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/systm.h> 46 #include <sys/exec.h> 47 #include <sys/fcntl.h> 48 #include <sys/imgact.h> 49 #include <sys/imgact_elf.h> 50 #include <sys/kernel.h> 51 #include <sys/lock.h> 52 #include <sys/malloc.h> 53 #include <sys/module.h> 54 #include <sys/mutex.h> 55 #include <sys/proc.h> 56 #include <sys/resourcevar.h> 57 #include <sys/signalvar.h> 58 #include <sys/syscallsubr.h> 59 #include <sys/sysctl.h> 60 #include <sys/sysent.h> 61 #include <sys/sysproto.h> 62 #include <sys/vnode.h> 63 #include <sys/eventhandler.h> 64 65 #include <vm/vm.h> 66 #include <vm/pmap.h> 67 #include <vm/vm_extern.h> 68 #include <vm/vm_map.h> 69 #include <vm/vm_object.h> 70 #include <vm/vm_page.h> 71 #include <vm/vm_param.h> 72 73 #include <machine/cpu.h> 74 #include <machine/md_var.h> 75 #include <machine/pcb.h> 76 #include <machine/specialreg.h> 77 #include <machine/trap.h> 78 79 #include <amd64/linux32/linux.h> 80 #include <amd64/linux32/linux32_proto.h> 81 #include <compat/linux/linux_emul.h> 82 #include <compat/linux/linux_futex.h> 83 #include <compat/linux/linux_ioctl.h> 84 #include <compat/linux/linux_mib.h> 85 #include <compat/linux/linux_misc.h> 86 #include <compat/linux/linux_signal.h> 87 #include <compat/linux/linux_util.h> 88 #include <compat/linux/linux_vdso.h> 89 90 MODULE_VERSION(linux, 1); 91 92 #define AUXARGS_ENTRY_32(pos, id, val) \ 93 do { \ 94 suword32(pos++, id); \ 95 suword32(pos++, val); \ 96 } while (0) 97 98 /* 99 * Allow the sendsig functions to use the ldebug() facility even though they 100 * are not syscalls themselves. Map them to syscall 0. This is slightly less 101 * bogus than using ldebug(sigreturn). 102 */ 103 #define LINUX32_SYS_linux_rt_sendsig 0 104 #define LINUX32_SYS_linux_sendsig 0 105 106 const char *linux_kplatform; 107 static int linux_szsigcode; 108 static vm_object_t linux_shared_page_obj; 109 static char *linux_shared_page_mapping; 110 extern char _binary_linux32_locore_o_start; 111 extern char _binary_linux32_locore_o_end; 112 113 extern struct sysent linux32_sysent[LINUX32_SYS_MAXSYSCALL]; 114 115 SET_DECLARE(linux_ioctl_handler_set, struct linux_ioctl_handler); 116 117 static int linux_fixup_elf(register_t **stack_base, 118 struct image_params *iparams); 119 static register_t *linux_copyout_strings(struct image_params *imgp); 120 static void linux_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask); 121 static void linux_exec_setregs(struct thread *td, 122 struct image_params *imgp, u_long stack); 123 static void linux32_fixlimit(struct rlimit *rl, int which); 124 static bool linux32_trans_osrel(const Elf_Note *note, int32_t *osrel); 125 static void linux_vdso_install(void *param); 126 static void linux_vdso_deinstall(void *param); 127 128 #define LINUX_T_UNKNOWN 255 129 static int _bsd_to_linux_trapcode[] = { 130 LINUX_T_UNKNOWN, /* 0 */ 131 6, /* 1 T_PRIVINFLT */ 132 LINUX_T_UNKNOWN, /* 2 */ 133 3, /* 3 T_BPTFLT */ 134 LINUX_T_UNKNOWN, /* 4 */ 135 LINUX_T_UNKNOWN, /* 5 */ 136 16, /* 6 T_ARITHTRAP */ 137 254, /* 7 T_ASTFLT */ 138 LINUX_T_UNKNOWN, /* 8 */ 139 13, /* 9 T_PROTFLT */ 140 1, /* 10 T_TRCTRAP */ 141 LINUX_T_UNKNOWN, /* 11 */ 142 14, /* 12 T_PAGEFLT */ 143 LINUX_T_UNKNOWN, /* 13 */ 144 17, /* 14 T_ALIGNFLT */ 145 LINUX_T_UNKNOWN, /* 15 */ 146 LINUX_T_UNKNOWN, /* 16 */ 147 LINUX_T_UNKNOWN, /* 17 */ 148 0, /* 18 T_DIVIDE */ 149 2, /* 19 T_NMI */ 150 4, /* 20 T_OFLOW */ 151 5, /* 21 T_BOUND */ 152 7, /* 22 T_DNA */ 153 8, /* 23 T_DOUBLEFLT */ 154 9, /* 24 T_FPOPFLT */ 155 10, /* 25 T_TSSFLT */ 156 11, /* 26 T_SEGNPFLT */ 157 12, /* 27 T_STKFLT */ 158 18, /* 28 T_MCHK */ 159 19, /* 29 T_XMMFLT */ 160 15 /* 30 T_RESERVED */ 161 }; 162 #define bsd_to_linux_trapcode(code) \ 163 ((code)<nitems(_bsd_to_linux_trapcode)? \ 164 _bsd_to_linux_trapcode[(code)]: \ 165 LINUX_T_UNKNOWN) 166 167 struct linux32_ps_strings { 168 u_int32_t ps_argvstr; /* first of 0 or more argument strings */ 169 u_int ps_nargvstr; /* the number of argument strings */ 170 u_int32_t ps_envstr; /* first of 0 or more environment strings */ 171 u_int ps_nenvstr; /* the number of environment strings */ 172 }; 173 174 LINUX_VDSO_SYM_INTPTR(linux32_sigcode); 175 LINUX_VDSO_SYM_INTPTR(linux32_rt_sigcode); 176 LINUX_VDSO_SYM_INTPTR(linux32_vsyscall); 177 LINUX_VDSO_SYM_CHAR(linux_platform); 178 179 /* 180 * If FreeBSD & Linux have a difference of opinion about what a trap 181 * means, deal with it here. 182 * 183 * MPSAFE 184 */ 185 static int 186 linux_translate_traps(int signal, int trap_code) 187 { 188 if (signal != SIGBUS) 189 return (signal); 190 switch (trap_code) { 191 case T_PROTFLT: 192 case T_TSSFLT: 193 case T_DOUBLEFLT: 194 case T_PAGEFLT: 195 return (SIGSEGV); 196 default: 197 return (signal); 198 } 199 } 200 201 static int 202 linux_fixup_elf(register_t **stack_base, struct image_params *imgp) 203 { 204 Elf32_Auxargs *args; 205 Elf32_Addr *base; 206 Elf32_Addr *pos; 207 struct linux32_ps_strings *arginfo; 208 int issetugid; 209 210 arginfo = (struct linux32_ps_strings *)LINUX32_PS_STRINGS; 211 212 KASSERT(curthread->td_proc == imgp->proc, 213 ("unsafe linux_fixup_elf(), should be curproc")); 214 base = (Elf32_Addr *)*stack_base; 215 args = (Elf32_Auxargs *)imgp->auxargs; 216 pos = base + (imgp->args->argc + imgp->args->envc + 2); 217 218 issetugid = imgp->proc->p_flag & P_SUGID ? 1 : 0; 219 AUXARGS_ENTRY_32(pos, LINUX_AT_SYSINFO_EHDR, 220 imgp->proc->p_sysent->sv_shared_page_base); 221 AUXARGS_ENTRY_32(pos, LINUX_AT_SYSINFO, linux32_vsyscall); 222 AUXARGS_ENTRY_32(pos, LINUX_AT_HWCAP, cpu_feature); 223 224 /* 225 * Do not export AT_CLKTCK when emulating Linux kernel prior to 2.4.0, 226 * as it has appeared in the 2.4.0-rc7 first time. 227 * Being exported, AT_CLKTCK is returned by sysconf(_SC_CLK_TCK), 228 * glibc falls back to the hard-coded CLK_TCK value when aux entry 229 * is not present. 230 * Also see linux_times() implementation. 231 */ 232 if (linux_kernver(curthread) >= LINUX_KERNVER_2004000) 233 AUXARGS_ENTRY_32(pos, LINUX_AT_CLKTCK, stclohz); 234 AUXARGS_ENTRY_32(pos, AT_PHDR, args->phdr); 235 AUXARGS_ENTRY_32(pos, AT_PHENT, args->phent); 236 AUXARGS_ENTRY_32(pos, AT_PHNUM, args->phnum); 237 AUXARGS_ENTRY_32(pos, AT_PAGESZ, args->pagesz); 238 AUXARGS_ENTRY_32(pos, AT_FLAGS, args->flags); 239 AUXARGS_ENTRY_32(pos, AT_ENTRY, args->entry); 240 AUXARGS_ENTRY_32(pos, AT_BASE, args->base); 241 AUXARGS_ENTRY_32(pos, LINUX_AT_SECURE, issetugid); 242 AUXARGS_ENTRY_32(pos, AT_UID, imgp->proc->p_ucred->cr_ruid); 243 AUXARGS_ENTRY_32(pos, AT_EUID, imgp->proc->p_ucred->cr_svuid); 244 AUXARGS_ENTRY_32(pos, AT_GID, imgp->proc->p_ucred->cr_rgid); 245 AUXARGS_ENTRY_32(pos, AT_EGID, imgp->proc->p_ucred->cr_svgid); 246 AUXARGS_ENTRY_32(pos, LINUX_AT_PLATFORM, PTROUT(linux_platform)); 247 AUXARGS_ENTRY(pos, LINUX_AT_RANDOM, PTROUT(imgp->canary)); 248 if (imgp->execpathp != 0) 249 AUXARGS_ENTRY(pos, LINUX_AT_EXECFN, PTROUT(imgp->execpathp)); 250 if (args->execfd != -1) 251 AUXARGS_ENTRY_32(pos, AT_EXECFD, args->execfd); 252 AUXARGS_ENTRY_32(pos, AT_NULL, 0); 253 254 free(imgp->auxargs, M_TEMP); 255 imgp->auxargs = NULL; 256 257 base--; 258 suword32(base, (uint32_t)imgp->args->argc); 259 *stack_base = (register_t *)base; 260 return (0); 261 } 262 263 static void 264 linux_rt_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_rt_sigframe *fp, frame; 271 int oonstack; 272 int sig; 273 int code; 274 275 sig = ksi->ksi_signo; 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 regs = td->td_frame; 281 oonstack = sigonstack(regs->tf_rsp); 282 283 #ifdef DEBUG 284 if (ldebug(rt_sendsig)) 285 printf(ARGS(rt_sendsig, "%p, %d, %p, %u"), 286 catcher, sig, (void*)mask, code); 287 #endif 288 /* Allocate space for the signal handler context. */ 289 if ((td->td_pflags & TDP_ALTSTACK) && !oonstack && 290 SIGISMEMBER(psp->ps_sigonstack, sig)) { 291 fp = (struct l_rt_sigframe *)((uintptr_t)td->td_sigstk.ss_sp + 292 td->td_sigstk.ss_size - sizeof(struct l_rt_sigframe)); 293 } else 294 fp = (struct l_rt_sigframe *)regs->tf_rsp - 1; 295 mtx_unlock(&psp->ps_mtx); 296 297 /* Build the argument list for the signal handler. */ 298 sig = bsd_to_linux_signal(sig); 299 300 bzero(&frame, sizeof(frame)); 301 302 frame.sf_handler = PTROUT(catcher); 303 frame.sf_sig = sig; 304 frame.sf_siginfo = PTROUT(&fp->sf_si); 305 frame.sf_ucontext = PTROUT(&fp->sf_sc); 306 307 /* Fill in POSIX parts. */ 308 ksiginfo_to_lsiginfo(ksi, &frame.sf_si, sig); 309 310 /* 311 * Build the signal context to be used by sigreturn and libgcc unwind. 312 */ 313 frame.sf_sc.uc_flags = 0; /* XXX ??? */ 314 frame.sf_sc.uc_link = 0; /* XXX ??? */ 315 316 frame.sf_sc.uc_stack.ss_sp = PTROUT(td->td_sigstk.ss_sp); 317 frame.sf_sc.uc_stack.ss_size = td->td_sigstk.ss_size; 318 frame.sf_sc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK) 319 ? ((oonstack) ? LINUX_SS_ONSTACK : 0) : LINUX_SS_DISABLE; 320 PROC_UNLOCK(p); 321 322 bsd_to_linux_sigset(mask, &frame.sf_sc.uc_sigmask); 323 324 frame.sf_sc.uc_mcontext.sc_mask = frame.sf_sc.uc_sigmask.__mask; 325 frame.sf_sc.uc_mcontext.sc_edi = regs->tf_rdi; 326 frame.sf_sc.uc_mcontext.sc_esi = regs->tf_rsi; 327 frame.sf_sc.uc_mcontext.sc_ebp = regs->tf_rbp; 328 frame.sf_sc.uc_mcontext.sc_ebx = regs->tf_rbx; 329 frame.sf_sc.uc_mcontext.sc_esp = regs->tf_rsp; 330 frame.sf_sc.uc_mcontext.sc_edx = regs->tf_rdx; 331 frame.sf_sc.uc_mcontext.sc_ecx = regs->tf_rcx; 332 frame.sf_sc.uc_mcontext.sc_eax = regs->tf_rax; 333 frame.sf_sc.uc_mcontext.sc_eip = regs->tf_rip; 334 frame.sf_sc.uc_mcontext.sc_cs = regs->tf_cs; 335 frame.sf_sc.uc_mcontext.sc_gs = regs->tf_gs; 336 frame.sf_sc.uc_mcontext.sc_fs = regs->tf_fs; 337 frame.sf_sc.uc_mcontext.sc_es = regs->tf_es; 338 frame.sf_sc.uc_mcontext.sc_ds = regs->tf_ds; 339 frame.sf_sc.uc_mcontext.sc_eflags = regs->tf_rflags; 340 frame.sf_sc.uc_mcontext.sc_esp_at_signal = regs->tf_rsp; 341 frame.sf_sc.uc_mcontext.sc_ss = regs->tf_ss; 342 frame.sf_sc.uc_mcontext.sc_err = regs->tf_err; 343 frame.sf_sc.uc_mcontext.sc_cr2 = (u_int32_t)(uintptr_t)ksi->ksi_addr; 344 frame.sf_sc.uc_mcontext.sc_trapno = bsd_to_linux_trapcode(code); 345 346 #ifdef DEBUG 347 if (ldebug(rt_sendsig)) 348 printf(LMSG("rt_sendsig flags: 0x%x, sp: %p, ss: 0x%lx, mask: 0x%x"), 349 frame.sf_sc.uc_stack.ss_flags, td->td_sigstk.ss_sp, 350 td->td_sigstk.ss_size, frame.sf_sc.uc_mcontext.sc_mask); 351 #endif 352 353 if (copyout(&frame, fp, sizeof(frame)) != 0) { 354 /* 355 * Process has trashed its stack; give it an illegal 356 * instruction to halt it in its tracks. 357 */ 358 #ifdef DEBUG 359 if (ldebug(rt_sendsig)) 360 printf(LMSG("rt_sendsig: bad stack %p, oonstack=%x"), 361 fp, oonstack); 362 #endif 363 PROC_LOCK(p); 364 sigexit(td, SIGILL); 365 } 366 367 /* Build context to run handler in. */ 368 regs->tf_rsp = PTROUT(fp); 369 regs->tf_rip = linux32_rt_sigcode; 370 regs->tf_rflags &= ~(PSL_T | PSL_D); 371 regs->tf_cs = _ucode32sel; 372 regs->tf_ss = _udatasel; 373 regs->tf_ds = _udatasel; 374 regs->tf_es = _udatasel; 375 regs->tf_fs = _ufssel; 376 regs->tf_gs = _ugssel; 377 regs->tf_flags = TF_HASSEGS; 378 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 379 PROC_LOCK(p); 380 mtx_lock(&psp->ps_mtx); 381 } 382 383 384 /* 385 * Send an interrupt to process. 386 * 387 * Stack is set up to allow sigcode stored 388 * in u. to call routine, followed by kcall 389 * to sigreturn routine below. After sigreturn 390 * resets the signal mask, the stack, and the 391 * frame pointer, it returns to the user 392 * specified pc, psl. 393 */ 394 static void 395 linux_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask) 396 { 397 struct thread *td = curthread; 398 struct proc *p = td->td_proc; 399 struct sigacts *psp; 400 struct trapframe *regs; 401 struct l_sigframe *fp, frame; 402 l_sigset_t lmask; 403 int oonstack; 404 int sig, code; 405 406 sig = ksi->ksi_signo; 407 code = ksi->ksi_code; 408 PROC_LOCK_ASSERT(p, MA_OWNED); 409 psp = p->p_sigacts; 410 mtx_assert(&psp->ps_mtx, MA_OWNED); 411 if (SIGISMEMBER(psp->ps_siginfo, sig)) { 412 /* Signal handler installed with SA_SIGINFO. */ 413 linux_rt_sendsig(catcher, ksi, mask); 414 return; 415 } 416 417 regs = td->td_frame; 418 oonstack = sigonstack(regs->tf_rsp); 419 420 #ifdef DEBUG 421 if (ldebug(sendsig)) 422 printf(ARGS(sendsig, "%p, %d, %p, %u"), 423 catcher, sig, (void*)mask, code); 424 #endif 425 426 /* Allocate space for the signal handler context. */ 427 if ((td->td_pflags & TDP_ALTSTACK) && !oonstack && 428 SIGISMEMBER(psp->ps_sigonstack, sig)) { 429 fp = (struct l_sigframe *)((uintptr_t)td->td_sigstk.ss_sp + 430 td->td_sigstk.ss_size - sizeof(struct l_sigframe)); 431 } else 432 fp = (struct l_sigframe *)regs->tf_rsp - 1; 433 mtx_unlock(&psp->ps_mtx); 434 PROC_UNLOCK(p); 435 436 /* Build the argument list for the signal handler. */ 437 sig = bsd_to_linux_signal(sig); 438 439 bzero(&frame, sizeof(frame)); 440 441 frame.sf_handler = PTROUT(catcher); 442 frame.sf_sig = sig; 443 444 bsd_to_linux_sigset(mask, &lmask); 445 446 /* Build the signal context to be used by sigreturn. */ 447 frame.sf_sc.sc_mask = lmask.__mask; 448 frame.sf_sc.sc_gs = regs->tf_gs; 449 frame.sf_sc.sc_fs = regs->tf_fs; 450 frame.sf_sc.sc_es = regs->tf_es; 451 frame.sf_sc.sc_ds = regs->tf_ds; 452 frame.sf_sc.sc_edi = regs->tf_rdi; 453 frame.sf_sc.sc_esi = regs->tf_rsi; 454 frame.sf_sc.sc_ebp = regs->tf_rbp; 455 frame.sf_sc.sc_ebx = regs->tf_rbx; 456 frame.sf_sc.sc_esp = regs->tf_rsp; 457 frame.sf_sc.sc_edx = regs->tf_rdx; 458 frame.sf_sc.sc_ecx = regs->tf_rcx; 459 frame.sf_sc.sc_eax = regs->tf_rax; 460 frame.sf_sc.sc_eip = regs->tf_rip; 461 frame.sf_sc.sc_cs = regs->tf_cs; 462 frame.sf_sc.sc_eflags = regs->tf_rflags; 463 frame.sf_sc.sc_esp_at_signal = regs->tf_rsp; 464 frame.sf_sc.sc_ss = regs->tf_ss; 465 frame.sf_sc.sc_err = regs->tf_err; 466 frame.sf_sc.sc_cr2 = (u_int32_t)(uintptr_t)ksi->ksi_addr; 467 frame.sf_sc.sc_trapno = bsd_to_linux_trapcode(code); 468 469 frame.sf_extramask[0] = lmask.__mask; 470 471 if (copyout(&frame, fp, sizeof(frame)) != 0) { 472 /* 473 * Process has trashed its stack; give it an illegal 474 * instruction to halt it in its tracks. 475 */ 476 PROC_LOCK(p); 477 sigexit(td, SIGILL); 478 } 479 480 /* Build context to run handler in. */ 481 regs->tf_rsp = PTROUT(fp); 482 regs->tf_rip = linux32_sigcode; 483 regs->tf_rflags &= ~(PSL_T | PSL_D); 484 regs->tf_cs = _ucode32sel; 485 regs->tf_ss = _udatasel; 486 regs->tf_ds = _udatasel; 487 regs->tf_es = _udatasel; 488 regs->tf_fs = _ufssel; 489 regs->tf_gs = _ugssel; 490 regs->tf_flags = TF_HASSEGS; 491 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 492 PROC_LOCK(p); 493 mtx_lock(&psp->ps_mtx); 494 } 495 496 /* 497 * System call to cleanup state after a signal 498 * has been taken. Reset signal mask and 499 * stack state from context left by sendsig (above). 500 * Return to previous pc and psl as specified by 501 * context left by sendsig. Check carefully to 502 * make sure that the user has not modified the 503 * psl to gain improper privileges or to cause 504 * a machine fault. 505 */ 506 int 507 linux_sigreturn(struct thread *td, struct linux_sigreturn_args *args) 508 { 509 struct l_sigframe frame; 510 struct trapframe *regs; 511 sigset_t bmask; 512 l_sigset_t lmask; 513 int eflags; 514 ksiginfo_t ksi; 515 516 regs = td->td_frame; 517 518 #ifdef DEBUG 519 if (ldebug(sigreturn)) 520 printf(ARGS(sigreturn, "%p"), (void *)args->sfp); 521 #endif 522 /* 523 * The trampoline code hands us the sigframe. 524 * It is unsafe to keep track of it ourselves, in the event that a 525 * program jumps out of a signal handler. 526 */ 527 if (copyin(args->sfp, &frame, sizeof(frame)) != 0) 528 return (EFAULT); 529 530 /* Check for security violations. */ 531 #define EFLAGS_SECURE(ef, oef) ((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0) 532 eflags = frame.sf_sc.sc_eflags; 533 if (!EFLAGS_SECURE(eflags, regs->tf_rflags)) 534 return(EINVAL); 535 536 /* 537 * Don't allow users to load a valid privileged %cs. Let the 538 * hardware check for invalid selectors, excess privilege in 539 * other selectors, invalid %eip's and invalid %esp's. 540 */ 541 #define CS_SECURE(cs) (ISPL(cs) == SEL_UPL) 542 if (!CS_SECURE(frame.sf_sc.sc_cs)) { 543 ksiginfo_init_trap(&ksi); 544 ksi.ksi_signo = SIGBUS; 545 ksi.ksi_code = BUS_OBJERR; 546 ksi.ksi_trapno = T_PROTFLT; 547 ksi.ksi_addr = (void *)regs->tf_rip; 548 trapsignal(td, &ksi); 549 return(EINVAL); 550 } 551 552 lmask.__mask = frame.sf_sc.sc_mask; 553 lmask.__mask = frame.sf_extramask[0]; 554 linux_to_bsd_sigset(&lmask, &bmask); 555 kern_sigprocmask(td, SIG_SETMASK, &bmask, NULL, 0); 556 557 /* Restore signal context. */ 558 regs->tf_rdi = frame.sf_sc.sc_edi; 559 regs->tf_rsi = frame.sf_sc.sc_esi; 560 regs->tf_rbp = frame.sf_sc.sc_ebp; 561 regs->tf_rbx = frame.sf_sc.sc_ebx; 562 regs->tf_rdx = frame.sf_sc.sc_edx; 563 regs->tf_rcx = frame.sf_sc.sc_ecx; 564 regs->tf_rax = frame.sf_sc.sc_eax; 565 regs->tf_rip = frame.sf_sc.sc_eip; 566 regs->tf_cs = frame.sf_sc.sc_cs; 567 regs->tf_ds = frame.sf_sc.sc_ds; 568 regs->tf_es = frame.sf_sc.sc_es; 569 regs->tf_fs = frame.sf_sc.sc_fs; 570 regs->tf_gs = frame.sf_sc.sc_gs; 571 regs->tf_rflags = eflags; 572 regs->tf_rsp = frame.sf_sc.sc_esp_at_signal; 573 regs->tf_ss = frame.sf_sc.sc_ss; 574 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 575 576 return (EJUSTRETURN); 577 } 578 579 /* 580 * System call to cleanup state after a signal 581 * has been taken. Reset signal mask and 582 * stack state from context left by rt_sendsig (above). 583 * Return to previous pc and psl as specified by 584 * context left by sendsig. Check carefully to 585 * make sure that the user has not modified the 586 * psl to gain improper privileges or to cause 587 * a machine fault. 588 */ 589 int 590 linux_rt_sigreturn(struct thread *td, struct linux_rt_sigreturn_args *args) 591 { 592 struct l_ucontext uc; 593 struct l_sigcontext *context; 594 sigset_t bmask; 595 l_stack_t *lss; 596 stack_t ss; 597 struct trapframe *regs; 598 int eflags; 599 ksiginfo_t ksi; 600 601 regs = td->td_frame; 602 603 #ifdef DEBUG 604 if (ldebug(rt_sigreturn)) 605 printf(ARGS(rt_sigreturn, "%p"), (void *)args->ucp); 606 #endif 607 /* 608 * The trampoline code hands us the ucontext. 609 * It is unsafe to keep track of it ourselves, in the event that a 610 * program jumps out of a signal handler. 611 */ 612 if (copyin(args->ucp, &uc, sizeof(uc)) != 0) 613 return (EFAULT); 614 615 context = &uc.uc_mcontext; 616 617 /* Check for security violations. */ 618 #define EFLAGS_SECURE(ef, oef) ((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0) 619 eflags = context->sc_eflags; 620 if (!EFLAGS_SECURE(eflags, regs->tf_rflags)) 621 return(EINVAL); 622 623 /* 624 * Don't allow users to load a valid privileged %cs. Let the 625 * hardware check for invalid selectors, excess privilege in 626 * other selectors, invalid %eip's and invalid %esp's. 627 */ 628 #define CS_SECURE(cs) (ISPL(cs) == SEL_UPL) 629 if (!CS_SECURE(context->sc_cs)) { 630 ksiginfo_init_trap(&ksi); 631 ksi.ksi_signo = SIGBUS; 632 ksi.ksi_code = BUS_OBJERR; 633 ksi.ksi_trapno = T_PROTFLT; 634 ksi.ksi_addr = (void *)regs->tf_rip; 635 trapsignal(td, &ksi); 636 return(EINVAL); 637 } 638 639 linux_to_bsd_sigset(&uc.uc_sigmask, &bmask); 640 kern_sigprocmask(td, SIG_SETMASK, &bmask, NULL, 0); 641 642 /* 643 * Restore signal context 644 */ 645 regs->tf_gs = context->sc_gs; 646 regs->tf_fs = context->sc_fs; 647 regs->tf_es = context->sc_es; 648 regs->tf_ds = context->sc_ds; 649 regs->tf_rdi = context->sc_edi; 650 regs->tf_rsi = context->sc_esi; 651 regs->tf_rbp = context->sc_ebp; 652 regs->tf_rbx = context->sc_ebx; 653 regs->tf_rdx = context->sc_edx; 654 regs->tf_rcx = context->sc_ecx; 655 regs->tf_rax = context->sc_eax; 656 regs->tf_rip = context->sc_eip; 657 regs->tf_cs = context->sc_cs; 658 regs->tf_rflags = eflags; 659 regs->tf_rsp = context->sc_esp_at_signal; 660 regs->tf_ss = context->sc_ss; 661 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 662 663 /* 664 * call sigaltstack & ignore results.. 665 */ 666 lss = &uc.uc_stack; 667 ss.ss_sp = PTRIN(lss->ss_sp); 668 ss.ss_size = lss->ss_size; 669 ss.ss_flags = linux_to_bsd_sigaltstack(lss->ss_flags); 670 671 #ifdef DEBUG 672 if (ldebug(rt_sigreturn)) 673 printf(LMSG("rt_sigret flags: 0x%x, sp: %p, ss: 0x%lx, mask: 0x%x"), 674 ss.ss_flags, ss.ss_sp, ss.ss_size, context->sc_mask); 675 #endif 676 (void)kern_sigaltstack(td, &ss, NULL); 677 678 return (EJUSTRETURN); 679 } 680 681 static int 682 linux32_fetch_syscall_args(struct thread *td) 683 { 684 struct proc *p; 685 struct trapframe *frame; 686 struct syscall_args *sa; 687 688 p = td->td_proc; 689 frame = td->td_frame; 690 sa = &td->td_sa; 691 692 sa->args[0] = frame->tf_rbx; 693 sa->args[1] = frame->tf_rcx; 694 sa->args[2] = frame->tf_rdx; 695 sa->args[3] = frame->tf_rsi; 696 sa->args[4] = frame->tf_rdi; 697 sa->args[5] = frame->tf_rbp; /* Unconfirmed */ 698 sa->code = frame->tf_rax; 699 700 if (sa->code >= p->p_sysent->sv_size) 701 /* nosys */ 702 sa->callp = &p->p_sysent->sv_table[p->p_sysent->sv_size - 1]; 703 else 704 sa->callp = &p->p_sysent->sv_table[sa->code]; 705 sa->narg = sa->callp->sy_narg; 706 707 td->td_retval[0] = 0; 708 td->td_retval[1] = frame->tf_rdx; 709 710 return (0); 711 } 712 713 /* 714 * Clear registers on exec 715 * XXX copied from ia32_signal.c. 716 */ 717 static void 718 linux_exec_setregs(struct thread *td, struct image_params *imgp, u_long stack) 719 { 720 struct trapframe *regs = td->td_frame; 721 struct pcb *pcb = td->td_pcb; 722 register_t saved_rflags; 723 724 regs = td->td_frame; 725 pcb = td->td_pcb; 726 727 if (td->td_proc->p_md.md_ldt != NULL) 728 user_ldt_free(td); 729 730 critical_enter(); 731 wrmsr(MSR_FSBASE, 0); 732 wrmsr(MSR_KGSBASE, 0); /* User value while we're in the kernel */ 733 pcb->pcb_fsbase = 0; 734 pcb->pcb_gsbase = 0; 735 critical_exit(); 736 pcb->pcb_initial_fpucw = __LINUX_NPXCW__; 737 738 saved_rflags = regs->tf_rflags & PSL_T; 739 bzero((char *)regs, sizeof(struct trapframe)); 740 regs->tf_rip = imgp->entry_addr; 741 regs->tf_rsp = stack; 742 regs->tf_rflags = PSL_USER | saved_rflags; 743 regs->tf_gs = _ugssel; 744 regs->tf_fs = _ufssel; 745 regs->tf_es = _udatasel; 746 regs->tf_ds = _udatasel; 747 regs->tf_ss = _udatasel; 748 regs->tf_flags = TF_HASSEGS; 749 regs->tf_cs = _ucode32sel; 750 regs->tf_rbx = imgp->ps_strings; 751 752 fpstate_drop(td); 753 754 /* Do full restore on return so that we can change to a different %cs */ 755 set_pcb_flags(pcb, PCB_32BIT | PCB_FULL_IRET); 756 } 757 758 /* 759 * XXX copied from ia32_sysvec.c. 760 */ 761 static register_t * 762 linux_copyout_strings(struct image_params *imgp) 763 { 764 int argc, envc; 765 u_int32_t *vectp; 766 char *stringp, *destp; 767 u_int32_t *stack_base; 768 struct linux32_ps_strings *arginfo; 769 char canary[LINUX_AT_RANDOM_LEN]; 770 size_t execpath_len; 771 772 /* Calculate string base and vector table pointers. */ 773 if (imgp->execpath != NULL && imgp->auxargs != NULL) 774 execpath_len = strlen(imgp->execpath) + 1; 775 else 776 execpath_len = 0; 777 778 arginfo = (struct linux32_ps_strings *)LINUX32_PS_STRINGS; 779 destp = (caddr_t)arginfo - SPARE_USRSPACE - 780 roundup(sizeof(canary), sizeof(char *)) - 781 roundup(execpath_len, sizeof(char *)) - 782 roundup(ARG_MAX - imgp->args->stringspace, sizeof(char *)); 783 784 if (execpath_len != 0) { 785 imgp->execpathp = (uintptr_t)arginfo - execpath_len; 786 copyout(imgp->execpath, (void *)imgp->execpathp, execpath_len); 787 } 788 789 /* Prepare the canary for SSP. */ 790 arc4rand(canary, sizeof(canary), 0); 791 imgp->canary = (uintptr_t)arginfo - 792 roundup(execpath_len, sizeof(char *)) - 793 roundup(sizeof(canary), sizeof(char *)); 794 copyout(canary, (void *)imgp->canary, sizeof(canary)); 795 796 vectp = (uint32_t *)destp; 797 if (imgp->auxargs) { 798 /* 799 * Allocate room on the stack for the ELF auxargs 800 * array. It has LINUX_AT_COUNT entries. 801 */ 802 vectp -= howmany(LINUX_AT_COUNT * sizeof(Elf32_Auxinfo), 803 sizeof(*vectp)); 804 } 805 806 /* 807 * Allocate room for the argv[] and env vectors including the 808 * terminating NULL pointers. 809 */ 810 vectp -= imgp->args->argc + 1 + imgp->args->envc + 1; 811 812 /* vectp also becomes our initial stack base. */ 813 stack_base = vectp; 814 815 stringp = imgp->args->begin_argv; 816 argc = imgp->args->argc; 817 envc = imgp->args->envc; 818 /* Copy out strings - arguments and environment. */ 819 copyout(stringp, destp, ARG_MAX - imgp->args->stringspace); 820 821 /* Fill in "ps_strings" struct for ps, w, etc. */ 822 suword32(&arginfo->ps_argvstr, (uint32_t)(intptr_t)vectp); 823 suword32(&arginfo->ps_nargvstr, argc); 824 825 /* Fill in argument portion of vector table. */ 826 for (; argc > 0; --argc) { 827 suword32(vectp++, (uint32_t)(intptr_t)destp); 828 while (*stringp++ != 0) 829 destp++; 830 destp++; 831 } 832 833 /* A null vector table pointer separates the argp's from the envp's. */ 834 suword32(vectp++, 0); 835 836 suword32(&arginfo->ps_envstr, (uint32_t)(intptr_t)vectp); 837 suword32(&arginfo->ps_nenvstr, envc); 838 839 /* Fill in environment portion of vector table. */ 840 for (; envc > 0; --envc) { 841 suword32(vectp++, (uint32_t)(intptr_t)destp); 842 while (*stringp++ != 0) 843 destp++; 844 destp++; 845 } 846 847 /* The end of the vector table is a null pointer. */ 848 suword32(vectp, 0); 849 850 return ((register_t *)stack_base); 851 } 852 853 static SYSCTL_NODE(_compat, OID_AUTO, linux32, CTLFLAG_RW, 0, 854 "32-bit Linux emulation"); 855 856 static u_long linux32_maxdsiz = LINUX32_MAXDSIZ; 857 SYSCTL_ULONG(_compat_linux32, OID_AUTO, maxdsiz, CTLFLAG_RW, 858 &linux32_maxdsiz, 0, ""); 859 static u_long linux32_maxssiz = LINUX32_MAXSSIZ; 860 SYSCTL_ULONG(_compat_linux32, OID_AUTO, maxssiz, CTLFLAG_RW, 861 &linux32_maxssiz, 0, ""); 862 static u_long linux32_maxvmem = LINUX32_MAXVMEM; 863 SYSCTL_ULONG(_compat_linux32, OID_AUTO, maxvmem, CTLFLAG_RW, 864 &linux32_maxvmem, 0, ""); 865 866 #if defined(DEBUG) 867 SYSCTL_PROC(_compat_linux32, OID_AUTO, debug, CTLTYPE_STRING | CTLFLAG_RW, 0, 0, 868 linux_sysctl_debug, "A", "Linux debugging control"); 869 #endif 870 871 static void 872 linux32_fixlimit(struct rlimit *rl, int which) 873 { 874 875 switch (which) { 876 case RLIMIT_DATA: 877 if (linux32_maxdsiz != 0) { 878 if (rl->rlim_cur > linux32_maxdsiz) 879 rl->rlim_cur = linux32_maxdsiz; 880 if (rl->rlim_max > linux32_maxdsiz) 881 rl->rlim_max = linux32_maxdsiz; 882 } 883 break; 884 case RLIMIT_STACK: 885 if (linux32_maxssiz != 0) { 886 if (rl->rlim_cur > linux32_maxssiz) 887 rl->rlim_cur = linux32_maxssiz; 888 if (rl->rlim_max > linux32_maxssiz) 889 rl->rlim_max = linux32_maxssiz; 890 } 891 break; 892 case RLIMIT_VMEM: 893 if (linux32_maxvmem != 0) { 894 if (rl->rlim_cur > linux32_maxvmem) 895 rl->rlim_cur = linux32_maxvmem; 896 if (rl->rlim_max > linux32_maxvmem) 897 rl->rlim_max = linux32_maxvmem; 898 } 899 break; 900 } 901 } 902 903 struct sysentvec elf_linux_sysvec = { 904 .sv_size = LINUX32_SYS_MAXSYSCALL, 905 .sv_table = linux32_sysent, 906 .sv_mask = 0, 907 .sv_errsize = ELAST + 1, 908 .sv_errtbl = linux_errtbl, 909 .sv_transtrap = linux_translate_traps, 910 .sv_fixup = linux_fixup_elf, 911 .sv_sendsig = linux_sendsig, 912 .sv_sigcode = &_binary_linux32_locore_o_start, 913 .sv_szsigcode = &linux_szsigcode, 914 .sv_name = "Linux ELF32", 915 .sv_coredump = elf32_coredump, 916 .sv_imgact_try = linux_exec_imgact_try, 917 .sv_minsigstksz = LINUX_MINSIGSTKSZ, 918 .sv_pagesize = PAGE_SIZE, 919 .sv_minuser = VM_MIN_ADDRESS, 920 .sv_maxuser = LINUX32_MAXUSER, 921 .sv_usrstack = LINUX32_USRSTACK, 922 .sv_psstrings = LINUX32_PS_STRINGS, 923 .sv_stackprot = VM_PROT_ALL, 924 .sv_copyout_strings = linux_copyout_strings, 925 .sv_setregs = linux_exec_setregs, 926 .sv_fixlimit = linux32_fixlimit, 927 .sv_maxssiz = &linux32_maxssiz, 928 .sv_flags = SV_ABI_LINUX | SV_ILP32 | SV_IA32 | SV_SHP, 929 .sv_set_syscall_retval = cpu_set_syscall_retval, 930 .sv_fetch_syscall_args = linux32_fetch_syscall_args, 931 .sv_syscallnames = NULL, 932 .sv_shared_page_base = LINUX32_SHAREDPAGE, 933 .sv_shared_page_len = PAGE_SIZE, 934 .sv_schedtail = linux_schedtail, 935 .sv_thread_detach = linux_thread_detach, 936 .sv_trap = NULL, 937 }; 938 939 static void 940 linux_vdso_install(void *param) 941 { 942 943 linux_szsigcode = (&_binary_linux32_locore_o_end - 944 &_binary_linux32_locore_o_start); 945 946 if (linux_szsigcode > elf_linux_sysvec.sv_shared_page_len) 947 panic("Linux invalid vdso size\n"); 948 949 __elfN(linux_vdso_fixup)(&elf_linux_sysvec); 950 951 linux_shared_page_obj = __elfN(linux_shared_page_init) 952 (&linux_shared_page_mapping); 953 954 __elfN(linux_vdso_reloc)(&elf_linux_sysvec); 955 956 bcopy(elf_linux_sysvec.sv_sigcode, linux_shared_page_mapping, 957 linux_szsigcode); 958 elf_linux_sysvec.sv_shared_page_obj = linux_shared_page_obj; 959 960 linux_kplatform = linux_shared_page_mapping + 961 (linux_platform - (caddr_t)elf_linux_sysvec.sv_shared_page_base); 962 } 963 SYSINIT(elf_linux_vdso_init, SI_SUB_EXEC, SI_ORDER_ANY, 964 linux_vdso_install, NULL); 965 966 static void 967 linux_vdso_deinstall(void *param) 968 { 969 970 __elfN(linux_shared_page_fini)(linux_shared_page_obj); 971 } 972 SYSUNINIT(elf_linux_vdso_uninit, SI_SUB_EXEC, SI_ORDER_FIRST, 973 linux_vdso_deinstall, NULL); 974 975 static char GNU_ABI_VENDOR[] = "GNU"; 976 static int GNULINUX_ABI_DESC = 0; 977 978 static bool 979 linux32_trans_osrel(const Elf_Note *note, int32_t *osrel) 980 { 981 const Elf32_Word *desc; 982 uintptr_t p; 983 984 p = (uintptr_t)(note + 1); 985 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 986 987 desc = (const Elf32_Word *)p; 988 if (desc[0] != GNULINUX_ABI_DESC) 989 return (false); 990 991 /* 992 * For Linux we encode osrel as follows (see linux_mib.c): 993 * VVVMMMIII (version, major, minor), see linux_mib.c. 994 */ 995 *osrel = desc[1] * 1000000 + desc[2] * 1000 + desc[3]; 996 997 return (true); 998 } 999 1000 static Elf_Brandnote linux32_brandnote = { 1001 .hdr.n_namesz = sizeof(GNU_ABI_VENDOR), 1002 .hdr.n_descsz = 16, /* XXX at least 16 */ 1003 .hdr.n_type = 1, 1004 .vendor = GNU_ABI_VENDOR, 1005 .flags = BN_TRANSLATE_OSREL, 1006 .trans_osrel = linux32_trans_osrel 1007 }; 1008 1009 static Elf32_Brandinfo linux_brand = { 1010 .brand = ELFOSABI_LINUX, 1011 .machine = EM_386, 1012 .compat_3_brand = "Linux", 1013 .emul_path = "/compat/linux", 1014 .interp_path = "/lib/ld-linux.so.1", 1015 .sysvec = &elf_linux_sysvec, 1016 .interp_newpath = NULL, 1017 .brand_note = &linux32_brandnote, 1018 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 1019 }; 1020 1021 static Elf32_Brandinfo linux_glibc2brand = { 1022 .brand = ELFOSABI_LINUX, 1023 .machine = EM_386, 1024 .compat_3_brand = "Linux", 1025 .emul_path = "/compat/linux", 1026 .interp_path = "/lib/ld-linux.so.2", 1027 .sysvec = &elf_linux_sysvec, 1028 .interp_newpath = NULL, 1029 .brand_note = &linux32_brandnote, 1030 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 1031 }; 1032 1033 static Elf32_Brandinfo linux_muslbrand = { 1034 .brand = ELFOSABI_LINUX, 1035 .machine = EM_386, 1036 .compat_3_brand = "Linux", 1037 .emul_path = "/compat/linux", 1038 .interp_path = "/lib/ld-musl-i386.so.1", 1039 .sysvec = &elf_linux_sysvec, 1040 .interp_newpath = NULL, 1041 .brand_note = &linux32_brandnote, 1042 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 1043 }; 1044 1045 Elf32_Brandinfo *linux_brandlist[] = { 1046 &linux_brand, 1047 &linux_glibc2brand, 1048 &linux_muslbrand, 1049 NULL 1050 }; 1051 1052 static int 1053 linux_elf_modevent(module_t mod, int type, void *data) 1054 { 1055 Elf32_Brandinfo **brandinfo; 1056 int error; 1057 struct linux_ioctl_handler **lihp; 1058 1059 error = 0; 1060 1061 switch(type) { 1062 case MOD_LOAD: 1063 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL; 1064 ++brandinfo) 1065 if (elf32_insert_brand_entry(*brandinfo) < 0) 1066 error = EINVAL; 1067 if (error == 0) { 1068 SET_FOREACH(lihp, linux_ioctl_handler_set) 1069 linux_ioctl_register_handler(*lihp); 1070 LIST_INIT(&futex_list); 1071 mtx_init(&futex_mtx, "ftllk", NULL, MTX_DEF); 1072 stclohz = (stathz ? stathz : hz); 1073 if (bootverbose) 1074 printf("Linux ELF exec handler installed\n"); 1075 } else 1076 printf("cannot insert Linux ELF brand handler\n"); 1077 break; 1078 case MOD_UNLOAD: 1079 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL; 1080 ++brandinfo) 1081 if (elf32_brand_inuse(*brandinfo)) 1082 error = EBUSY; 1083 if (error == 0) { 1084 for (brandinfo = &linux_brandlist[0]; 1085 *brandinfo != NULL; ++brandinfo) 1086 if (elf32_remove_brand_entry(*brandinfo) < 0) 1087 error = EINVAL; 1088 } 1089 if (error == 0) { 1090 SET_FOREACH(lihp, linux_ioctl_handler_set) 1091 linux_ioctl_unregister_handler(*lihp); 1092 mtx_destroy(&futex_mtx); 1093 if (bootverbose) 1094 printf("Linux ELF exec handler removed\n"); 1095 } else 1096 printf("Could not deinstall ELF interpreter entry\n"); 1097 break; 1098 default: 1099 return (EOPNOTSUPP); 1100 } 1101 return (error); 1102 } 1103 1104 static moduledata_t linux_elf_mod = { 1105 "linuxelf", 1106 linux_elf_modevent, 1107 0 1108 }; 1109 1110 DECLARE_MODULE_TIED(linuxelf, linux_elf_mod, SI_SUB_EXEC, SI_ORDER_ANY); 1111 MODULE_DEPEND(linuxelf, linux_common, 1, 1, 1); 1112 FEATURE(linux, "Linux 32bit support"); 1113