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 * Copyright (c) 2013, 2021 Dmitry Chagin <dchagin@FreeBSD.org> 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer 15 * in this position and unchanged. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. The name of the author may not be used to endorse or promote products 20 * derived from this software without specific prior written permission 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 25 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 27 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 31 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 32 */ 33 34 #define __ELF_WORD_SIZE 64 35 36 #include <sys/param.h> 37 #include <sys/exec.h> 38 #include <sys/imgact.h> 39 #include <sys/imgact_elf.h> 40 #include <sys/kernel.h> 41 #include <sys/ktr.h> 42 #include <sys/lock.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 51 #include <vm/pmap.h> 52 #include <vm/vm.h> 53 #include <vm/vm_param.h> 54 55 #include <machine/md_var.h> 56 #include <machine/trap.h> 57 58 #include <x86/linux/linux_x86.h> 59 #include <amd64/linux/linux.h> 60 #include <amd64/linux/linux_emul_md.h> 61 #include <amd64/linux/linux_proto.h> 62 #include <compat/linux/linux_elf.h> 63 #include <compat/linux/linux_emul.h> 64 #include <compat/linux/linux_fork.h> 65 #include <compat/linux/linux_ioctl.h> 66 #include <compat/linux/linux_mib.h> 67 #include <compat/linux/linux_misc.h> 68 #include <compat/linux/linux_signal.h> 69 #include <compat/linux/linux_util.h> 70 #include <compat/linux/linux_vdso.h> 71 72 #include <x86/linux/linux_x86_sigframe.h> 73 74 _Static_assert(sizeof(struct l_fpstate) == 75 sizeof(__typeof(((mcontext_t *)0)->mc_fpstate)), 76 "fxsave area size incorrect"); 77 78 MODULE_VERSION(linux64, 1); 79 80 #define LINUX_VDSOPAGE_SIZE PAGE_SIZE * 2 81 #define LINUX_VDSOPAGE_LA48 (VM_MAXUSER_ADDRESS_LA48 - \ 82 LINUX_VDSOPAGE_SIZE) 83 #define LINUX_SHAREDPAGE_LA48 (LINUX_VDSOPAGE_LA48 - PAGE_SIZE) 84 /* 85 * PAGE_SIZE - the size 86 * of the native SHAREDPAGE 87 */ 88 #define LINUX_USRSTACK_LA48 LINUX_SHAREDPAGE_LA48 89 #define LINUX_PS_STRINGS_LA48 (LINUX_USRSTACK_LA48 - \ 90 sizeof(struct ps_strings)) 91 92 static int linux_szsigcode; 93 static vm_object_t linux_vdso_obj; 94 static char *linux_vdso_mapping; 95 extern char _binary_linux_vdso_so_o_start; 96 extern char _binary_linux_vdso_so_o_end; 97 static vm_offset_t linux_vdso_base; 98 99 extern struct sysent linux_sysent[LINUX_SYS_MAXSYSCALL]; 100 extern const char *linux_syscallnames[]; 101 102 SET_DECLARE(linux_ioctl_handler_set, struct linux_ioctl_handler); 103 104 static void linux_vdso_install(const void *param); 105 static void linux_vdso_deinstall(const void *param); 106 static void linux_vdso_reloc(char *mapping, Elf_Addr offset); 107 static void linux_set_syscall_retval(struct thread *td, int error); 108 static int linux_fetch_syscall_args(struct thread *td); 109 static void linux_exec_setregs(struct thread *td, struct image_params *imgp, 110 uintptr_t stack); 111 static void linux_exec_sysvec_init(void *param); 112 static int linux_on_exec_vmspace(struct proc *p, 113 struct image_params *imgp); 114 static void linux_set_fork_retval(struct thread *td); 115 static int linux_vsyscall(struct thread *td); 116 117 LINUX_VDSO_SYM_INTPTR(linux_rt_sigcode); 118 LINUX_VDSO_SYM_CHAR(linux_platform); 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 /* 124 * According to the Intel x86 ISA 64-bit syscall 125 * saves %rip to %rcx and rflags to %r11. Registers on syscall entry: 126 * %rax system call number 127 * %rcx return address 128 * %r11 saved rflags 129 * %rdi arg1 130 * %rsi arg2 131 * %rdx arg3 132 * %r10 arg4 133 * %r8 arg5 134 * %r9 arg6 135 * 136 * Then FreeBSD fast_syscall() move registers: 137 * %rcx -> trapframe.tf_rip 138 * %r10 -> trapframe.tf_rcx 139 */ 140 static int 141 linux_fetch_syscall_args(struct thread *td) 142 { 143 struct proc *p; 144 struct trapframe *frame; 145 struct syscall_args *sa; 146 147 p = td->td_proc; 148 frame = td->td_frame; 149 sa = &td->td_sa; 150 151 sa->args[0] = frame->tf_rdi; 152 sa->args[1] = frame->tf_rsi; 153 sa->args[2] = frame->tf_rdx; 154 sa->args[3] = frame->tf_rcx; 155 sa->args[4] = frame->tf_r8; 156 sa->args[5] = frame->tf_r9; 157 sa->code = frame->tf_rax; 158 sa->original_code = sa->code; 159 160 if (sa->code >= p->p_sysent->sv_size) 161 /* nosys */ 162 sa->callp = &nosys_sysent; 163 else 164 sa->callp = &p->p_sysent->sv_table[sa->code]; 165 166 /* Restore r10 earlier to avoid doing this multiply times. */ 167 frame->tf_r10 = frame->tf_rcx; 168 /* Restore %rcx for machine context. */ 169 frame->tf_rcx = frame->tf_rip; 170 171 td->td_retval[0] = 0; 172 return (0); 173 } 174 175 static void 176 linux_set_syscall_retval(struct thread *td, int error) 177 { 178 struct trapframe *frame; 179 180 frame = td->td_frame; 181 182 switch (error) { 183 case 0: 184 frame->tf_rax = td->td_retval[0]; 185 break; 186 187 case ERESTART: 188 /* 189 * Reconstruct pc, we know that 'syscall' is 2 bytes, 190 * lcall $X,y is 7 bytes, int 0x80 is 2 bytes. 191 * We saved this in tf_err. 192 * 193 */ 194 frame->tf_rip -= frame->tf_err; 195 break; 196 197 case EJUSTRETURN: 198 break; 199 200 default: 201 frame->tf_rax = bsd_to_linux_errno(error); 202 break; 203 } 204 205 /* 206 * Differently from FreeBSD native ABI, on Linux only %rcx 207 * and %r11 values are not preserved across the syscall. 208 * Require full context restore to get all registers except 209 * those two restored at return to usermode. 210 */ 211 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 212 } 213 214 static void 215 linux_set_fork_retval(struct thread *td) 216 { 217 struct trapframe *frame = td->td_frame; 218 219 frame->tf_rax = 0; 220 } 221 222 void 223 linux64_arch_copyout_auxargs(struct image_params *imgp, Elf_Auxinfo **pos) 224 { 225 226 AUXARGS_ENTRY((*pos), LINUX_AT_SYSINFO_EHDR, linux_vdso_base); 227 AUXARGS_ENTRY((*pos), LINUX_AT_HWCAP, cpu_feature); 228 AUXARGS_ENTRY((*pos), LINUX_AT_HWCAP2, linux_x86_elf_hwcap2()); 229 AUXARGS_ENTRY((*pos), LINUX_AT_PLATFORM, PTROUT(linux_platform)); 230 } 231 232 /* 233 * Reset registers to default values on exec. 234 */ 235 static void 236 linux_exec_setregs(struct thread *td, struct image_params *imgp, 237 uintptr_t stack) 238 { 239 struct trapframe *regs; 240 struct pcb *pcb; 241 register_t saved_rflags; 242 243 regs = td->td_frame; 244 pcb = td->td_pcb; 245 246 if (td->td_proc->p_md.md_ldt != NULL) 247 user_ldt_free(td); 248 249 pcb->pcb_fsbase = 0; 250 pcb->pcb_gsbase = 0; 251 clear_pcb_flags(pcb, PCB_32BIT | PCB_TLSBASE); 252 pcb->pcb_initial_fpucw = __LINUX_NPXCW__; 253 set_pcb_flags(pcb, PCB_FULL_IRET); 254 255 saved_rflags = regs->tf_rflags & PSL_T; 256 bzero((char *)regs, sizeof(struct trapframe)); 257 regs->tf_rip = imgp->entry_addr; 258 regs->tf_rsp = stack; 259 regs->tf_rflags = PSL_USER | saved_rflags; 260 regs->tf_ss = _udatasel; 261 regs->tf_cs = _ucodesel; 262 regs->tf_ds = _udatasel; 263 regs->tf_es = _udatasel; 264 regs->tf_fs = _ufssel; 265 regs->tf_gs = _ugssel; 266 regs->tf_flags = TF_HASSEGS; 267 268 x86_clear_dbregs(pcb); 269 270 /* 271 * Drop the FP state if we hold it, so that the process gets a 272 * clean FP state if it uses the FPU again. 273 */ 274 fpstate_drop(td); 275 276 /* Linux processes start with PKRU denying unallocated keys. */ 277 linux_pkru_exec_init(td); 278 } 279 280 static int 281 linux_fxrstor(struct thread *td, mcontext_t *mcp, struct l_sigcontext *sc) 282 { 283 struct savefpu *fp = (struct savefpu *)&mcp->mc_fpstate[0]; 284 int error; 285 286 error = copyin(PTRIN(sc->sc_fpstate), fp, sizeof(mcp->mc_fpstate)); 287 if (error != 0) 288 return (error); 289 bzero(&fp->sv_pad[0], sizeof(fp->sv_pad)); 290 return (set_fpcontext(td, mcp, NULL, 0)); 291 } 292 293 static int 294 linux_xrstor(struct thread *td, mcontext_t *mcp, struct l_sigcontext *sc) 295 { 296 struct savefpu *fp = (struct savefpu *)&mcp->mc_fpstate[0]; 297 char *xfpustate; 298 struct proc *p; 299 uint32_t magic2; 300 int error; 301 302 p = td->td_proc; 303 mcp->mc_xfpustate_len = cpu_max_ext_state_size - sizeof(struct savefpu); 304 305 /* Legacy region of an xsave area. */ 306 error = copyin(PTRIN(sc->sc_fpstate), fp, sizeof(mcp->mc_fpstate)); 307 if (error != 0) 308 return (error); 309 bzero(&fp->sv_pad[0], sizeof(fp->sv_pad)); 310 311 /* Extended region of an xsave area. */ 312 sc->sc_fpstate += sizeof(mcp->mc_fpstate); 313 xfpustate = (char *)fpu_save_area_alloc(); 314 error = copyin(PTRIN(sc->sc_fpstate), xfpustate, mcp->mc_xfpustate_len); 315 if (error != 0) { 316 fpu_save_area_free((struct savefpu *)xfpustate); 317 uprintf("pid %d (%s): linux xrstor failed\n", p->p_pid, 318 td->td_name); 319 return (error); 320 } 321 322 /* Linux specific end of xsave area marker. */ 323 sc->sc_fpstate += mcp->mc_xfpustate_len; 324 error = copyin(PTRIN(sc->sc_fpstate), &magic2, LINUX_FP_XSTATE_MAGIC2_SIZE); 325 if (error != 0 || magic2 != LINUX_FP_XSTATE_MAGIC2) { 326 fpu_save_area_free((struct savefpu *)xfpustate); 327 uprintf("pid %d (%s): sigreturn magic2 0x%x error %d\n", 328 p->p_pid, td->td_name, magic2, error); 329 return (error); 330 } 331 332 error = set_fpcontext(td, mcp, xfpustate, mcp->mc_xfpustate_len); 333 fpu_save_area_free((struct savefpu *)xfpustate); 334 if (error != 0) { 335 uprintf("pid %d (%s): sigreturn set_fpcontext error %d\n", 336 p->p_pid, td->td_name, error); 337 } 338 return (error); 339 } 340 341 static int 342 linux_copyin_fpstate(struct thread *td, struct l_ucontext *uc) 343 { 344 mcontext_t mc; 345 346 bzero(&mc, sizeof(mc)); 347 mc.mc_ownedfp = _MC_FPOWNED_FPU; 348 mc.mc_fpformat = _MC_FPFMT_XMM; 349 350 if ((uc->uc_flags & LINUX_UC_FP_XSTATE) != 0) 351 return (linux_xrstor(td, &mc, &uc->uc_mcontext)); 352 else 353 return (linux_fxrstor(td, &mc, &uc->uc_mcontext)); 354 } 355 356 /* 357 * Copied from amd64/amd64/machdep.c 358 */ 359 int 360 linux_rt_sigreturn(struct thread *td, struct linux_rt_sigreturn_args *args) 361 { 362 struct proc *p; 363 struct l_rt_sigframe sf; 364 struct l_sigcontext *context; 365 struct trapframe *regs; 366 unsigned long rflags; 367 sigset_t bmask; 368 int error; 369 ksiginfo_t ksi; 370 371 regs = td->td_frame; 372 error = copyin((void *)regs->tf_rbx, &sf, sizeof(sf)); 373 if (error != 0) 374 return (error); 375 376 p = td->td_proc; 377 context = &sf.sf_uc.uc_mcontext; 378 rflags = context->sc_rflags; 379 380 /* 381 * Don't allow users to change privileged or reserved flags. 382 */ 383 /* 384 * XXX do allow users to change the privileged flag PSL_RF. 385 * The cpu sets PSL_RF in tf_rflags for faults. Debuggers 386 * should sometimes set it there too. tf_rflags is kept in 387 * the signal context during signal handling and there is no 388 * other place to remember it, so the PSL_RF bit may be 389 * corrupted by the signal handler without us knowing. 390 * Corruption of the PSL_RF bit at worst causes one more or 391 * one less debugger trap, so allowing it is fairly harmless. 392 */ 393 if (!EFL_SECURE(rflags & ~PSL_RF, regs->tf_rflags & ~PSL_RF)) { 394 uprintf("pid %d comm %s linux mangled rflags %#lx\n", 395 p->p_pid, p->p_comm, rflags); 396 return (EINVAL); 397 } 398 399 /* 400 * Don't allow users to load a valid privileged %cs. Let the 401 * hardware check for invalid selectors, excess privilege in 402 * other selectors, invalid %eip's and invalid %esp's. 403 */ 404 if (!CS_SECURE(context->sc_cs)) { 405 uprintf("pid %d comm %s linux mangled cs %#x\n", 406 p->p_pid, p->p_comm, context->sc_cs); 407 ksiginfo_init_trap(&ksi); 408 ksi.ksi_signo = SIGBUS; 409 ksi.ksi_code = BUS_OBJERR; 410 ksi.ksi_trapno = T_PROTFLT; 411 ksi.ksi_addr = (void *)regs->tf_rip; 412 trapsignal(td, &ksi); 413 return (EINVAL); 414 } 415 416 linux_to_bsd_sigset(&sf.sf_uc.uc_sigmask, &bmask); 417 kern_sigprocmask(td, SIG_SETMASK, &bmask, NULL, 0); 418 419 regs->tf_rdi = context->sc_rdi; 420 regs->tf_rsi = context->sc_rsi; 421 regs->tf_rdx = context->sc_rdx; 422 regs->tf_rbp = context->sc_rbp; 423 regs->tf_rbx = context->sc_rbx; 424 regs->tf_rcx = context->sc_rcx; 425 regs->tf_rax = context->sc_rax; 426 regs->tf_rip = context->sc_rip; 427 regs->tf_rsp = context->sc_rsp; 428 regs->tf_r8 = context->sc_r8; 429 regs->tf_r9 = context->sc_r9; 430 regs->tf_r10 = context->sc_r10; 431 regs->tf_r11 = context->sc_r11; 432 regs->tf_r12 = context->sc_r12; 433 regs->tf_r13 = context->sc_r13; 434 regs->tf_r14 = context->sc_r14; 435 regs->tf_r15 = context->sc_r15; 436 regs->tf_cs = context->sc_cs; 437 regs->tf_err = context->sc_err; 438 regs->tf_rflags = rflags; 439 440 error = linux_copyin_fpstate(td, &sf.sf_uc); 441 if (error != 0) { 442 uprintf("pid %d comm %s linux can't restore fpu state %d\n", 443 p->p_pid, p->p_comm, error); 444 return (error); 445 } 446 447 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 448 return (EJUSTRETURN); 449 } 450 451 static int 452 linux_fxsave(mcontext_t *mcp, void *ufp) 453 { 454 struct l_fpstate *fx = (struct l_fpstate *)&mcp->mc_fpstate[0]; 455 456 bzero(&fx->reserved2[0], sizeof(fx->reserved2)); 457 return (copyout(fx, ufp, sizeof(*fx))); 458 } 459 460 static int 461 linux_xsave(mcontext_t *mcp, char *xfpusave, char *ufp) 462 { 463 struct l_fpstate *fx = (struct l_fpstate *)&mcp->mc_fpstate[0]; 464 uint32_t magic2; 465 int error; 466 467 /* Legacy region of an xsave area. */ 468 fx->sw_reserved.magic1 = LINUX_FP_XSTATE_MAGIC1; 469 fx->sw_reserved.xstate_size = mcp->mc_xfpustate_len + sizeof(*fx); 470 fx->sw_reserved.extended_size = fx->sw_reserved.xstate_size + 471 LINUX_FP_XSTATE_MAGIC2_SIZE; 472 fx->sw_reserved.xfeatures = xsave_mask; 473 474 error = copyout(fx, ufp, sizeof(*fx)); 475 if (error != 0) 476 return (error); 477 ufp += sizeof(*fx); 478 479 /* Extended region of an xsave area. */ 480 error = copyout(xfpusave, ufp, mcp->mc_xfpustate_len); 481 if (error != 0) 482 return (error); 483 484 /* Linux specific end of xsave area marker. */ 485 ufp += mcp->mc_xfpustate_len; 486 magic2 = LINUX_FP_XSTATE_MAGIC2; 487 return (copyout(&magic2, ufp, LINUX_FP_XSTATE_MAGIC2_SIZE)); 488 } 489 490 static int 491 linux_copyout_fpstate(struct thread *td, struct l_ucontext *uc, char **sp) 492 { 493 size_t xfpusave_len; 494 char *xfpusave; 495 mcontext_t mc; 496 char *ufp = *sp; 497 498 get_fpcontext(td, &mc, &xfpusave, &xfpusave_len); 499 KASSERT(mc.mc_fpformat != _MC_FPFMT_NODEV, ("fpu not present")); 500 501 /* Room for fxsave area. */ 502 ufp -= sizeof(struct l_fpstate); 503 if (xfpusave != NULL) { 504 /* Room for xsave area. */ 505 ufp -= (xfpusave_len + LINUX_FP_XSTATE_MAGIC2_SIZE); 506 uc->uc_flags |= LINUX_UC_FP_XSTATE; 507 } 508 *sp = ufp = (char *)((unsigned long)ufp & ~0x3Ful); 509 510 if (xfpusave != NULL) 511 return (linux_xsave(&mc, xfpusave, ufp)); 512 else 513 return (linux_fxsave(&mc, ufp)); 514 } 515 516 /* 517 * copied from amd64/amd64/machdep.c 518 * 519 * Send an interrupt to process. 520 */ 521 static void 522 linux_rt_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask) 523 { 524 struct l_rt_sigframe sf, *sfp; 525 struct proc *p; 526 struct thread *td; 527 struct sigacts *psp; 528 char *sp; 529 struct trapframe *regs; 530 int sig, code; 531 int oonstack, issiginfo; 532 533 td = curthread; 534 p = td->td_proc; 535 PROC_LOCK_ASSERT(p, MA_OWNED); 536 sig = linux_translate_traps(ksi->ksi_signo, ksi->ksi_trapno); 537 psp = p->p_sigacts; 538 issiginfo = SIGISMEMBER(psp->ps_siginfo, sig); 539 code = ksi->ksi_code; 540 mtx_assert(&psp->ps_mtx, MA_OWNED); 541 regs = td->td_frame; 542 oonstack = sigonstack(regs->tf_rsp); 543 544 LINUX_CTR4(rt_sendsig, "%p, %d, %p, %u", 545 catcher, sig, mask, code); 546 547 bzero(&sf, sizeof(sf)); 548 sf.sf_uc.uc_stack.ss_sp = PTROUT(td->td_sigstk.ss_sp); 549 sf.sf_uc.uc_stack.ss_size = td->td_sigstk.ss_size; 550 sf.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK) 551 ? ((oonstack) ? LINUX_SS_ONSTACK : 0) : LINUX_SS_DISABLE; 552 553 /* Allocate space for the signal handler context. */ 554 if ((td->td_pflags & TDP_ALTSTACK) != 0 && !oonstack && 555 SIGISMEMBER(psp->ps_sigonstack, sig)) { 556 sp = (char *)td->td_sigstk.ss_sp + td->td_sigstk.ss_size; 557 } else 558 sp = (char *)regs->tf_rsp - 128; 559 560 mtx_unlock(&psp->ps_mtx); 561 PROC_UNLOCK(p); 562 563 if (linux_copyout_fpstate(td, &sf.sf_uc, &sp) != 0) { 564 uprintf("pid %d comm %s linux can't save fpu state, killing\n", 565 p->p_pid, p->p_comm); 566 PROC_LOCK(p); 567 sigexit(td, SIGILL); 568 } 569 sf.sf_uc.uc_mcontext.sc_fpstate = (register_t)sp; 570 571 /* Make room, keeping the stack aligned. */ 572 sp -= sizeof(struct l_rt_sigframe); 573 sfp = (struct l_rt_sigframe *)((unsigned long)sp & ~0xFul); 574 575 /* Save user context. */ 576 bsd_to_linux_sigset(mask, &sf.sf_uc.uc_sigmask); 577 sf.sf_uc.uc_mcontext.sc_mask = sf.sf_uc.uc_sigmask; 578 sf.sf_uc.uc_mcontext.sc_rdi = regs->tf_rdi; 579 sf.sf_uc.uc_mcontext.sc_rsi = regs->tf_rsi; 580 sf.sf_uc.uc_mcontext.sc_rdx = regs->tf_rdx; 581 sf.sf_uc.uc_mcontext.sc_rbp = regs->tf_rbp; 582 sf.sf_uc.uc_mcontext.sc_rbx = regs->tf_rbx; 583 sf.sf_uc.uc_mcontext.sc_rcx = regs->tf_rcx; 584 sf.sf_uc.uc_mcontext.sc_rax = regs->tf_rax; 585 sf.sf_uc.uc_mcontext.sc_rip = regs->tf_rip; 586 sf.sf_uc.uc_mcontext.sc_rsp = regs->tf_rsp; 587 sf.sf_uc.uc_mcontext.sc_r8 = regs->tf_r8; 588 sf.sf_uc.uc_mcontext.sc_r9 = regs->tf_r9; 589 sf.sf_uc.uc_mcontext.sc_r10 = regs->tf_r10; 590 sf.sf_uc.uc_mcontext.sc_r11 = regs->tf_r11; 591 sf.sf_uc.uc_mcontext.sc_r12 = regs->tf_r12; 592 sf.sf_uc.uc_mcontext.sc_r13 = regs->tf_r13; 593 sf.sf_uc.uc_mcontext.sc_r14 = regs->tf_r14; 594 sf.sf_uc.uc_mcontext.sc_r15 = regs->tf_r15; 595 sf.sf_uc.uc_mcontext.sc_cs = regs->tf_cs; 596 sf.sf_uc.uc_mcontext.sc_rflags = regs->tf_rflags; 597 sf.sf_uc.uc_mcontext.sc_err = regs->tf_err; 598 sf.sf_uc.uc_mcontext.sc_trapno = bsd_to_linux_trapcode(code); 599 sf.sf_uc.uc_mcontext.sc_cr2 = (register_t)ksi->ksi_addr; 600 601 /* Translate the signal. */ 602 sig = bsd_to_linux_signal(sig); 603 /* Fill in POSIX parts. */ 604 siginfo_to_lsiginfo(&ksi->ksi_info, &sf.sf_si, sig); 605 606 /* Copy the sigframe out to the user's stack. */ 607 if (copyout(&sf, sfp, sizeof(*sfp)) != 0) { 608 uprintf("pid %d comm %s has trashed its stack, killing\n", 609 p->p_pid, p->p_comm); 610 PROC_LOCK(p); 611 sigexit(td, SIGILL); 612 } 613 614 fpstate_drop(td); 615 /* Build the argument list for the signal handler. */ 616 regs->tf_rdi = sig; /* arg 1 in %rdi */ 617 regs->tf_rax = 0; 618 if (issiginfo) { 619 regs->tf_rsi = (register_t)&sfp->sf_si; /* arg 2 in %rsi */ 620 regs->tf_rdx = (register_t)&sfp->sf_uc; /* arg 3 in %rdx */ 621 } else { 622 regs->tf_rsi = 0; 623 regs->tf_rdx = 0; 624 } 625 regs->tf_rcx = (register_t)catcher; 626 regs->tf_rsp = (long)sfp; 627 regs->tf_rip = linux_rt_sigcode; 628 regs->tf_rflags &= ~(PSL_T | PSL_D); 629 regs->tf_cs = _ucodesel; 630 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 631 PROC_LOCK(p); 632 mtx_lock(&psp->ps_mtx); 633 } 634 635 #define LINUX_VSYSCALL_START (-10UL << 20) 636 #define LINUX_VSYSCALL_SZ 1024 637 638 const unsigned long linux_vsyscall_vector[] = { 639 LINUX_SYS_gettimeofday, 640 LINUX_SYS_linux_time, 641 LINUX_SYS_linux_getcpu, 642 }; 643 644 static int 645 linux_vsyscall(struct thread *td) 646 { 647 struct trapframe *frame; 648 uint64_t retqaddr; 649 int code, traced; 650 int error; 651 652 frame = td->td_frame; 653 654 /* Check %rip for vsyscall area. */ 655 if (__predict_true(frame->tf_rip < LINUX_VSYSCALL_START)) 656 return (EINVAL); 657 if ((frame->tf_rip & (LINUX_VSYSCALL_SZ - 1)) != 0) 658 return (EINVAL); 659 code = (frame->tf_rip - LINUX_VSYSCALL_START) / LINUX_VSYSCALL_SZ; 660 if (code >= nitems(linux_vsyscall_vector)) 661 return (EINVAL); 662 663 /* 664 * vsyscall called as callq *(%rax), so we must 665 * use return address from %rsp and also fixup %rsp. 666 */ 667 error = copyin((void *)frame->tf_rsp, &retqaddr, sizeof(retqaddr)); 668 if (error) 669 return (error); 670 671 frame->tf_rip = retqaddr; 672 frame->tf_rax = linux_vsyscall_vector[code]; 673 frame->tf_rsp += 8; 674 675 traced = (frame->tf_flags & PSL_T); 676 677 amd64_syscall(td, traced); 678 679 return (0); 680 } 681 682 struct sysentvec elf_linux_sysvec = { 683 .sv_size = LINUX_SYS_MAXSYSCALL, 684 .sv_table = linux_sysent, 685 .sv_fixup = __elfN(freebsd_fixup), 686 .sv_sendsig = linux_rt_sendsig, 687 .sv_sigcode = &_binary_linux_vdso_so_o_start, 688 .sv_szsigcode = &linux_szsigcode, 689 .sv_name = "Linux ELF64", 690 .sv_coredump = elf64_coredump, 691 .sv_elf_core_osabi = ELFOSABI_NONE, 692 .sv_elf_core_abi_vendor = LINUX_ABI_VENDOR, 693 .sv_elf_core_prepare_notes = linux64_prepare_notes, 694 .sv_minsigstksz = LINUX_MINSIGSTKSZ, 695 .sv_minuser = VM_MIN_ADDRESS, 696 .sv_maxuser = VM_MAXUSER_ADDRESS_LA48, 697 .sv_usrstack = LINUX_USRSTACK_LA48, 698 .sv_psstrings = LINUX_PS_STRINGS_LA48, 699 .sv_psstringssz = sizeof(struct ps_strings), 700 .sv_stackprot = VM_PROT_ALL, 701 .sv_copyout_auxargs = __linuxN(copyout_auxargs), 702 .sv_copyout_strings = __linuxN(copyout_strings), 703 .sv_setregs = linux_exec_setregs, 704 .sv_fixlimit = NULL, 705 .sv_maxssiz = NULL, 706 .sv_flags = SV_ABI_LINUX | SV_LP64 | SV_SHP | SV_SIG_DISCIGN | 707 SV_SIG_WAITNDQ | SV_TIMEKEEP, 708 .sv_set_syscall_retval = linux_set_syscall_retval, 709 .sv_fetch_syscall_args = linux_fetch_syscall_args, 710 .sv_syscallnames = linux_syscallnames, 711 .sv_shared_page_base = LINUX_SHAREDPAGE_LA48, 712 .sv_shared_page_len = PAGE_SIZE, 713 .sv_schedtail = linux_schedtail, 714 .sv_thread_detach = linux_thread_detach, 715 .sv_trap = linux_vsyscall, 716 .sv_hwcap = NULL, 717 .sv_hwcap2 = NULL, 718 .sv_hwcap3 = NULL, 719 .sv_hwcap4 = NULL, 720 .sv_onexec = linux_on_exec_vmspace, 721 .sv_onexit = linux_on_exit, 722 .sv_ontdexit = linux_thread_dtor, 723 .sv_setid_allowed = &linux_setid_allowed_query, 724 .sv_set_fork_retval = linux_set_fork_retval, 725 }; 726 727 static int 728 linux_on_exec_vmspace(struct proc *p, struct image_params *imgp) 729 { 730 int error; 731 732 error = linux_map_vdso(p, linux_vdso_obj, linux_vdso_base, 733 LINUX_VDSOPAGE_SIZE, imgp); 734 if (error == 0) 735 error = linux_on_exec(p, imgp); 736 return (error); 737 } 738 739 /* 740 * linux_vdso_install() and linux_exec_sysvec_init() must be called 741 * after exec_sysvec_init() which is SI_SUB_EXEC (SI_ORDER_ANY). 742 */ 743 static void 744 linux_exec_sysvec_init(void *param) 745 { 746 l_uintptr_t *ktimekeep_base, *ktsc_selector; 747 struct sysentvec *sv; 748 ptrdiff_t tkoff; 749 750 sv = param; 751 amd64_lower_shared_page(sv); 752 /* Fill timekeep_base */ 753 exec_sysvec_init(sv); 754 755 tkoff = kern_timekeep_base - linux_vdso_base; 756 ktimekeep_base = (l_uintptr_t *)(linux_vdso_mapping + tkoff); 757 *ktimekeep_base = sv->sv_shared_page_base + sv->sv_timekeep_offset; 758 759 tkoff = kern_tsc_selector - linux_vdso_base; 760 ktsc_selector = (l_uintptr_t *)(linux_vdso_mapping + tkoff); 761 *ktsc_selector = linux_vdso_tsc_selector_idx(); 762 if (bootverbose) 763 printf("Linux x86-64 vDSO tsc_selector: %lu\n", *ktsc_selector); 764 765 tkoff = kern_cpu_selector - linux_vdso_base; 766 ktsc_selector = (l_uintptr_t *)(linux_vdso_mapping + tkoff); 767 *ktsc_selector = linux_vdso_cpu_selector_idx(); 768 if (bootverbose) 769 printf("Linux x86-64 vDSO cpu_selector: %lu\n", *ktsc_selector); 770 } 771 SYSINIT(elf_linux_exec_sysvec_init, SI_SUB_EXEC + 1, SI_ORDER_ANY, 772 linux_exec_sysvec_init, &elf_linux_sysvec); 773 774 static void 775 linux_vdso_install(const void *param) 776 { 777 char *vdso_start = &_binary_linux_vdso_so_o_start; 778 char *vdso_end = &_binary_linux_vdso_so_o_end; 779 780 linux_szsigcode = vdso_end - vdso_start; 781 MPASS(linux_szsigcode <= LINUX_VDSOPAGE_SIZE); 782 783 linux_vdso_base = LINUX_VDSOPAGE_LA48; 784 if (hw_lower_amd64_sharedpage != 0) 785 linux_vdso_base -= PAGE_SIZE; 786 787 __elfN(linux_vdso_fixup)(vdso_start, linux_vdso_base); 788 789 linux_vdso_obj = __elfN(linux_shared_page_init) 790 (&linux_vdso_mapping, LINUX_VDSOPAGE_SIZE); 791 bcopy(vdso_start, linux_vdso_mapping, linux_szsigcode); 792 793 linux_vdso_reloc(linux_vdso_mapping, linux_vdso_base); 794 } 795 SYSINIT(elf_linux_vdso_init, SI_SUB_EXEC + 1, SI_ORDER_FIRST, 796 linux_vdso_install, NULL); 797 798 static void 799 linux_vdso_deinstall(const void *param) 800 { 801 802 __elfN(linux_shared_page_fini)(linux_vdso_obj, 803 linux_vdso_mapping, LINUX_VDSOPAGE_SIZE); 804 } 805 SYSUNINIT(elf_linux_vdso_uninit, SI_SUB_EXEC, SI_ORDER_FIRST, 806 linux_vdso_deinstall, NULL); 807 808 static void 809 linux_vdso_reloc(char *mapping, Elf_Addr offset) 810 { 811 const Elf_Ehdr *ehdr; 812 const Elf_Shdr *shdr; 813 Elf64_Addr *where, val; 814 Elf_Size rtype, symidx; 815 const Elf_Rela *rela; 816 Elf_Addr addr, addend; 817 int relacnt; 818 int i, j; 819 820 MPASS(offset != 0); 821 822 relacnt = 0; 823 ehdr = (const Elf_Ehdr *)mapping; 824 shdr = (const Elf_Shdr *)(mapping + ehdr->e_shoff); 825 for (i = 0; i < ehdr->e_shnum; i++) 826 { 827 switch (shdr[i].sh_type) { 828 case SHT_REL: 829 printf("Linux x86_64 vDSO: unexpected Rel section\n"); 830 break; 831 case SHT_RELA: 832 rela = (const Elf_Rela *)(mapping + shdr[i].sh_offset); 833 relacnt = shdr[i].sh_size / sizeof(*rela); 834 } 835 } 836 837 for (j = 0; j < relacnt; j++, rela++) { 838 where = (Elf_Addr *)(mapping + rela->r_offset); 839 addend = rela->r_addend; 840 rtype = ELF_R_TYPE(rela->r_info); 841 symidx = ELF_R_SYM(rela->r_info); 842 843 switch (rtype) { 844 case R_X86_64_NONE: /* none */ 845 break; 846 847 case R_X86_64_RELATIVE: /* B + A */ 848 addr = (Elf_Addr)(offset + addend); 849 val = addr; 850 if (*where != val) 851 *where = val; 852 break; 853 case R_X86_64_IRELATIVE: 854 printf("Linux x86_64 vDSO: unexpected ifunc relocation, " 855 "symbol index %ld\n", symidx); 856 break; 857 default: 858 printf("Linux x86_64 vDSO: unexpected relocation type %ld, " 859 "symbol index %ld\n", rtype, symidx); 860 } 861 } 862 } 863 864 static const Elf_Brandnote linux64_brandnote = { 865 .hdr.n_namesz = sizeof(GNU_ABI_VENDOR), 866 .hdr.n_descsz = 16, 867 .hdr.n_type = 1, 868 .vendor = GNU_ABI_VENDOR, 869 .flags = BN_TRANSLATE_OSREL, 870 .trans_osrel = linux_trans_osrel 871 }; 872 873 static const Elf64_Brandinfo linux_glibc2brand = { 874 .brand = ELFOSABI_LINUX, 875 .machine = EM_X86_64, 876 .compat_3_brand = "Linux", 877 .interp_path = "/lib64/ld-linux-x86-64.so.2", 878 .sysvec = &elf_linux_sysvec, 879 .interp_newpath = NULL, 880 .brand_note = &linux64_brandnote, 881 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 882 }; 883 884 static const Elf64_Brandinfo linux_glibc2brandshort = { 885 .brand = ELFOSABI_LINUX, 886 .machine = EM_X86_64, 887 .compat_3_brand = "Linux", 888 .interp_path = "/lib64/ld-linux.so.2", 889 .sysvec = &elf_linux_sysvec, 890 .interp_newpath = NULL, 891 .brand_note = &linux64_brandnote, 892 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 893 }; 894 895 static const Elf64_Brandinfo linux_muslbrand = { 896 .brand = ELFOSABI_LINUX, 897 .machine = EM_X86_64, 898 .compat_3_brand = "Linux", 899 .interp_path = "/lib/ld-musl-x86_64.so.1", 900 .sysvec = &elf_linux_sysvec, 901 .interp_newpath = NULL, 902 .brand_note = &linux64_brandnote, 903 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE | 904 LINUX_BI_FUTEX_REQUEUE 905 }; 906 907 static const Elf64_Brandinfo *linux_brandlist[] = { 908 &linux_glibc2brand, 909 &linux_glibc2brandshort, 910 &linux_muslbrand, 911 NULL 912 }; 913 914 static int 915 linux64_elf_modevent(module_t mod, int type, void *data) 916 { 917 const Elf64_Brandinfo **brandinfo; 918 int error; 919 struct linux_ioctl_handler **lihp; 920 921 error = 0; 922 923 switch(type) { 924 case MOD_LOAD: 925 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL; 926 ++brandinfo) 927 if (elf64_insert_brand_entry(*brandinfo) < 0) 928 error = EINVAL; 929 if (error == 0) { 930 SET_FOREACH(lihp, linux_ioctl_handler_set) 931 linux_ioctl_register_handler(*lihp); 932 stclohz = (stathz ? stathz : hz); 933 if (bootverbose) 934 printf("Linux x86-64 ELF exec handler installed\n"); 935 } else 936 printf("cannot insert Linux x86-64 ELF brand handler\n"); 937 break; 938 case MOD_UNLOAD: 939 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL; 940 ++brandinfo) 941 if (elf64_brand_inuse(*brandinfo)) 942 error = EBUSY; 943 if (error == 0) { 944 for (brandinfo = &linux_brandlist[0]; 945 *brandinfo != NULL; ++brandinfo) 946 if (elf64_remove_brand_entry(*brandinfo) < 0) 947 error = EINVAL; 948 } 949 if (error == 0) { 950 SET_FOREACH(lihp, linux_ioctl_handler_set) 951 linux_ioctl_unregister_handler(*lihp); 952 if (bootverbose) 953 printf("Linux x86_64 ELF exec handler removed\n"); 954 } else 955 printf("Could not deinstall Linux x86_64 ELF interpreter entry\n"); 956 break; 957 default: 958 return (EOPNOTSUPP); 959 } 960 return (error); 961 } 962 963 static moduledata_t linux64_elf_mod = { 964 "linux64elf", 965 linux64_elf_modevent, 966 0 967 }; 968 969 DECLARE_MODULE_TIED(linux64elf, linux64_elf_mod, SI_SUB_EXEC, SI_ORDER_ANY); 970 MODULE_DEPEND(linux64elf, linux_common, 1, 1, 1); 971 FEATURE(linux64, "Linux 64bit support"); 972