(uint32_t)); 639 imgp->execpathp = (void *)destp; 640 error = copyout(imgp->execpath, imgp->execpathp, execpath_len); 641 if (error != 0) 642 return (error); 643 } 644 645 /* Prepare the canary for SSP. */ 646 arc4rand(canary, sizeof(canary), 0); 647 destp -= roundup(sizeof(canary), sizeof(uint32_t)); 648 imgp->canary = (void *)destp; 649 error = copyout(canary, imgp->canary, sizeof(canary)); 650 if (error != 0) 651 return (error); 652 653 /* Allocate room for the argument and environment strings. */ 654 destp -= ARG_MAX - imgp->args->stringspace; 655 destp = rounddown2(destp, sizeof(uint32_t)); 656 ustringp = destp; 657 658 if (imgp->auxargs) { 659 /* 660 * Allocate room on the stack for the ELF auxargs 661 * array. It has LINUX_AT_COUNT entries. 662 */ 663 destp -= LINUX_AT_COUNT * sizeof(Elf32_Auxinfo); 664 destp = rounddown2(destp, sizeof(uint32_t)); 665 } 666 667 vectp = (uint32_t *)destp; 668 669 /* 670 * Allocate room for the argv[] and env vectors including the 671 * terminating NULL pointers. 672 */ 673 vectp -= imgp->args->argc + 1 + imgp->args->envc + 1; 674 675 /* vectp also becomes our initial stack base. */ 676 *stack_base = (uintptr_t)vectp; 677 678 stringp = imgp->args->begin_argv; 679 argc = imgp->args->argc; 680 envc = imgp->args->envc; 681 682 /* Copy out strings - arguments and environment. */ 683 error = copyout(stringp, (void *)ustringp, 684 ARG_MAX - imgp->args->stringspace); 685 if (error != 0) 686 return (error); 687 688 /* Fill in "ps_strings" struct for ps, w, etc. */ 689 if (suword32(&arginfo->ps_argvstr, (uint32_t)(intptr_t)vectp) != 0 || 690 suword32(&arginfo->ps_nargvstr, argc) != 0) 691 return (EFAULT); 692 693 /* Fill in argument portion of vector table. */ 694 for (; argc > 0; --argc) { 695 if (suword32(vectp++, ustringp) != 0) 696 return (EFAULT); 697 while (*stringp++ != 0) 698 ustringp++; 699 ustringp++; 700 } 701 702 /* A null vector table pointer separates the argp's from the envp's. */ 703 if (suword32(vectp++, 0) != 0) 704 return (EFAULT); 705 706 if (suword32(&arginfo->ps_envstr, (uint32_t)(intptr_t)vectp) != 0 || 707 suword32(&arginfo->ps_nenvstr, envc) != 0) 708 return (EFAULT); 709 710 /* Fill in environment portion of vector table. */ 711 for (; envc > 0; --envc) { 712 if (suword32(vectp++, ustringp) != 0) 713 return (EFAULT); 714 while (*stringp++ != 0) 715 ustringp++; 716 ustringp++; 717 } 718 719 /* The end of the vector table is a null pointer. */ 720 if (suword32(vectp, 0) != 0) 721 return (EFAULT); 722 723 if (imgp->auxargs) { 724 vectp++; 725 error = imgp->sysent->sv_copyout_auxargs(imgp, 726 (uintptr_t)vectp); 727 if (error != 0) 728 return (error); 729 } 730 731 return (0); 732 } 733 734 static SYSCTL_NODE(_compat, OID_AUTO, linux32, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 735 "32-bit Linux emulation"); 736 737 static u_long linux32_maxdsiz = LINUX32_MAXDSIZ; 738 SYSCTL_ULONG(_compat_linux32, OID_AUTO, maxdsiz, CTLFLAG_RW, 739 &linux32_maxdsiz, 0, ""); 740 static u_long linux32_maxssiz = LINUX32_MAXSSIZ; 741 SYSCTL_ULONG(_compat_linux32, OID_AUTO, maxssiz, CTLFLAG_RW, 742 &linux32_maxssiz, 0, ""); 743 static u_long linux32_maxvmem = LINUX32_MAXVMEM; 744 SYSCTL_ULONG(_compat_linux32, OID_AUTO, maxvmem, CTLFLAG_RW, 745 &linux32_maxvmem, 0, ""); 746 bool linux32_emulate_i386 = false; 747 SYSCTL_BOOL(_compat_linux32, OID_AUTO, emulate_i386, CTLFLAG_RWTUN, 748 &linux32_emulate_i386, 0, "Emulate the real i386"); 749 750 static void 751 linux32_fixlimit(struct rlimit *rl, int which) 752 { 753 754 switch (which) { 755 case RLIMIT_DATA: 756 if (linux32_maxdsiz != 0) { 757 if (rl->rlim_cur > linux32_maxdsiz) 758 rl->rlim_cur = linux32_maxdsiz; 759 if (rl->rlim_max > linux32_maxdsiz) 760 rl->rlim_max = linux32_maxdsiz; 761 } 762 break; 763 case RLIMIT_STACK: 764 if (linux32_maxssiz != 0) { 765 if (rl->rlim_cur > linux32_maxssiz) 766 rl->rlim_cur = linux32_maxssiz; 767 if (rl->rlim_max > linux32_maxssiz) 768 rl->rlim_max = linux32_maxssiz; 769 } 770 break; 771 case RLIMIT_VMEM: 772 if (linux32_maxvmem != 0) { 773 if (rl->rlim_cur > linux32_maxvmem) 774 rl->rlim_cur = linux32_maxvmem; 775 if (rl->rlim_max > linux32_maxvmem) 776 rl->rlim_max = linux32_maxvmem; 777 } 778 break; 779 } 780 } 781 782 struct sysentvec elf_linux_sysvec = { 783 .sv_size = LINUX32_SYS_MAXSYSCALL, 784 .sv_table = linux32_sysent, 785 .sv_fixup = elf32_freebsd_fixup, 786 .sv_sendsig = linux_sendsig, 787 .sv_sigcode = &_binary_linux32_vdso_so_o_start, 788 .sv_szsigcode = &linux_szsigcode, 789 .sv_name = "Linux ELF32", 790 .sv_coredump = elf32_coredump, 791 .sv_elf_core_osabi = ELFOSABI_NONE, 792 .sv_elf_core_abi_vendor = LINUX_ABI_VENDOR, 793 .sv_elf_core_prepare_notes = linux32_prepare_notes, 794 .sv_minsigstksz = LINUX_MINSIGSTKSZ, 795 .sv_minuser = VM_MIN_ADDRESS, 796 .sv_maxuser = LINUX32_MAXUSER, 797 .sv_usrstack = LINUX32_USRSTACK, 798 .sv_psstrings = LINUX32_PS_STRINGS, 799 .sv_psstringssz = sizeof(struct linux32_ps_strings), 800 .sv_stackprot = VM_PROT_ALL, 801 .sv_copyout_auxargs = __linuxN(copyout_auxargs), 802 .sv_copyout_strings = linux_copyout_strings, 803 .sv_setregs = linux_exec_setregs, 804 .sv_fixlimit = linux32_fixlimit, 805 .sv_maxssiz = &linux32_maxssiz, 806 .sv_flags = SV_ABI_LINUX | SV_ILP32 | SV_SHP | 807 SV_SIG_DISCIGN | SV_SIG_WAITNDQ | SV_TIMEKEEP, 808 .sv_set_syscall_retval = linux32_set_syscall_retval, 809 .sv_fetch_syscall_args = linux32_fetch_syscall_args, 810 .sv_syscallnames = linux32_syscallnames, 811 .sv_shared_page_base = LINUX32_SHAREDPAGE, 812 .sv_shared_page_len = PAGE_SIZE, 813 .sv_schedtail = linux_schedtail, 814 .sv_thread_detach = linux_thread_detach, 815 .sv_trap = NULL, 816 .sv_hwcap = NULL, 817 .sv_hwcap2 = NULL, 818 .sv_hwcap3 = NULL, 819 .sv_hwcap4 = NULL, 820 .sv_onexec = linux_on_exec_vmspace, 821 .sv_onexit = linux_on_exit, 822 .sv_ontdexit = linux_thread_dtor, 823 .sv_setid_allowed = &linux_setid_allowed_query, 824 .sv_set_fork_retval = linux32_set_fork_retval, 825 }; 826 827 static int 828 linux_on_exec_vmspace(struct proc *p, struct image_params *imgp) 829 { 830 int error; 831 832 error = linux_map_vdso(p, linux_vdso_obj, linux_vdso_base, 833 LINUX32_VDSOPAGE_SIZE, imgp); 834 if (error == 0) 835 error = linux_on_exec(p, imgp); 836 return (error); 837 } 838 839 /* 840 * linux_vdso_install() and linux_exec_sysvec_init() must be called 841 * after exec_sysvec_init() which is SI_SUB_EXEC (SI_ORDER_ANY). 842 */ 843 static void 844 linux_exec_sysvec_init(void *param) 845 { 846 l_uintptr_t *ktimekeep_base, *ktsc_selector; 847 struct sysentvec *sv; 848 ptrdiff_t tkoff; 849 850 sv = param; 851 /* Fill timekeep_base */ 852 exec_sysvec_init(sv); 853 854 tkoff = kern_timekeep_base - linux_vdso_base; 855 ktimekeep_base = (l_uintptr_t *)(linux_vdso_mapping + tkoff); 856 *ktimekeep_base = sv->sv_shared_page_base + sv->sv_timekeep_offset; 857 858 tkoff = kern_tsc_selector - linux_vdso_base; 859 ktsc_selector = (l_uintptr_t *)(linux_vdso_mapping + tkoff); 860 *ktsc_selector = linux_vdso_tsc_selector_idx(); 861 if (bootverbose) 862 printf("Linux i386 vDSO tsc_selector: %u\n", *ktsc_selector); 863 864 tkoff = kern_cpu_selector - linux_vdso_base; 865 ktsc_selector = (l_uintptr_t *)(linux_vdso_mapping + tkoff); 866 *ktsc_selector = linux_vdso_cpu_selector_idx(); 867 if (bootverbose) 868 printf("Linux i386 vDSO cpu_selector: %u\n", *ktsc_selector); 869 } 870 SYSINIT(elf_linux_exec_sysvec_init, SI_SUB_EXEC + 1, SI_ORDER_ANY, 871 linux_exec_sysvec_init, &elf_linux_sysvec); 872 873 static void 874 linux_vdso_install(const void *param) 875 { 876 char *vdso_start = &_binary_linux32_vdso_so_o_start; 877 char *vdso_end = &_binary_linux32_vdso_so_o_end; 878 879 linux_szsigcode = vdso_end - vdso_start; 880 MPASS(linux_szsigcode <= LINUX32_VDSOPAGE_SIZE); 881 882 linux_vdso_base = LINUX32_VDSOPAGE; 883 884 __elfN(linux_vdso_fixup)(vdso_start, linux_vdso_base); 885 886 linux_vdso_obj = __elfN(linux_shared_page_init) 887 (&linux_vdso_mapping, LINUX32_VDSOPAGE_SIZE); 888 bcopy(vdso_start, linux_vdso_mapping, linux_szsigcode); 889 890 linux_vdso_reloc(linux_vdso_mapping, linux_vdso_base); 891 } 892 SYSINIT(elf_linux_vdso_init, SI_SUB_EXEC + 1, SI_ORDER_FIRST, 893 linux_vdso_install, NULL); 894 895 static void 896 linux_vdso_deinstall(const void *param) 897 { 898 899 __elfN(linux_shared_page_fini)(linux_vdso_obj, 900 linux_vdso_mapping, LINUX32_VDSOPAGE_SIZE); 901 } 902 SYSUNINIT(elf_linux_vdso_uninit, SI_SUB_EXEC, SI_ORDER_FIRST, 903 linux_vdso_deinstall, NULL); 904 905 static void 906 linux_vdso_reloc(char *mapping, Elf_Addr offset) 907 { 908 const Elf_Shdr *shdr; 909 const Elf_Rel *rel; 910 const Elf_Ehdr *ehdr; 911 Elf32_Addr *where; 912 Elf_Size rtype, symidx; 913 Elf32_Addr addr, addend; 914 int i, relcnt; 915 916 MPASS(offset != 0); 917 918 relcnt = 0; 919 ehdr = (const Elf_Ehdr *)mapping; 920 shdr = (const Elf_Shdr *)(mapping + ehdr->e_shoff); 921 for (i = 0; i < ehdr->e_shnum; i++) 922 { 923 switch (shdr[i].sh_type) { 924 case SHT_REL: 925 rel = (const Elf_Rel *)(mapping + shdr[i].sh_offset); 926 relcnt = shdr[i].sh_size / sizeof(*rel); 927 break; 928 case SHT_RELA: 929 printf("Linux i386 vDSO: unexpected Rela section\n"); 930 break; 931 } 932 } 933 934 for (i = 0; i < relcnt; i++, rel++) { 935 where = (Elf32_Addr *)(mapping + rel->r_offset); 936 addend = *where; 937 rtype = ELF_R_TYPE(rel->r_info); 938 symidx = ELF_R_SYM(rel->r_info); 939 940 switch (rtype) { 941 case R_386_NONE: /* none */ 942 break; 943 944 case R_386_RELATIVE: /* B + A */ 945 addr = (Elf32_Addr)PTROUT(offset + addend); 946 if (*where != addr) 947 *where = addr; 948 break; 949 950 case R_386_IRELATIVE: 951 printf("Linux i386 vDSO: unexpected ifunc relocation, " 952 "symbol index %ld\n", (intmax_t)symidx); 953 break; 954 default: 955 printf("Linux i386 vDSO: unexpected relocation type %ld, " 956 "symbol index %ld\n", (intmax_t)rtype, (intmax_t)symidx); 957 } 958 } 959 } 960 961 static const Elf_Brandnote linux32_brandnote = { 962 .hdr.n_namesz = sizeof(GNU_ABI_VENDOR), 963 .hdr.n_descsz = 16, /* XXX at least 16 */ 964 .hdr.n_type = 1, 965 .vendor = GNU_ABI_VENDOR, 966 .flags = BN_TRANSLATE_OSREL, 967 .trans_osrel = linux_trans_osrel 968 }; 969 970 static const Elf32_Brandinfo linux_brand = { 971 .brand = ELFOSABI_LINUX, 972 .machine = EM_386, 973 .compat_3_brand = "Linux", 974 .interp_path = "/lib/ld-linux.so.1", 975 .sysvec = &elf_linux_sysvec, 976 .interp_newpath = NULL, 977 .brand_note = &linux32_brandnote, 978 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 979 }; 980 981 static const Elf32_Brandinfo linux_glibc2brand = { 982 .brand = ELFOSABI_LINUX, 983 .machine = EM_386, 984 .compat_3_brand = "Linux", 985 .interp_path = "/lib/ld-linux.so.2", 986 .sysvec = &elf_linux_sysvec, 987 .interp_newpath = NULL, 988 .brand_note = &linux32_brandnote, 989 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 990 }; 991 992 static const Elf32_Brandinfo linux_muslbrand = { 993 .brand = ELFOSABI_LINUX, 994 .machine = EM_386, 995 .compat_3_brand = "Linux", 996 .interp_path = "/lib/ld-musl-i386.so.1", 997 .sysvec = &elf_linux_sysvec, 998 .interp_newpath = NULL, 999 .brand_note = &linux32_brandnote, 1000 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE | 1001 LINUX_BI_FUTEX_REQUEUE 1002 }; 1003 1004 static const Elf32_Brandinfo *linux_brandlist[] = { 1005 &linux_brand, 1006 &linux_glibc2brand, 1007 &linux_muslbrand, 1008 NULL 1009 }; 1010 1011 static int 1012 linux_elf_modevent(module_t mod, int type, void *data) 1013 { 1014 const Elf32_Brandinfo **brandinfo; 1015 int error; 1016 struct linux_ioctl_handler **lihp; 1017 1018 error = 0; 1019 1020 switch(type) { 1021 case MOD_LOAD: 1022 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL; 1023 ++brandinfo) 1024 if (elf32_insert_brand_entry(*brandinfo) < 0) 1025 error = EINVAL; 1026 if (error == 0) { 1027 SET_FOREACH(lihp, linux_ioctl_handler_set) 1028 linux32_ioctl_register_handler(*lihp); 1029 stclohz = (stathz ? stathz : hz); 1030 if (bootverbose) 1031 printf("Linux i386 ELF exec handler installed\n"); 1032 } else 1033 printf("cannot insert Linux i386 ELF brand handler\n"); 1034 break; 1035 case MOD_UNLOAD: 1036 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL; 1037 ++brandinfo) 1038 if (elf32_brand_inuse(*brandinfo)) 1039 error = EBUSY; 1040 if (error == 0) { 1041 for (brandinfo = &linux_brandlist[0]; 1042 *brandinfo != NULL; ++brandinfo) 1043 if (elf32_remove_brand_entry(*brandinfo) < 0) 1044 error = EINVAL; 1045 } 1046 if (error == 0) { 1047 SET_FOREACH(lihp, linux_ioctl_handler_set) 1048 linux32_ioctl_unregister_handler(*lihp); 1049 if (bootverbose) 1050 printf("Linux i386 ELF exec handler removed\n"); 1051 } else 1052 printf("Could not deinstall Linux i386 ELF interpreter entry\n"); 1053 break; 1054 default: 1055 return (EOPNOTSUPP); 1056 } 1057 return (error); 1058 } 1059 1060 static moduledata_t linux_elf_mod = { 1061 "linuxelf", 1062 linux_elf_modevent, 1063 0 1064 }; 1065 1066 DECLARE_MODULE_TIED(linuxelf, linux_elf_mod, SI_SUB_EXEC, SI_ORDER_ANY); 1067 MODULE_DEPEND(linuxelf, linux_common, 1, 1, 1); 1068 FEATURE(linux, "Linux 32bit support"); 1069