1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 1994-1996 Søren Schmidt 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32 #define __ELF_WORD_SIZE 32 33 34 #include <sys/param.h> 35 #include <sys/exec.h> 36 #include <sys/fcntl.h> 37 #include <sys/imgact.h> 38 #include <sys/imgact_aout.h> 39 #include <sys/imgact_elf.h> 40 #include <sys/kernel.h> 41 #include <sys/lock.h> 42 #include <sys/malloc.h> 43 #include <sys/module.h> 44 #include <sys/mutex.h> 45 #include <sys/proc.h> 46 #include <sys/stddef.h> 47 #include <sys/syscallsubr.h> 48 #include <sys/sysctl.h> 49 #include <sys/sysent.h> 50 #include <sys/sysproto.h> 51 52 #include <vm/pmap.h> 53 #include <vm/vm.h> 54 #include <vm/vm_map.h> 55 #include <vm/vm_page.h> 56 57 #include <machine/cpu.h> 58 #include <machine/cputypes.h> 59 #include <machine/md_var.h> 60 #include <machine/pcb.h> 61 #include <machine/trap.h> 62 63 #include <x86/linux/linux_x86.h> 64 #include <i386/linux/linux.h> 65 #include <i386/linux/linux_proto.h> 66 #include <compat/linux/linux_elf.h> 67 #include <compat/linux/linux_emul.h> 68 #include <compat/linux/linux_fork.h> 69 #include <compat/linux/linux_ioctl.h> 70 #include <compat/linux/linux_mib.h> 71 #include <compat/linux/linux_misc.h> 72 #include <compat/linux/linux_signal.h> 73 #include <compat/linux/linux_util.h> 74 #include <compat/linux/linux_vdso.h> 75 76 #include <x86/linux/linux_x86_sigframe.h> 77 78 MODULE_VERSION(linux, 1); 79 80 #define LINUX_VDSOPAGE_SIZE PAGE_SIZE * 2 81 #define LINUX_VDSOPAGE (VM_MAXUSER_ADDRESS - LINUX_VDSOPAGE_SIZE) 82 #define LINUX_SHAREDPAGE (LINUX_VDSOPAGE - PAGE_SIZE) 83 /* 84 * PAGE_SIZE - the size 85 * of the native SHAREDPAGE 86 */ 87 #define LINUX_USRSTACK LINUX_SHAREDPAGE 88 #define LINUX_PS_STRINGS (LINUX_USRSTACK - sizeof(struct ps_strings)) 89 90 static int linux_szsigcode; 91 static vm_object_t linux_vdso_obj; 92 static char *linux_vdso_mapping; 93 extern char _binary_linux_vdso_so_o_start; 94 extern char _binary_linux_vdso_so_o_end; 95 static vm_offset_t linux_vdso_base; 96 97 extern struct sysent linux_sysent[LINUX_SYS_MAXSYSCALL]; 98 extern const char *linux_syscallnames[]; 99 100 SET_DECLARE(linux_ioctl_handler_set, struct linux_ioctl_handler); 101 102 static int linux_fixup(uintptr_t *stack_base, 103 struct image_params *iparams); 104 static void linux_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask); 105 static void linux_exec_setregs(struct thread *td, 106 struct image_params *imgp, uintptr_t stack); 107 static void linux_exec_sysvec_init(void *param); 108 static int linux_on_exec_vmspace(struct proc *p, 109 struct image_params *imgp); 110 static void linux_set_fork_retval(struct thread *td); 111 static void linux_vdso_install(const void *param); 112 static void linux_vdso_deinstall(const void *param); 113 static void linux_vdso_reloc(char *mapping, Elf_Addr offset); 114 115 LINUX_VDSO_SYM_CHAR(linux_platform); 116 LINUX_VDSO_SYM_INTPTR(__kernel_vsyscall); 117 LINUX_VDSO_SYM_INTPTR(linux_vdso_sigcode); 118 LINUX_VDSO_SYM_INTPTR(linux_vdso_rt_sigcode); 119 LINUX_VDSO_SYM_INTPTR(kern_timekeep_base); 120 LINUX_VDSO_SYM_INTPTR(kern_tsc_selector); 121 LINUX_VDSO_SYM_INTPTR(kern_cpu_selector); 122 123 static int 124 linux_fixup(uintptr_t *stack_base, struct image_params *imgp) 125 { 126 register_t *base, *argv, *envp; 127 128 base = (register_t *)*stack_base; 129 argv = base; 130 envp = base + (imgp->args->argc + 1); 131 base--; 132 suword(base, (intptr_t)envp); 133 base--; 134 suword(base, (intptr_t)argv); 135 base--; 136 suword(base, imgp->args->argc); 137 *stack_base = (uintptr_t)base; 138 return (0); 139 } 140 141 static int 142 linux_copyout_auxargs(struct image_params *imgp, uintptr_t base) 143 { 144 Elf32_Auxargs *args; 145 Elf32_Auxinfo *argarray, *pos; 146 int error, issetugid; 147 148 issetugid = imgp->proc->p_flag & P_SUGID ? 1 : 0; 149 args = (Elf32_Auxargs *)imgp->auxargs; 150 argarray = pos = malloc(LINUX_AT_COUNT * sizeof(*pos), M_TEMP, 151 M_WAITOK | M_ZERO); 152 153 AUXARGS_ENTRY(pos, LINUX_AT_SYSINFO_EHDR, linux_vdso_base); 154 AUXARGS_ENTRY(pos, LINUX_AT_SYSINFO, __kernel_vsyscall); 155 AUXARGS_ENTRY(pos, LINUX_AT_HWCAP, cpu_feature); 156 157 /* 158 * Do not export AT_CLKTCK when emulating Linux kernel prior to 2.4.0, 159 * as it has appeared in the 2.4.0-rc7 first time. 160 * Being exported, AT_CLKTCK is returned by sysconf(_SC_CLK_TCK), 161 * glibc falls back to the hard-coded CLK_TCK value when aux entry 162 * is not present. 163 * Also see linux_times() implementation. 164 */ 165 if (linux_kernver(curthread) >= LINUX_KERNVER_2004000) 166 AUXARGS_ENTRY(pos, LINUX_AT_CLKTCK, stclohz); 167 AUXARGS_ENTRY(pos, AT_PHDR, args->phdr); 168 AUXARGS_ENTRY(pos, AT_PHENT, args->phent); 169 AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum); 170 AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz); 171 AUXARGS_ENTRY(pos, AT_FLAGS, args->flags); 172 AUXARGS_ENTRY(pos, AT_ENTRY, args->entry); 173 AUXARGS_ENTRY(pos, AT_BASE, args->base); 174 AUXARGS_ENTRY(pos, LINUX_AT_SECURE, issetugid); 175 AUXARGS_ENTRY(pos, AT_UID, imgp->proc->p_ucred->cr_ruid); 176 AUXARGS_ENTRY(pos, AT_EUID, imgp->proc->p_ucred->cr_svuid); 177 AUXARGS_ENTRY(pos, AT_GID, imgp->proc->p_ucred->cr_rgid); 178 AUXARGS_ENTRY(pos, AT_EGID, imgp->proc->p_ucred->cr_svgid); 179 AUXARGS_ENTRY(pos, LINUX_AT_PLATFORM, PTROUT(linux_platform)); 180 AUXARGS_ENTRY_PTR(pos, LINUX_AT_RANDOM, imgp->canary); 181 if (imgp->execpathp != 0) 182 AUXARGS_ENTRY_PTR(pos, LINUX_AT_EXECFN, imgp->execpathp); 183 if (args->execfd != -1) 184 AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd); 185 AUXARGS_ENTRY(pos, AT_NULL, 0); 186 187 free(imgp->auxargs, M_TEMP); 188 imgp->auxargs = NULL; 189 KASSERT(pos - argarray <= LINUX_AT_COUNT, ("Too many auxargs")); 190 191 error = copyout(argarray, (void *)base, 192 sizeof(*argarray) * LINUX_AT_COUNT); 193 free(argarray, M_TEMP); 194 return (error); 195 } 196 197 static void 198 linux_rt_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask) 199 { 200 struct thread *td = curthread; 201 struct proc *p = td->td_proc; 202 struct sigacts *psp; 203 struct trapframe *regs; 204 struct l_rt_sigframe *fp, frame; 205 int sig, code; 206 int oonstack; 207 208 sig = linux_translate_traps(ksi->ksi_signo, ksi->ksi_trapno); 209 code = ksi->ksi_code; 210 PROC_LOCK_ASSERT(p, MA_OWNED); 211 psp = p->p_sigacts; 212 mtx_assert(&psp->ps_mtx, MA_OWNED); 213 regs = td->td_frame; 214 oonstack = sigonstack(regs->tf_esp); 215 216 /* Allocate space for the signal handler context. */ 217 if ((td->td_pflags & TDP_ALTSTACK) && !oonstack && 218 SIGISMEMBER(psp->ps_sigonstack, sig)) { 219 fp = (struct l_rt_sigframe *)((uintptr_t)td->td_sigstk.ss_sp + 220 td->td_sigstk.ss_size - sizeof(struct l_rt_sigframe)); 221 } else 222 fp = (struct l_rt_sigframe *)regs->tf_esp - 1; 223 mtx_unlock(&psp->ps_mtx); 224 225 /* Build the argument list for the signal handler. */ 226 sig = bsd_to_linux_signal(sig); 227 228 bzero(&frame, sizeof(frame)); 229 230 frame.sf_sig = sig; 231 frame.sf_siginfo = PTROUT(&fp->sf_si); 232 frame.sf_ucontext = PTROUT(&fp->sf_uc); 233 234 /* Fill in POSIX parts. */ 235 siginfo_to_lsiginfo(&ksi->ksi_info, &frame.sf_si, sig); 236 237 /* Build the signal context to be used by sigreturn. */ 238 frame.sf_uc.uc_stack.ss_sp = PTROUT(td->td_sigstk.ss_sp); 239 frame.sf_uc.uc_stack.ss_size = td->td_sigstk.ss_size; 240 frame.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK) 241 ? ((oonstack) ? LINUX_SS_ONSTACK : 0) : LINUX_SS_DISABLE; 242 PROC_UNLOCK(p); 243 244 bsd_to_linux_sigset(mask, &frame.sf_uc.uc_sigmask); 245 246 frame.sf_uc.uc_mcontext.sc_mask = frame.sf_uc.uc_sigmask.__mask; 247 frame.sf_uc.uc_mcontext.sc_gs = rgs(); 248 frame.sf_uc.uc_mcontext.sc_fs = regs->tf_fs; 249 frame.sf_uc.uc_mcontext.sc_es = regs->tf_es; 250 frame.sf_uc.uc_mcontext.sc_ds = regs->tf_ds; 251 frame.sf_uc.uc_mcontext.sc_edi = regs->tf_edi; 252 frame.sf_uc.uc_mcontext.sc_esi = regs->tf_esi; 253 frame.sf_uc.uc_mcontext.sc_ebp = regs->tf_ebp; 254 frame.sf_uc.uc_mcontext.sc_ebx = regs->tf_ebx; 255 frame.sf_uc.uc_mcontext.sc_esp = regs->tf_esp; 256 frame.sf_uc.uc_mcontext.sc_edx = regs->tf_edx; 257 frame.sf_uc.uc_mcontext.sc_ecx = regs->tf_ecx; 258 frame.sf_uc.uc_mcontext.sc_eax = regs->tf_eax; 259 frame.sf_uc.uc_mcontext.sc_eip = regs->tf_eip; 260 frame.sf_uc.uc_mcontext.sc_cs = regs->tf_cs; 261 frame.sf_uc.uc_mcontext.sc_eflags = regs->tf_eflags; 262 frame.sf_uc.uc_mcontext.sc_esp_at_signal = regs->tf_esp; 263 frame.sf_uc.uc_mcontext.sc_ss = regs->tf_ss; 264 frame.sf_uc.uc_mcontext.sc_err = regs->tf_err; 265 frame.sf_uc.uc_mcontext.sc_cr2 = (register_t)ksi->ksi_addr; 266 frame.sf_uc.uc_mcontext.sc_trapno = bsd_to_linux_trapcode(code); 267 268 if (copyout(&frame, fp, sizeof(frame)) != 0) { 269 /* 270 * Process has trashed its stack; give it an illegal 271 * instruction to halt it in its tracks. 272 */ 273 PROC_LOCK(p); 274 sigexit(td, SIGILL); 275 } 276 277 /* Build context to run handler in. */ 278 regs->tf_esp = PTROUT(fp); 279 regs->tf_eip = linux_vdso_rt_sigcode; 280 regs->tf_edi = PTROUT(catcher); 281 regs->tf_eflags &= ~(PSL_T | PSL_VM | PSL_D); 282 regs->tf_cs = _ucodesel; 283 regs->tf_ds = _udatasel; 284 regs->tf_es = _udatasel; 285 regs->tf_fs = _udatasel; 286 regs->tf_ss = _udatasel; 287 PROC_LOCK(p); 288 mtx_lock(&psp->ps_mtx); 289 } 290 291 /* 292 * Send an interrupt to process. 293 * 294 * Stack is set up to allow sigcode stored 295 * in u. to call routine, followed by kcall 296 * to sigreturn routine below. After sigreturn 297 * resets the signal mask, the stack, and the 298 * frame pointer, it returns to the user 299 * specified pc, psl. 300 */ 301 static void 302 linux_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask) 303 { 304 struct thread *td = curthread; 305 struct proc *p = td->td_proc; 306 struct sigacts *psp; 307 struct trapframe *regs; 308 struct l_sigframe *fp, frame; 309 l_sigset_t lmask; 310 int sig; 311 int oonstack; 312 313 PROC_LOCK_ASSERT(p, MA_OWNED); 314 psp = p->p_sigacts; 315 sig = linux_translate_traps(ksi->ksi_signo, ksi->ksi_trapno); 316 mtx_assert(&psp->ps_mtx, MA_OWNED); 317 if (SIGISMEMBER(psp->ps_siginfo, sig)) { 318 /* Signal handler installed with SA_SIGINFO. */ 319 linux_rt_sendsig(catcher, ksi, mask); 320 return; 321 } 322 regs = td->td_frame; 323 oonstack = sigonstack(regs->tf_esp); 324 325 /* Allocate space for the signal handler context. */ 326 if ((td->td_pflags & TDP_ALTSTACK) && !oonstack && 327 SIGISMEMBER(psp->ps_sigonstack, sig)) { 328 fp = (struct l_sigframe *)((uintptr_t)td->td_sigstk.ss_sp + 329 td->td_sigstk.ss_size - sizeof(struct l_sigframe)); 330 } else 331 fp = (struct l_sigframe *)regs->tf_esp - 1; 332 mtx_unlock(&psp->ps_mtx); 333 PROC_UNLOCK(p); 334 335 /* Build the argument list for the signal handler. */ 336 sig = bsd_to_linux_signal(sig); 337 338 bzero(&frame, sizeof(frame)); 339 340 frame.sf_sig = sig; 341 frame.sf_sigmask = *mask; 342 bsd_to_linux_sigset(mask, &lmask); 343 344 /* Build the signal context to be used by sigreturn. */ 345 frame.sf_sc.sc_mask = lmask.__mask; 346 frame.sf_sc.sc_gs = rgs(); 347 frame.sf_sc.sc_fs = regs->tf_fs; 348 frame.sf_sc.sc_es = regs->tf_es; 349 frame.sf_sc.sc_ds = regs->tf_ds; 350 frame.sf_sc.sc_edi = regs->tf_edi; 351 frame.sf_sc.sc_esi = regs->tf_esi; 352 frame.sf_sc.sc_ebp = regs->tf_ebp; 353 frame.sf_sc.sc_ebx = regs->tf_ebx; 354 frame.sf_sc.sc_esp = regs->tf_esp; 355 frame.sf_sc.sc_edx = regs->tf_edx; 356 frame.sf_sc.sc_ecx = regs->tf_ecx; 357 frame.sf_sc.sc_eax = regs->tf_eax; 358 frame.sf_sc.sc_eip = regs->tf_eip; 359 frame.sf_sc.sc_cs = regs->tf_cs; 360 frame.sf_sc.sc_eflags = regs->tf_eflags; 361 frame.sf_sc.sc_esp_at_signal = regs->tf_esp; 362 frame.sf_sc.sc_ss = regs->tf_ss; 363 frame.sf_sc.sc_err = regs->tf_err; 364 frame.sf_sc.sc_cr2 = (register_t)ksi->ksi_addr; 365 frame.sf_sc.sc_trapno = bsd_to_linux_trapcode(ksi->ksi_trapno); 366 367 if (copyout(&frame, fp, sizeof(frame)) != 0) { 368 /* 369 * Process has trashed its stack; give it an illegal 370 * instruction to halt it in its tracks. 371 */ 372 PROC_LOCK(p); 373 sigexit(td, SIGILL); 374 } 375 376 /* Build context to run handler in. */ 377 regs->tf_esp = PTROUT(fp); 378 regs->tf_eip = linux_vdso_sigcode; 379 regs->tf_edi = PTROUT(catcher); 380 regs->tf_eflags &= ~(PSL_T | PSL_VM | PSL_D); 381 regs->tf_cs = _ucodesel; 382 regs->tf_ds = _udatasel; 383 regs->tf_es = _udatasel; 384 regs->tf_fs = _udatasel; 385 regs->tf_ss = _udatasel; 386 PROC_LOCK(p); 387 mtx_lock(&psp->ps_mtx); 388 } 389 390 /* 391 * System call to cleanup state after a signal 392 * has been taken. Reset signal mask and 393 * stack state from context left by sendsig (above). 394 * Return to previous pc and psl as specified by 395 * context left by sendsig. Check carefully to 396 * make sure that the user has not modified the 397 * psl to gain improper privileges or to cause 398 * a machine fault. 399 */ 400 int 401 linux_sigreturn(struct thread *td, struct linux_sigreturn_args *args) 402 { 403 struct l_sigframe frame; 404 struct trapframe *regs; 405 int eflags; 406 ksiginfo_t ksi; 407 408 regs = td->td_frame; 409 410 /* 411 * The trampoline code hands us the sigframe. 412 * It is unsafe to keep track of it ourselves, in the event that a 413 * program jumps out of a signal handler. 414 */ 415 if (copyin(args->sfp, &frame, sizeof(frame)) != 0) 416 return (EFAULT); 417 418 /* Check for security violations. */ 419 #define EFLAGS_SECURE(ef, oef) ((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0) 420 eflags = frame.sf_sc.sc_eflags; 421 if (!EFLAGS_SECURE(eflags, regs->tf_eflags)) 422 return (EINVAL); 423 424 /* 425 * Don't allow users to load a valid privileged %cs. Let the 426 * hardware check for invalid selectors, excess privilege in 427 * other selectors, invalid %eip's and invalid %esp's. 428 */ 429 #define CS_SECURE(cs) (ISPL(cs) == SEL_UPL) 430 if (!CS_SECURE(frame.sf_sc.sc_cs)) { 431 ksiginfo_init_trap(&ksi); 432 ksi.ksi_signo = SIGBUS; 433 ksi.ksi_code = BUS_OBJERR; 434 ksi.ksi_trapno = T_PROTFLT; 435 ksi.ksi_addr = (void *)regs->tf_eip; 436 trapsignal(td, &ksi); 437 return (EINVAL); 438 } 439 440 kern_sigprocmask(td, SIG_SETMASK, &frame.sf_sigmask, NULL, 0); 441 442 /* Restore signal context. */ 443 /* %gs was restored by the trampoline. */ 444 regs->tf_fs = frame.sf_sc.sc_fs; 445 regs->tf_es = frame.sf_sc.sc_es; 446 regs->tf_ds = frame.sf_sc.sc_ds; 447 regs->tf_edi = frame.sf_sc.sc_edi; 448 regs->tf_esi = frame.sf_sc.sc_esi; 449 regs->tf_ebp = frame.sf_sc.sc_ebp; 450 regs->tf_ebx = frame.sf_sc.sc_ebx; 451 regs->tf_edx = frame.sf_sc.sc_edx; 452 regs->tf_ecx = frame.sf_sc.sc_ecx; 453 regs->tf_eax = frame.sf_sc.sc_eax; 454 regs->tf_eip = frame.sf_sc.sc_eip; 455 regs->tf_cs = frame.sf_sc.sc_cs; 456 regs->tf_eflags = eflags; 457 regs->tf_esp = frame.sf_sc.sc_esp_at_signal; 458 regs->tf_ss = frame.sf_sc.sc_ss; 459 460 return (EJUSTRETURN); 461 } 462 463 /* 464 * System call to cleanup state after a signal 465 * has been taken. Reset signal mask and 466 * stack state from context left by rt_sendsig (above). 467 * Return to previous pc and psl as specified by 468 * context left by sendsig. Check carefully to 469 * make sure that the user has not modified the 470 * psl to gain improper privileges or to cause 471 * a machine fault. 472 */ 473 int 474 linux_rt_sigreturn(struct thread *td, struct linux_rt_sigreturn_args *args) 475 { 476 struct l_ucontext uc; 477 struct l_sigcontext *context; 478 sigset_t bmask; 479 l_stack_t *lss; 480 stack_t ss; 481 struct trapframe *regs; 482 int eflags; 483 ksiginfo_t ksi; 484 485 regs = td->td_frame; 486 487 /* 488 * The trampoline code hands us the ucontext. 489 * It is unsafe to keep track of it ourselves, in the event that a 490 * program jumps out of a signal handler. 491 */ 492 if (copyin(args->ucp, &uc, sizeof(uc)) != 0) 493 return (EFAULT); 494 495 context = &uc.uc_mcontext; 496 497 /* Check for security violations. */ 498 #define EFLAGS_SECURE(ef, oef) ((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0) 499 eflags = context->sc_eflags; 500 if (!EFLAGS_SECURE(eflags, regs->tf_eflags)) 501 return (EINVAL); 502 503 /* 504 * Don't allow users to load a valid privileged %cs. Let the 505 * hardware check for invalid selectors, excess privilege in 506 * other selectors, invalid %eip's and invalid %esp's. 507 */ 508 #define CS_SECURE(cs) (ISPL(cs) == SEL_UPL) 509 if (!CS_SECURE(context->sc_cs)) { 510 ksiginfo_init_trap(&ksi); 511 ksi.ksi_signo = SIGBUS; 512 ksi.ksi_code = BUS_OBJERR; 513 ksi.ksi_trapno = T_PROTFLT; 514 ksi.ksi_addr = (void *)regs->tf_eip; 515 trapsignal(td, &ksi); 516 return (EINVAL); 517 } 518 519 linux_to_bsd_sigset(&uc.uc_sigmask, &bmask); 520 kern_sigprocmask(td, SIG_SETMASK, &bmask, NULL, 0); 521 522 /* Restore signal context. */ 523 /* %gs was restored by the trampoline. */ 524 regs->tf_fs = context->sc_fs; 525 regs->tf_es = context->sc_es; 526 regs->tf_ds = context->sc_ds; 527 regs->tf_edi = context->sc_edi; 528 regs->tf_esi = context->sc_esi; 529 regs->tf_ebp = context->sc_ebp; 530 regs->tf_ebx = context->sc_ebx; 531 regs->tf_edx = context->sc_edx; 532 regs->tf_ecx = context->sc_ecx; 533 regs->tf_eax = context->sc_eax; 534 regs->tf_eip = context->sc_eip; 535 regs->tf_cs = context->sc_cs; 536 regs->tf_eflags = eflags; 537 regs->tf_esp = context->sc_esp_at_signal; 538 regs->tf_ss = context->sc_ss; 539 540 /* Call sigaltstack & ignore results. */ 541 lss = &uc.uc_stack; 542 ss.ss_sp = PTRIN(lss->ss_sp); 543 ss.ss_size = lss->ss_size; 544 ss.ss_flags = linux_to_bsd_sigaltstack(lss->ss_flags); 545 546 (void)kern_sigaltstack(td, &ss, NULL); 547 548 return (EJUSTRETURN); 549 } 550 551 static int 552 linux_fetch_syscall_args(struct thread *td) 553 { 554 struct proc *p; 555 struct trapframe *frame; 556 struct syscall_args *sa; 557 558 p = td->td_proc; 559 frame = td->td_frame; 560 sa = &td->td_sa; 561 562 sa->code = frame->tf_eax; 563 sa->original_code = sa->code; 564 sa->args[0] = frame->tf_ebx; 565 sa->args[1] = frame->tf_ecx; 566 sa->args[2] = frame->tf_edx; 567 sa->args[3] = frame->tf_esi; 568 sa->args[4] = frame->tf_edi; 569 sa->args[5] = frame->tf_ebp; /* Unconfirmed */ 570 571 if (sa->code >= p->p_sysent->sv_size) 572 /* nosys */ 573 sa->callp = &p->p_sysent->sv_table[p->p_sysent->sv_size - 1]; 574 else 575 sa->callp = &p->p_sysent->sv_table[sa->code]; 576 577 td->td_retval[0] = 0; 578 td->td_retval[1] = frame->tf_edx; 579 580 return (0); 581 } 582 583 static void 584 linux_set_syscall_retval(struct thread *td, int error) 585 { 586 struct trapframe *frame = td->td_frame; 587 588 cpu_set_syscall_retval(td, error); 589 590 if (__predict_false(error != 0)) { 591 if (error != ERESTART && error != EJUSTRETURN) 592 frame->tf_eax = bsd_to_linux_errno(error); 593 } 594 } 595 596 static void 597 linux_set_fork_retval(struct thread *td) 598 { 599 struct trapframe *frame = td->td_frame; 600 601 frame->tf_eax = 0; 602 } 603 604 /* 605 * exec_setregs may initialize some registers differently than Linux 606 * does, thus potentially confusing Linux binaries. If necessary, we 607 * override the exec_setregs default(s) here. 608 */ 609 static void 610 linux_exec_setregs(struct thread *td, struct image_params *imgp, 611 uintptr_t stack) 612 { 613 struct pcb *pcb = td->td_pcb; 614 615 exec_setregs(td, imgp, stack); 616 617 /* Linux sets %gs to 0, we default to _udatasel. */ 618 pcb->pcb_gs = 0; 619 load_gs(0); 620 621 pcb->pcb_initial_npxcw = __LINUX_NPXCW__; 622 } 623 624 struct sysentvec linux_sysvec = { 625 .sv_size = LINUX_SYS_MAXSYSCALL, 626 .sv_table = linux_sysent, 627 .sv_fixup = linux_fixup, 628 .sv_sendsig = linux_sendsig, 629 .sv_sigcode = &_binary_linux_vdso_so_o_start, 630 .sv_szsigcode = &linux_szsigcode, 631 .sv_name = "Linux a.out", 632 .sv_coredump = NULL, 633 .sv_imgact_try = linux_exec_imgact_try, 634 .sv_minsigstksz = LINUX_MINSIGSTKSZ, 635 .sv_minuser = VM_MIN_ADDRESS, 636 .sv_maxuser = VM_MAXUSER_ADDRESS, 637 .sv_usrstack = LINUX_USRSTACK, 638 .sv_psstrings = PS_STRINGS, 639 .sv_psstringssz = sizeof(struct ps_strings), 640 .sv_stackprot = VM_PROT_ALL, 641 .sv_copyout_strings = exec_copyout_strings, 642 .sv_setregs = linux_exec_setregs, 643 .sv_fixlimit = NULL, 644 .sv_maxssiz = NULL, 645 .sv_flags = SV_ABI_LINUX | SV_AOUT | SV_IA32 | SV_ILP32 | 646 SV_SIG_DISCIGN | SV_SIG_WAITNDQ, 647 .sv_set_syscall_retval = linux_set_syscall_retval, 648 .sv_fetch_syscall_args = linux_fetch_syscall_args, 649 .sv_syscallnames = linux_syscallnames, 650 .sv_schedtail = linux_schedtail, 651 .sv_thread_detach = linux_thread_detach, 652 .sv_trap = NULL, 653 .sv_onexec = linux_on_exec_vmspace, 654 .sv_onexit = linux_on_exit, 655 .sv_ontdexit = linux_thread_dtor, 656 .sv_setid_allowed = &linux_setid_allowed_query, 657 .sv_set_fork_retval = linux_set_fork_retval, 658 }; 659 INIT_SYSENTVEC(aout_sysvec, &linux_sysvec); 660 661 struct sysentvec elf_linux_sysvec = { 662 .sv_size = LINUX_SYS_MAXSYSCALL, 663 .sv_table = linux_sysent, 664 .sv_fixup = __elfN(freebsd_fixup), 665 .sv_sendsig = linux_sendsig, 666 .sv_sigcode = &_binary_linux_vdso_so_o_start, 667 .sv_szsigcode = &linux_szsigcode, 668 .sv_name = "Linux ELF32", 669 .sv_coredump = elf32_coredump, 670 .sv_elf_core_osabi = ELFOSABI_NONE, 671 .sv_elf_core_abi_vendor = LINUX_ABI_VENDOR, 672 .sv_elf_core_prepare_notes = __linuxN(prepare_notes), 673 .sv_imgact_try = linux_exec_imgact_try, 674 .sv_minsigstksz = LINUX_MINSIGSTKSZ, 675 .sv_minuser = VM_MIN_ADDRESS, 676 .sv_maxuser = VM_MAXUSER_ADDRESS, 677 .sv_usrstack = LINUX_USRSTACK, 678 .sv_psstrings = LINUX_PS_STRINGS, 679 .sv_psstringssz = sizeof(struct ps_strings), 680 .sv_stackprot = VM_PROT_ALL, 681 .sv_copyout_auxargs = linux_copyout_auxargs, 682 .sv_copyout_strings = __linuxN(copyout_strings), 683 .sv_setregs = linux_exec_setregs, 684 .sv_fixlimit = NULL, 685 .sv_maxssiz = NULL, 686 .sv_flags = SV_ABI_LINUX | SV_IA32 | SV_ILP32 | SV_SHP | 687 SV_SIG_DISCIGN | SV_SIG_WAITNDQ | SV_TIMEKEEP, 688 .sv_set_syscall_retval = linux_set_syscall_retval, 689 .sv_fetch_syscall_args = linux_fetch_syscall_args, 690 .sv_syscallnames = NULL, 691 .sv_shared_page_base = LINUX_SHAREDPAGE, 692 .sv_shared_page_len = PAGE_SIZE, 693 .sv_schedtail = linux_schedtail, 694 .sv_thread_detach = linux_thread_detach, 695 .sv_trap = NULL, 696 .sv_onexec = linux_on_exec_vmspace, 697 .sv_onexit = linux_on_exit, 698 .sv_ontdexit = linux_thread_dtor, 699 .sv_setid_allowed = &linux_setid_allowed_query, 700 .sv_set_fork_retval = linux_set_fork_retval, 701 }; 702 703 static int 704 linux_on_exec_vmspace(struct proc *p, struct image_params *imgp) 705 { 706 int error = 0; 707 708 if (SV_PROC_FLAG(p, SV_SHP) != 0) 709 error = linux_map_vdso(p, linux_vdso_obj, 710 linux_vdso_base, LINUX_VDSOPAGE_SIZE, imgp); 711 if (error == 0) 712 linux_on_exec(p, imgp); 713 return (error); 714 } 715 716 /* 717 * linux_vdso_install() and linux_exec_sysvec_init() must be called 718 * after exec_sysvec_init() which is SI_SUB_EXEC (SI_ORDER_ANY). 719 */ 720 static void 721 linux_exec_sysvec_init(void *param) 722 { 723 l_uintptr_t *ktimekeep_base, *ktsc_selector; 724 struct sysentvec *sv; 725 ptrdiff_t tkoff; 726 727 sv = param; 728 /* Fill timekeep_base */ 729 exec_sysvec_init(sv); 730 731 tkoff = kern_timekeep_base - linux_vdso_base; 732 ktimekeep_base = (l_uintptr_t *)(linux_vdso_mapping + tkoff); 733 *ktimekeep_base = sv->sv_shared_page_base + sv->sv_timekeep_offset; 734 735 tkoff = kern_tsc_selector - linux_vdso_base; 736 ktsc_selector = (l_uintptr_t *)(linux_vdso_mapping + tkoff); 737 *ktsc_selector = linux_vdso_tsc_selector_idx(); 738 if (bootverbose) 739 printf("Linux i386 vDSO tsc_selector: %u\n", *ktsc_selector); 740 741 tkoff = kern_cpu_selector - linux_vdso_base; 742 ktsc_selector = (l_uintptr_t *)(linux_vdso_mapping + tkoff); 743 *ktsc_selector = linux_vdso_cpu_selector_idx(); 744 if (bootverbose) 745 printf("Linux i386 vDSO cpu_selector: %u\n", *ktsc_selector); 746 } 747 SYSINIT(elf_linux_exec_sysvec_init, SI_SUB_EXEC + 1, SI_ORDER_ANY, 748 linux_exec_sysvec_init, &elf_linux_sysvec); 749 750 static void 751 linux_vdso_install(const void *param) 752 { 753 char *vdso_start = &_binary_linux_vdso_so_o_start; 754 char *vdso_end = &_binary_linux_vdso_so_o_end; 755 756 linux_szsigcode = vdso_end - vdso_start; 757 MPASS(linux_szsigcode <= LINUX_VDSOPAGE_SIZE); 758 759 linux_vdso_base = LINUX_VDSOPAGE; 760 761 __elfN(linux_vdso_fixup)(vdso_start, linux_vdso_base); 762 763 linux_vdso_obj = __elfN(linux_shared_page_init) 764 (&linux_vdso_mapping, LINUX_VDSOPAGE_SIZE); 765 bcopy(vdso_start, linux_vdso_mapping, linux_szsigcode); 766 767 linux_vdso_reloc(linux_vdso_mapping, linux_vdso_base); 768 } 769 SYSINIT(elf_linux_vdso_init, SI_SUB_EXEC + 1, SI_ORDER_FIRST, 770 linux_vdso_install, NULL); 771 772 static void 773 linux_vdso_deinstall(const void *param) 774 { 775 776 __elfN(linux_shared_page_fini)(linux_vdso_obj, 777 linux_vdso_mapping, LINUX_VDSOPAGE_SIZE); 778 } 779 SYSUNINIT(elf_linux_vdso_uninit, SI_SUB_EXEC, SI_ORDER_FIRST, 780 linux_vdso_deinstall, NULL); 781 782 static void 783 linux_vdso_reloc(char *mapping, Elf_Addr offset) 784 { 785 const Elf_Shdr *shdr; 786 const Elf_Rel *rel; 787 const Elf_Ehdr *ehdr; 788 Elf_Addr *where; 789 Elf_Size rtype, symidx; 790 Elf_Addr addr, addend; 791 int i, relcnt; 792 793 MPASS(offset != 0); 794 795 relcnt = 0; 796 ehdr = (const Elf_Ehdr *)mapping; 797 shdr = (const Elf_Shdr *)(mapping + ehdr->e_shoff); 798 for (i = 0; i < ehdr->e_shnum; i++) 799 { 800 switch (shdr[i].sh_type) { 801 case SHT_REL: 802 rel = (const Elf_Rel *)(mapping + shdr[i].sh_offset); 803 relcnt = shdr[i].sh_size / sizeof(*rel); 804 break; 805 case SHT_RELA: 806 printf("Linux i386 vDSO: unexpected Rela section\n"); 807 break; 808 } 809 } 810 811 for (i = 0; i < relcnt; i++, rel++) { 812 where = (Elf_Addr *)(mapping + rel->r_offset); 813 addend = *where; 814 rtype = ELF_R_TYPE(rel->r_info); 815 symidx = ELF_R_SYM(rel->r_info); 816 817 switch (rtype) { 818 case R_386_NONE: /* none */ 819 break; 820 821 case R_386_RELATIVE: /* B + A */ 822 addr = (Elf_Addr)PTROUT(offset + addend); 823 if (*where != addr) 824 *where = addr; 825 break; 826 827 case R_386_IRELATIVE: 828 printf("Linux i386 vDSO: unexpected ifunc relocation, " 829 "symbol index %d\n", symidx); 830 break; 831 default: 832 printf("Linux i386 vDSO: unexpected relocation type %d, " 833 "symbol index %d\n", rtype, symidx); 834 } 835 } 836 } 837 838 static Elf_Brandnote linux_brandnote = { 839 .hdr.n_namesz = sizeof(GNU_ABI_VENDOR), 840 .hdr.n_descsz = 16, /* XXX at least 16 */ 841 .hdr.n_type = 1, 842 .vendor = GNU_ABI_VENDOR, 843 .flags = BN_TRANSLATE_OSREL, 844 .trans_osrel = linux_trans_osrel 845 }; 846 847 static Elf32_Brandinfo linux_brand = { 848 .brand = ELFOSABI_LINUX, 849 .machine = EM_386, 850 .compat_3_brand = "Linux", 851 .emul_path = linux_emul_path, 852 .interp_path = "/lib/ld-linux.so.1", 853 .sysvec = &elf_linux_sysvec, 854 .interp_newpath = NULL, 855 .brand_note = &linux_brandnote, 856 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 857 }; 858 859 static Elf32_Brandinfo linux_glibc2brand = { 860 .brand = ELFOSABI_LINUX, 861 .machine = EM_386, 862 .compat_3_brand = "Linux", 863 .emul_path = linux_emul_path, 864 .interp_path = "/lib/ld-linux.so.2", 865 .sysvec = &elf_linux_sysvec, 866 .interp_newpath = NULL, 867 .brand_note = &linux_brandnote, 868 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 869 }; 870 871 static Elf32_Brandinfo linux_muslbrand = { 872 .brand = ELFOSABI_LINUX, 873 .machine = EM_386, 874 .compat_3_brand = "Linux", 875 .emul_path = linux_emul_path, 876 .interp_path = "/lib/ld-musl-i386.so.1", 877 .sysvec = &elf_linux_sysvec, 878 .interp_newpath = NULL, 879 .brand_note = &linux_brandnote, 880 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE | 881 LINUX_BI_FUTEX_REQUEUE 882 }; 883 884 Elf32_Brandinfo *linux_brandlist[] = { 885 &linux_brand, 886 &linux_glibc2brand, 887 &linux_muslbrand, 888 NULL 889 }; 890 891 static int 892 linux_elf_modevent(module_t mod, int type, void *data) 893 { 894 Elf32_Brandinfo **brandinfo; 895 int error; 896 struct linux_ioctl_handler **lihp; 897 898 error = 0; 899 900 switch(type) { 901 case MOD_LOAD: 902 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL; 903 ++brandinfo) 904 if (elf32_insert_brand_entry(*brandinfo) < 0) 905 error = EINVAL; 906 if (error == 0) { 907 SET_FOREACH(lihp, linux_ioctl_handler_set) 908 linux_ioctl_register_handler(*lihp); 909 linux_dev_shm_create(); 910 linux_osd_jail_register(); 911 linux_netlink_register(); 912 stclohz = (stathz ? stathz : hz); 913 if (bootverbose) 914 printf("Linux ELF exec handler installed\n"); 915 } else 916 printf("cannot insert Linux ELF brand handler\n"); 917 break; 918 case MOD_UNLOAD: 919 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL; 920 ++brandinfo) 921 if (elf32_brand_inuse(*brandinfo)) 922 error = EBUSY; 923 if (error == 0) { 924 for (brandinfo = &linux_brandlist[0]; 925 *brandinfo != NULL; ++brandinfo) 926 if (elf32_remove_brand_entry(*brandinfo) < 0) 927 error = EINVAL; 928 } 929 if (error == 0) { 930 SET_FOREACH(lihp, linux_ioctl_handler_set) 931 linux_ioctl_unregister_handler(*lihp); 932 linux_netlink_deregister(); 933 linux_dev_shm_destroy(); 934 linux_osd_jail_deregister(); 935 if (bootverbose) 936 printf("Linux ELF exec handler removed\n"); 937 } else 938 printf("Could not deinstall ELF interpreter entry\n"); 939 break; 940 default: 941 return (EOPNOTSUPP); 942 } 943 return (error); 944 } 945 946 static moduledata_t linux_elf_mod = { 947 "linuxelf", 948 linux_elf_modevent, 949 0 950 }; 951 952 DECLARE_MODULE_TIED(linuxelf, linux_elf_mod, SI_SUB_EXEC, SI_ORDER_ANY); 953 MODULE_DEPEND(linuxelf, netlink, 1, 1, 1); 954 FEATURE(linux, "Linux 32bit support"); 955