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/linux32/linux.h> 65 #include <amd64/linux32/linux32_proto.h> 66 #include <compat/linux/linux_elf.h> 67 #include <compat/linux/linux_emul.h> 68 #include <compat/linux/linux_fork.h> 69 #include <compat/linux/linux_ioctl.h> 70 #include <compat/linux/linux_mib.h> 71 #include <compat/linux/linux_misc.h> 72 #include <compat/linux/linux_signal.h> 73 #include <compat/linux/linux_util.h> 74 #include <compat/linux/linux_vdso.h> 75 76 #include <x86/linux/linux_x86_sigframe.h> 77 78 MODULE_VERSION(linux, 1); 79 80 #define LINUX32_MAXUSER ((1ul << 32) - PAGE_SIZE) 81 #define LINUX32_VDSOPAGE_SIZE PAGE_SIZE * 2 82 #define LINUX32_VDSOPAGE (LINUX32_MAXUSER - LINUX32_VDSOPAGE_SIZE) 83 #define LINUX32_SHAREDPAGE (LINUX32_VDSOPAGE - PAGE_SIZE) 84 /* 85 * PAGE_SIZE - the size 86 * of the native SHAREDPAGE 87 */ 88 #define LINUX32_USRSTACK LINUX32_SHAREDPAGE 89 90 static int linux_szsigcode; 91 static vm_object_t linux_vdso_obj; 92 static char *linux_vdso_mapping; 93 extern char _binary_linux32_vdso_so_o_start; 94 extern char _binary_linux32_vdso_so_o_end; 95 static vm_offset_t linux_vdso_base; 96 97 extern struct sysent linux32_sysent[LINUX32_SYS_MAXSYSCALL]; 98 extern const char *linux32_syscallnames[]; 99 100 SET_DECLARE(linux_ioctl_handler_set, struct linux_ioctl_handler); 101 102 static int linux_copyout_strings(struct image_params *imgp, 103 uintptr_t *stack_base); 104 static void linux_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask); 105 static void linux_exec_setregs(struct thread *td, 106 struct image_params *imgp, uintptr_t stack); 107 static void linux_exec_sysvec_init(void *param); 108 static int linux_on_exec_vmspace(struct proc *p, 109 struct image_params *imgp); 110 static void linux32_fixlimit(struct rlimit *rl, int which); 111 static void linux_vdso_install(const void *param); 112 static void linux_vdso_deinstall(const void *param); 113 static void linux_vdso_reloc(char *mapping, Elf_Addr offset); 114 static void linux32_set_fork_retval(struct thread *td); 115 static void linux32_set_syscall_retval(struct thread *td, int error); 116 117 struct linux32_ps_strings { 118 u_int32_t ps_argvstr; /* first of 0 or more argument strings */ 119 u_int ps_nargvstr; /* the number of argument strings */ 120 u_int32_t ps_envstr; /* first of 0 or more environment strings */ 121 u_int ps_nenvstr; /* the number of environment strings */ 122 }; 123 #define LINUX32_PS_STRINGS (LINUX32_USRSTACK - \ 124 sizeof(struct linux32_ps_strings)) 125 126 LINUX_VDSO_SYM_INTPTR(__kernel_vsyscall); 127 LINUX_VDSO_SYM_INTPTR(linux32_vdso_sigcode); 128 LINUX_VDSO_SYM_INTPTR(linux32_vdso_rt_sigcode); 129 LINUX_VDSO_SYM_INTPTR(kern_timekeep_base); 130 LINUX_VDSO_SYM_INTPTR(kern_tsc_selector); 131 LINUX_VDSO_SYM_INTPTR(kern_cpu_selector); 132 LINUX_VDSO_SYM_CHAR(linux_platform); 133 134 void 135 linux32_arch_copyout_auxargs(struct image_params *imgp, Elf_Auxinfo **pos) 136 { 137 138 AUXARGS_ENTRY((*pos), LINUX_AT_SYSINFO, __kernel_vsyscall); 139 AUXARGS_ENTRY((*pos), LINUX_AT_SYSINFO_EHDR, linux_vdso_base); 140 AUXARGS_ENTRY((*pos), LINUX_AT_HWCAP, cpu_feature); 141 AUXARGS_ENTRY((*pos), LINUX_AT_HWCAP2, linux_x86_elf_hwcap2()); 142 AUXARGS_ENTRY((*pos), LINUX_AT_PLATFORM, PTROUT(linux_platform)); 143 } 144 145 static void 146 linux_rt_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask) 147 { 148 struct thread *td = curthread; 149 struct proc *p = td->td_proc; 150 struct sigacts *psp; 151 struct trapframe *regs; 152 struct l_rt_sigframe *fp, frame; 153 int oonstack; 154 int sig; 155 int code; 156 157 sig = linux_translate_traps(ksi->ksi_signo, ksi->ksi_trapno); 158 code = ksi->ksi_code; 159 PROC_LOCK_ASSERT(p, MA_OWNED); 160 psp = p->p_sigacts; 161 mtx_assert(&psp->ps_mtx, MA_OWNED); 162 regs = td->td_frame; 163 oonstack = sigonstack(regs->tf_rsp); 164 165 /* Allocate space for the signal handler context. */ 166 if ((td->td_pflags & TDP_ALTSTACK) && !oonstack && 167 SIGISMEMBER(psp->ps_sigonstack, sig)) { 168 fp = (struct l_rt_sigframe *)((uintptr_t)td->td_sigstk.ss_sp + 169 td->td_sigstk.ss_size - sizeof(struct l_rt_sigframe)); 170 } else 171 fp = (struct l_rt_sigframe *)regs->tf_rsp - 1; 172 mtx_unlock(&psp->ps_mtx); 173 174 /* Build the argument list for the signal handler. */ 175 sig = bsd_to_linux_signal(sig); 176 177 bzero(&frame, sizeof(frame)); 178 179 frame.sf_sig = sig; 180 frame.sf_siginfo = PTROUT(&fp->sf_si); 181 frame.sf_ucontext = PTROUT(&fp->sf_uc); 182 183 /* Fill in POSIX parts. */ 184 siginfo_to_lsiginfo(&ksi->ksi_info, &frame.sf_si, sig); 185 186 /* 187 * Build the signal context to be used by sigreturn and libgcc unwind. 188 */ 189 frame.sf_uc.uc_stack.ss_sp = PTROUT(td->td_sigstk.ss_sp); 190 frame.sf_uc.uc_stack.ss_size = td->td_sigstk.ss_size; 191 frame.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK) 192 ? ((oonstack) ? LINUX_SS_ONSTACK : 0) : LINUX_SS_DISABLE; 193 PROC_UNLOCK(p); 194 195 bsd_to_linux_sigset(mask, &frame.sf_uc.uc_sigmask); 196 197 frame.sf_uc.uc_mcontext.sc_mask = frame.sf_uc.uc_sigmask.__mask; 198 frame.sf_uc.uc_mcontext.sc_edi = regs->tf_rdi; 199 frame.sf_uc.uc_mcontext.sc_esi = regs->tf_rsi; 200 frame.sf_uc.uc_mcontext.sc_ebp = regs->tf_rbp; 201 frame.sf_uc.uc_mcontext.sc_ebx = regs->tf_rbx; 202 frame.sf_uc.uc_mcontext.sc_esp = regs->tf_rsp; 203 frame.sf_uc.uc_mcontext.sc_edx = regs->tf_rdx; 204 frame.sf_uc.uc_mcontext.sc_ecx = regs->tf_rcx; 205 frame.sf_uc.uc_mcontext.sc_eax = regs->tf_rax; 206 frame.sf_uc.uc_mcontext.sc_eip = regs->tf_rip; 207 frame.sf_uc.uc_mcontext.sc_cs = regs->tf_cs; 208 frame.sf_uc.uc_mcontext.sc_gs = regs->tf_gs; 209 frame.sf_uc.uc_mcontext.sc_fs = regs->tf_fs; 210 frame.sf_uc.uc_mcontext.sc_es = regs->tf_es; 211 frame.sf_uc.uc_mcontext.sc_ds = regs->tf_ds; 212 frame.sf_uc.uc_mcontext.sc_eflags = regs->tf_rflags; 213 frame.sf_uc.uc_mcontext.sc_esp_at_signal = regs->tf_rsp; 214 frame.sf_uc.uc_mcontext.sc_ss = regs->tf_ss; 215 frame.sf_uc.uc_mcontext.sc_err = regs->tf_err; 216 frame.sf_uc.uc_mcontext.sc_cr2 = (u_int32_t)(uintptr_t)ksi->ksi_addr; 217 frame.sf_uc.uc_mcontext.sc_trapno = bsd_to_linux_trapcode(code); 218 219 if (copyout(&frame, fp, sizeof(frame)) != 0) { 220 /* 221 * Process has trashed its stack; give it an illegal 222 * instruction to halt it in its tracks. 223 */ 224 PROC_LOCK(p); 225 sigexit(td, SIGILL); 226 } 227 228 /* Build context to run handler in. */ 229 regs->tf_rsp = PTROUT(fp); 230 regs->tf_rip = linux32_vdso_rt_sigcode; 231 regs->tf_rdi = PTROUT(catcher); 232 regs->tf_rflags &= ~(PSL_T | PSL_D); 233 regs->tf_cs = _ucode32sel; 234 regs->tf_ss = _udatasel; 235 regs->tf_ds = _udatasel; 236 regs->tf_es = _udatasel; 237 regs->tf_fs = _ufssel; 238 regs->tf_gs = _ugssel; 239 regs->tf_flags = TF_HASSEGS; 240 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 241 PROC_LOCK(p); 242 mtx_lock(&psp->ps_mtx); 243 } 244 245 /* 246 * Send an interrupt to process. 247 * 248 * Stack is set up to allow sigcode stored 249 * in u. to call routine, followed by kcall 250 * to sigreturn routine below. After sigreturn 251 * resets the signal mask, the stack, and the 252 * frame pointer, it returns to the user 253 * specified pc, psl. 254 */ 255 static void 256 linux_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask) 257 { 258 struct thread *td = curthread; 259 struct proc *p = td->td_proc; 260 struct sigacts *psp; 261 struct trapframe *regs; 262 struct l_sigframe *fp, frame; 263 l_sigset_t lmask; 264 int oonstack; 265 int sig, code; 266 267 sig = linux_translate_traps(ksi->ksi_signo, ksi->ksi_trapno); 268 code = ksi->ksi_code; 269 PROC_LOCK_ASSERT(p, MA_OWNED); 270 psp = p->p_sigacts; 271 mtx_assert(&psp->ps_mtx, MA_OWNED); 272 if (SIGISMEMBER(psp->ps_siginfo, sig)) { 273 /* Signal handler installed with SA_SIGINFO. */ 274 linux_rt_sendsig(catcher, ksi, mask); 275 return; 276 } 277 278 regs = td->td_frame; 279 oonstack = sigonstack(regs->tf_rsp); 280 281 /* Allocate space for the signal handler context. */ 282 if ((td->td_pflags & TDP_ALTSTACK) && !oonstack && 283 SIGISMEMBER(psp->ps_sigonstack, sig)) { 284 fp = (struct l_sigframe *)((uintptr_t)td->td_sigstk.ss_sp + 285 td->td_sigstk.ss_size - sizeof(struct l_sigframe)); 286 } else 287 fp = (struct l_sigframe *)regs->tf_rsp - 1; 288 mtx_unlock(&psp->ps_mtx); 289 PROC_UNLOCK(p); 290 291 /* Build the argument list for the signal handler. */ 292 sig = bsd_to_linux_signal(sig); 293 294 bzero(&frame, sizeof(frame)); 295 296 frame.sf_sig = sig; 297 frame.sf_sigmask = *mask; 298 bsd_to_linux_sigset(mask, &lmask); 299 300 /* Build the signal context to be used by sigreturn. */ 301 frame.sf_sc.sc_mask = lmask.__mask; 302 frame.sf_sc.sc_gs = regs->tf_gs; 303 frame.sf_sc.sc_fs = regs->tf_fs; 304 frame.sf_sc.sc_es = regs->tf_es; 305 frame.sf_sc.sc_ds = regs->tf_ds; 306 frame.sf_sc.sc_edi = regs->tf_rdi; 307 frame.sf_sc.sc_esi = regs->tf_rsi; 308 frame.sf_sc.sc_ebp = regs->tf_rbp; 309 frame.sf_sc.sc_ebx = regs->tf_rbx; 310 frame.sf_sc.sc_esp = regs->tf_rsp; 311 frame.sf_sc.sc_edx = regs->tf_rdx; 312 frame.sf_sc.sc_ecx = regs->tf_rcx; 313 frame.sf_sc.sc_eax = regs->tf_rax; 314 frame.sf_sc.sc_eip = regs->tf_rip; 315 frame.sf_sc.sc_cs = regs->tf_cs; 316 frame.sf_sc.sc_eflags = regs->tf_rflags; 317 frame.sf_sc.sc_esp_at_signal = regs->tf_rsp; 318 frame.sf_sc.sc_ss = regs->tf_ss; 319 frame.sf_sc.sc_err = regs->tf_err; 320 frame.sf_sc.sc_cr2 = (u_int32_t)(uintptr_t)ksi->ksi_addr; 321 frame.sf_sc.sc_trapno = bsd_to_linux_trapcode(code); 322 323 if (copyout(&frame, fp, sizeof(frame)) != 0) { 324 /* 325 * Process has trashed its stack; give it an illegal 326 * instruction to halt it in its tracks. 327 */ 328 PROC_LOCK(p); 329 sigexit(td, SIGILL); 330 } 331 332 /* Build context to run handler in. */ 333 regs->tf_rsp = PTROUT(fp); 334 regs->tf_rip = linux32_vdso_sigcode; 335 regs->tf_rdi = PTROUT(catcher); 336 regs->tf_rflags &= ~(PSL_T | PSL_D); 337 regs->tf_cs = _ucode32sel; 338 regs->tf_ss = _udatasel; 339 regs->tf_ds = _udatasel; 340 regs->tf_es = _udatasel; 341 regs->tf_fs = _ufssel; 342 regs->tf_gs = _ugssel; 343 regs->tf_flags = TF_HASSEGS; 344 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 345 PROC_LOCK(p); 346 mtx_lock(&psp->ps_mtx); 347 } 348 349 /* 350 * System call to cleanup state after a signal 351 * has been taken. Reset signal mask and 352 * stack state from context left by sendsig (above). 353 * Return to previous pc and psl as specified by 354 * context left by sendsig. Check carefully to 355 * make sure that the user has not modified the 356 * psl to gain improper privileges or to cause 357 * a machine fault. 358 */ 359 int 360 linux_sigreturn(struct thread *td, struct linux_sigreturn_args *args) 361 { 362 struct l_sigframe frame; 363 struct trapframe *regs; 364 int eflags; 365 ksiginfo_t ksi; 366 367 regs = td->td_frame; 368 369 /* 370 * The trampoline code hands us the sigframe. 371 * It is unsafe to keep track of it ourselves, in the event that a 372 * program jumps out of a signal handler. 373 */ 374 if (copyin(args->sfp, &frame, sizeof(frame)) != 0) 375 return (EFAULT); 376 377 /* Check for security violations. */ 378 eflags = frame.sf_sc.sc_eflags; 379 if (!EFL_SECURE(eflags, regs->tf_rflags)) 380 return(EINVAL); 381 382 /* 383 * Don't allow users to load a valid privileged %cs. Let the 384 * hardware check for invalid selectors, excess privilege in 385 * other selectors, invalid %eip's and invalid %esp's. 386 */ 387 if (!CS_SECURE(frame.sf_sc.sc_cs)) { 388 ksiginfo_init_trap(&ksi); 389 ksi.ksi_signo = SIGBUS; 390 ksi.ksi_code = BUS_OBJERR; 391 ksi.ksi_trapno = T_PROTFLT; 392 ksi.ksi_addr = (void *)regs->tf_rip; 393 trapsignal(td, &ksi); 394 return(EINVAL); 395 } 396 397 kern_sigprocmask(td, SIG_SETMASK, &frame.sf_sigmask, NULL, 0); 398 399 /* Restore signal context. */ 400 regs->tf_rdi = frame.sf_sc.sc_edi; 401 regs->tf_rsi = frame.sf_sc.sc_esi; 402 regs->tf_rbp = frame.sf_sc.sc_ebp; 403 regs->tf_rbx = frame.sf_sc.sc_ebx; 404 regs->tf_rdx = frame.sf_sc.sc_edx; 405 regs->tf_rcx = frame.sf_sc.sc_ecx; 406 regs->tf_rax = frame.sf_sc.sc_eax; 407 regs->tf_rip = frame.sf_sc.sc_eip; 408 regs->tf_cs = frame.sf_sc.sc_cs; 409 regs->tf_ds = frame.sf_sc.sc_ds; 410 regs->tf_es = frame.sf_sc.sc_es; 411 regs->tf_fs = frame.sf_sc.sc_fs; 412 regs->tf_gs = frame.sf_sc.sc_gs; 413 regs->tf_rflags = eflags; 414 regs->tf_rsp = frame.sf_sc.sc_esp_at_signal; 415 regs->tf_ss = frame.sf_sc.sc_ss; 416 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 417 418 return (EJUSTRETURN); 419 } 420 421 /* 422 * System call to cleanup state after a signal 423 * has been taken. Reset signal mask and 424 * stack state from context left by rt_sendsig (above). 425 * Return to previous pc and psl as specified by 426 * context left by sendsig. Check carefully to 427 * make sure that the user has not modified the 428 * psl to gain improper privileges or to cause 429 * a machine fault. 430 */ 431 int 432 linux_rt_sigreturn(struct thread *td, struct linux_rt_sigreturn_args *args) 433 { 434 struct l_ucontext uc; 435 struct l_sigcontext *context; 436 sigset_t bmask; 437 l_stack_t *lss; 438 stack_t ss; 439 struct trapframe *regs; 440 int eflags; 441 ksiginfo_t ksi; 442 443 regs = td->td_frame; 444 445 /* 446 * The trampoline code hands us the ucontext. 447 * It is unsafe to keep track of it ourselves, in the event that a 448 * program jumps out of a signal handler. 449 */ 450 if (copyin(args->ucp, &uc, sizeof(uc)) != 0) 451 return (EFAULT); 452 453 context = &uc.uc_mcontext; 454 455 /* Check for security violations. */ 456 eflags = context->sc_eflags; 457 if (!EFL_SECURE(eflags, regs->tf_rflags)) 458 return(EINVAL); 459 460 /* 461 * Don't allow users to load a valid privileged %cs. Let the 462 * hardware check for invalid selectors, excess privilege in 463 * other selectors, invalid %eip's and invalid %esp's. 464 */ 465 if (!CS_SECURE(context->sc_cs)) { 466 ksiginfo_init_trap(&ksi); 467 ksi.ksi_signo = SIGBUS; 468 ksi.ksi_code = BUS_OBJERR; 469 ksi.ksi_trapno = T_PROTFLT; 470 ksi.ksi_addr = (void *)regs->tf_rip; 471 trapsignal(td, &ksi); 472 return(EINVAL); 473 } 474 475 linux_to_bsd_sigset(&uc.uc_sigmask, &bmask); 476 kern_sigprocmask(td, SIG_SETMASK, &bmask, NULL, 0); 477 478 /* 479 * Restore signal context 480 */ 481 regs->tf_gs = context->sc_gs; 482 regs->tf_fs = context->sc_fs; 483 regs->tf_es = context->sc_es; 484 regs->tf_ds = context->sc_ds; 485 regs->tf_rdi = context->sc_edi; 486 regs->tf_rsi = context->sc_esi; 487 regs->tf_rbp = context->sc_ebp; 488 regs->tf_rbx = context->sc_ebx; 489 regs->tf_rdx = context->sc_edx; 490 regs->tf_rcx = context->sc_ecx; 491 regs->tf_rax = context->sc_eax; 492 regs->tf_rip = context->sc_eip; 493 regs->tf_cs = context->sc_cs; 494 regs->tf_rflags = eflags; 495 regs->tf_rsp = context->sc_esp_at_signal; 496 regs->tf_ss = context->sc_ss; 497 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 498 499 /* 500 * call sigaltstack & ignore results.. 501 */ 502 lss = &uc.uc_stack; 503 ss.ss_sp = PTRIN(lss->ss_sp); 504 ss.ss_size = lss->ss_size; 505 ss.ss_flags = linux_to_bsd_sigaltstack(lss->ss_flags); 506 507 (void)kern_sigaltstack(td, &ss, NULL); 508 509 return (EJUSTRETURN); 510 } 511 512 static int 513 linux32_fetch_syscall_args(struct thread *td) 514 { 515 struct proc *p; 516 struct trapframe *frame; 517 struct syscall_args *sa; 518 519 p = td->td_proc; 520 frame = td->td_frame; 521 sa = &td->td_sa; 522 523 sa->args[0] = frame->tf_rbx; 524 sa->args[1] = frame->tf_rcx; 525 sa->args[2] = frame->tf_rdx; 526 sa->args[3] = frame->tf_rsi; 527 sa->args[4] = frame->tf_rdi; 528 sa->args[5] = frame->tf_rbp; 529 sa->code = frame->tf_rax; 530 sa->original_code = sa->code; 531 532 if (sa->code >= p->p_sysent->sv_size) 533 /* nosys */ 534 sa->callp = &nosys_sysent; 535 else 536 sa->callp = &p->p_sysent->sv_table[sa->code]; 537 538 td->td_retval[0] = 0; 539 td->td_retval[1] = frame->tf_rdx; 540 541 return (0); 542 } 543 544 static void 545 linux32_set_syscall_retval(struct thread *td, int error) 546 { 547 struct trapframe *frame = td->td_frame; 548 549 cpu_set_syscall_retval(td, error); 550 551 if (__predict_false(error != 0)) { 552 if (error != ERESTART && error != EJUSTRETURN) 553 frame->tf_rax = bsd_to_linux_errno(error); 554 } 555 } 556 557 static void 558 linux32_set_fork_retval(struct thread *td) 559 { 560 struct trapframe *frame = td->td_frame; 561 562 frame->tf_rax = 0; 563 } 564 565 /* 566 * Clear registers on exec 567 * XXX copied from ia32_signal.c. 568 */ 569 static void 570 linux_exec_setregs(struct thread *td, struct image_params *imgp, 571 uintptr_t stack) 572 { 573 struct trapframe *regs = td->td_frame; 574 struct pcb *pcb = td->td_pcb; 575 register_t saved_rflags; 576 577 regs = td->td_frame; 578 pcb = td->td_pcb; 579 580 if (td->td_proc->p_md.md_ldt != NULL) 581 user_ldt_free(td); 582 583 critical_enter(); 584 wrmsr(MSR_FSBASE, 0); 585 wrmsr(MSR_KGSBASE, 0); /* User value while we're in the kernel */ 586 pcb->pcb_fsbase = 0; 587 pcb->pcb_gsbase = 0; 588 critical_exit(); 589 pcb->pcb_initial_fpucw = __LINUX_NPXCW__; 590 591 saved_rflags = regs->tf_rflags & PSL_T; 592 bzero((char *)regs, sizeof(struct trapframe)); 593 regs->tf_rip = imgp->entry_addr; 594 regs->tf_rsp = stack; 595 regs->tf_rflags = PSL_USER | saved_rflags; 596 regs->tf_gs = _ugssel; 597 regs->tf_fs = _ufssel; 598 regs->tf_es = _udatasel; 599 regs->tf_ds = _udatasel; 600 regs->tf_ss = _udatasel; 601 regs->tf_flags = TF_HASSEGS; 602 regs->tf_cs = _ucode32sel; 603 regs->tf_rbx = (register_t)imgp->ps_strings; 604 605 x86_clear_dbregs(pcb); 606 607 fpstate_drop(td); 608 609 /* Do full restore on return so that we can change to a different %cs */ 610 set_pcb_flags(pcb, PCB_32BIT | PCB_FULL_IRET); 611 } 612 613 /* 614 * XXX copied from ia32_sysvec.c. 615 */ 616 static int 617 linux_copyout_strings(struct image_params *imgp, uintptr_t *stack_base) 618 { 619 int argc, envc, error; 620 u_int32_t *vectp; 621 char *stringp; 622 uintptr_t destp, ustringp; 623 struct linux32_ps_strings *arginfo; 624 char canary[LINUX_AT_RANDOM_LEN]; 625 size_t execpath_len; 626 627 arginfo = (struct linux32_ps_strings *)PROC_PS_STRINGS(imgp->proc); 628 destp = (uintptr_t)arginfo; 629 630 if (imgp->execpath != NULL && imgp->auxargs != NULL) { 631 execpath_len = strlen(imgp->execpath) + 1; 632 destp -= execpath_len; 633 destp = rounddown2(destp, sizeof(uint32_t)); 634 imgp->execpathp = (void *)destp; 635 error = copyout(imgp->execpath, imgp->execpathp, execpath_len); 636 if (error != 0) 637 return (error); 638 } 639 640 /* Prepare the canary for SSP. */ 641 arc4rand(canary, sizeof(canary), 0); 642 destp -= roundup(sizeof(canary), sizeof(uint32_t)); 643 imgp->canary = (void *)destp; 644 error = copyout(canary, imgp->canary, sizeof(canary)); 645 if (error != 0) 646 return (error); 647 648 /* Allocate room for the argument and environment strings. */ 649 destp -= ARG_MAX - imgp->args->stringspace; 650 destp = rounddown2(destp, sizeof(uint32_t)); 651 ustringp = destp; 652 653 if (imgp->auxargs) { 654 /* 655 * Allocate room on the stack for the ELF auxargs 656 * array. It has LINUX_AT_COUNT entries. 657 */ 658 destp -= LINUX_AT_COUNT * sizeof(Elf32_Auxinfo); 659 destp = rounddown2(destp, sizeof(uint32_t)); 660 } 661 662 vectp = (uint32_t *)destp; 663 664 /* 665 * Allocate room for the argv[] and env vectors including the 666 * terminating NULL pointers. 667 */ 668 vectp -= imgp->args->argc + 1 + imgp->args->envc + 1; 669 670 /* vectp also becomes our initial stack base. */ 671 *stack_base = (uintptr_t)vectp; 672 673 stringp = imgp->args->begin_argv; 674 argc = imgp->args->argc; 675 envc = imgp->args->envc; 676 677 /* Copy out strings - arguments and environment. */ 678 error = copyout(stringp, (void *)ustringp, 679 ARG_MAX - imgp->args->stringspace); 680 if (error != 0) 681 return (error); 682 683 /* Fill in "ps_strings" struct for ps, w, etc. */ 684 if (suword32(&arginfo->ps_argvstr, (uint32_t)(intptr_t)vectp) != 0 || 685 suword32(&arginfo->ps_nargvstr, argc) != 0) 686 return (EFAULT); 687 688 /* Fill in argument portion of vector table. */ 689 for (; argc > 0; --argc) { 690 if (suword32(vectp++, ustringp) != 0) 691 return (EFAULT); 692 while (*stringp++ != 0) 693 ustringp++; 694 ustringp++; 695 } 696 697 /* A null vector table pointer separates the argp's from the envp's. */ 698 if (suword32(vectp++, 0) != 0) 699 return (EFAULT); 700 701 if (suword32(&arginfo->ps_envstr, (uint32_t)(intptr_t)vectp) != 0 || 702 suword32(&arginfo->ps_nenvstr, envc) != 0) 703 return (EFAULT); 704 705 /* Fill in environment portion of vector table. */ 706 for (; envc > 0; --envc) { 707 if (suword32(vectp++, ustringp) != 0) 708 return (EFAULT); 709 while (*stringp++ != 0) 710 ustringp++; 711 ustringp++; 712 } 713 714 /* The end of the vector table is a null pointer. */ 715 if (suword32(vectp, 0) != 0) 716 return (EFAULT); 717 718 if (imgp->auxargs) { 719 vectp++; 720 error = imgp->sysent->sv_copyout_auxargs(imgp, 721 (uintptr_t)vectp); 722 if (error != 0) 723 return (error); 724 } 725 726 return (0); 727 } 728 729 static SYSCTL_NODE(_compat, OID_AUTO, linux32, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 730 "32-bit Linux emulation"); 731 732 static u_long linux32_maxdsiz = LINUX32_MAXDSIZ; 733 SYSCTL_ULONG(_compat_linux32, OID_AUTO, maxdsiz, CTLFLAG_RW, 734 &linux32_maxdsiz, 0, ""); 735 static u_long linux32_maxssiz = LINUX32_MAXSSIZ; 736 SYSCTL_ULONG(_compat_linux32, OID_AUTO, maxssiz, CTLFLAG_RW, 737 &linux32_maxssiz, 0, ""); 738 static u_long linux32_maxvmem = LINUX32_MAXVMEM; 739 SYSCTL_ULONG(_compat_linux32, OID_AUTO, maxvmem, CTLFLAG_RW, 740 &linux32_maxvmem, 0, ""); 741 bool linux32_emulate_i386 = false; 742 SYSCTL_BOOL(_compat_linux32, OID_AUTO, emulate_i386, CTLFLAG_RWTUN, 743 &linux32_emulate_i386, 0, "Emulate the real i386"); 744 745 static void 746 linux32_fixlimit(struct rlimit *rl, int which) 747 { 748 749 switch (which) { 750 case RLIMIT_DATA: 751 if (linux32_maxdsiz != 0) { 752 if (rl->rlim_cur > linux32_maxdsiz) 753 rl->rlim_cur = linux32_maxdsiz; 754 if (rl->rlim_max > linux32_maxdsiz) 755 rl->rlim_max = linux32_maxdsiz; 756 } 757 break; 758 case RLIMIT_STACK: 759 if (linux32_maxssiz != 0) { 760 if (rl->rlim_cur > linux32_maxssiz) 761 rl->rlim_cur = linux32_maxssiz; 762 if (rl->rlim_max > linux32_maxssiz) 763 rl->rlim_max = linux32_maxssiz; 764 } 765 break; 766 case RLIMIT_VMEM: 767 if (linux32_maxvmem != 0) { 768 if (rl->rlim_cur > linux32_maxvmem) 769 rl->rlim_cur = linux32_maxvmem; 770 if (rl->rlim_max > linux32_maxvmem) 771 rl->rlim_max = linux32_maxvmem; 772 } 773 break; 774 } 775 } 776 777 struct sysentvec elf_linux_sysvec = { 778 .sv_size = LINUX32_SYS_MAXSYSCALL, 779 .sv_table = linux32_sysent, 780 .sv_fixup = elf32_freebsd_fixup, 781 .sv_sendsig = linux_sendsig, 782 .sv_sigcode = &_binary_linux32_vdso_so_o_start, 783 .sv_szsigcode = &linux_szsigcode, 784 .sv_name = "Linux ELF32", 785 .sv_coredump = elf32_coredump, 786 .sv_elf_core_osabi = ELFOSABI_NONE, 787 .sv_elf_core_abi_vendor = LINUX_ABI_VENDOR, 788 .sv_elf_core_prepare_notes = linux32_prepare_notes, 789 .sv_minsigstksz = LINUX_MINSIGSTKSZ, 790 .sv_minuser = VM_MIN_ADDRESS, 791 .sv_maxuser = LINUX32_MAXUSER, 792 .sv_usrstack = LINUX32_USRSTACK, 793 .sv_psstrings = LINUX32_PS_STRINGS, 794 .sv_psstringssz = sizeof(struct linux32_ps_strings), 795 .sv_stackprot = VM_PROT_ALL, 796 .sv_copyout_auxargs = __linuxN(copyout_auxargs), 797 .sv_copyout_strings = linux_copyout_strings, 798 .sv_setregs = linux_exec_setregs, 799 .sv_fixlimit = linux32_fixlimit, 800 .sv_maxssiz = &linux32_maxssiz, 801 .sv_flags = SV_ABI_LINUX | SV_ILP32 | SV_IA32 | SV_SHP | 802 SV_SIG_DISCIGN | SV_SIG_WAITNDQ | SV_TIMEKEEP, 803 .sv_set_syscall_retval = linux32_set_syscall_retval, 804 .sv_fetch_syscall_args = linux32_fetch_syscall_args, 805 .sv_syscallnames = linux32_syscallnames, 806 .sv_shared_page_base = LINUX32_SHAREDPAGE, 807 .sv_shared_page_len = PAGE_SIZE, 808 .sv_schedtail = linux_schedtail, 809 .sv_thread_detach = linux_thread_detach, 810 .sv_trap = NULL, 811 .sv_hwcap = NULL, 812 .sv_hwcap2 = NULL, 813 .sv_onexec = linux_on_exec_vmspace, 814 .sv_onexit = linux_on_exit, 815 .sv_ontdexit = linux_thread_dtor, 816 .sv_setid_allowed = &linux_setid_allowed_query, 817 .sv_set_fork_retval = linux32_set_fork_retval, 818 }; 819 820 static int 821 linux_on_exec_vmspace(struct proc *p, struct image_params *imgp) 822 { 823 int error; 824 825 error = linux_map_vdso(p, linux_vdso_obj, linux_vdso_base, 826 LINUX32_VDSOPAGE_SIZE, imgp); 827 if (error == 0) 828 error = linux_on_exec(p, imgp); 829 return (error); 830 } 831 832 /* 833 * linux_vdso_install() and linux_exec_sysvec_init() must be called 834 * after exec_sysvec_init() which is SI_SUB_EXEC (SI_ORDER_ANY). 835 */ 836 static void 837 linux_exec_sysvec_init(void *param) 838 { 839 l_uintptr_t *ktimekeep_base, *ktsc_selector; 840 struct sysentvec *sv; 841 ptrdiff_t tkoff; 842 843 sv = param; 844 /* Fill timekeep_base */ 845 exec_sysvec_init(sv); 846 847 tkoff = kern_timekeep_base - linux_vdso_base; 848 ktimekeep_base = (l_uintptr_t *)(linux_vdso_mapping + tkoff); 849 *ktimekeep_base = sv->sv_shared_page_base + sv->sv_timekeep_offset; 850 851 tkoff = kern_tsc_selector - linux_vdso_base; 852 ktsc_selector = (l_uintptr_t *)(linux_vdso_mapping + tkoff); 853 *ktsc_selector = linux_vdso_tsc_selector_idx(); 854 if (bootverbose) 855 printf("Linux i386 vDSO tsc_selector: %u\n", *ktsc_selector); 856 857 tkoff = kern_cpu_selector - linux_vdso_base; 858 ktsc_selector = (l_uintptr_t *)(linux_vdso_mapping + tkoff); 859 *ktsc_selector = linux_vdso_cpu_selector_idx(); 860 if (bootverbose) 861 printf("Linux i386 vDSO cpu_selector: %u\n", *ktsc_selector); 862 } 863 SYSINIT(elf_linux_exec_sysvec_init, SI_SUB_EXEC + 1, SI_ORDER_ANY, 864 linux_exec_sysvec_init, &elf_linux_sysvec); 865 866 static void 867 linux_vdso_install(const void *param) 868 { 869 char *vdso_start = &_binary_linux32_vdso_so_o_start; 870 char *vdso_end = &_binary_linux32_vdso_so_o_end; 871 872 linux_szsigcode = vdso_end - vdso_start; 873 MPASS(linux_szsigcode <= LINUX32_VDSOPAGE_SIZE); 874 875 linux_vdso_base = LINUX32_VDSOPAGE; 876 877 __elfN(linux_vdso_fixup)(vdso_start, linux_vdso_base); 878 879 linux_vdso_obj = __elfN(linux_shared_page_init) 880 (&linux_vdso_mapping, LINUX32_VDSOPAGE_SIZE); 881 bcopy(vdso_start, linux_vdso_mapping, linux_szsigcode); 882 883 linux_vdso_reloc(linux_vdso_mapping, linux_vdso_base); 884 } 885 SYSINIT(elf_linux_vdso_init, SI_SUB_EXEC + 1, SI_ORDER_FIRST, 886 linux_vdso_install, NULL); 887 888 static void 889 linux_vdso_deinstall(const void *param) 890 { 891 892 __elfN(linux_shared_page_fini)(linux_vdso_obj, 893 linux_vdso_mapping, LINUX32_VDSOPAGE_SIZE); 894 } 895 SYSUNINIT(elf_linux_vdso_uninit, SI_SUB_EXEC, SI_ORDER_FIRST, 896 linux_vdso_deinstall, NULL); 897 898 static void 899 linux_vdso_reloc(char *mapping, Elf_Addr offset) 900 { 901 const Elf_Shdr *shdr; 902 const Elf_Rel *rel; 903 const Elf_Ehdr *ehdr; 904 Elf32_Addr *where; 905 Elf_Size rtype, symidx; 906 Elf32_Addr addr, addend; 907 int i, relcnt; 908 909 MPASS(offset != 0); 910 911 relcnt = 0; 912 ehdr = (const Elf_Ehdr *)mapping; 913 shdr = (const Elf_Shdr *)(mapping + ehdr->e_shoff); 914 for (i = 0; i < ehdr->e_shnum; i++) 915 { 916 switch (shdr[i].sh_type) { 917 case SHT_REL: 918 rel = (const Elf_Rel *)(mapping + shdr[i].sh_offset); 919 relcnt = shdr[i].sh_size / sizeof(*rel); 920 break; 921 case SHT_RELA: 922 printf("Linux i386 vDSO: unexpected Rela section\n"); 923 break; 924 } 925 } 926 927 for (i = 0; i < relcnt; i++, rel++) { 928 where = (Elf32_Addr *)(mapping + rel->r_offset); 929 addend = *where; 930 rtype = ELF_R_TYPE(rel->r_info); 931 symidx = ELF_R_SYM(rel->r_info); 932 933 switch (rtype) { 934 case R_386_NONE: /* none */ 935 break; 936 937 case R_386_RELATIVE: /* B + A */ 938 addr = (Elf32_Addr)PTROUT(offset + addend); 939 if (*where != addr) 940 *where = addr; 941 break; 942 943 case R_386_IRELATIVE: 944 printf("Linux i386 vDSO: unexpected ifunc relocation, " 945 "symbol index %ld\n", (intmax_t)symidx); 946 break; 947 default: 948 printf("Linux i386 vDSO: unexpected relocation type %ld, " 949 "symbol index %ld\n", (intmax_t)rtype, (intmax_t)symidx); 950 } 951 } 952 } 953 954 static Elf_Brandnote linux32_brandnote = { 955 .hdr.n_namesz = sizeof(GNU_ABI_VENDOR), 956 .hdr.n_descsz = 16, /* XXX at least 16 */ 957 .hdr.n_type = 1, 958 .vendor = GNU_ABI_VENDOR, 959 .flags = BN_TRANSLATE_OSREL, 960 .trans_osrel = linux_trans_osrel 961 }; 962 963 static Elf32_Brandinfo linux_brand = { 964 .brand = ELFOSABI_LINUX, 965 .machine = EM_386, 966 .compat_3_brand = "Linux", 967 .interp_path = "/lib/ld-linux.so.1", 968 .sysvec = &elf_linux_sysvec, 969 .interp_newpath = NULL, 970 .brand_note = &linux32_brandnote, 971 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 972 }; 973 974 static Elf32_Brandinfo linux_glibc2brand = { 975 .brand = ELFOSABI_LINUX, 976 .machine = EM_386, 977 .compat_3_brand = "Linux", 978 .interp_path = "/lib/ld-linux.so.2", 979 .sysvec = &elf_linux_sysvec, 980 .interp_newpath = NULL, 981 .brand_note = &linux32_brandnote, 982 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 983 }; 984 985 static Elf32_Brandinfo linux_muslbrand = { 986 .brand = ELFOSABI_LINUX, 987 .machine = EM_386, 988 .compat_3_brand = "Linux", 989 .interp_path = "/lib/ld-musl-i386.so.1", 990 .sysvec = &elf_linux_sysvec, 991 .interp_newpath = NULL, 992 .brand_note = &linux32_brandnote, 993 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE | 994 LINUX_BI_FUTEX_REQUEUE 995 }; 996 997 static Elf32_Brandinfo *linux_brandlist[] = { 998 &linux_brand, 999 &linux_glibc2brand, 1000 &linux_muslbrand, 1001 NULL 1002 }; 1003 1004 static int 1005 linux_elf_modevent(module_t mod, int type, void *data) 1006 { 1007 Elf32_Brandinfo **brandinfo; 1008 int error; 1009 struct linux_ioctl_handler **lihp; 1010 1011 error = 0; 1012 1013 switch(type) { 1014 case MOD_LOAD: 1015 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL; 1016 ++brandinfo) 1017 if (elf32_insert_brand_entry(*brandinfo) < 0) 1018 error = EINVAL; 1019 if (error == 0) { 1020 SET_FOREACH(lihp, linux_ioctl_handler_set) 1021 linux32_ioctl_register_handler(*lihp); 1022 stclohz = (stathz ? stathz : hz); 1023 if (bootverbose) 1024 printf("Linux i386 ELF exec handler installed\n"); 1025 } else 1026 printf("cannot insert Linux i386 ELF brand handler\n"); 1027 break; 1028 case MOD_UNLOAD: 1029 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL; 1030 ++brandinfo) 1031 if (elf32_brand_inuse(*brandinfo)) 1032 error = EBUSY; 1033 if (error == 0) { 1034 for (brandinfo = &linux_brandlist[0]; 1035 *brandinfo != NULL; ++brandinfo) 1036 if (elf32_remove_brand_entry(*brandinfo) < 0) 1037 error = EINVAL; 1038 } 1039 if (error == 0) { 1040 SET_FOREACH(lihp, linux_ioctl_handler_set) 1041 linux32_ioctl_unregister_handler(*lihp); 1042 if (bootverbose) 1043 printf("Linux i386 ELF exec handler removed\n"); 1044 } else 1045 printf("Could not deinstall Linux i386 ELF interpreter entry\n"); 1046 break; 1047 default: 1048 return (EOPNOTSUPP); 1049 } 1050 return (error); 1051 } 1052 1053 static moduledata_t linux_elf_mod = { 1054 "linuxelf", 1055 linux_elf_modevent, 1056 0 1057 }; 1058 1059 DECLARE_MODULE_TIED(linuxelf, linux_elf_mod, SI_SUB_EXEC, SI_ORDER_ANY); 1060 MODULE_DEPEND(linuxelf, linux_common, 1, 1, 1); 1061 FEATURE(linux, "Linux 32bit support"); 1062