Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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sys/amd64/linux32/linux32_sysvec.c
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1 /*- 2 * Copyright (c) 2004 Tim J. Robbins 3 * Copyright (c) 2003 Peter Wemm 4 * Copyright (c) 2002 Doug Rabson 5 * Copyright (c) 1998-1999 Andrew Gallatin 6 * Copyright (c) 1994-1996 Søren Schmidt 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer 14 * in this position and unchanged. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. The name of the author may not be used to endorse or promote products 19 * derived from this software without specific prior written permission 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 22 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 23 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 24 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 26 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 30 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33 #include <sys/cdefs.h> 34 __FBSDID("$FreeBSD: releng/6.4/sys/amd64/linux32/linux32_sysvec.c 177665 2008-03-27 13:53:52Z kib $"); 35 36 /* XXX we use functions that might not exist. */ 37 #include "opt_compat.h" 38 39 #ifndef COMPAT_IA32 40 #error "Unable to compile Linux-emulator due to missing COMPAT_IA32 option!" 41 #endif 42 43 #define __ELF_WORD_SIZE 32 44 45 #include <sys/param.h> 46 #include <sys/systm.h> 47 #include <sys/exec.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/sysctl.h> 59 #include <sys/syscallsubr.h> 60 #include <sys/sysent.h> 61 #include <sys/sysproto.h> 62 #include <sys/vnode.h> 63 64 #include <vm/vm.h> 65 #include <vm/pmap.h> 66 #include <vm/vm_extern.h> 67 #include <vm/vm_map.h> 68 #include <vm/vm_object.h> 69 #include <vm/vm_page.h> 70 #include <vm/vm_param.h> 71 72 #include <machine/cpu.h> 73 #include <machine/md_var.h> 74 #include <machine/pcb.h> 75 #include <machine/specialreg.h> 76 77 #include <amd64/linux32/linux.h> 78 #include <amd64/linux32/linux32_proto.h> 79 #include <compat/linux/linux_mib.h> 80 #include <compat/linux/linux_signal.h> 81 #include <compat/linux/linux_util.h> 82 83 MODULE_VERSION(linux, 1); 84 MODULE_DEPEND(linux, sysvmsg, 1, 1, 1); 85 MODULE_DEPEND(linux, sysvsem, 1, 1, 1); 86 MODULE_DEPEND(linux, sysvshm, 1, 1, 1); 87 88 MALLOC_DEFINE(M_LINUX, "linux", "Linux mode structures"); 89 90 #define AUXARGS_ENTRY_32(pos, id, val) \ 91 do { \ 92 suword32(pos++, id); \ 93 suword32(pos++, val); \ 94 } while (0) 95 96 #if BYTE_ORDER == LITTLE_ENDIAN 97 #define SHELLMAGIC 0x2123 /* #! */ 98 #else 99 #define SHELLMAGIC 0x2321 100 #endif 101 102 /* 103 * Allow the sendsig functions to use the ldebug() facility 104 * even though they are not syscalls themselves. Map them 105 * to syscall 0. This is slightly less bogus than using 106 * ldebug(sigreturn). 107 */ 108 #define LINUX_SYS_linux_rt_sendsig 0 109 #define LINUX_SYS_linux_sendsig 0 110 111 extern char linux_sigcode[]; 112 extern int linux_szsigcode; 113 114 extern struct sysent linux_sysent[LINUX_SYS_MAXSYSCALL]; 115 116 SET_DECLARE(linux_ioctl_handler_set, struct linux_ioctl_handler); 117 SET_DECLARE(linux_device_handler_set, struct linux_device_handler); 118 119 static int elf_linux_fixup(register_t **stack_base, 120 struct image_params *iparams); 121 static register_t *linux_copyout_strings(struct image_params *imgp); 122 static void linux_prepsyscall(struct trapframe *tf, int *args, u_int *code, 123 caddr_t *params); 124 static void linux_sendsig(sig_t catcher, int sig, sigset_t *mask, 125 u_long code); 126 static void exec_linux_setregs(struct thread *td, u_long entry, 127 u_long stack, u_long ps_strings); 128 static void linux32_fixlimit(struct rlimit *rl, int which); 129 130 /* 131 * Linux syscalls return negative errno's, we do positive and map them 132 */ 133 static int bsd_to_linux_errno[ELAST + 1] = { 134 -0, -1, -2, -3, -4, -5, -6, -7, -8, -9, 135 -10, -35, -12, -13, -14, -15, -16, -17, -18, -19, 136 -20, -21, -22, -23, -24, -25, -26, -27, -28, -29, 137 -30, -31, -32, -33, -34, -11,-115,-114, -88, -89, 138 -90, -91, -92, -93, -94, -95, -96, -97, -98, -99, 139 -100,-101,-102,-103,-104,-105,-106,-107,-108,-109, 140 -110,-111, -40, -36,-112,-113, -39, -11, -87,-122, 141 -116, -66, -6, -6, -6, -6, -6, -37, -38, -9, 142 -6, -6, -43, -42, -75,-125, -84, -95, -16, -74, 143 -72, -67, -71 144 }; 145 146 int bsd_to_linux_signal[LINUX_SIGTBLSZ] = { 147 LINUX_SIGHUP, LINUX_SIGINT, LINUX_SIGQUIT, LINUX_SIGILL, 148 LINUX_SIGTRAP, LINUX_SIGABRT, 0, LINUX_SIGFPE, 149 LINUX_SIGKILL, LINUX_SIGBUS, LINUX_SIGSEGV, LINUX_SIGSYS, 150 LINUX_SIGPIPE, LINUX_SIGALRM, LINUX_SIGTERM, LINUX_SIGURG, 151 LINUX_SIGSTOP, LINUX_SIGTSTP, LINUX_SIGCONT, LINUX_SIGCHLD, 152 LINUX_SIGTTIN, LINUX_SIGTTOU, LINUX_SIGIO, LINUX_SIGXCPU, 153 LINUX_SIGXFSZ, LINUX_SIGVTALRM, LINUX_SIGPROF, LINUX_SIGWINCH, 154 0, LINUX_SIGUSR1, LINUX_SIGUSR2 155 }; 156 157 int linux_to_bsd_signal[LINUX_SIGTBLSZ] = { 158 SIGHUP, SIGINT, SIGQUIT, SIGILL, 159 SIGTRAP, SIGABRT, SIGBUS, SIGFPE, 160 SIGKILL, SIGUSR1, SIGSEGV, SIGUSR2, 161 SIGPIPE, SIGALRM, SIGTERM, SIGBUS, 162 SIGCHLD, SIGCONT, SIGSTOP, SIGTSTP, 163 SIGTTIN, SIGTTOU, SIGURG, SIGXCPU, 164 SIGXFSZ, SIGVTALRM, SIGPROF, SIGWINCH, 165 SIGIO, SIGURG, SIGSYS 166 }; 167 168 #define LINUX_T_UNKNOWN 255 169 static int _bsd_to_linux_trapcode[] = { 170 LINUX_T_UNKNOWN, /* 0 */ 171 6, /* 1 T_PRIVINFLT */ 172 LINUX_T_UNKNOWN, /* 2 */ 173 3, /* 3 T_BPTFLT */ 174 LINUX_T_UNKNOWN, /* 4 */ 175 LINUX_T_UNKNOWN, /* 5 */ 176 16, /* 6 T_ARITHTRAP */ 177 254, /* 7 T_ASTFLT */ 178 LINUX_T_UNKNOWN, /* 8 */ 179 13, /* 9 T_PROTFLT */ 180 1, /* 10 T_TRCTRAP */ 181 LINUX_T_UNKNOWN, /* 11 */ 182 14, /* 12 T_PAGEFLT */ 183 LINUX_T_UNKNOWN, /* 13 */ 184 17, /* 14 T_ALIGNFLT */ 185 LINUX_T_UNKNOWN, /* 15 */ 186 LINUX_T_UNKNOWN, /* 16 */ 187 LINUX_T_UNKNOWN, /* 17 */ 188 0, /* 18 T_DIVIDE */ 189 2, /* 19 T_NMI */ 190 4, /* 20 T_OFLOW */ 191 5, /* 21 T_BOUND */ 192 7, /* 22 T_DNA */ 193 8, /* 23 T_DOUBLEFLT */ 194 9, /* 24 T_FPOPFLT */ 195 10, /* 25 T_TSSFLT */ 196 11, /* 26 T_SEGNPFLT */ 197 12, /* 27 T_STKFLT */ 198 18, /* 28 T_MCHK */ 199 19, /* 29 T_XMMFLT */ 200 15 /* 30 T_RESERVED */ 201 }; 202 #define bsd_to_linux_trapcode(code) \ 203 ((code)<sizeof(_bsd_to_linux_trapcode)/sizeof(*_bsd_to_linux_trapcode)? \ 204 _bsd_to_linux_trapcode[(code)]: \ 205 LINUX_T_UNKNOWN) 206 207 struct linux32_ps_strings { 208 u_int32_t ps_argvstr; /* first of 0 or more argument strings */ 209 u_int ps_nargvstr; /* the number of argument strings */ 210 u_int32_t ps_envstr; /* first of 0 or more environment strings */ 211 u_int ps_nenvstr; /* the number of environment strings */ 212 }; 213 214 /* 215 * If FreeBSD & Linux have a difference of opinion about what a trap 216 * means, deal with it here. 217 * 218 * MPSAFE 219 */ 220 static int 221 translate_traps(int signal, int trap_code) 222 { 223 if (signal != SIGBUS) 224 return signal; 225 switch (trap_code) { 226 case T_PROTFLT: 227 case T_TSSFLT: 228 case T_DOUBLEFLT: 229 case T_PAGEFLT: 230 return SIGSEGV; 231 default: 232 return signal; 233 } 234 } 235 236 static int 237 elf_linux_fixup(register_t **stack_base, struct image_params *imgp) 238 { 239 Elf32_Auxargs *args; 240 Elf32_Addr *base; 241 Elf32_Addr *pos; 242 243 KASSERT(curthread->td_proc == imgp->proc && 244 (curthread->td_proc->p_flag & P_SA) == 0, 245 ("unsafe elf_linux_fixup(), should be curproc")); 246 base = (Elf32_Addr *)*stack_base; 247 args = (Elf32_Auxargs *)imgp->auxargs; 248 pos = base + (imgp->args->argc + imgp->args->envc + 2); 249 250 if (args->trace) 251 AUXARGS_ENTRY_32(pos, AT_DEBUG, 1); 252 if (args->execfd != -1) 253 AUXARGS_ENTRY_32(pos, AT_EXECFD, args->execfd); 254 AUXARGS_ENTRY_32(pos, AT_PHDR, args->phdr); 255 AUXARGS_ENTRY_32(pos, AT_PHENT, args->phent); 256 AUXARGS_ENTRY_32(pos, AT_PHNUM, args->phnum); 257 AUXARGS_ENTRY_32(pos, AT_PAGESZ, args->pagesz); 258 AUXARGS_ENTRY_32(pos, AT_FLAGS, args->flags); 259 AUXARGS_ENTRY_32(pos, AT_ENTRY, args->entry); 260 AUXARGS_ENTRY_32(pos, AT_BASE, args->base); 261 AUXARGS_ENTRY_32(pos, AT_UID, imgp->proc->p_ucred->cr_ruid); 262 AUXARGS_ENTRY_32(pos, AT_EUID, imgp->proc->p_ucred->cr_svuid); 263 AUXARGS_ENTRY_32(pos, AT_GID, imgp->proc->p_ucred->cr_rgid); 264 AUXARGS_ENTRY_32(pos, AT_EGID, imgp->proc->p_ucred->cr_svgid); 265 AUXARGS_ENTRY_32(pos, AT_NULL, 0); 266 267 free(imgp->auxargs, M_TEMP); 268 imgp->auxargs = NULL; 269 270 base--; 271 suword32(base, (uint32_t)imgp->args->argc); 272 *stack_base = (register_t *)base; 273 return 0; 274 } 275 276 extern int _ucodesel, _ucode32sel, _udatasel; 277 extern unsigned long linux_sznonrtsigcode; 278 279 static void 280 linux_rt_sendsig(sig_t catcher, int sig, sigset_t *mask, u_long code) 281 { 282 struct thread *td = curthread; 283 struct proc *p = td->td_proc; 284 struct sigacts *psp; 285 struct trapframe *regs; 286 struct l_rt_sigframe *fp, frame; 287 int oonstack; 288 289 PROC_LOCK_ASSERT(p, MA_OWNED); 290 psp = p->p_sigacts; 291 mtx_assert(&psp->ps_mtx, MA_OWNED); 292 regs = td->td_frame; 293 oonstack = sigonstack(regs->tf_rsp); 294 295 #ifdef DEBUG 296 if (ldebug(rt_sendsig)) 297 printf(ARGS(rt_sendsig, "%p, %d, %p, %lu"), 298 catcher, sig, (void*)mask, code); 299 #endif 300 /* 301 * Allocate space for the signal handler context. 302 */ 303 if ((td->td_pflags & TDP_ALTSTACK) && !oonstack && 304 SIGISMEMBER(psp->ps_sigonstack, sig)) { 305 fp = (struct l_rt_sigframe *)(td->td_sigstk.ss_sp + 306 td->td_sigstk.ss_size - sizeof(struct l_rt_sigframe)); 307 } else 308 fp = (struct l_rt_sigframe *)regs->tf_rsp - 1; 309 mtx_unlock(&psp->ps_mtx); 310 311 /* 312 * Build the argument list for the signal handler. 313 */ 314 if (p->p_sysent->sv_sigtbl) 315 if (sig <= p->p_sysent->sv_sigsize) 316 sig = p->p_sysent->sv_sigtbl[_SIG_IDX(sig)]; 317 318 bzero(&frame, sizeof(frame)); 319 320 frame.sf_handler = PTROUT(catcher); 321 frame.sf_sig = sig; 322 frame.sf_siginfo = PTROUT(&fp->sf_si); 323 frame.sf_ucontext = PTROUT(&fp->sf_sc); 324 325 /* Fill in POSIX parts */ 326 frame.sf_si.lsi_signo = sig; 327 frame.sf_si.lsi_code = code; 328 frame.sf_si.lsi_addr = PTROUT(regs->tf_addr); 329 330 /* 331 * Build the signal context to be used by sigreturn. 332 */ 333 frame.sf_sc.uc_flags = 0; /* XXX ??? */ 334 frame.sf_sc.uc_link = 0; /* XXX ??? */ 335 336 frame.sf_sc.uc_stack.ss_sp = PTROUT(td->td_sigstk.ss_sp); 337 frame.sf_sc.uc_stack.ss_size = td->td_sigstk.ss_size; 338 frame.sf_sc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK) 339 ? ((oonstack) ? LINUX_SS_ONSTACK : 0) : LINUX_SS_DISABLE; 340 PROC_UNLOCK(p); 341 342 bsd_to_linux_sigset(mask, &frame.sf_sc.uc_sigmask); 343 344 frame.sf_sc.uc_mcontext.sc_mask = frame.sf_sc.uc_sigmask.__bits[0]; 345 frame.sf_sc.uc_mcontext.sc_gs = rgs(); 346 frame.sf_sc.uc_mcontext.sc_fs = rfs(); 347 __asm __volatile("movl %%es,%0" : 348 "=rm" (frame.sf_sc.uc_mcontext.sc_es)); 349 __asm __volatile("movl %%ds,%0" : 350 "=rm" (frame.sf_sc.uc_mcontext.sc_ds)); 351 frame.sf_sc.uc_mcontext.sc_edi = regs->tf_rdi; 352 frame.sf_sc.uc_mcontext.sc_esi = regs->tf_rsi; 353 frame.sf_sc.uc_mcontext.sc_ebp = regs->tf_rbp; 354 frame.sf_sc.uc_mcontext.sc_ebx = regs->tf_rbx; 355 frame.sf_sc.uc_mcontext.sc_edx = regs->tf_rdx; 356 frame.sf_sc.uc_mcontext.sc_ecx = regs->tf_rcx; 357 frame.sf_sc.uc_mcontext.sc_eax = regs->tf_rax; 358 frame.sf_sc.uc_mcontext.sc_eip = regs->tf_rip; 359 frame.sf_sc.uc_mcontext.sc_cs = regs->tf_cs; 360 frame.sf_sc.uc_mcontext.sc_eflags = regs->tf_rflags; 361 frame.sf_sc.uc_mcontext.sc_esp_at_signal = regs->tf_rsp; 362 frame.sf_sc.uc_mcontext.sc_ss = regs->tf_ss; 363 frame.sf_sc.uc_mcontext.sc_err = regs->tf_err; 364 frame.sf_sc.uc_mcontext.sc_trapno = bsd_to_linux_trapcode(code); 365 366 #ifdef DEBUG 367 if (ldebug(rt_sendsig)) 368 printf(LMSG("rt_sendsig flags: 0x%x, sp: %p, ss: 0x%lx, mask: 0x%x"), 369 frame.sf_sc.uc_stack.ss_flags, td->td_sigstk.ss_sp, 370 td->td_sigstk.ss_size, frame.sf_sc.uc_mcontext.sc_mask); 371 #endif 372 373 if (copyout(&frame, fp, sizeof(frame)) != 0) { 374 /* 375 * Process has trashed its stack; give it an illegal 376 * instruction to halt it in its tracks. 377 */ 378 #ifdef DEBUG 379 if (ldebug(rt_sendsig)) 380 printf(LMSG("rt_sendsig: bad stack %p, oonstack=%x"), 381 fp, oonstack); 382 #endif 383 PROC_LOCK(p); 384 sigexit(td, SIGILL); 385 } 386 387 /* 388 * Build context to run handler in. 389 */ 390 regs->tf_rsp = PTROUT(fp); 391 regs->tf_rip = LINUX32_PS_STRINGS - *(p->p_sysent->sv_szsigcode) + 392 linux_sznonrtsigcode; 393 regs->tf_rflags &= ~(PSL_T | PSL_D); 394 regs->tf_cs = _ucode32sel; 395 regs->tf_ss = _udatasel; 396 load_ds(_udatasel); 397 td->td_pcb->pcb_ds = _udatasel; 398 load_es(_udatasel); 399 td->td_pcb->pcb_es = _udatasel; 400 /* leave user %fs and %gs untouched */ 401 PROC_LOCK(p); 402 mtx_lock(&psp->ps_mtx); 403 } 404 405 406 /* 407 * Send an interrupt to process. 408 * 409 * Stack is set up to allow sigcode stored 410 * in u. to call routine, followed by kcall 411 * to sigreturn routine below. After sigreturn 412 * resets the signal mask, the stack, and the 413 * frame pointer, it returns to the user 414 * specified pc, psl. 415 */ 416 static void 417 linux_sendsig(sig_t catcher, int sig, sigset_t *mask, u_long code) 418 { 419 struct thread *td = curthread; 420 struct proc *p = td->td_proc; 421 struct sigacts *psp; 422 struct trapframe *regs; 423 struct l_sigframe *fp, frame; 424 l_sigset_t lmask; 425 int oonstack, i; 426 427 PROC_LOCK_ASSERT(p, MA_OWNED); 428 psp = p->p_sigacts; 429 mtx_assert(&psp->ps_mtx, MA_OWNED); 430 if (SIGISMEMBER(psp->ps_siginfo, sig)) { 431 /* Signal handler installed with SA_SIGINFO. */ 432 linux_rt_sendsig(catcher, sig, mask, code); 433 return; 434 } 435 436 regs = td->td_frame; 437 oonstack = sigonstack(regs->tf_rsp); 438 439 #ifdef DEBUG 440 if (ldebug(sendsig)) 441 printf(ARGS(sendsig, "%p, %d, %p, %lu"), 442 catcher, sig, (void*)mask, code); 443 #endif 444 445 /* 446 * Allocate space for the signal handler context. 447 */ 448 if ((td->td_pflags & TDP_ALTSTACK) && !oonstack && 449 SIGISMEMBER(psp->ps_sigonstack, sig)) { 450 fp = (struct l_sigframe *)(td->td_sigstk.ss_sp + 451 td->td_sigstk.ss_size - sizeof(struct l_sigframe)); 452 } else 453 fp = (struct l_sigframe *)regs->tf_rsp - 1; 454 mtx_unlock(&psp->ps_mtx); 455 PROC_UNLOCK(p); 456 457 /* 458 * Build the argument list for the signal handler. 459 */ 460 if (p->p_sysent->sv_sigtbl) 461 if (sig <= p->p_sysent->sv_sigsize) 462 sig = p->p_sysent->sv_sigtbl[_SIG_IDX(sig)]; 463 464 bzero(&frame, sizeof(frame)); 465 466 frame.sf_handler = PTROUT(catcher); 467 frame.sf_sig = sig; 468 469 bsd_to_linux_sigset(mask, &lmask); 470 471 /* 472 * Build the signal context to be used by sigreturn. 473 */ 474 frame.sf_sc.sc_mask = lmask.__bits[0]; 475 frame.sf_sc.sc_gs = rgs(); 476 frame.sf_sc.sc_fs = rfs(); 477 __asm __volatile("movl %%es,%0" : "=rm" (frame.sf_sc.sc_es)); 478 __asm __volatile("movl %%ds,%0" : "=rm" (frame.sf_sc.sc_ds)); 479 frame.sf_sc.sc_edi = regs->tf_rdi; 480 frame.sf_sc.sc_esi = regs->tf_rsi; 481 frame.sf_sc.sc_ebp = regs->tf_rbp; 482 frame.sf_sc.sc_ebx = regs->tf_rbx; 483 frame.sf_sc.sc_edx = regs->tf_rdx; 484 frame.sf_sc.sc_ecx = regs->tf_rcx; 485 frame.sf_sc.sc_eax = regs->tf_rax; 486 frame.sf_sc.sc_eip = regs->tf_rip; 487 frame.sf_sc.sc_cs = regs->tf_cs; 488 frame.sf_sc.sc_eflags = regs->tf_rflags; 489 frame.sf_sc.sc_esp_at_signal = regs->tf_rsp; 490 frame.sf_sc.sc_ss = regs->tf_ss; 491 frame.sf_sc.sc_err = regs->tf_err; 492 frame.sf_sc.sc_trapno = bsd_to_linux_trapcode(code); 493 494 for (i = 0; i < (LINUX_NSIG_WORDS-1); i++) 495 frame.sf_extramask[i] = lmask.__bits[i+1]; 496 497 if (copyout(&frame, fp, sizeof(frame)) != 0) { 498 /* 499 * Process has trashed its stack; give it an illegal 500 * instruction to halt it in its tracks. 501 */ 502 PROC_LOCK(p); 503 sigexit(td, SIGILL); 504 } 505 506 /* 507 * Build context to run handler in. 508 */ 509 regs->tf_rsp = PTROUT(fp); 510 regs->tf_rip = LINUX32_PS_STRINGS - *(p->p_sysent->sv_szsigcode); 511 regs->tf_rflags &= ~(PSL_T | PSL_D); 512 regs->tf_cs = _ucode32sel; 513 regs->tf_ss = _udatasel; 514 load_ds(_udatasel); 515 td->td_pcb->pcb_ds = _udatasel; 516 load_es(_udatasel); 517 td->td_pcb->pcb_es = _udatasel; 518 /* leave user %fs and %gs untouched */ 519 PROC_LOCK(p); 520 mtx_lock(&psp->ps_mtx); 521 } 522 523 /* 524 * System call to cleanup state after a signal 525 * has been taken. Reset signal mask and 526 * stack state from context left by sendsig (above). 527 * Return to previous pc and psl as specified by 528 * context left by sendsig. Check carefully to 529 * make sure that the user has not modified the 530 * psl to gain improper privileges or to cause 531 * a machine fault. 532 */ 533 int 534 linux_sigreturn(struct thread *td, struct linux_sigreturn_args *args) 535 { 536 struct proc *p = td->td_proc; 537 struct l_sigframe frame; 538 struct trapframe *regs; 539 l_sigset_t lmask; 540 int eflags, i; 541 542 regs = td->td_frame; 543 544 #ifdef DEBUG 545 if (ldebug(sigreturn)) 546 printf(ARGS(sigreturn, "%p"), (void *)args->sfp); 547 #endif 548 /* 549 * The trampoline code hands us the sigframe. 550 * It is unsafe to keep track of it ourselves, in the event that a 551 * program jumps out of a signal handler. 552 */ 553 if (copyin(args->sfp, &frame, sizeof(frame)) != 0) 554 return (EFAULT); 555 556 /* 557 * Check for security violations. 558 */ 559 #define EFLAGS_SECURE(ef, oef) ((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0) 560 eflags = frame.sf_sc.sc_eflags; 561 /* 562 * XXX do allow users to change the privileged flag PSL_RF. The 563 * cpu sets PSL_RF in tf_eflags for faults. Debuggers should 564 * sometimes set it there too. tf_eflags is kept in the signal 565 * context during signal handling and there is no other place 566 * to remember it, so the PSL_RF bit may be corrupted by the 567 * signal handler without us knowing. Corruption of the PSL_RF 568 * bit at worst causes one more or one less debugger trap, so 569 * allowing it is fairly harmless. 570 */ 571 if (!EFLAGS_SECURE(eflags & ~PSL_RF, regs->tf_rflags & ~PSL_RF)) 572 return(EINVAL); 573 574 /* 575 * Don't allow users to load a valid privileged %cs. Let the 576 * hardware check for invalid selectors, excess privilege in 577 * other selectors, invalid %eip's and invalid %esp's. 578 */ 579 #define CS_SECURE(cs) (ISPL(cs) == SEL_UPL) 580 if (!CS_SECURE(frame.sf_sc.sc_cs)) { 581 trapsignal(td, SIGBUS, T_PROTFLT); 582 return(EINVAL); 583 } 584 585 lmask.__bits[0] = frame.sf_sc.sc_mask; 586 for (i = 0; i < (LINUX_NSIG_WORDS-1); i++) 587 lmask.__bits[i+1] = frame.sf_extramask[i]; 588 PROC_LOCK(p); 589 linux_to_bsd_sigset(&lmask, &td->td_sigmask); 590 SIG_CANTMASK(td->td_sigmask); 591 signotify(td); 592 PROC_UNLOCK(p); 593 594 /* 595 * Restore signal context. 596 */ 597 /* Selectors were restored by the trampoline. */ 598 regs->tf_rdi = frame.sf_sc.sc_edi; 599 regs->tf_rsi = frame.sf_sc.sc_esi; 600 regs->tf_rbp = frame.sf_sc.sc_ebp; 601 regs->tf_rbx = frame.sf_sc.sc_ebx; 602 regs->tf_rdx = frame.sf_sc.sc_edx; 603 regs->tf_rcx = frame.sf_sc.sc_ecx; 604 regs->tf_rax = frame.sf_sc.sc_eax; 605 regs->tf_rip = frame.sf_sc.sc_eip; 606 regs->tf_cs = frame.sf_sc.sc_cs; 607 regs->tf_rflags = eflags; 608 regs->tf_rsp = frame.sf_sc.sc_esp_at_signal; 609 regs->tf_ss = frame.sf_sc.sc_ss; 610 611 return (EJUSTRETURN); 612 } 613 614 /* 615 * System call to cleanup state after a signal 616 * has been taken. Reset signal mask and 617 * stack state from context left by rt_sendsig (above). 618 * Return to previous pc and psl as specified by 619 * context left by sendsig. Check carefully to 620 * make sure that the user has not modified the 621 * psl to gain improper privileges or to cause 622 * a machine fault. 623 */ 624 int 625 linux_rt_sigreturn(struct thread *td, struct linux_rt_sigreturn_args *args) 626 { 627 struct proc *p = td->td_proc; 628 struct l_ucontext uc; 629 struct l_sigcontext *context; 630 l_stack_t *lss; 631 stack_t ss; 632 struct trapframe *regs; 633 int eflags; 634 635 regs = td->td_frame; 636 637 #ifdef DEBUG 638 if (ldebug(rt_sigreturn)) 639 printf(ARGS(rt_sigreturn, "%p"), (void *)args->ucp); 640 #endif 641 /* 642 * The trampoline code hands us the ucontext. 643 * It is unsafe to keep track of it ourselves, in the event that a 644 * program jumps out of a signal handler. 645 */ 646 if (copyin(args->ucp, &uc, sizeof(uc)) != 0) 647 return (EFAULT); 648 649 context = &uc.uc_mcontext; 650 651 /* 652 * Check for security violations. 653 */ 654 #define EFLAGS_SECURE(ef, oef) ((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0) 655 eflags = context->sc_eflags; 656 /* 657 * XXX do allow users to change the privileged flag PSL_RF. The 658 * cpu sets PSL_RF in tf_eflags for faults. Debuggers should 659 * sometimes set it there too. tf_eflags is kept in the signal 660 * context during signal handling and there is no other place 661 * to remember it, so the PSL_RF bit may be corrupted by the 662 * signal handler without us knowing. Corruption of the PSL_RF 663 * bit at worst causes one more or one less debugger trap, so 664 * allowing it is fairly harmless. 665 */ 666 if (!EFLAGS_SECURE(eflags & ~PSL_RF, regs->tf_rflags & ~PSL_RF)) 667 return(EINVAL); 668 669 /* 670 * Don't allow users to load a valid privileged %cs. Let the 671 * hardware check for invalid selectors, excess privilege in 672 * other selectors, invalid %eip's and invalid %esp's. 673 */ 674 #define CS_SECURE(cs) (ISPL(cs) == SEL_UPL) 675 if (!CS_SECURE(context->sc_cs)) { 676 trapsignal(td, SIGBUS, T_PROTFLT); 677 return(EINVAL); 678 } 679 680 PROC_LOCK(p); 681 linux_to_bsd_sigset(&uc.uc_sigmask, &td->td_sigmask); 682 SIG_CANTMASK(td->td_sigmask); 683 signotify(td); 684 PROC_UNLOCK(p); 685 686 /* 687 * Restore signal context 688 */ 689 /* Selectors were restored by the trampoline. */ 690 regs->tf_rdi = context->sc_edi; 691 regs->tf_rsi = context->sc_esi; 692 regs->tf_rbp = context->sc_ebp; 693 regs->tf_rbx = context->sc_ebx; 694 regs->tf_rdx = context->sc_edx; 695 regs->tf_rcx = context->sc_ecx; 696 regs->tf_rax = context->sc_eax; 697 regs->tf_rip = context->sc_eip; 698 regs->tf_cs = context->sc_cs; 699 regs->tf_rflags = eflags; 700 regs->tf_rsp = context->sc_esp_at_signal; 701 regs->tf_ss = context->sc_ss; 702 703 /* 704 * call sigaltstack & ignore results.. 705 */ 706 lss = &uc.uc_stack; 707 ss.ss_sp = PTRIN(lss->ss_sp); 708 ss.ss_size = lss->ss_size; 709 ss.ss_flags = linux_to_bsd_sigaltstack(lss->ss_flags); 710 711 #ifdef DEBUG 712 if (ldebug(rt_sigreturn)) 713 printf(LMSG("rt_sigret flags: 0x%x, sp: %p, ss: 0x%lx, mask: 0x%x"), 714 ss.ss_flags, ss.ss_sp, ss.ss_size, context->sc_mask); 715 #endif 716 (void)kern_sigaltstack(td, &ss, NULL); 717 718 return (EJUSTRETURN); 719 } 720 721 /* 722 * MPSAFE 723 */ 724 static void 725 linux_prepsyscall(struct trapframe *tf, int *args, u_int *code, caddr_t *params) 726 { 727 args[0] = tf->tf_rbx; 728 args[1] = tf->tf_rcx; 729 args[2] = tf->tf_rdx; 730 args[3] = tf->tf_rsi; 731 args[4] = tf->tf_rdi; 732 args[5] = tf->tf_rbp; /* Unconfirmed */ 733 *params = NULL; /* no copyin */ 734 } 735 736 /* 737 * If a linux binary is exec'ing something, try this image activator 738 * first. We override standard shell script execution in order to 739 * be able to modify the interpreter path. We only do this if a linux 740 * binary is doing the exec, so we do not create an EXEC module for it. 741 */ 742 static int exec_linux_imgact_try(struct image_params *iparams); 743 744 static int 745 exec_linux_imgact_try(struct image_params *imgp) 746 { 747 const char *head = (const char *)imgp->image_header; 748 char *rpath; 749 int error = -1, len; 750 751 /* 752 * The interpreter for shell scripts run from a linux binary needs 753 * to be located in /compat/linux if possible in order to recursively 754 * maintain linux path emulation. 755 */ 756 if (((const short *)head)[0] == SHELLMAGIC) { 757 /* 758 * Run our normal shell image activator. If it succeeds attempt 759 * to use the alternate path for the interpreter. If an alternate 760 * path is found, use our stringspace to store it. 761 */ 762 if ((error = exec_shell_imgact(imgp)) == 0) { 763 linux_emul_convpath(FIRST_THREAD_IN_PROC(imgp->proc), 764 imgp->interpreter_name, UIO_SYSSPACE, &rpath, 0); 765 if (rpath != NULL) { 766 len = strlen(rpath) + 1; 767 768 if (len <= MAXSHELLCMDLEN) { 769 memcpy(imgp->interpreter_name, rpath, len); 770 } 771 free(rpath, M_TEMP); 772 } 773 } 774 } 775 return(error); 776 } 777 778 /* 779 * Clear registers on exec 780 * XXX copied from ia32_signal.c. 781 */ 782 static void 783 exec_linux_setregs(td, entry, stack, ps_strings) 784 struct thread *td; 785 u_long entry; 786 u_long stack; 787 u_long ps_strings; 788 { 789 struct trapframe *regs = td->td_frame; 790 struct pcb *pcb = td->td_pcb; 791 792 wrmsr(MSR_FSBASE, 0); 793 wrmsr(MSR_KGSBASE, 0); /* User value while we're in the kernel */ 794 pcb->pcb_fsbase = 0; 795 pcb->pcb_gsbase = 0; 796 load_ds(_udatasel); 797 load_es(_udatasel); 798 load_fs(_udatasel); 799 load_gs(0); 800 pcb->pcb_ds = _udatasel; 801 pcb->pcb_es = _udatasel; 802 pcb->pcb_fs = _udatasel; 803 pcb->pcb_gs = 0; 804 805 bzero((char *)regs, sizeof(struct trapframe)); 806 regs->tf_rip = entry; 807 regs->tf_rsp = stack; 808 regs->tf_rflags = PSL_USER | (regs->tf_rflags & PSL_T); 809 regs->tf_ss = _udatasel; 810 regs->tf_cs = _ucode32sel; 811 regs->tf_rbx = ps_strings; 812 load_cr0(rcr0() | CR0_MP | CR0_TS); 813 fpstate_drop(td); 814 815 /* Return via doreti so that we can change to a different %cs */ 816 pcb->pcb_flags |= PCB_FULLCTX; 817 td->td_retval[1] = 0; 818 } 819 820 /* 821 * XXX copied from ia32_sysvec.c. 822 */ 823 static register_t * 824 linux_copyout_strings(struct image_params *imgp) 825 { 826 int argc, envc; 827 u_int32_t *vectp; 828 char *stringp, *destp; 829 u_int32_t *stack_base; 830 struct linux32_ps_strings *arginfo; 831 int sigcodesz; 832 833 /* 834 * Calculate string base and vector table pointers. 835 * Also deal with signal trampoline code for this exec type. 836 */ 837 arginfo = (struct linux32_ps_strings *)LINUX32_PS_STRINGS; 838 sigcodesz = *(imgp->proc->p_sysent->sv_szsigcode); 839 destp = (caddr_t)arginfo - sigcodesz - SPARE_USRSPACE - 840 roundup((ARG_MAX - imgp->args->stringspace), sizeof(char *)); 841 842 /* 843 * install sigcode 844 */ 845 if (sigcodesz) 846 copyout(imgp->proc->p_sysent->sv_sigcode, 847 ((caddr_t)arginfo - sigcodesz), sigcodesz); 848 849 /* 850 * If we have a valid auxargs ptr, prepare some room 851 * on the stack. 852 */ 853 if (imgp->auxargs) { 854 /* 855 * 'AT_COUNT*2' is size for the ELF Auxargs data. This is for 856 * lower compatibility. 857 */ 858 imgp->auxarg_size = (imgp->auxarg_size) ? imgp->auxarg_size 859 : (AT_COUNT * 2); 860 /* 861 * The '+ 2' is for the null pointers at the end of each of 862 * the arg and env vector sets,and imgp->auxarg_size is room 863 * for argument of Runtime loader. 864 */ 865 vectp = (u_int32_t *) (destp - (imgp->args->argc + imgp->args->envc + 2 + 866 imgp->auxarg_size) * sizeof(u_int32_t)); 867 868 } else 869 /* 870 * The '+ 2' is for the null pointers at the end of each of 871 * the arg and env vector sets 872 */ 873 vectp = (u_int32_t *) 874 (destp - (imgp->args->argc + imgp->args->envc + 2) * sizeof(u_int32_t)); 875 876 /* 877 * vectp also becomes our initial stack base 878 */ 879 stack_base = vectp; 880 881 stringp = imgp->args->begin_argv; 882 argc = imgp->args->argc; 883 envc = imgp->args->envc; 884 /* 885 * Copy out strings - arguments and environment. 886 */ 887 copyout(stringp, destp, ARG_MAX - imgp->args->stringspace); 888 889 /* 890 * Fill in "ps_strings" struct for ps, w, etc. 891 */ 892 suword32(&arginfo->ps_argvstr, (u_int32_t)(intptr_t)vectp); 893 suword32(&arginfo->ps_nargvstr, argc); 894 895 /* 896 * Fill in argument portion of vector table. 897 */ 898 for (; argc > 0; --argc) { 899 suword32(vectp++, (u_int32_t)(intptr_t)destp); 900 while (*stringp++ != 0) 901 destp++; 902 destp++; 903 } 904 905 /* a null vector table pointer separates the argp's from the envp's */ 906 suword32(vectp++, 0); 907 908 suword32(&arginfo->ps_envstr, (u_int32_t)(intptr_t)vectp); 909 suword32(&arginfo->ps_nenvstr, envc); 910 911 /* 912 * Fill in environment portion of vector table. 913 */ 914 for (; envc > 0; --envc) { 915 suword32(vectp++, (u_int32_t)(intptr_t)destp); 916 while (*stringp++ != 0) 917 destp++; 918 destp++; 919 } 920 921 /* end of vector table is a null pointer */ 922 suword32(vectp, 0); 923 924 return ((register_t *)stack_base); 925 } 926 927 SYSCTL_NODE(_compat, OID_AUTO, linux32, CTLFLAG_RW, 0, 928 "32-bit Linux emulation"); 929 930 static u_long linux32_maxdsiz = LINUX32_MAXDSIZ; 931 SYSCTL_ULONG(_compat_linux32, OID_AUTO, maxdsiz, CTLFLAG_RW, 932 &linux32_maxdsiz, 0, ""); 933 static u_long linux32_maxssiz = LINUX32_MAXSSIZ; 934 SYSCTL_ULONG(_compat_linux32, OID_AUTO, maxssiz, CTLFLAG_RW, 935 &linux32_maxssiz, 0, ""); 936 static u_long linux32_maxvmem = LINUX32_MAXVMEM; 937 SYSCTL_ULONG(_compat_linux32, OID_AUTO, maxvmem, CTLFLAG_RW, 938 &linux32_maxvmem, 0, ""); 939 940 static void 941 linux32_fixlimit(struct rlimit *rl, int which) 942 { 943 944 switch (which) { 945 case RLIMIT_DATA: 946 if (linux32_maxdsiz != 0) { 947 if (rl->rlim_cur > linux32_maxdsiz) 948 rl->rlim_cur = linux32_maxdsiz; 949 if (rl->rlim_max > linux32_maxdsiz) 950 rl->rlim_max = linux32_maxdsiz; 951 } 952 break; 953 case RLIMIT_STACK: 954 if (linux32_maxssiz != 0) { 955 if (rl->rlim_cur > linux32_maxssiz) 956 rl->rlim_cur = linux32_maxssiz; 957 if (rl->rlim_max > linux32_maxssiz) 958 rl->rlim_max = linux32_maxssiz; 959 } 960 break; 961 case RLIMIT_VMEM: 962 if (linux32_maxvmem != 0) { 963 if (rl->rlim_cur > linux32_maxvmem) 964 rl->rlim_cur = linux32_maxvmem; 965 if (rl->rlim_max > linux32_maxvmem) 966 rl->rlim_max = linux32_maxvmem; 967 } 968 break; 969 } 970 } 971 972 struct sysentvec elf_linux_sysvec = { 973 LINUX_SYS_MAXSYSCALL, 974 linux_sysent, 975 0, 976 LINUX_SIGTBLSZ, 977 bsd_to_linux_signal, 978 ELAST + 1, 979 bsd_to_linux_errno, 980 translate_traps, 981 elf_linux_fixup, 982 linux_sendsig, 983 linux_sigcode, 984 &linux_szsigcode, 985 linux_prepsyscall, 986 "Linux ELF32", 987 elf32_coredump, 988 exec_linux_imgact_try, 989 LINUX_MINSIGSTKSZ, 990 PAGE_SIZE, 991 VM_MIN_ADDRESS, 992 LINUX32_USRSTACK, 993 LINUX32_USRSTACK, 994 LINUX32_PS_STRINGS, 995 VM_PROT_ALL, 996 linux_copyout_strings, 997 exec_linux_setregs, 998 linux32_fixlimit 999 }; 1000 1001 static Elf32_Brandinfo linux_brand = { 1002 ELFOSABI_LINUX, 1003 EM_386, 1004 "Linux", 1005 "/compat/linux", 1006 "/lib/ld-linux.so.1", 1007 &elf_linux_sysvec, 1008 NULL, 1009 }; 1010 1011 static Elf32_Brandinfo linux_glibc2brand = { 1012 ELFOSABI_LINUX, 1013 EM_386, 1014 "Linux", 1015 "/compat/linux", 1016 "/lib/ld-linux.so.2", 1017 &elf_linux_sysvec, 1018 NULL, 1019 }; 1020 1021 Elf32_Brandinfo *linux_brandlist[] = { 1022 &linux_brand, 1023 &linux_glibc2brand, 1024 NULL 1025 }; 1026 1027 static int 1028 linux_elf_modevent(module_t mod, int type, void *data) 1029 { 1030 Elf32_Brandinfo **brandinfo; 1031 int error; 1032 struct linux_ioctl_handler **lihp; 1033 struct linux_device_handler **ldhp; 1034 1035 error = 0; 1036 1037 switch(type) { 1038 case MOD_LOAD: 1039 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL; 1040 ++brandinfo) 1041 if (elf32_insert_brand_entry(*brandinfo) < 0) 1042 error = EINVAL; 1043 if (error == 0) { 1044 SET_FOREACH(lihp, linux_ioctl_handler_set) 1045 linux_ioctl_register_handler(*lihp); 1046 SET_FOREACH(ldhp, linux_device_handler_set) 1047 linux_device_register_handler(*ldhp); 1048 if (bootverbose) 1049 printf("Linux ELF exec handler installed\n"); 1050 } else 1051 printf("cannot insert Linux ELF brand handler\n"); 1052 break; 1053 case MOD_UNLOAD: 1054 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL; 1055 ++brandinfo) 1056 if (elf32_brand_inuse(*brandinfo)) 1057 error = EBUSY; 1058 if (error == 0) { 1059 for (brandinfo = &linux_brandlist[0]; 1060 *brandinfo != NULL; ++brandinfo) 1061 if (elf32_remove_brand_entry(*brandinfo) < 0) 1062 error = EINVAL; 1063 } 1064 if (error == 0) { 1065 SET_FOREACH(lihp, linux_ioctl_handler_set) 1066 linux_ioctl_unregister_handler(*lihp); 1067 SET_FOREACH(ldhp, linux_device_handler_set) 1068 linux_device_unregister_handler(*ldhp); 1069 if (bootverbose) 1070 printf("Linux ELF exec handler removed\n"); 1071 } else 1072 printf("Could not deinstall ELF interpreter entry\n"); 1073 break; 1074 default: 1075 break; 1076 } 1077 return error; 1078 } 1079 1080 static moduledata_t linux_elf_mod = { 1081 "linuxelf", 1082 linux_elf_modevent, 1083 0 1084 }; 1085 1086 DECLARE_MODULE(linuxelf, linux_elf_mod, SI_SUB_EXEC, SI_ORDER_ANY);
Cache object: b6f439035e79258c54fe669904eba1d1
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