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 "opt_compat.h" 36 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD$"); 39 40 #ifndef COMPAT_FREEBSD32 41 #error "Unable to compile Linux-emulator due to missing COMPAT_FREEBSD32 option!" 42 #endif 43 44 #define __ELF_WORD_SIZE 32 45 46 #include <sys/param.h> 47 #include <sys/systm.h> 48 #include <sys/exec.h> 49 #include <sys/fcntl.h> 50 #include <sys/imgact.h> 51 #include <sys/imgact_elf.h> 52 #include <sys/kernel.h> 53 #include <sys/lock.h> 54 #include <sys/malloc.h> 55 #include <sys/module.h> 56 #include <sys/mutex.h> 57 #include <sys/proc.h> 58 #include <sys/resourcevar.h> 59 #include <sys/signalvar.h> 60 #include <sys/syscallsubr.h> 61 #include <sys/sysctl.h> 62 #include <sys/sysent.h> 63 #include <sys/sysproto.h> 64 #include <sys/vnode.h> 65 #include <sys/eventhandler.h> 66 67 #include <vm/vm.h> 68 #include <vm/pmap.h> 69 #include <vm/vm_extern.h> 70 #include <vm/vm_map.h> 71 #include <vm/vm_object.h> 72 #include <vm/vm_page.h> 73 #include <vm/vm_param.h> 74 75 #include <machine/cpu.h> 76 #include <machine/md_var.h> 77 #include <machine/pcb.h> 78 #include <machine/specialreg.h> 79 #include <machine/trap.h> 80 81 #include <amd64/linux32/linux.h> 82 #include <amd64/linux32/linux32_proto.h> 83 #include <compat/linux/linux_emul.h> 84 #include <compat/linux/linux_ioctl.h> 85 #include <compat/linux/linux_mib.h> 86 #include <compat/linux/linux_misc.h> 87 #include <compat/linux/linux_signal.h> 88 #include <compat/linux/linux_util.h> 89 #include <compat/linux/linux_vdso.h> 90 91 MODULE_VERSION(linux, 1); 92 93 const char *linux_kplatform; 94 static int linux_szsigcode; 95 static vm_object_t linux_shared_page_obj; 96 static char *linux_shared_page_mapping; 97 extern char _binary_linux32_locore_o_start; 98 extern char _binary_linux32_locore_o_end; 99 100 extern struct sysent linux32_sysent[LINUX32_SYS_MAXSYSCALL]; 101 102 SET_DECLARE(linux_ioctl_handler_set, struct linux_ioctl_handler); 103 104 static int linux_fixup_elf(uintptr_t *stack_base, 105 struct image_params *iparams); 106 static int linux_copyout_strings(struct image_params *imgp, 107 uintptr_t *stack_base); 108 static void linux_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask); 109 static void linux_exec_setregs(struct thread *td, 110 struct image_params *imgp, uintptr_t stack); 111 static void linux32_fixlimit(struct rlimit *rl, int which); 112 static bool linux32_trans_osrel(const Elf_Note *note, int32_t *osrel); 113 static void linux_vdso_install(void *param); 114 static void linux_vdso_deinstall(void *param); 115 116 #define LINUX_T_UNKNOWN 255 117 static int _bsd_to_linux_trapcode[] = { 118 LINUX_T_UNKNOWN, /* 0 */ 119 6, /* 1 T_PRIVINFLT */ 120 LINUX_T_UNKNOWN, /* 2 */ 121 3, /* 3 T_BPTFLT */ 122 LINUX_T_UNKNOWN, /* 4 */ 123 LINUX_T_UNKNOWN, /* 5 */ 124 16, /* 6 T_ARITHTRAP */ 125 254, /* 7 T_ASTFLT */ 126 LINUX_T_UNKNOWN, /* 8 */ 127 13, /* 9 T_PROTFLT */ 128 1, /* 10 T_TRCTRAP */ 129 LINUX_T_UNKNOWN, /* 11 */ 130 14, /* 12 T_PAGEFLT */ 131 LINUX_T_UNKNOWN, /* 13 */ 132 17, /* 14 T_ALIGNFLT */ 133 LINUX_T_UNKNOWN, /* 15 */ 134 LINUX_T_UNKNOWN, /* 16 */ 135 LINUX_T_UNKNOWN, /* 17 */ 136 0, /* 18 T_DIVIDE */ 137 2, /* 19 T_NMI */ 138 4, /* 20 T_OFLOW */ 139 5, /* 21 T_BOUND */ 140 7, /* 22 T_DNA */ 141 8, /* 23 T_DOUBLEFLT */ 142 9, /* 24 T_FPOPFLT */ 143 10, /* 25 T_TSSFLT */ 144 11, /* 26 T_SEGNPFLT */ 145 12, /* 27 T_STKFLT */ 146 18, /* 28 T_MCHK */ 147 19, /* 29 T_XMMFLT */ 148 15 /* 30 T_RESERVED */ 149 }; 150 #define bsd_to_linux_trapcode(code) \ 151 ((code)<nitems(_bsd_to_linux_trapcode)? \ 152 _bsd_to_linux_trapcode[(code)]: \ 153 LINUX_T_UNKNOWN) 154 155 struct linux32_ps_strings { 156 u_int32_t ps_argvstr; /* first of 0 or more argument strings */ 157 u_int ps_nargvstr; /* the number of argument strings */ 158 u_int32_t ps_envstr; /* first of 0 or more environment strings */ 159 u_int ps_nenvstr; /* the number of environment strings */ 160 }; 161 162 LINUX_VDSO_SYM_INTPTR(linux32_sigcode); 163 LINUX_VDSO_SYM_INTPTR(linux32_rt_sigcode); 164 LINUX_VDSO_SYM_INTPTR(linux32_vsyscall); 165 LINUX_VDSO_SYM_CHAR(linux_platform); 166 167 /* 168 * If FreeBSD & Linux have a difference of opinion about what a trap 169 * means, deal with it here. 170 * 171 * MPSAFE 172 */ 173 static int 174 linux_translate_traps(int signal, int trap_code) 175 { 176 if (signal != SIGBUS) 177 return (signal); 178 switch (trap_code) { 179 case T_PROTFLT: 180 case T_TSSFLT: 181 case T_DOUBLEFLT: 182 case T_PAGEFLT: 183 return (SIGSEGV); 184 default: 185 return (signal); 186 } 187 } 188 189 static int 190 linux_copyout_auxargs(struct image_params *imgp, uintptr_t base) 191 { 192 Elf32_Auxargs *args; 193 Elf32_Auxinfo *argarray, *pos; 194 int error, issetugid; 195 196 args = (Elf32_Auxargs *)imgp->auxargs; 197 argarray = pos = malloc(LINUX_AT_COUNT * sizeof(*pos), M_TEMP, 198 M_WAITOK | M_ZERO); 199 200 issetugid = imgp->proc->p_flag & P_SUGID ? 1 : 0; 201 AUXARGS_ENTRY(pos, LINUX_AT_SYSINFO_EHDR, 202 imgp->proc->p_sysent->sv_shared_page_base); 203 AUXARGS_ENTRY(pos, LINUX_AT_SYSINFO, linux32_vsyscall); 204 AUXARGS_ENTRY(pos, LINUX_AT_HWCAP, cpu_feature); 205 206 /* 207 * Do not export AT_CLKTCK when emulating Linux kernel prior to 2.4.0, 208 * as it has appeared in the 2.4.0-rc7 first time. 209 * Being exported, AT_CLKTCK is returned by sysconf(_SC_CLK_TCK), 210 * glibc falls back to the hard-coded CLK_TCK value when aux entry 211 * is not present. 212 * Also see linux_times() implementation. 213 */ 214 if (linux_kernver(curthread) >= LINUX_KERNVER_2004000) 215 AUXARGS_ENTRY(pos, LINUX_AT_CLKTCK, stclohz); 216 AUXARGS_ENTRY(pos, AT_PHDR, args->phdr); 217 AUXARGS_ENTRY(pos, AT_PHENT, args->phent); 218 AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum); 219 AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz); 220 AUXARGS_ENTRY(pos, AT_FLAGS, args->flags); 221 AUXARGS_ENTRY(pos, AT_ENTRY, args->entry); 222 AUXARGS_ENTRY(pos, AT_BASE, args->base); 223 AUXARGS_ENTRY(pos, LINUX_AT_SECURE, issetugid); 224 AUXARGS_ENTRY(pos, AT_UID, imgp->proc->p_ucred->cr_ruid); 225 AUXARGS_ENTRY(pos, AT_EUID, imgp->proc->p_ucred->cr_svuid); 226 AUXARGS_ENTRY(pos, AT_GID, imgp->proc->p_ucred->cr_rgid); 227 AUXARGS_ENTRY(pos, AT_EGID, imgp->proc->p_ucred->cr_svgid); 228 AUXARGS_ENTRY(pos, LINUX_AT_PLATFORM, PTROUT(linux_platform)); 229 AUXARGS_ENTRY(pos, LINUX_AT_RANDOM, PTROUT(imgp->canary)); 230 if (imgp->execpathp != 0) 231 AUXARGS_ENTRY(pos, LINUX_AT_EXECFN, PTROUT(imgp->execpathp)); 232 if (args->execfd != -1) 233 AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd); 234 AUXARGS_ENTRY(pos, AT_NULL, 0); 235 236 free(imgp->auxargs, M_TEMP); 237 imgp->auxargs = NULL; 238 KASSERT(pos - argarray <= LINUX_AT_COUNT, ("Too many auxargs")); 239 240 error = copyout(argarray, (void *)base, 241 sizeof(*argarray) * LINUX_AT_COUNT); 242 free(argarray, M_TEMP); 243 return (error); 244 } 245 246 static int 247 linux_fixup_elf(uintptr_t *stack_base, struct image_params *imgp) 248 { 249 Elf32_Addr *base; 250 251 base = (Elf32_Addr *)*stack_base; 252 base--; 253 if (suword32(base, (uint32_t)imgp->args->argc) == -1) 254 return (EFAULT); 255 *stack_base = (uintptr_t)base; 256 return (0); 257 } 258 259 static void 260 linux_rt_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask) 261 { 262 struct thread *td = curthread; 263 struct proc *p = td->td_proc; 264 struct sigacts *psp; 265 struct trapframe *regs; 266 struct l_rt_sigframe *fp, frame; 267 int oonstack; 268 int sig; 269 int code; 270 271 sig = ksi->ksi_signo; 272 code = ksi->ksi_code; 273 PROC_LOCK_ASSERT(p, MA_OWNED); 274 psp = p->p_sigacts; 275 mtx_assert(&psp->ps_mtx, MA_OWNED); 276 regs = td->td_frame; 277 oonstack = sigonstack(regs->tf_rsp); 278 279 /* Allocate space for the signal handler context. */ 280 if ((td->td_pflags & TDP_ALTSTACK) && !oonstack && 281 SIGISMEMBER(psp->ps_sigonstack, sig)) { 282 fp = (struct l_rt_sigframe *)((uintptr_t)td->td_sigstk.ss_sp + 283 td->td_sigstk.ss_size - sizeof(struct l_rt_sigframe)); 284 } else 285 fp = (struct l_rt_sigframe *)regs->tf_rsp - 1; 286 mtx_unlock(&psp->ps_mtx); 287 288 /* Build the argument list for the signal handler. */ 289 sig = bsd_to_linux_signal(sig); 290 291 bzero(&frame, sizeof(frame)); 292 293 frame.sf_handler = PTROUT(catcher); 294 frame.sf_sig = sig; 295 frame.sf_siginfo = PTROUT(&fp->sf_si); 296 frame.sf_ucontext = PTROUT(&fp->sf_sc); 297 298 /* Fill in POSIX parts. */ 299 ksiginfo_to_lsiginfo(ksi, &frame.sf_si, sig); 300 301 /* 302 * Build the signal context to be used by sigreturn and libgcc unwind. 303 */ 304 frame.sf_sc.uc_flags = 0; /* XXX ??? */ 305 frame.sf_sc.uc_link = 0; /* XXX ??? */ 306 307 frame.sf_sc.uc_stack.ss_sp = PTROUT(td->td_sigstk.ss_sp); 308 frame.sf_sc.uc_stack.ss_size = td->td_sigstk.ss_size; 309 frame.sf_sc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK) 310 ? ((oonstack) ? LINUX_SS_ONSTACK : 0) : LINUX_SS_DISABLE; 311 PROC_UNLOCK(p); 312 313 bsd_to_linux_sigset(mask, &frame.sf_sc.uc_sigmask); 314 315 frame.sf_sc.uc_mcontext.sc_mask = frame.sf_sc.uc_sigmask.__mask; 316 frame.sf_sc.uc_mcontext.sc_edi = regs->tf_rdi; 317 frame.sf_sc.uc_mcontext.sc_esi = regs->tf_rsi; 318 frame.sf_sc.uc_mcontext.sc_ebp = regs->tf_rbp; 319 frame.sf_sc.uc_mcontext.sc_ebx = regs->tf_rbx; 320 frame.sf_sc.uc_mcontext.sc_esp = regs->tf_rsp; 321 frame.sf_sc.uc_mcontext.sc_edx = regs->tf_rdx; 322 frame.sf_sc.uc_mcontext.sc_ecx = regs->tf_rcx; 323 frame.sf_sc.uc_mcontext.sc_eax = regs->tf_rax; 324 frame.sf_sc.uc_mcontext.sc_eip = regs->tf_rip; 325 frame.sf_sc.uc_mcontext.sc_cs = regs->tf_cs; 326 frame.sf_sc.uc_mcontext.sc_gs = regs->tf_gs; 327 frame.sf_sc.uc_mcontext.sc_fs = regs->tf_fs; 328 frame.sf_sc.uc_mcontext.sc_es = regs->tf_es; 329 frame.sf_sc.uc_mcontext.sc_ds = regs->tf_ds; 330 frame.sf_sc.uc_mcontext.sc_eflags = regs->tf_rflags; 331 frame.sf_sc.uc_mcontext.sc_esp_at_signal = regs->tf_rsp; 332 frame.sf_sc.uc_mcontext.sc_ss = regs->tf_ss; 333 frame.sf_sc.uc_mcontext.sc_err = regs->tf_err; 334 frame.sf_sc.uc_mcontext.sc_cr2 = (u_int32_t)(uintptr_t)ksi->ksi_addr; 335 frame.sf_sc.uc_mcontext.sc_trapno = bsd_to_linux_trapcode(code); 336 337 if (copyout(&frame, fp, sizeof(frame)) != 0) { 338 /* 339 * Process has trashed its stack; give it an illegal 340 * instruction to halt it in its tracks. 341 */ 342 PROC_LOCK(p); 343 sigexit(td, SIGILL); 344 } 345 346 /* Build context to run handler in. */ 347 regs->tf_rsp = PTROUT(fp); 348 regs->tf_rip = linux32_rt_sigcode; 349 regs->tf_rflags &= ~(PSL_T | PSL_D); 350 regs->tf_cs = _ucode32sel; 351 regs->tf_ss = _udatasel; 352 regs->tf_ds = _udatasel; 353 regs->tf_es = _udatasel; 354 regs->tf_fs = _ufssel; 355 regs->tf_gs = _ugssel; 356 regs->tf_flags = TF_HASSEGS; 357 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 358 PROC_LOCK(p); 359 mtx_lock(&psp->ps_mtx); 360 } 361 362 363 /* 364 * Send an interrupt to process. 365 * 366 * Stack is set up to allow sigcode stored 367 * in u. to call routine, followed by kcall 368 * to sigreturn routine below. After sigreturn 369 * resets the signal mask, the stack, and the 370 * frame pointer, it returns to the user 371 * specified pc, psl. 372 */ 373 static void 374 linux_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask) 375 { 376 struct thread *td = curthread; 377 struct proc *p = td->td_proc; 378 struct sigacts *psp; 379 struct trapframe *regs; 380 struct l_sigframe *fp, frame; 381 l_sigset_t lmask; 382 int oonstack; 383 int sig, code; 384 385 sig = ksi->ksi_signo; 386 code = ksi->ksi_code; 387 PROC_LOCK_ASSERT(p, MA_OWNED); 388 psp = p->p_sigacts; 389 mtx_assert(&psp->ps_mtx, MA_OWNED); 390 if (SIGISMEMBER(psp->ps_siginfo, sig)) { 391 /* Signal handler installed with SA_SIGINFO. */ 392 linux_rt_sendsig(catcher, ksi, mask); 393 return; 394 } 395 396 regs = td->td_frame; 397 oonstack = sigonstack(regs->tf_rsp); 398 399 /* Allocate space for the signal handler context. */ 400 if ((td->td_pflags & TDP_ALTSTACK) && !oonstack && 401 SIGISMEMBER(psp->ps_sigonstack, sig)) { 402 fp = (struct l_sigframe *)((uintptr_t)td->td_sigstk.ss_sp + 403 td->td_sigstk.ss_size - sizeof(struct l_sigframe)); 404 } else 405 fp = (struct l_sigframe *)regs->tf_rsp - 1; 406 mtx_unlock(&psp->ps_mtx); 407 PROC_UNLOCK(p); 408 409 /* Build the argument list for the signal handler. */ 410 sig = bsd_to_linux_signal(sig); 411 412 bzero(&frame, sizeof(frame)); 413 414 frame.sf_handler = PTROUT(catcher); 415 frame.sf_sig = sig; 416 417 bsd_to_linux_sigset(mask, &lmask); 418 419 /* Build the signal context to be used by sigreturn. */ 420 frame.sf_sc.sc_mask = lmask.__mask; 421 frame.sf_sc.sc_gs = regs->tf_gs; 422 frame.sf_sc.sc_fs = regs->tf_fs; 423 frame.sf_sc.sc_es = regs->tf_es; 424 frame.sf_sc.sc_ds = regs->tf_ds; 425 frame.sf_sc.sc_edi = regs->tf_rdi; 426 frame.sf_sc.sc_esi = regs->tf_rsi; 427 frame.sf_sc.sc_ebp = regs->tf_rbp; 428 frame.sf_sc.sc_ebx = regs->tf_rbx; 429 frame.sf_sc.sc_esp = regs->tf_rsp; 430 frame.sf_sc.sc_edx = regs->tf_rdx; 431 frame.sf_sc.sc_ecx = regs->tf_rcx; 432 frame.sf_sc.sc_eax = regs->tf_rax; 433 frame.sf_sc.sc_eip = regs->tf_rip; 434 frame.sf_sc.sc_cs = regs->tf_cs; 435 frame.sf_sc.sc_eflags = regs->tf_rflags; 436 frame.sf_sc.sc_esp_at_signal = regs->tf_rsp; 437 frame.sf_sc.sc_ss = regs->tf_ss; 438 frame.sf_sc.sc_err = regs->tf_err; 439 frame.sf_sc.sc_cr2 = (u_int32_t)(uintptr_t)ksi->ksi_addr; 440 frame.sf_sc.sc_trapno = bsd_to_linux_trapcode(code); 441 442 frame.sf_extramask[0] = lmask.__mask; 443 444 if (copyout(&frame, fp, sizeof(frame)) != 0) { 445 /* 446 * Process has trashed its stack; give it an illegal 447 * instruction to halt it in its tracks. 448 */ 449 PROC_LOCK(p); 450 sigexit(td, SIGILL); 451 } 452 453 /* Build context to run handler in. */ 454 regs->tf_rsp = PTROUT(fp); 455 regs->tf_rip = linux32_sigcode; 456 regs->tf_rflags &= ~(PSL_T | PSL_D); 457 regs->tf_cs = _ucode32sel; 458 regs->tf_ss = _udatasel; 459 regs->tf_ds = _udatasel; 460 regs->tf_es = _udatasel; 461 regs->tf_fs = _ufssel; 462 regs->tf_gs = _ugssel; 463 regs->tf_flags = TF_HASSEGS; 464 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 465 PROC_LOCK(p); 466 mtx_lock(&psp->ps_mtx); 467 } 468 469 /* 470 * System call to cleanup state after a signal 471 * has been taken. Reset signal mask and 472 * stack state from context left by sendsig (above). 473 * Return to previous pc and psl as specified by 474 * context left by sendsig. Check carefully to 475 * make sure that the user has not modified the 476 * psl to gain improper privileges or to cause 477 * a machine fault. 478 */ 479 int 480 linux_sigreturn(struct thread *td, struct linux_sigreturn_args *args) 481 { 482 struct l_sigframe frame; 483 struct trapframe *regs; 484 sigset_t bmask; 485 l_sigset_t lmask; 486 int eflags; 487 ksiginfo_t ksi; 488 489 regs = td->td_frame; 490 491 /* 492 * The trampoline code hands us the sigframe. 493 * It is unsafe to keep track of it ourselves, in the event that a 494 * program jumps out of a signal handler. 495 */ 496 if (copyin(args->sfp, &frame, sizeof(frame)) != 0) 497 return (EFAULT); 498 499 /* Check for security violations. */ 500 #define EFLAGS_SECURE(ef, oef) ((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0) 501 eflags = frame.sf_sc.sc_eflags; 502 if (!EFLAGS_SECURE(eflags, regs->tf_rflags)) 503 return(EINVAL); 504 505 /* 506 * Don't allow users to load a valid privileged %cs. Let the 507 * hardware check for invalid selectors, excess privilege in 508 * other selectors, invalid %eip's and invalid %esp's. 509 */ 510 #define CS_SECURE(cs) (ISPL(cs) == SEL_UPL) 511 if (!CS_SECURE(frame.sf_sc.sc_cs)) { 512 ksiginfo_init_trap(&ksi); 513 ksi.ksi_signo = SIGBUS; 514 ksi.ksi_code = BUS_OBJERR; 515 ksi.ksi_trapno = T_PROTFLT; 516 ksi.ksi_addr = (void *)regs->tf_rip; 517 trapsignal(td, &ksi); 518 return(EINVAL); 519 } 520 521 lmask.__mask = frame.sf_sc.sc_mask; 522 lmask.__mask = frame.sf_extramask[0]; 523 linux_to_bsd_sigset(&lmask, &bmask); 524 kern_sigprocmask(td, SIG_SETMASK, &bmask, NULL, 0); 525 526 /* Restore signal context. */ 527 regs->tf_rdi = frame.sf_sc.sc_edi; 528 regs->tf_rsi = frame.sf_sc.sc_esi; 529 regs->tf_rbp = frame.sf_sc.sc_ebp; 530 regs->tf_rbx = frame.sf_sc.sc_ebx; 531 regs->tf_rdx = frame.sf_sc.sc_edx; 532 regs->tf_rcx = frame.sf_sc.sc_ecx; 533 regs->tf_rax = frame.sf_sc.sc_eax; 534 regs->tf_rip = frame.sf_sc.sc_eip; 535 regs->tf_cs = frame.sf_sc.sc_cs; 536 regs->tf_ds = frame.sf_sc.sc_ds; 537 regs->tf_es = frame.sf_sc.sc_es; 538 regs->tf_fs = frame.sf_sc.sc_fs; 539 regs->tf_gs = frame.sf_sc.sc_gs; 540 regs->tf_rflags = eflags; 541 regs->tf_rsp = frame.sf_sc.sc_esp_at_signal; 542 regs->tf_ss = frame.sf_sc.sc_ss; 543 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 544 545 return (EJUSTRETURN); 546 } 547 548 /* 549 * System call to cleanup state after a signal 550 * has been taken. Reset signal mask and 551 * stack state from context left by rt_sendsig (above). 552 * Return to previous pc and psl as specified by 553 * context left by sendsig. Check carefully to 554 * make sure that the user has not modified the 555 * psl to gain improper privileges or to cause 556 * a machine fault. 557 */ 558 int 559 linux_rt_sigreturn(struct thread *td, struct linux_rt_sigreturn_args *args) 560 { 561 struct l_ucontext uc; 562 struct l_sigcontext *context; 563 sigset_t bmask; 564 l_stack_t *lss; 565 stack_t ss; 566 struct trapframe *regs; 567 int eflags; 568 ksiginfo_t ksi; 569 570 regs = td->td_frame; 571 572 /* 573 * The trampoline code hands us the ucontext. 574 * It is unsafe to keep track of it ourselves, in the event that a 575 * program jumps out of a signal handler. 576 */ 577 if (copyin(args->ucp, &uc, sizeof(uc)) != 0) 578 return (EFAULT); 579 580 context = &uc.uc_mcontext; 581 582 /* Check for security violations. */ 583 #define EFLAGS_SECURE(ef, oef) ((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0) 584 eflags = context->sc_eflags; 585 if (!EFLAGS_SECURE(eflags, regs->tf_rflags)) 586 return(EINVAL); 587 588 /* 589 * Don't allow users to load a valid privileged %cs. Let the 590 * hardware check for invalid selectors, excess privilege in 591 * other selectors, invalid %eip's and invalid %esp's. 592 */ 593 #define CS_SECURE(cs) (ISPL(cs) == SEL_UPL) 594 if (!CS_SECURE(context->sc_cs)) { 595 ksiginfo_init_trap(&ksi); 596 ksi.ksi_signo = SIGBUS; 597 ksi.ksi_code = BUS_OBJERR; 598 ksi.ksi_trapno = T_PROTFLT; 599 ksi.ksi_addr = (void *)regs->tf_rip; 600 trapsignal(td, &ksi); 601 return(EINVAL); 602 } 603 604 linux_to_bsd_sigset(&uc.uc_sigmask, &bmask); 605 kern_sigprocmask(td, SIG_SETMASK, &bmask, NULL, 0); 606 607 /* 608 * Restore signal context 609 */ 610 regs->tf_gs = context->sc_gs; 611 regs->tf_fs = context->sc_fs; 612 regs->tf_es = context->sc_es; 613 regs->tf_ds = context->sc_ds; 614 regs->tf_rdi = context->sc_edi; 615 regs->tf_rsi = context->sc_esi; 616 regs->tf_rbp = context->sc_ebp; 617 regs->tf_rbx = context->sc_ebx; 618 regs->tf_rdx = context->sc_edx; 619 regs->tf_rcx = context->sc_ecx; 620 regs->tf_rax = context->sc_eax; 621 regs->tf_rip = context->sc_eip; 622 regs->tf_cs = context->sc_cs; 623 regs->tf_rflags = eflags; 624 regs->tf_rsp = context->sc_esp_at_signal; 625 regs->tf_ss = context->sc_ss; 626 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 627 628 /* 629 * call sigaltstack & ignore results.. 630 */ 631 lss = &uc.uc_stack; 632 ss.ss_sp = PTRIN(lss->ss_sp); 633 ss.ss_size = lss->ss_size; 634 ss.ss_flags = linux_to_bsd_sigaltstack(lss->ss_flags); 635 636 (void)kern_sigaltstack(td, &ss, NULL); 637 638 return (EJUSTRETURN); 639 } 640 641 static int 642 linux32_fetch_syscall_args(struct thread *td) 643 { 644 struct proc *p; 645 struct trapframe *frame; 646 struct syscall_args *sa; 647 648 p = td->td_proc; 649 frame = td->td_frame; 650 sa = &td->td_sa; 651 652 sa->args[0] = frame->tf_rbx; 653 sa->args[1] = frame->tf_rcx; 654 sa->args[2] = frame->tf_rdx; 655 sa->args[3] = frame->tf_rsi; 656 sa->args[4] = frame->tf_rdi; 657 sa->args[5] = frame->tf_rbp; /* Unconfirmed */ 658 sa->code = frame->tf_rax; 659 660 if (sa->code >= p->p_sysent->sv_size) 661 /* nosys */ 662 sa->callp = &p->p_sysent->sv_table[p->p_sysent->sv_size - 1]; 663 else 664 sa->callp = &p->p_sysent->sv_table[sa->code]; 665 sa->narg = sa->callp->sy_narg; 666 667 td->td_retval[0] = 0; 668 td->td_retval[1] = frame->tf_rdx; 669 670 return (0); 671 } 672 673 /* 674 * Clear registers on exec 675 * XXX copied from ia32_signal.c. 676 */ 677 static void 678 linux_exec_setregs(struct thread *td, struct image_params *imgp, 679 uintptr_t stack) 680 { 681 struct trapframe *regs = td->td_frame; 682 struct pcb *pcb = td->td_pcb; 683 register_t saved_rflags; 684 685 regs = td->td_frame; 686 pcb = td->td_pcb; 687 688 if (td->td_proc->p_md.md_ldt != NULL) 689 user_ldt_free(td); 690 691 critical_enter(); 692 wrmsr(MSR_FSBASE, 0); 693 wrmsr(MSR_KGSBASE, 0); /* User value while we're in the kernel */ 694 pcb->pcb_fsbase = 0; 695 pcb->pcb_gsbase = 0; 696 critical_exit(); 697 pcb->pcb_initial_fpucw = __LINUX_NPXCW__; 698 699 saved_rflags = regs->tf_rflags & PSL_T; 700 bzero((char *)regs, sizeof(struct trapframe)); 701 regs->tf_rip = imgp->entry_addr; 702 regs->tf_rsp = stack; 703 regs->tf_rflags = PSL_USER | saved_rflags; 704 regs->tf_gs = _ugssel; 705 regs->tf_fs = _ufssel; 706 regs->tf_es = _udatasel; 707 regs->tf_ds = _udatasel; 708 regs->tf_ss = _udatasel; 709 regs->tf_flags = TF_HASSEGS; 710 regs->tf_cs = _ucode32sel; 711 regs->tf_rbx = imgp->ps_strings; 712 713 fpstate_drop(td); 714 715 /* Do full restore on return so that we can change to a different %cs */ 716 set_pcb_flags(pcb, PCB_32BIT | PCB_FULL_IRET); 717 } 718 719 /* 720 * XXX copied from ia32_sysvec.c. 721 */ 722 static int 723 linux_copyout_strings(struct image_params *imgp, uintptr_t *stack_base) 724 { 725 int argc, envc, error; 726 u_int32_t *vectp; 727 char *stringp; 728 uintptr_t destp, ustringp; 729 struct linux32_ps_strings *arginfo; 730 char canary[LINUX_AT_RANDOM_LEN]; 731 size_t execpath_len; 732 733 /* Calculate string base and vector table pointers. */ 734 if (imgp->execpath != NULL && imgp->auxargs != NULL) 735 execpath_len = strlen(imgp->execpath) + 1; 736 else 737 execpath_len = 0; 738 739 arginfo = (struct linux32_ps_strings *)LINUX32_PS_STRINGS; 740 destp = (uintptr_t)arginfo; 741 742 if (execpath_len != 0) { 743 destp -= execpath_len; 744 destp = rounddown2(destp, sizeof(uint32_t)); 745 imgp->execpathp = destp; 746 error = copyout(imgp->execpath, (void *)destp, execpath_len); 747 if (error != 0) 748 return (error); 749 } 750 751 /* Prepare the canary for SSP. */ 752 arc4rand(canary, sizeof(canary), 0); 753 destp -= roundup(sizeof(canary), sizeof(uint32_t)); 754 imgp->canary = destp; 755 error = copyout(canary, (void *)destp, sizeof(canary)); 756 if (error != 0) 757 return (error); 758 759 /* Allocate room for the argument and environment strings. */ 760 destp -= ARG_MAX - imgp->args->stringspace; 761 destp = rounddown2(destp, sizeof(uint32_t)); 762 ustringp = destp; 763 764 if (imgp->auxargs) { 765 /* 766 * Allocate room on the stack for the ELF auxargs 767 * array. It has LINUX_AT_COUNT entries. 768 */ 769 destp -= LINUX_AT_COUNT * sizeof(Elf32_Auxinfo); 770 destp = rounddown2(destp, sizeof(uint32_t)); 771 } 772 773 vectp = (uint32_t *)destp; 774 775 /* 776 * Allocate room for the argv[] and env vectors including the 777 * terminating NULL pointers. 778 */ 779 vectp -= imgp->args->argc + 1 + imgp->args->envc + 1; 780 781 /* vectp also becomes our initial stack base. */ 782 *stack_base = (uintptr_t)vectp; 783 784 stringp = imgp->args->begin_argv; 785 argc = imgp->args->argc; 786 envc = imgp->args->envc; 787 788 /* Copy out strings - arguments and environment. */ 789 error = copyout(stringp, (void *)ustringp, 790 ARG_MAX - imgp->args->stringspace); 791 if (error != 0) 792 return (error); 793 794 /* Fill in "ps_strings" struct for ps, w, etc. */ 795 if (suword32(&arginfo->ps_argvstr, (uint32_t)(intptr_t)vectp) != 0 || 796 suword32(&arginfo->ps_nargvstr, argc) != 0) 797 return (EFAULT); 798 799 /* Fill in argument portion of vector table. */ 800 for (; argc > 0; --argc) { 801 if (suword32(vectp++, ustringp) != 0) 802 return (EFAULT); 803 while (*stringp++ != 0) 804 ustringp++; 805 ustringp++; 806 } 807 808 /* A null vector table pointer separates the argp's from the envp's. */ 809 if (suword32(vectp++, 0) != 0) 810 return (EFAULT); 811 812 if (suword32(&arginfo->ps_envstr, (uint32_t)(intptr_t)vectp) != 0 || 813 suword32(&arginfo->ps_nenvstr, envc) != 0) 814 return (EFAULT); 815 816 /* Fill in environment portion of vector table. */ 817 for (; envc > 0; --envc) { 818 if (suword32(vectp++, ustringp) != 0) 819 return (EFAULT); 820 while (*stringp++ != 0) 821 ustringp++; 822 ustringp++; 823 } 824 825 /* The end of the vector table is a null pointer. */ 826 if (suword32(vectp, 0) != 0) 827 return (EFAULT); 828 829 if (imgp->auxargs) { 830 vectp++; 831 error = imgp->sysent->sv_copyout_auxargs(imgp, 832 (uintptr_t)vectp); 833 if (error != 0) 834 return (error); 835 } 836 837 return (0); 838 } 839 840 static SYSCTL_NODE(_compat, OID_AUTO, linux32, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 841 "32-bit Linux emulation"); 842 843 static u_long linux32_maxdsiz = LINUX32_MAXDSIZ; 844 SYSCTL_ULONG(_compat_linux32, OID_AUTO, maxdsiz, CTLFLAG_RW, 845 &linux32_maxdsiz, 0, ""); 846 static u_long linux32_maxssiz = LINUX32_MAXSSIZ; 847 SYSCTL_ULONG(_compat_linux32, OID_AUTO, maxssiz, CTLFLAG_RW, 848 &linux32_maxssiz, 0, ""); 849 static u_long linux32_maxvmem = LINUX32_MAXVMEM; 850 SYSCTL_ULONG(_compat_linux32, OID_AUTO, maxvmem, CTLFLAG_RW, 851 &linux32_maxvmem, 0, ""); 852 853 static void 854 linux32_fixlimit(struct rlimit *rl, int which) 855 { 856 857 switch (which) { 858 case RLIMIT_DATA: 859 if (linux32_maxdsiz != 0) { 860 if (rl->rlim_cur > linux32_maxdsiz) 861 rl->rlim_cur = linux32_maxdsiz; 862 if (rl->rlim_max > linux32_maxdsiz) 863 rl->rlim_max = linux32_maxdsiz; 864 } 865 break; 866 case RLIMIT_STACK: 867 if (linux32_maxssiz != 0) { 868 if (rl->rlim_cur > linux32_maxssiz) 869 rl->rlim_cur = linux32_maxssiz; 870 if (rl->rlim_max > linux32_maxssiz) 871 rl->rlim_max = linux32_maxssiz; 872 } 873 break; 874 case RLIMIT_VMEM: 875 if (linux32_maxvmem != 0) { 876 if (rl->rlim_cur > linux32_maxvmem) 877 rl->rlim_cur = linux32_maxvmem; 878 if (rl->rlim_max > linux32_maxvmem) 879 rl->rlim_max = linux32_maxvmem; 880 } 881 break; 882 } 883 } 884 885 struct sysentvec elf_linux_sysvec = { 886 .sv_size = LINUX32_SYS_MAXSYSCALL, 887 .sv_table = linux32_sysent, 888 .sv_errsize = ELAST + 1, 889 .sv_errtbl = linux_errtbl, 890 .sv_transtrap = linux_translate_traps, 891 .sv_fixup = linux_fixup_elf, 892 .sv_sendsig = linux_sendsig, 893 .sv_sigcode = &_binary_linux32_locore_o_start, 894 .sv_szsigcode = &linux_szsigcode, 895 .sv_name = "Linux ELF32", 896 .sv_coredump = elf32_coredump, 897 .sv_imgact_try = linux_exec_imgact_try, 898 .sv_minsigstksz = LINUX_MINSIGSTKSZ, 899 .sv_minuser = VM_MIN_ADDRESS, 900 .sv_maxuser = LINUX32_MAXUSER, 901 .sv_usrstack = LINUX32_USRSTACK, 902 .sv_psstrings = LINUX32_PS_STRINGS, 903 .sv_stackprot = VM_PROT_ALL, 904 .sv_copyout_auxargs = linux_copyout_auxargs, 905 .sv_copyout_strings = linux_copyout_strings, 906 .sv_setregs = linux_exec_setregs, 907 .sv_fixlimit = linux32_fixlimit, 908 .sv_maxssiz = &linux32_maxssiz, 909 .sv_flags = SV_ABI_LINUX | SV_ILP32 | SV_IA32 | SV_SHP, 910 .sv_set_syscall_retval = cpu_set_syscall_retval, 911 .sv_fetch_syscall_args = linux32_fetch_syscall_args, 912 .sv_syscallnames = NULL, 913 .sv_shared_page_base = LINUX32_SHAREDPAGE, 914 .sv_shared_page_len = PAGE_SIZE, 915 .sv_schedtail = linux_schedtail, 916 .sv_thread_detach = linux_thread_detach, 917 .sv_trap = NULL, 918 }; 919 920 static void 921 linux_vdso_install(void *param) 922 { 923 924 linux_szsigcode = (&_binary_linux32_locore_o_end - 925 &_binary_linux32_locore_o_start); 926 927 if (linux_szsigcode > elf_linux_sysvec.sv_shared_page_len) 928 panic("Linux invalid vdso size\n"); 929 930 __elfN(linux_vdso_fixup)(&elf_linux_sysvec); 931 932 linux_shared_page_obj = __elfN(linux_shared_page_init) 933 (&linux_shared_page_mapping); 934 935 __elfN(linux_vdso_reloc)(&elf_linux_sysvec); 936 937 bcopy(elf_linux_sysvec.sv_sigcode, linux_shared_page_mapping, 938 linux_szsigcode); 939 elf_linux_sysvec.sv_shared_page_obj = linux_shared_page_obj; 940 941 linux_kplatform = linux_shared_page_mapping + 942 (linux_platform - (caddr_t)elf_linux_sysvec.sv_shared_page_base); 943 } 944 SYSINIT(elf_linux_vdso_init, SI_SUB_EXEC, SI_ORDER_ANY, 945 linux_vdso_install, NULL); 946 947 static void 948 linux_vdso_deinstall(void *param) 949 { 950 951 __elfN(linux_shared_page_fini)(linux_shared_page_obj); 952 } 953 SYSUNINIT(elf_linux_vdso_uninit, SI_SUB_EXEC, SI_ORDER_FIRST, 954 linux_vdso_deinstall, NULL); 955 956 static char GNU_ABI_VENDOR[] = "GNU"; 957 static int GNULINUX_ABI_DESC = 0; 958 959 static bool 960 linux32_trans_osrel(const Elf_Note *note, int32_t *osrel) 961 { 962 const Elf32_Word *desc; 963 uintptr_t p; 964 965 p = (uintptr_t)(note + 1); 966 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 967 968 desc = (const Elf32_Word *)p; 969 if (desc[0] != GNULINUX_ABI_DESC) 970 return (false); 971 972 /* 973 * For Linux we encode osrel using the Linux convention of 974 * (version << 16) | (major << 8) | (minor) 975 * See macro in linux_mib.h 976 */ 977 *osrel = LINUX_KERNVER(desc[1], desc[2], desc[3]); 978 979 return (true); 980 } 981 982 static Elf_Brandnote linux32_brandnote = { 983 .hdr.n_namesz = sizeof(GNU_ABI_VENDOR), 984 .hdr.n_descsz = 16, /* XXX at least 16 */ 985 .hdr.n_type = 1, 986 .vendor = GNU_ABI_VENDOR, 987 .flags = BN_TRANSLATE_OSREL, 988 .trans_osrel = linux32_trans_osrel 989 }; 990 991 static Elf32_Brandinfo linux_brand = { 992 .brand = ELFOSABI_LINUX, 993 .machine = EM_386, 994 .compat_3_brand = "Linux", 995 .emul_path = linux_emul_path, 996 .interp_path = "/lib/ld-linux.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 }; 1002 1003 static Elf32_Brandinfo linux_glibc2brand = { 1004 .brand = ELFOSABI_LINUX, 1005 .machine = EM_386, 1006 .compat_3_brand = "Linux", 1007 .emul_path = linux_emul_path, 1008 .interp_path = "/lib/ld-linux.so.2", 1009 .sysvec = &elf_linux_sysvec, 1010 .interp_newpath = NULL, 1011 .brand_note = &linux32_brandnote, 1012 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 1013 }; 1014 1015 static Elf32_Brandinfo linux_muslbrand = { 1016 .brand = ELFOSABI_LINUX, 1017 .machine = EM_386, 1018 .compat_3_brand = "Linux", 1019 .emul_path = linux_emul_path, 1020 .interp_path = "/lib/ld-musl-i386.so.1", 1021 .sysvec = &elf_linux_sysvec, 1022 .interp_newpath = NULL, 1023 .brand_note = &linux32_brandnote, 1024 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 1025 }; 1026 1027 Elf32_Brandinfo *linux_brandlist[] = { 1028 &linux_brand, 1029 &linux_glibc2brand, 1030 &linux_muslbrand, 1031 NULL 1032 }; 1033 1034 static int 1035 linux_elf_modevent(module_t mod, int type, void *data) 1036 { 1037 Elf32_Brandinfo **brandinfo; 1038 int error; 1039 struct linux_ioctl_handler **lihp; 1040 1041 error = 0; 1042 1043 switch(type) { 1044 case MOD_LOAD: 1045 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL; 1046 ++brandinfo) 1047 if (elf32_insert_brand_entry(*brandinfo) < 0) 1048 error = EINVAL; 1049 if (error == 0) { 1050 SET_FOREACH(lihp, linux_ioctl_handler_set) 1051 linux32_ioctl_register_handler(*lihp); 1052 stclohz = (stathz ? stathz : hz); 1053 if (bootverbose) 1054 printf("Linux ELF exec handler installed\n"); 1055 } else 1056 printf("cannot insert Linux ELF brand handler\n"); 1057 break; 1058 case MOD_UNLOAD: 1059 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL; 1060 ++brandinfo) 1061 if (elf32_brand_inuse(*brandinfo)) 1062 error = EBUSY; 1063 if (error == 0) { 1064 for (brandinfo = &linux_brandlist[0]; 1065 *brandinfo != NULL; ++brandinfo) 1066 if (elf32_remove_brand_entry(*brandinfo) < 0) 1067 error = EINVAL; 1068 } 1069 if (error == 0) { 1070 SET_FOREACH(lihp, linux_ioctl_handler_set) 1071 linux32_ioctl_unregister_handler(*lihp); 1072 if (bootverbose) 1073 printf("Linux ELF exec handler removed\n"); 1074 } else 1075 printf("Could not deinstall ELF interpreter entry\n"); 1076 break; 1077 default: 1078 return (EOPNOTSUPP); 1079 } 1080 return (error); 1081 } 1082 1083 static moduledata_t linux_elf_mod = { 1084 "linuxelf", 1085 linux_elf_modevent, 1086 0 1087 }; 1088 1089 DECLARE_MODULE_TIED(linuxelf, linux_elf_mod, SI_SUB_EXEC, SI_ORDER_ANY); 1090 MODULE_DEPEND(linuxelf, linux_common, 1, 1, 1); 1091 FEATURE(linux, "Linux 32bit support"); 1092