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 #include <sys/cdefs.h> 36 __FBSDID("$FreeBSD$"); 37 38 #ifndef COMPAT_FREEBSD32 39 #error "Unable to compile Linux-emulator due to missing COMPAT_FREEBSD32 option!" 40 #endif 41 42 #define __ELF_WORD_SIZE 32 43 44 #include <sys/param.h> 45 #include <sys/exec.h> 46 #include <sys/fcntl.h> 47 #include <sys/imgact.h> 48 #include <sys/imgact_elf.h> 49 #include <sys/kernel.h> 50 #include <sys/lock.h> 51 #include <sys/malloc.h> 52 #include <sys/module.h> 53 #include <sys/mutex.h> 54 #include <sys/proc.h> 55 #include <sys/stddef.h> 56 #include <sys/syscallsubr.h> 57 #include <sys/sysctl.h> 58 #include <sys/sysent.h> 59 60 #include <vm/pmap.h> 61 #include <vm/vm.h> 62 #include <vm/vm_map.h> 63 #include <vm/vm_page.h> 64 65 #include <machine/cpu.h> 66 #include <machine/md_var.h> 67 #include <machine/pcb.h> 68 #include <machine/specialreg.h> 69 #include <machine/trap.h> 70 71 #include <x86/linux/linux_x86.h> 72 #include <amd64/linux32/linux.h> 73 #include <amd64/linux32/linux32_proto.h> 74 #include <compat/linux/linux_elf.h> 75 #include <compat/linux/linux_emul.h> 76 #include <compat/linux/linux_fork.h> 77 #include <compat/linux/linux_ioctl.h> 78 #include <compat/linux/linux_mib.h> 79 #include <compat/linux/linux_misc.h> 80 #include <compat/linux/linux_signal.h> 81 #include <compat/linux/linux_util.h> 82 #include <compat/linux/linux_vdso.h> 83 84 #include <x86/linux/linux_x86_sigframe.h> 85 86 MODULE_VERSION(linux, 1); 87 88 #define LINUX32_MAXUSER ((1ul << 32) - PAGE_SIZE) 89 #define LINUX32_VDSOPAGE_SIZE PAGE_SIZE * 2 90 #define LINUX32_VDSOPAGE (LINUX32_MAXUSER - LINUX32_VDSOPAGE_SIZE) 91 #define LINUX32_SHAREDPAGE (LINUX32_VDSOPAGE - PAGE_SIZE) 92 /* 93 * PAGE_SIZE - the size 94 * of the native SHAREDPAGE 95 */ 96 #define LINUX32_USRSTACK LINUX32_SHAREDPAGE 97 98 static int linux_szsigcode; 99 static vm_object_t linux_vdso_obj; 100 static char *linux_vdso_mapping; 101 extern char _binary_linux32_vdso_so_o_start; 102 extern char _binary_linux32_vdso_so_o_end; 103 static vm_offset_t linux_vdso_base; 104 105 extern struct sysent linux32_sysent[LINUX32_SYS_MAXSYSCALL]; 106 extern const char *linux32_syscallnames[]; 107 108 SET_DECLARE(linux_ioctl_handler_set, struct linux_ioctl_handler); 109 110 static int linux_copyout_strings(struct image_params *imgp, 111 uintptr_t *stack_base); 112 static void linux_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask); 113 static void linux_exec_setregs(struct thread *td, 114 struct image_params *imgp, uintptr_t stack); 115 static void linux_exec_sysvec_init(void *param); 116 static int linux_on_exec_vmspace(struct proc *p, 117 struct image_params *imgp); 118 static void linux32_fixlimit(struct rlimit *rl, int which); 119 static void linux_vdso_install(const void *param); 120 static void linux_vdso_deinstall(const void *param); 121 static void linux_vdso_reloc(char *mapping, Elf_Addr offset); 122 static void linux32_set_fork_retval(struct thread *td); 123 static void linux32_set_syscall_retval(struct thread *td, int error); 124 125 struct linux32_ps_strings { 126 u_int32_t ps_argvstr; /* first of 0 or more argument strings */ 127 u_int ps_nargvstr; /* the number of argument strings */ 128 u_int32_t ps_envstr; /* first of 0 or more environment strings */ 129 u_int ps_nenvstr; /* the number of environment strings */ 130 }; 131 #define LINUX32_PS_STRINGS (LINUX32_USRSTACK - \ 132 sizeof(struct linux32_ps_strings)) 133 134 LINUX_VDSO_SYM_INTPTR(__kernel_vsyscall); 135 LINUX_VDSO_SYM_INTPTR(linux32_vdso_sigcode); 136 LINUX_VDSO_SYM_INTPTR(linux32_vdso_rt_sigcode); 137 LINUX_VDSO_SYM_INTPTR(kern_timekeep_base); 138 LINUX_VDSO_SYM_INTPTR(kern_tsc_selector); 139 LINUX_VDSO_SYM_INTPTR(kern_cpu_selector); 140 LINUX_VDSO_SYM_CHAR(linux_platform); 141 142 void 143 linux32_arch_copyout_auxargs(struct image_params *imgp, Elf_Auxinfo **pos) 144 { 145 146 AUXARGS_ENTRY((*pos), LINUX_AT_SYSINFO, __kernel_vsyscall); 147 AUXARGS_ENTRY((*pos), LINUX_AT_SYSINFO_EHDR, linux_vdso_base); 148 AUXARGS_ENTRY((*pos), LINUX_AT_HWCAP, cpu_feature); 149 AUXARGS_ENTRY((*pos), LINUX_AT_HWCAP2, 0); 150 AUXARGS_ENTRY((*pos), LINUX_AT_PLATFORM, PTROUT(linux_platform)); 151 } 152 153 static void 154 linux_rt_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask) 155 { 156 struct thread *td = curthread; 157 struct proc *p = td->td_proc; 158 struct sigacts *psp; 159 struct trapframe *regs; 160 struct l_rt_sigframe *fp, frame; 161 int oonstack; 162 int sig; 163 int code; 164 165 sig = linux_translate_traps(ksi->ksi_signo, ksi->ksi_trapno); 166 code = ksi->ksi_code; 167 PROC_LOCK_ASSERT(p, MA_OWNED); 168 psp = p->p_sigacts; 169 mtx_assert(&psp->ps_mtx, MA_OWNED); 170 regs = td->td_frame; 171 oonstack = sigonstack(regs->tf_rsp); 172 173 /* Allocate space for the signal handler context. */ 174 if ((td->td_pflags & TDP_ALTSTACK) && !oonstack && 175 SIGISMEMBER(psp->ps_sigonstack, sig)) { 176 fp = (struct l_rt_sigframe *)((uintptr_t)td->td_sigstk.ss_sp + 177 td->td_sigstk.ss_size - sizeof(struct l_rt_sigframe)); 178 } else 179 fp = (struct l_rt_sigframe *)regs->tf_rsp - 1; 180 mtx_unlock(&psp->ps_mtx); 181 182 /* Build the argument list for the signal handler. */ 183 sig = bsd_to_linux_signal(sig); 184 185 bzero(&frame, sizeof(frame)); 186 187 frame.sf_sig = sig; 188 frame.sf_siginfo = PTROUT(&fp->sf_si); 189 frame.sf_ucontext = PTROUT(&fp->sf_uc); 190 191 /* Fill in POSIX parts. */ 192 siginfo_to_lsiginfo(&ksi->ksi_info, &frame.sf_si, sig); 193 194 /* 195 * Build the signal context to be used by sigreturn and libgcc unwind. 196 */ 197 frame.sf_uc.uc_stack.ss_sp = PTROUT(td->td_sigstk.ss_sp); 198 frame.sf_uc.uc_stack.ss_size = td->td_sigstk.ss_size; 199 frame.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK) 200 ? ((oonstack) ? LINUX_SS_ONSTACK : 0) : LINUX_SS_DISABLE; 201 PROC_UNLOCK(p); 202 203 bsd_to_linux_sigset(mask, &frame.sf_uc.uc_sigmask); 204 205 frame.sf_uc.uc_mcontext.sc_mask = frame.sf_uc.uc_sigmask.__mask; 206 frame.sf_uc.uc_mcontext.sc_edi = regs->tf_rdi; 207 frame.sf_uc.uc_mcontext.sc_esi = regs->tf_rsi; 208 frame.sf_uc.uc_mcontext.sc_ebp = regs->tf_rbp; 209 frame.sf_uc.uc_mcontext.sc_ebx = regs->tf_rbx; 210 frame.sf_uc.uc_mcontext.sc_esp = regs->tf_rsp; 211 frame.sf_uc.uc_mcontext.sc_edx = regs->tf_rdx; 212 frame.sf_uc.uc_mcontext.sc_ecx = regs->tf_rcx; 213 frame.sf_uc.uc_mcontext.sc_eax = regs->tf_rax; 214 frame.sf_uc.uc_mcontext.sc_eip = regs->tf_rip; 215 frame.sf_uc.uc_mcontext.sc_cs = regs->tf_cs; 216 frame.sf_uc.uc_mcontext.sc_gs = regs->tf_gs; 217 frame.sf_uc.uc_mcontext.sc_fs = regs->tf_fs; 218 frame.sf_uc.uc_mcontext.sc_es = regs->tf_es; 219 frame.sf_uc.uc_mcontext.sc_ds = regs->tf_ds; 220 frame.sf_uc.uc_mcontext.sc_eflags = regs->tf_rflags; 221 frame.sf_uc.uc_mcontext.sc_esp_at_signal = regs->tf_rsp; 222 frame.sf_uc.uc_mcontext.sc_ss = regs->tf_ss; 223 frame.sf_uc.uc_mcontext.sc_err = regs->tf_err; 224 frame.sf_uc.uc_mcontext.sc_cr2 = (u_int32_t)(uintptr_t)ksi->ksi_addr; 225 frame.sf_uc.uc_mcontext.sc_trapno = bsd_to_linux_trapcode(code); 226 227 if (copyout(&frame, fp, sizeof(frame)) != 0) { 228 /* 229 * Process has trashed its stack; give it an illegal 230 * instruction to halt it in its tracks. 231 */ 232 PROC_LOCK(p); 233 sigexit(td, SIGILL); 234 } 235 236 /* Build context to run handler in. */ 237 regs->tf_rsp = PTROUT(fp); 238 regs->tf_rip = linux32_vdso_rt_sigcode; 239 regs->tf_rdi = PTROUT(catcher); 240 regs->tf_rflags &= ~(PSL_T | PSL_D); 241 regs->tf_cs = _ucode32sel; 242 regs->tf_ss = _udatasel; 243 regs->tf_ds = _udatasel; 244 regs->tf_es = _udatasel; 245 regs->tf_fs = _ufssel; 246 regs->tf_gs = _ugssel; 247 regs->tf_flags = TF_HASSEGS; 248 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 249 PROC_LOCK(p); 250 mtx_lock(&psp->ps_mtx); 251 } 252 253 /* 254 * Send an interrupt to process. 255 * 256 * Stack is set up to allow sigcode stored 257 * in u. to call routine, followed by kcall 258 * to sigreturn routine below. After sigreturn 259 * resets the signal mask, the stack, and the 260 * frame pointer, it returns to the user 261 * specified pc, psl. 262 */ 263 static void 264 linux_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask) 265 { 266 struct thread *td = curthread; 267 struct proc *p = td->td_proc; 268 struct sigacts *psp; 269 struct trapframe *regs; 270 struct l_sigframe *fp, frame; 271 l_sigset_t lmask; 272 int oonstack; 273 int sig, code; 274 275 sig = linux_translate_traps(ksi->ksi_signo, ksi->ksi_trapno); 276 code = ksi->ksi_code; 277 PROC_LOCK_ASSERT(p, MA_OWNED); 278 psp = p->p_sigacts; 279 mtx_assert(&psp->ps_mtx, MA_OWNED); 280 if (SIGISMEMBER(psp->ps_siginfo, sig)) { 281 /* Signal handler installed with SA_SIGINFO. */ 282 linux_rt_sendsig(catcher, ksi, mask); 283 return; 284 } 285 286 regs = td->td_frame; 287 oonstack = sigonstack(regs->tf_rsp); 288 289 /* Allocate space for the signal handler context. */ 290 if ((td->td_pflags & TDP_ALTSTACK) && !oonstack && 291 SIGISMEMBER(psp->ps_sigonstack, sig)) { 292 fp = (struct l_sigframe *)((uintptr_t)td->td_sigstk.ss_sp + 293 td->td_sigstk.ss_size - sizeof(struct l_sigframe)); 294 } else 295 fp = (struct l_sigframe *)regs->tf_rsp - 1; 296 mtx_unlock(&psp->ps_mtx); 297 PROC_UNLOCK(p); 298 299 /* Build the argument list for the signal handler. */ 300 sig = bsd_to_linux_signal(sig); 301 302 bzero(&frame, sizeof(frame)); 303 304 frame.sf_sig = sig; 305 frame.sf_sigmask = *mask; 306 bsd_to_linux_sigset(mask, &lmask); 307 308 /* Build the signal context to be used by sigreturn. */ 309 frame.sf_sc.sc_mask = lmask.__mask; 310 frame.sf_sc.sc_gs = regs->tf_gs; 311 frame.sf_sc.sc_fs = regs->tf_fs; 312 frame.sf_sc.sc_es = regs->tf_es; 313 frame.sf_sc.sc_ds = regs->tf_ds; 314 frame.sf_sc.sc_edi = regs->tf_rdi; 315 frame.sf_sc.sc_esi = regs->tf_rsi; 316 frame.sf_sc.sc_ebp = regs->tf_rbp; 317 frame.sf_sc.sc_ebx = regs->tf_rbx; 318 frame.sf_sc.sc_esp = regs->tf_rsp; 319 frame.sf_sc.sc_edx = regs->tf_rdx; 320 frame.sf_sc.sc_ecx = regs->tf_rcx; 321 frame.sf_sc.sc_eax = regs->tf_rax; 322 frame.sf_sc.sc_eip = regs->tf_rip; 323 frame.sf_sc.sc_cs = regs->tf_cs; 324 frame.sf_sc.sc_eflags = regs->tf_rflags; 325 frame.sf_sc.sc_esp_at_signal = regs->tf_rsp; 326 frame.sf_sc.sc_ss = regs->tf_ss; 327 frame.sf_sc.sc_err = regs->tf_err; 328 frame.sf_sc.sc_cr2 = (u_int32_t)(uintptr_t)ksi->ksi_addr; 329 frame.sf_sc.sc_trapno = bsd_to_linux_trapcode(code); 330 331 if (copyout(&frame, fp, sizeof(frame)) != 0) { 332 /* 333 * Process has trashed its stack; give it an illegal 334 * instruction to halt it in its tracks. 335 */ 336 PROC_LOCK(p); 337 sigexit(td, SIGILL); 338 } 339 340 /* Build context to run handler in. */ 341 regs->tf_rsp = PTROUT(fp); 342 regs->tf_rip = linux32_vdso_sigcode; 343 regs->tf_rdi = PTROUT(catcher); 344 regs->tf_rflags &= ~(PSL_T | PSL_D); 345 regs->tf_cs = _ucode32sel; 346 regs->tf_ss = _udatasel; 347 regs->tf_ds = _udatasel; 348 regs->tf_es = _udatasel; 349 regs->tf_fs = _ufssel; 350 regs->tf_gs = _ugssel; 351 regs->tf_flags = TF_HASSEGS; 352 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 353 PROC_LOCK(p); 354 mtx_lock(&psp->ps_mtx); 355 } 356 357 /* 358 * System call to cleanup state after a signal 359 * has been taken. Reset signal mask and 360 * stack state from context left by sendsig (above). 361 * Return to previous pc and psl as specified by 362 * context left by sendsig. Check carefully to 363 * make sure that the user has not modified the 364 * psl to gain improper privileges or to cause 365 * a machine fault. 366 */ 367 int 368 linux_sigreturn(struct thread *td, struct linux_sigreturn_args *args) 369 { 370 struct l_sigframe frame; 371 struct trapframe *regs; 372 int eflags; 373 ksiginfo_t ksi; 374 375 regs = td->td_frame; 376 377 /* 378 * The trampoline code hands us the sigframe. 379 * It is unsafe to keep track of it ourselves, in the event that a 380 * program jumps out of a signal handler. 381 */ 382 if (copyin(args->sfp, &frame, sizeof(frame)) != 0) 383 return (EFAULT); 384 385 /* Check for security violations. */ 386 eflags = frame.sf_sc.sc_eflags; 387 if (!EFL_SECURE(eflags, regs->tf_rflags)) 388 return(EINVAL); 389 390 /* 391 * Don't allow users to load a valid privileged %cs. Let the 392 * hardware check for invalid selectors, excess privilege in 393 * other selectors, invalid %eip's and invalid %esp's. 394 */ 395 if (!CS_SECURE(frame.sf_sc.sc_cs)) { 396 ksiginfo_init_trap(&ksi); 397 ksi.ksi_signo = SIGBUS; 398 ksi.ksi_code = BUS_OBJERR; 399 ksi.ksi_trapno = T_PROTFLT; 400 ksi.ksi_addr = (void *)regs->tf_rip; 401 trapsignal(td, &ksi); 402 return(EINVAL); 403 } 404 405 kern_sigprocmask(td, SIG_SETMASK, &frame.sf_sigmask, NULL, 0); 406 407 /* Restore signal context. */ 408 regs->tf_rdi = frame.sf_sc.sc_edi; 409 regs->tf_rsi = frame.sf_sc.sc_esi; 410 regs->tf_rbp = frame.sf_sc.sc_ebp; 411 regs->tf_rbx = frame.sf_sc.sc_ebx; 412 regs->tf_rdx = frame.sf_sc.sc_edx; 413 regs->tf_rcx = frame.sf_sc.sc_ecx; 414 regs->tf_rax = frame.sf_sc.sc_eax; 415 regs->tf_rip = frame.sf_sc.sc_eip; 416 regs->tf_cs = frame.sf_sc.sc_cs; 417 regs->tf_ds = frame.sf_sc.sc_ds; 418 regs->tf_es = frame.sf_sc.sc_es; 419 regs->tf_fs = frame.sf_sc.sc_fs; 420 regs->tf_gs = frame.sf_sc.sc_gs; 421 regs->tf_rflags = eflags; 422 regs->tf_rsp = frame.sf_sc.sc_esp_at_signal; 423 regs->tf_ss = frame.sf_sc.sc_ss; 424 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 425 426 return (EJUSTRETURN); 427 } 428 429 /* 430 * System call to cleanup state after a signal 431 * has been taken. Reset signal mask and 432 * stack state from context left by rt_sendsig (above). 433 * Return to previous pc and psl as specified by 434 * context left by sendsig. Check carefully to 435 * make sure that the user has not modified the 436 * psl to gain improper privileges or to cause 437 * a machine fault. 438 */ 439 int 440 linux_rt_sigreturn(struct thread *td, struct linux_rt_sigreturn_args *args) 441 { 442 struct l_ucontext uc; 443 struct l_sigcontext *context; 444 sigset_t bmask; 445 l_stack_t *lss; 446 stack_t ss; 447 struct trapframe *regs; 448 int eflags; 449 ksiginfo_t ksi; 450 451 regs = td->td_frame; 452 453 /* 454 * The trampoline code hands us the ucontext. 455 * It is unsafe to keep track of it ourselves, in the event that a 456 * program jumps out of a signal handler. 457 */ 458 if (copyin(args->ucp, &uc, sizeof(uc)) != 0) 459 return (EFAULT); 460 461 context = &uc.uc_mcontext; 462 463 /* Check for security violations. */ 464 eflags = context->sc_eflags; 465 if (!EFL_SECURE(eflags, regs->tf_rflags)) 466 return(EINVAL); 467 468 /* 469 * Don't allow users to load a valid privileged %cs. Let the 470 * hardware check for invalid selectors, excess privilege in 471 * other selectors, invalid %eip's and invalid %esp's. 472 */ 473 if (!CS_SECURE(context->sc_cs)) { 474 ksiginfo_init_trap(&ksi); 475 ksi.ksi_signo = SIGBUS; 476 ksi.ksi_code = BUS_OBJERR; 477 ksi.ksi_trapno = T_PROTFLT; 478 ksi.ksi_addr = (void *)regs->tf_rip; 479 trapsignal(td, &ksi); 480 return(EINVAL); 481 } 482 483 linux_to_bsd_sigset(&uc.uc_sigmask, &bmask); 484 kern_sigprocmask(td, SIG_SETMASK, &bmask, NULL, 0); 485 486 /* 487 * Restore signal context 488 */ 489 regs->tf_gs = context->sc_gs; 490 regs->tf_fs = context->sc_fs; 491 regs->tf_es = context->sc_es; 492 regs->tf_ds = context->sc_ds; 493 regs->tf_rdi = context->sc_edi; 494 regs->tf_rsi = context->sc_esi; 495 regs->tf_rbp = context->sc_ebp; 496 regs->tf_rbx = context->sc_ebx; 497 regs->tf_rdx = context->sc_edx; 498 regs->tf_rcx = context->sc_ecx; 499 regs->tf_rax = context->sc_eax; 500 regs->tf_rip = context->sc_eip; 501 regs->tf_cs = context->sc_cs; 502 regs->tf_rflags = eflags; 503 regs->tf_rsp = context->sc_esp_at_signal; 504 regs->tf_ss = context->sc_ss; 505 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 506 507 /* 508 * call sigaltstack & ignore results.. 509 */ 510 lss = &uc.uc_stack; 511 ss.ss_sp = PTRIN(lss->ss_sp); 512 ss.ss_size = lss->ss_size; 513 ss.ss_flags = linux_to_bsd_sigaltstack(lss->ss_flags); 514 515 (void)kern_sigaltstack(td, &ss, NULL); 516 517 return (EJUSTRETURN); 518 } 519 520 static int 521 linux32_fetch_syscall_args(struct thread *td) 522 { 523 struct proc *p; 524 struct trapframe *frame; 525 struct syscall_args *sa; 526 527 p = td->td_proc; 528 frame = td->td_frame; 529 sa = &td->td_sa; 530 531 sa->args[0] = frame->tf_rbx; 532 sa->args[1] = frame->tf_rcx; 533 sa->args[2] = frame->tf_rdx; 534 sa->args[3] = frame->tf_rsi; 535 sa->args[4] = frame->tf_rdi; 536 sa->args[5] = frame->tf_rbp; /* Unconfirmed */ 537 sa->code = frame->tf_rax; 538 sa->original_code = sa->code; 539 540 if (sa->code >= p->p_sysent->sv_size) 541 /* nosys */ 542 sa->callp = &p->p_sysent->sv_table[p->p_sysent->sv_size - 1]; 543 else 544 sa->callp = &p->p_sysent->sv_table[sa->code]; 545 546 td->td_retval[0] = 0; 547 td->td_retval[1] = frame->tf_rdx; 548 549 return (0); 550 } 551 552 static void 553 linux32_set_syscall_retval(struct thread *td, int error) 554 { 555 struct trapframe *frame = td->td_frame; 556 557 cpu_set_syscall_retval(td, error); 558 559 if (__predict_false(error != 0)) { 560 if (error != ERESTART && error != EJUSTRETURN) 561 frame->tf_rax = bsd_to_linux_errno(error); 562 } 563 } 564 565 static void 566 linux32_set_fork_retval(struct thread *td) 567 { 568 struct trapframe *frame = td->td_frame; 569 570 frame->tf_rax = 0; 571 } 572 573 /* 574 * Clear registers on exec 575 * XXX copied from ia32_signal.c. 576 */ 577 static void 578 linux_exec_setregs(struct thread *td, struct image_params *imgp, 579 uintptr_t stack) 580 { 581 struct trapframe *regs = td->td_frame; 582 struct pcb *pcb = td->td_pcb; 583 register_t saved_rflags; 584 585 regs = td->td_frame; 586 pcb = td->td_pcb; 587 588 if (td->td_proc->p_md.md_ldt != NULL) 589 user_ldt_free(td); 590 591 critical_enter(); 592 wrmsr(MSR_FSBASE, 0); 593 wrmsr(MSR_KGSBASE, 0); /* User value while we're in the kernel */ 594 pcb->pcb_fsbase = 0; 595 pcb->pcb_gsbase = 0; 596 critical_exit(); 597 pcb->pcb_initial_fpucw = __LINUX_NPXCW__; 598 599 saved_rflags = regs->tf_rflags & PSL_T; 600 bzero((char *)regs, sizeof(struct trapframe)); 601 regs->tf_rip = imgp->entry_addr; 602 regs->tf_rsp = stack; 603 regs->tf_rflags = PSL_USER | saved_rflags; 604 regs->tf_gs = _ugssel; 605 regs->tf_fs = _ufssel; 606 regs->tf_es = _udatasel; 607 regs->tf_ds = _udatasel; 608 regs->tf_ss = _udatasel; 609 regs->tf_flags = TF_HASSEGS; 610 regs->tf_cs = _ucode32sel; 611 regs->tf_rbx = (register_t)imgp->ps_strings; 612 613 x86_clear_dbregs(pcb); 614 615 fpstate_drop(td); 616 617 /* Do full restore on return so that we can change to a different %cs */ 618 set_pcb_flags(pcb, PCB_32BIT | PCB_FULL_IRET); 619 } 620 621 /* 622 * XXX copied from ia32_sysvec.c. 623 */ 624 static int 625 linux_copyout_strings(struct image_params *imgp, uintptr_t *stack_base) 626 { 627 int argc, envc, error; 628 u_int32_t *vectp; 629 char *stringp; 630 uintptr_t destp, ustringp; 631 struct linux32_ps_strings *arginfo; 632 char canary[LINUX_AT_RANDOM_LEN]; 633 size_t execpath_len; 634 635 arginfo = (struct linux32_ps_strings *)PROC_PS_STRINGS(imgp->proc); 636 destp = (uintptr_t)arginfo; 637 638 if (imgp->execpath != NULL && imgp->auxargs != NULL) { 639 execpath_len = strlen(imgp->execpath) + 1; 640 destp -= execpath_len; 641 destp = rounddown2(destp, sizeof(uint32_t)); 642 imgp->execpathp = (void *)destp; 643 error = copyout(imgp->execpath, imgp->execpathp, execpath_len); 644 if (error != 0) 645 return (error); 646 } 647 648 /* Prepare the canary for SSP. */ 649 arc4rand(canary, sizeof(canary), 0); 650 destp -= roundup(sizeof(canary), sizeof(uint32_t)); 651 imgp->canary = (void *)destp; 652 error = copyout(canary, imgp->canary, sizeof(canary)); 653 if (error != 0) 654 return (error); 655 656 /* Allocate room for the argument and environment strings. */ 657 destp -= ARG_MAX - imgp->args->stringspace; 658 destp = rounddown2(destp, sizeof(uint32_t)); 659 ustringp = destp; 660 661 if (imgp->auxargs) { 662 /* 663 * Allocate room on the stack for the ELF auxargs 664 * array. It has LINUX_AT_COUNT entries. 665 */ 666 destp -= LINUX_AT_COUNT * sizeof(Elf32_Auxinfo); 667 destp = rounddown2(destp, sizeof(uint32_t)); 668 } 669 670 vectp = (uint32_t *)destp; 671 672 /* 673 * Allocate room for the argv[] and env vectors including the 674 * terminating NULL pointers. 675 */ 676 vectp -= imgp->args->argc + 1 + imgp->args->envc + 1; 677 678 /* vectp also becomes our initial stack base. */ 679 *stack_base = (uintptr_t)vectp; 680 681 stringp = imgp->args->begin_argv; 682 argc = imgp->args->argc; 683 envc = imgp->args->envc; 684 685 /* Copy out strings - arguments and environment. */ 686 error = copyout(stringp, (void *)ustringp, 687 ARG_MAX - imgp->args->stringspace); 688 if (error != 0) 689 return (error); 690 691 /* Fill in "ps_strings" struct for ps, w, etc. */ 692 if (suword32(&arginfo->ps_argvstr, (uint32_t)(intptr_t)vectp) != 0 || 693 suword32(&arginfo->ps_nargvstr, argc) != 0) 694 return (EFAULT); 695 696 /* Fill in argument portion of vector table. */ 697 for (; argc > 0; --argc) { 698 if (suword32(vectp++, ustringp) != 0) 699 return (EFAULT); 700 while (*stringp++ != 0) 701 ustringp++; 702 ustringp++; 703 } 704 705 /* A null vector table pointer separates the argp's from the envp's. */ 706 if (suword32(vectp++, 0) != 0) 707 return (EFAULT); 708 709 if (suword32(&arginfo->ps_envstr, (uint32_t)(intptr_t)vectp) != 0 || 710 suword32(&arginfo->ps_nenvstr, envc) != 0) 711 return (EFAULT); 712 713 /* Fill in environment portion of vector table. */ 714 for (; envc > 0; --envc) { 715 if (suword32(vectp++, ustringp) != 0) 716 return (EFAULT); 717 while (*stringp++ != 0) 718 ustringp++; 719 ustringp++; 720 } 721 722 /* The end of the vector table is a null pointer. */ 723 if (suword32(vectp, 0) != 0) 724 return (EFAULT); 725 726 if (imgp->auxargs) { 727 vectp++; 728 error = imgp->sysent->sv_copyout_auxargs(imgp, 729 (uintptr_t)vectp); 730 if (error != 0) 731 return (error); 732 } 733 734 return (0); 735 } 736 737 static SYSCTL_NODE(_compat, OID_AUTO, linux32, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 738 "32-bit Linux emulation"); 739 740 static u_long linux32_maxdsiz = LINUX32_MAXDSIZ; 741 SYSCTL_ULONG(_compat_linux32, OID_AUTO, maxdsiz, CTLFLAG_RW, 742 &linux32_maxdsiz, 0, ""); 743 static u_long linux32_maxssiz = LINUX32_MAXSSIZ; 744 SYSCTL_ULONG(_compat_linux32, OID_AUTO, maxssiz, CTLFLAG_RW, 745 &linux32_maxssiz, 0, ""); 746 static u_long linux32_maxvmem = LINUX32_MAXVMEM; 747 SYSCTL_ULONG(_compat_linux32, OID_AUTO, maxvmem, CTLFLAG_RW, 748 &linux32_maxvmem, 0, ""); 749 bool linux32_emulate_i386 = false; 750 SYSCTL_BOOL(_compat_linux32, OID_AUTO, emulate_i386, CTLFLAG_RWTUN, 751 &linux32_emulate_i386, 0, "Emulate the real i386"); 752 753 static void 754 linux32_fixlimit(struct rlimit *rl, int which) 755 { 756 757 switch (which) { 758 case RLIMIT_DATA: 759 if (linux32_maxdsiz != 0) { 760 if (rl->rlim_cur > linux32_maxdsiz) 761 rl->rlim_cur = linux32_maxdsiz; 762 if (rl->rlim_max > linux32_maxdsiz) 763 rl->rlim_max = linux32_maxdsiz; 764 } 765 break; 766 case RLIMIT_STACK: 767 if (linux32_maxssiz != 0) { 768 if (rl->rlim_cur > linux32_maxssiz) 769 rl->rlim_cur = linux32_maxssiz; 770 if (rl->rlim_max > linux32_maxssiz) 771 rl->rlim_max = linux32_maxssiz; 772 } 773 break; 774 case RLIMIT_VMEM: 775 if (linux32_maxvmem != 0) { 776 if (rl->rlim_cur > linux32_maxvmem) 777 rl->rlim_cur = linux32_maxvmem; 778 if (rl->rlim_max > linux32_maxvmem) 779 rl->rlim_max = linux32_maxvmem; 780 } 781 break; 782 } 783 } 784 785 struct sysentvec elf_linux_sysvec = { 786 .sv_size = LINUX32_SYS_MAXSYSCALL, 787 .sv_table = linux32_sysent, 788 .sv_fixup = elf32_freebsd_fixup, 789 .sv_sendsig = linux_sendsig, 790 .sv_sigcode = &_binary_linux32_vdso_so_o_start, 791 .sv_szsigcode = &linux_szsigcode, 792 .sv_name = "Linux ELF32", 793 .sv_coredump = elf32_coredump, 794 .sv_elf_core_osabi = ELFOSABI_NONE, 795 .sv_elf_core_abi_vendor = LINUX_ABI_VENDOR, 796 .sv_elf_core_prepare_notes = linux32_prepare_notes, 797 .sv_minsigstksz = LINUX_MINSIGSTKSZ, 798 .sv_minuser = VM_MIN_ADDRESS, 799 .sv_maxuser = LINUX32_MAXUSER, 800 .sv_usrstack = LINUX32_USRSTACK, 801 .sv_psstrings = LINUX32_PS_STRINGS, 802 .sv_psstringssz = sizeof(struct linux32_ps_strings), 803 .sv_stackprot = VM_PROT_ALL, 804 .sv_copyout_auxargs = __linuxN(copyout_auxargs), 805 .sv_copyout_strings = linux_copyout_strings, 806 .sv_setregs = linux_exec_setregs, 807 .sv_fixlimit = linux32_fixlimit, 808 .sv_maxssiz = &linux32_maxssiz, 809 .sv_flags = SV_ABI_LINUX | SV_ILP32 | SV_IA32 | SV_SHP | 810 SV_SIG_DISCIGN | SV_SIG_WAITNDQ | SV_TIMEKEEP, 811 .sv_set_syscall_retval = linux32_set_syscall_retval, 812 .sv_fetch_syscall_args = linux32_fetch_syscall_args, 813 .sv_syscallnames = linux32_syscallnames, 814 .sv_shared_page_base = LINUX32_SHAREDPAGE, 815 .sv_shared_page_len = PAGE_SIZE, 816 .sv_schedtail = linux_schedtail, 817 .sv_thread_detach = linux_thread_detach, 818 .sv_trap = NULL, 819 .sv_hwcap = NULL, 820 .sv_hwcap2 = NULL, 821 .sv_onexec = linux_on_exec_vmspace, 822 .sv_onexit = linux_on_exit, 823 .sv_ontdexit = linux_thread_dtor, 824 .sv_setid_allowed = &linux_setid_allowed_query, 825 .sv_set_fork_retval = linux32_set_fork_retval, 826 }; 827 828 static int 829 linux_on_exec_vmspace(struct proc *p, struct image_params *imgp) 830 { 831 int error; 832 833 error = linux_map_vdso(p, linux_vdso_obj, linux_vdso_base, 834 LINUX32_VDSOPAGE_SIZE, imgp); 835 if (error == 0) 836 error = linux_on_exec(p, imgp); 837 return (error); 838 } 839 840 /* 841 * linux_vdso_install() and linux_exec_sysvec_init() must be called 842 * after exec_sysvec_init() which is SI_SUB_EXEC (SI_ORDER_ANY). 843 */ 844 static void 845 linux_exec_sysvec_init(void *param) 846 { 847 l_uintptr_t *ktimekeep_base, *ktsc_selector; 848 struct sysentvec *sv; 849 ptrdiff_t tkoff; 850 851 sv = param; 852 /* Fill timekeep_base */ 853 exec_sysvec_init(sv); 854 855 tkoff = kern_timekeep_base - linux_vdso_base; 856 ktimekeep_base = (l_uintptr_t *)(linux_vdso_mapping + tkoff); 857 *ktimekeep_base = sv->sv_shared_page_base + sv->sv_timekeep_offset; 858 859 tkoff = kern_tsc_selector - linux_vdso_base; 860 ktsc_selector = (l_uintptr_t *)(linux_vdso_mapping + tkoff); 861 *ktsc_selector = linux_vdso_tsc_selector_idx(); 862 if (bootverbose) 863 printf("Linux i386 vDSO tsc_selector: %u\n", *ktsc_selector); 864 865 tkoff = kern_cpu_selector - linux_vdso_base; 866 ktsc_selector = (l_uintptr_t *)(linux_vdso_mapping + tkoff); 867 *ktsc_selector = linux_vdso_cpu_selector_idx(); 868 if (bootverbose) 869 printf("Linux i386 vDSO cpu_selector: %u\n", *ktsc_selector); 870 } 871 SYSINIT(elf_linux_exec_sysvec_init, SI_SUB_EXEC + 1, SI_ORDER_ANY, 872 linux_exec_sysvec_init, &elf_linux_sysvec); 873 874 static void 875 linux_vdso_install(const void *param) 876 { 877 char *vdso_start = &_binary_linux32_vdso_so_o_start; 878 char *vdso_end = &_binary_linux32_vdso_so_o_end; 879 880 linux_szsigcode = vdso_end - vdso_start; 881 MPASS(linux_szsigcode <= LINUX32_VDSOPAGE_SIZE); 882 883 linux_vdso_base = LINUX32_VDSOPAGE; 884 885 __elfN(linux_vdso_fixup)(vdso_start, linux_vdso_base); 886 887 linux_vdso_obj = __elfN(linux_shared_page_init) 888 (&linux_vdso_mapping, LINUX32_VDSOPAGE_SIZE); 889 bcopy(vdso_start, linux_vdso_mapping, linux_szsigcode); 890 891 linux_vdso_reloc(linux_vdso_mapping, linux_vdso_base); 892 } 893 SYSINIT(elf_linux_vdso_init, SI_SUB_EXEC + 1, SI_ORDER_FIRST, 894 linux_vdso_install, NULL); 895 896 static void 897 linux_vdso_deinstall(const void *param) 898 { 899 900 __elfN(linux_shared_page_fini)(linux_vdso_obj, 901 linux_vdso_mapping, LINUX32_VDSOPAGE_SIZE); 902 } 903 SYSUNINIT(elf_linux_vdso_uninit, SI_SUB_EXEC, SI_ORDER_FIRST, 904 linux_vdso_deinstall, NULL); 905 906 static void 907 linux_vdso_reloc(char *mapping, Elf_Addr offset) 908 { 909 const Elf_Shdr *shdr; 910 const Elf_Rel *rel; 911 const Elf_Ehdr *ehdr; 912 Elf32_Addr *where; 913 Elf_Size rtype, symidx; 914 Elf32_Addr addr, addend; 915 int i, relcnt; 916 917 MPASS(offset != 0); 918 919 relcnt = 0; 920 ehdr = (const Elf_Ehdr *)mapping; 921 shdr = (const Elf_Shdr *)(mapping + ehdr->e_shoff); 922 for (i = 0; i < ehdr->e_shnum; i++) 923 { 924 switch (shdr[i].sh_type) { 925 case SHT_REL: 926 rel = (const Elf_Rel *)(mapping + shdr[i].sh_offset); 927 relcnt = shdr[i].sh_size / sizeof(*rel); 928 break; 929 case SHT_RELA: 930 printf("Linux i386 vDSO: unexpected Rela section\n"); 931 break; 932 } 933 } 934 935 for (i = 0; i < relcnt; i++, rel++) { 936 where = (Elf32_Addr *)(mapping + rel->r_offset); 937 addend = *where; 938 rtype = ELF_R_TYPE(rel->r_info); 939 symidx = ELF_R_SYM(rel->r_info); 940 941 switch (rtype) { 942 case R_386_NONE: /* none */ 943 break; 944 945 case R_386_RELATIVE: /* B + A */ 946 addr = (Elf32_Addr)PTROUT(offset + addend); 947 if (*where != addr) 948 *where = addr; 949 break; 950 951 case R_386_IRELATIVE: 952 printf("Linux i386 vDSO: unexpected ifunc relocation, " 953 "symbol index %ld\n", (intmax_t)symidx); 954 break; 955 default: 956 printf("Linux i386 vDSO: unexpected relocation type %ld, " 957 "symbol index %ld\n", (intmax_t)rtype, (intmax_t)symidx); 958 } 959 } 960 } 961 962 static Elf_Brandnote linux32_brandnote = { 963 .hdr.n_namesz = sizeof(GNU_ABI_VENDOR), 964 .hdr.n_descsz = 16, /* XXX at least 16 */ 965 .hdr.n_type = 1, 966 .vendor = GNU_ABI_VENDOR, 967 .flags = BN_TRANSLATE_OSREL, 968 .trans_osrel = linux_trans_osrel 969 }; 970 971 static Elf32_Brandinfo linux_brand = { 972 .brand = ELFOSABI_LINUX, 973 .machine = EM_386, 974 .compat_3_brand = "Linux", 975 .interp_path = "/lib/ld-linux.so.1", 976 .sysvec = &elf_linux_sysvec, 977 .interp_newpath = NULL, 978 .brand_note = &linux32_brandnote, 979 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 980 }; 981 982 static Elf32_Brandinfo linux_glibc2brand = { 983 .brand = ELFOSABI_LINUX, 984 .machine = EM_386, 985 .compat_3_brand = "Linux", 986 .interp_path = "/lib/ld-linux.so.2", 987 .sysvec = &elf_linux_sysvec, 988 .interp_newpath = NULL, 989 .brand_note = &linux32_brandnote, 990 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 991 }; 992 993 static Elf32_Brandinfo linux_muslbrand = { 994 .brand = ELFOSABI_LINUX, 995 .machine = EM_386, 996 .compat_3_brand = "Linux", 997 .interp_path = "/lib/ld-musl-i386.so.1", 998 .sysvec = &elf_linux_sysvec, 999 .interp_newpath = NULL, 1000 .brand_note = &linux32_brandnote, 1001 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE | 1002 LINUX_BI_FUTEX_REQUEUE 1003 }; 1004 1005 Elf32_Brandinfo *linux_brandlist[] = { 1006 &linux_brand, 1007 &linux_glibc2brand, 1008 &linux_muslbrand, 1009 NULL 1010 }; 1011 1012 static int 1013 linux_elf_modevent(module_t mod, int type, void *data) 1014 { 1015 Elf32_Brandinfo **brandinfo; 1016 int error; 1017 struct linux_ioctl_handler **lihp; 1018 1019 error = 0; 1020 1021 switch(type) { 1022 case MOD_LOAD: 1023 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL; 1024 ++brandinfo) 1025 if (elf32_insert_brand_entry(*brandinfo) < 0) 1026 error = EINVAL; 1027 if (error == 0) { 1028 SET_FOREACH(lihp, linux_ioctl_handler_set) 1029 linux32_ioctl_register_handler(*lihp); 1030 stclohz = (stathz ? stathz : hz); 1031 if (bootverbose) 1032 printf("Linux i386 ELF exec handler installed\n"); 1033 } else 1034 printf("cannot insert Linux i386 ELF brand handler\n"); 1035 break; 1036 case MOD_UNLOAD: 1037 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL; 1038 ++brandinfo) 1039 if (elf32_brand_inuse(*brandinfo)) 1040 error = EBUSY; 1041 if (error == 0) { 1042 for (brandinfo = &linux_brandlist[0]; 1043 *brandinfo != NULL; ++brandinfo) 1044 if (elf32_remove_brand_entry(*brandinfo) < 0) 1045 error = EINVAL; 1046 } 1047 if (error == 0) { 1048 SET_FOREACH(lihp, linux_ioctl_handler_set) 1049 linux32_ioctl_unregister_handler(*lihp); 1050 if (bootverbose) 1051 printf("Linux i386 ELF exec handler removed\n"); 1052 } else 1053 printf("Could not deinstall Linux i386 ELF interpreter entry\n"); 1054 break; 1055 default: 1056 return (EOPNOTSUPP); 1057 } 1058 return (error); 1059 } 1060 1061 static moduledata_t linux_elf_mod = { 1062 "linuxelf", 1063 linux_elf_modevent, 1064 0 1065 }; 1066 1067 DECLARE_MODULE_TIED(linuxelf, linux_elf_mod, SI_SUB_EXEC, SI_ORDER_ANY); 1068 MODULE_DEPEND(linuxelf, linux_common, 1, 1, 1); 1069 FEATURE(linux, "Linux 32bit support"); 1070