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/malloc.h> 44 #include <sys/module.h> 45 #include <sys/mutex.h> 46 #include <sys/proc.h> 47 #include <sys/stddef.h> 48 #include <sys/syscallsubr.h> 49 #include <sys/sysctl.h> 50 #include <sys/sysent.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/md_var.h> 59 #include <machine/pcb.h> 60 #include <machine/specialreg.h> 61 #include <machine/trap.h> 62 63 #include <x86/linux/linux_x86.h> 64 #include <amd64/linux/linux.h> 65 #include <amd64/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_sysproto.h> 74 #include <compat/linux/linux_util.h> 75 #include <compat/linux/linux_vdso.h> 76 77 #include <x86/linux/linux_x86_sigframe.h> 78 79 _Static_assert(sizeof(struct l_fpstate) == 80 sizeof(__typeof(((mcontext_t *)0)->mc_fpstate)), 81 "fxsave area size incorrect"); 82 83 MODULE_VERSION(linux64, 1); 84 85 #define LINUX_VDSOPAGE_SIZE PAGE_SIZE * 2 86 #define LINUX_VDSOPAGE_LA48 (VM_MAXUSER_ADDRESS_LA48 - \ 87 LINUX_VDSOPAGE_SIZE) 88 #define LINUX_SHAREDPAGE_LA48 (LINUX_VDSOPAGE_LA48 - PAGE_SIZE) 89 /* 90 * PAGE_SIZE - the size 91 * of the native SHAREDPAGE 92 */ 93 #define LINUX_USRSTACK_LA48 LINUX_SHAREDPAGE_LA48 94 #define LINUX_PS_STRINGS_LA48 (LINUX_USRSTACK_LA48 - \ 95 sizeof(struct ps_strings)) 96 97 static int linux_szsigcode; 98 static vm_object_t linux_vdso_obj; 99 static char *linux_vdso_mapping; 100 extern char _binary_linux_vdso_so_o_start; 101 extern char _binary_linux_vdso_so_o_end; 102 static vm_offset_t linux_vdso_base; 103 104 extern struct sysent linux_sysent[LINUX_SYS_MAXSYSCALL]; 105 extern const char *linux_syscallnames[]; 106 107 SET_DECLARE(linux_ioctl_handler_set, struct linux_ioctl_handler); 108 109 static void linux_vdso_install(const void *param); 110 static void linux_vdso_deinstall(const void *param); 111 static void linux_vdso_reloc(char *mapping, Elf_Addr offset); 112 static void linux_set_syscall_retval(struct thread *td, int error); 113 static int linux_fetch_syscall_args(struct thread *td); 114 static void linux_exec_setregs(struct thread *td, struct image_params *imgp, 115 uintptr_t stack); 116 static void linux_exec_sysvec_init(void *param); 117 static int linux_on_exec_vmspace(struct proc *p, 118 struct image_params *imgp); 119 static void linux_set_fork_retval(struct thread *td); 120 static int linux_vsyscall(struct thread *td); 121 122 LINUX_VDSO_SYM_INTPTR(linux_rt_sigcode); 123 LINUX_VDSO_SYM_CHAR(linux_platform); 124 LINUX_VDSO_SYM_INTPTR(kern_timekeep_base); 125 LINUX_VDSO_SYM_INTPTR(kern_tsc_selector); 126 LINUX_VDSO_SYM_INTPTR(kern_cpu_selector); 127 128 /* 129 * According to the Intel x86 ISA 64-bit syscall 130 * saves %rip to %rcx and rflags to %r11. Registers on syscall entry: 131 * %rax system call number 132 * %rcx return address 133 * %r11 saved rflags 134 * %rdi arg1 135 * %rsi arg2 136 * %rdx arg3 137 * %r10 arg4 138 * %r8 arg5 139 * %r9 arg6 140 * 141 * Then FreeBSD fast_syscall() move registers: 142 * %rcx -> trapframe.tf_rip 143 * %r10 -> trapframe.tf_rcx 144 */ 145 static int 146 linux_fetch_syscall_args(struct thread *td) 147 { 148 struct proc *p; 149 struct trapframe *frame; 150 struct syscall_args *sa; 151 152 p = td->td_proc; 153 frame = td->td_frame; 154 sa = &td->td_sa; 155 156 sa->args[0] = frame->tf_rdi; 157 sa->args[1] = frame->tf_rsi; 158 sa->args[2] = frame->tf_rdx; 159 sa->args[3] = frame->tf_rcx; 160 sa->args[4] = frame->tf_r8; 161 sa->args[5] = frame->tf_r9; 162 sa->code = frame->tf_rax; 163 sa->original_code = sa->code; 164 165 if (sa->code >= p->p_sysent->sv_size) 166 /* nosys */ 167 sa->callp = &p->p_sysent->sv_table[p->p_sysent->sv_size - 1]; 168 else 169 sa->callp = &p->p_sysent->sv_table[sa->code]; 170 171 /* Restore r10 earlier to avoid doing this multiply times. */ 172 frame->tf_r10 = frame->tf_rcx; 173 /* Restore %rcx for machine context. */ 174 frame->tf_rcx = frame->tf_rip; 175 176 td->td_retval[0] = 0; 177 return (0); 178 } 179 180 static void 181 linux_set_syscall_retval(struct thread *td, int error) 182 { 183 struct trapframe *frame; 184 185 frame = td->td_frame; 186 187 switch (error) { 188 case 0: 189 frame->tf_rax = td->td_retval[0]; 190 break; 191 192 case ERESTART: 193 /* 194 * Reconstruct pc, we know that 'syscall' is 2 bytes, 195 * lcall $X,y is 7 bytes, int 0x80 is 2 bytes. 196 * We saved this in tf_err. 197 * 198 */ 199 frame->tf_rip -= frame->tf_err; 200 break; 201 202 case EJUSTRETURN: 203 break; 204 205 default: 206 frame->tf_rax = bsd_to_linux_errno(error); 207 break; 208 } 209 210 /* 211 * Differently from FreeBSD native ABI, on Linux only %rcx 212 * and %r11 values are not preserved across the syscall. 213 * Require full context restore to get all registers except 214 * those two restored at return to usermode. 215 */ 216 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 217 } 218 219 static void 220 linux_set_fork_retval(struct thread *td) 221 { 222 struct trapframe *frame = td->td_frame; 223 224 frame->tf_rax = 0; 225 } 226 227 void 228 linux64_arch_copyout_auxargs(struct image_params *imgp, Elf_Auxinfo **pos) 229 { 230 231 AUXARGS_ENTRY((*pos), LINUX_AT_SYSINFO_EHDR, linux_vdso_base); 232 AUXARGS_ENTRY((*pos), LINUX_AT_HWCAP, cpu_feature); 233 AUXARGS_ENTRY((*pos), LINUX_AT_HWCAP2, linux_x86_elf_hwcap2()); 234 AUXARGS_ENTRY((*pos), LINUX_AT_PLATFORM, PTROUT(linux_platform)); 235 } 236 237 /* 238 * Reset registers to default values on exec. 239 */ 240 static void 241 linux_exec_setregs(struct thread *td, struct image_params *imgp, 242 uintptr_t stack) 243 { 244 struct trapframe *regs; 245 struct pcb *pcb; 246 register_t saved_rflags; 247 248 regs = td->td_frame; 249 pcb = td->td_pcb; 250 251 if (td->td_proc->p_md.md_ldt != NULL) 252 user_ldt_free(td); 253 254 pcb->pcb_fsbase = 0; 255 pcb->pcb_gsbase = 0; 256 clear_pcb_flags(pcb, PCB_32BIT); 257 pcb->pcb_initial_fpucw = __LINUX_NPXCW__; 258 set_pcb_flags(pcb, PCB_FULL_IRET); 259 260 saved_rflags = regs->tf_rflags & PSL_T; 261 bzero((char *)regs, sizeof(struct trapframe)); 262 regs->tf_rip = imgp->entry_addr; 263 regs->tf_rsp = stack; 264 regs->tf_rflags = PSL_USER | saved_rflags; 265 regs->tf_ss = _udatasel; 266 regs->tf_cs = _ucodesel; 267 regs->tf_ds = _udatasel; 268 regs->tf_es = _udatasel; 269 regs->tf_fs = _ufssel; 270 regs->tf_gs = _ugssel; 271 regs->tf_flags = TF_HASSEGS; 272 273 x86_clear_dbregs(pcb); 274 275 /* 276 * Drop the FP state if we hold it, so that the process gets a 277 * clean FP state if it uses the FPU again. 278 */ 279 fpstate_drop(td); 280 } 281 282 static int 283 linux_fxrstor(struct thread *td, mcontext_t *mcp, struct l_sigcontext *sc) 284 { 285 struct savefpu *fp = (struct savefpu *)&mcp->mc_fpstate[0]; 286 int error; 287 288 error = copyin(PTRIN(sc->sc_fpstate), fp, sizeof(mcp->mc_fpstate)); 289 if (error != 0) 290 return (error); 291 bzero(&fp->sv_pad[0], sizeof(fp->sv_pad)); 292 return (set_fpcontext(td, mcp, NULL, 0)); 293 } 294 295 static int 296 linux_xrstor(struct thread *td, mcontext_t *mcp, struct l_sigcontext *sc) 297 { 298 struct savefpu *fp = (struct savefpu *)&mcp->mc_fpstate[0]; 299 char *xfpustate; 300 struct proc *p; 301 uint32_t magic2; 302 int error; 303 304 p = td->td_proc; 305 mcp->mc_xfpustate_len = cpu_max_ext_state_size - sizeof(struct savefpu); 306 307 /* Legacy region of an xsave area. */ 308 error = copyin(PTRIN(sc->sc_fpstate), fp, sizeof(mcp->mc_fpstate)); 309 if (error != 0) 310 return (error); 311 bzero(&fp->sv_pad[0], sizeof(fp->sv_pad)); 312 313 /* Extended region of an xsave area. */ 314 sc->sc_fpstate += sizeof(mcp->mc_fpstate); 315 xfpustate = (char *)fpu_save_area_alloc(); 316 error = copyin(PTRIN(sc->sc_fpstate), xfpustate, mcp->mc_xfpustate_len); 317 if (error != 0) { 318 fpu_save_area_free((struct savefpu *)xfpustate); 319 uprintf("pid %d (%s): linux xrstor failed\n", p->p_pid, 320 td->td_name); 321 return (error); 322 } 323 324 /* Linux specific end of xsave area marker. */ 325 sc->sc_fpstate += mcp->mc_xfpustate_len; 326 error = copyin(PTRIN(sc->sc_fpstate), &magic2, LINUX_FP_XSTATE_MAGIC2_SIZE); 327 if (error != 0 || magic2 != LINUX_FP_XSTATE_MAGIC2) { 328 fpu_save_area_free((struct savefpu *)xfpustate); 329 uprintf("pid %d (%s): sigreturn magic2 0x%x error %d\n", 330 p->p_pid, td->td_name, magic2, error); 331 return (error); 332 } 333 334 error = set_fpcontext(td, mcp, xfpustate, mcp->mc_xfpustate_len); 335 fpu_save_area_free((struct savefpu *)xfpustate); 336 if (error != 0) { 337 uprintf("pid %d (%s): sigreturn set_fpcontext error %d\n", 338 p->p_pid, td->td_name, error); 339 } 340 return (error); 341 } 342 343 static int 344 linux_copyin_fpstate(struct thread *td, struct l_ucontext *uc) 345 { 346 mcontext_t mc; 347 348 bzero(&mc, sizeof(mc)); 349 mc.mc_ownedfp = _MC_FPOWNED_FPU; 350 mc.mc_fpformat = _MC_FPFMT_XMM; 351 352 if ((uc->uc_flags & LINUX_UC_FP_XSTATE) != 0) 353 return (linux_xrstor(td, &mc, &uc->uc_mcontext)); 354 else 355 return (linux_fxrstor(td, &mc, &uc->uc_mcontext)); 356 } 357 358 /* 359 * Copied from amd64/amd64/machdep.c 360 */ 361 int 362 linux_rt_sigreturn(struct thread *td, struct linux_rt_sigreturn_args *args) 363 { 364 struct proc *p; 365 struct l_rt_sigframe sf; 366 struct l_sigcontext *context; 367 struct trapframe *regs; 368 unsigned long rflags; 369 sigset_t bmask; 370 int error; 371 ksiginfo_t ksi; 372 373 regs = td->td_frame; 374 error = copyin((void *)regs->tf_rbx, &sf, sizeof(sf)); 375 if (error != 0) 376 return (error); 377 378 p = td->td_proc; 379 context = &sf.sf_uc.uc_mcontext; 380 rflags = context->sc_rflags; 381 382 /* 383 * Don't allow users to change privileged or reserved flags. 384 */ 385 /* 386 * XXX do allow users to change the privileged flag PSL_RF. 387 * The cpu sets PSL_RF in tf_rflags for faults. Debuggers 388 * should sometimes set it there too. tf_rflags is kept in 389 * the signal context during signal handling and there is no 390 * other place to remember it, so the PSL_RF bit may be 391 * corrupted by the signal handler without us knowing. 392 * Corruption of the PSL_RF bit at worst causes one more or 393 * one less debugger trap, so allowing it is fairly harmless. 394 */ 395 if (!EFL_SECURE(rflags & ~PSL_RF, regs->tf_rflags & ~PSL_RF)) { 396 uprintf("pid %d comm %s linux mangled rflags %#lx\n", 397 p->p_pid, p->p_comm, rflags); 398 return (EINVAL); 399 } 400 401 /* 402 * Don't allow users to load a valid privileged %cs. Let the 403 * hardware check for invalid selectors, excess privilege in 404 * other selectors, invalid %eip's and invalid %esp's. 405 */ 406 if (!CS_SECURE(context->sc_cs)) { 407 uprintf("pid %d comm %s linux mangled cs %#x\n", 408 p->p_pid, p->p_comm, context->sc_cs); 409 ksiginfo_init_trap(&ksi); 410 ksi.ksi_signo = SIGBUS; 411 ksi.ksi_code = BUS_OBJERR; 412 ksi.ksi_trapno = T_PROTFLT; 413 ksi.ksi_addr = (void *)regs->tf_rip; 414 trapsignal(td, &ksi); 415 return (EINVAL); 416 } 417 418 linux_to_bsd_sigset(&sf.sf_uc.uc_sigmask, &bmask); 419 kern_sigprocmask(td, SIG_SETMASK, &bmask, NULL, 0); 420 421 regs->tf_rdi = context->sc_rdi; 422 regs->tf_rsi = context->sc_rsi; 423 regs->tf_rdx = context->sc_rdx; 424 regs->tf_rbp = context->sc_rbp; 425 regs->tf_rbx = context->sc_rbx; 426 regs->tf_rcx = context->sc_rcx; 427 regs->tf_rax = context->sc_rax; 428 regs->tf_rip = context->sc_rip; 429 regs->tf_rsp = context->sc_rsp; 430 regs->tf_r8 = context->sc_r8; 431 regs->tf_r9 = context->sc_r9; 432 regs->tf_r10 = context->sc_r10; 433 regs->tf_r11 = context->sc_r11; 434 regs->tf_r12 = context->sc_r12; 435 regs->tf_r13 = context->sc_r13; 436 regs->tf_r14 = context->sc_r14; 437 regs->tf_r15 = context->sc_r15; 438 regs->tf_cs = context->sc_cs; 439 regs->tf_err = context->sc_err; 440 regs->tf_rflags = rflags; 441 442 error = linux_copyin_fpstate(td, &sf.sf_uc); 443 if (error != 0) { 444 uprintf("pid %d comm %s linux can't restore fpu state %d\n", 445 p->p_pid, p->p_comm, error); 446 return (error); 447 } 448 449 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 450 return (EJUSTRETURN); 451 } 452 453 static int 454 linux_fxsave(mcontext_t *mcp, void *ufp) 455 { 456 struct l_fpstate *fx = (struct l_fpstate *)&mcp->mc_fpstate[0]; 457 458 bzero(&fx->reserved2[0], sizeof(fx->reserved2)); 459 return (copyout(fx, ufp, sizeof(*fx))); 460 } 461 462 static int 463 linux_xsave(mcontext_t *mcp, char *xfpusave, char *ufp) 464 { 465 struct l_fpstate *fx = (struct l_fpstate *)&mcp->mc_fpstate[0]; 466 uint32_t magic2; 467 int error; 468 469 /* Legacy region of an xsave area. */ 470 fx->sw_reserved.magic1 = LINUX_FP_XSTATE_MAGIC1; 471 fx->sw_reserved.xstate_size = mcp->mc_xfpustate_len + sizeof(*fx); 472 fx->sw_reserved.extended_size = fx->sw_reserved.xstate_size + 473 LINUX_FP_XSTATE_MAGIC2_SIZE; 474 fx->sw_reserved.xfeatures = xsave_mask; 475 476 error = copyout(fx, ufp, sizeof(*fx)); 477 if (error != 0) 478 return (error); 479 ufp += sizeof(*fx); 480 481 /* Extended region of an xsave area. */ 482 error = copyout(xfpusave, ufp, mcp->mc_xfpustate_len); 483 if (error != 0) 484 return (error); 485 486 /* Linux specific end of xsave area marker. */ 487 ufp += mcp->mc_xfpustate_len; 488 magic2 = LINUX_FP_XSTATE_MAGIC2; 489 return (copyout(&magic2, ufp, LINUX_FP_XSTATE_MAGIC2_SIZE)); 490 } 491 492 static int 493 linux_copyout_fpstate(struct thread *td, struct l_ucontext *uc, char **sp) 494 { 495 size_t xfpusave_len; 496 char *xfpusave; 497 mcontext_t mc; 498 char *ufp = *sp; 499 500 get_fpcontext(td, &mc, &xfpusave, &xfpusave_len); 501 KASSERT(mc.mc_fpformat != _MC_FPFMT_NODEV, ("fpu not present")); 502 503 /* Room for fxsave area. */ 504 ufp -= sizeof(struct l_fpstate); 505 if (xfpusave != NULL) { 506 /* Room for xsave area. */ 507 ufp -= (xfpusave_len + LINUX_FP_XSTATE_MAGIC2_SIZE); 508 uc->uc_flags |= LINUX_UC_FP_XSTATE; 509 } 510 *sp = ufp = (char *)((unsigned long)ufp & ~0x3Ful); 511 512 if (xfpusave != NULL) 513 return (linux_xsave(&mc, xfpusave, ufp)); 514 else 515 return (linux_fxsave(&mc, ufp)); 516 } 517 518 /* 519 * copied from amd64/amd64/machdep.c 520 * 521 * Send an interrupt to process. 522 */ 523 static void 524 linux_rt_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask) 525 { 526 struct l_rt_sigframe sf, *sfp; 527 struct proc *p; 528 struct thread *td; 529 struct sigacts *psp; 530 char *sp; 531 struct trapframe *regs; 532 int sig, code; 533 int oonstack, issiginfo; 534 535 td = curthread; 536 p = td->td_proc; 537 PROC_LOCK_ASSERT(p, MA_OWNED); 538 sig = linux_translate_traps(ksi->ksi_signo, ksi->ksi_trapno); 539 psp = p->p_sigacts; 540 issiginfo = SIGISMEMBER(psp->ps_siginfo, sig); 541 code = ksi->ksi_code; 542 mtx_assert(&psp->ps_mtx, MA_OWNED); 543 regs = td->td_frame; 544 oonstack = sigonstack(regs->tf_rsp); 545 546 LINUX_CTR4(rt_sendsig, "%p, %d, %p, %u", 547 catcher, sig, mask, code); 548 549 bzero(&sf, sizeof(sf)); 550 sf.sf_uc.uc_stack.ss_sp = PTROUT(td->td_sigstk.ss_sp); 551 sf.sf_uc.uc_stack.ss_size = td->td_sigstk.ss_size; 552 sf.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK) 553 ? ((oonstack) ? LINUX_SS_ONSTACK : 0) : LINUX_SS_DISABLE; 554 555 /* Allocate space for the signal handler context. */ 556 if ((td->td_pflags & TDP_ALTSTACK) != 0 && !oonstack && 557 SIGISMEMBER(psp->ps_sigonstack, sig)) { 558 sp = (char *)td->td_sigstk.ss_sp + td->td_sigstk.ss_size; 559 } else 560 sp = (char *)regs->tf_rsp - 128; 561 562 mtx_unlock(&psp->ps_mtx); 563 PROC_UNLOCK(p); 564 565 if (linux_copyout_fpstate(td, &sf.sf_uc, &sp) != 0) { 566 uprintf("pid %d comm %s linux can't save fpu state, killing\n", 567 p->p_pid, p->p_comm); 568 PROC_LOCK(p); 569 sigexit(td, SIGILL); 570 } 571 sf.sf_uc.uc_mcontext.sc_fpstate = (register_t)sp; 572 573 /* Make room, keeping the stack aligned. */ 574 sp -= sizeof(struct l_rt_sigframe); 575 sfp = (struct l_rt_sigframe *)((unsigned long)sp & ~0xFul); 576 577 /* Save user context. */ 578 bsd_to_linux_sigset(mask, &sf.sf_uc.uc_sigmask); 579 sf.sf_uc.uc_mcontext.sc_mask = sf.sf_uc.uc_sigmask; 580 sf.sf_uc.uc_mcontext.sc_rdi = regs->tf_rdi; 581 sf.sf_uc.uc_mcontext.sc_rsi = regs->tf_rsi; 582 sf.sf_uc.uc_mcontext.sc_rdx = regs->tf_rdx; 583 sf.sf_uc.uc_mcontext.sc_rbp = regs->tf_rbp; 584 sf.sf_uc.uc_mcontext.sc_rbx = regs->tf_rbx; 585 sf.sf_uc.uc_mcontext.sc_rcx = regs->tf_rcx; 586 sf.sf_uc.uc_mcontext.sc_rax = regs->tf_rax; 587 sf.sf_uc.uc_mcontext.sc_rip = regs->tf_rip; 588 sf.sf_uc.uc_mcontext.sc_rsp = regs->tf_rsp; 589 sf.sf_uc.uc_mcontext.sc_r8 = regs->tf_r8; 590 sf.sf_uc.uc_mcontext.sc_r9 = regs->tf_r9; 591 sf.sf_uc.uc_mcontext.sc_r10 = regs->tf_r10; 592 sf.sf_uc.uc_mcontext.sc_r11 = regs->tf_r11; 593 sf.sf_uc.uc_mcontext.sc_r12 = regs->tf_r12; 594 sf.sf_uc.uc_mcontext.sc_r13 = regs->tf_r13; 595 sf.sf_uc.uc_mcontext.sc_r14 = regs->tf_r14; 596 sf.sf_uc.uc_mcontext.sc_r15 = regs->tf_r15; 597 sf.sf_uc.uc_mcontext.sc_cs = regs->tf_cs; 598 sf.sf_uc.uc_mcontext.sc_rflags = regs->tf_rflags; 599 sf.sf_uc.uc_mcontext.sc_err = regs->tf_err; 600 sf.sf_uc.uc_mcontext.sc_trapno = bsd_to_linux_trapcode(code); 601 sf.sf_uc.uc_mcontext.sc_cr2 = (register_t)ksi->ksi_addr; 602 603 /* Translate the signal. */ 604 sig = bsd_to_linux_signal(sig); 605 /* Fill in POSIX parts. */ 606 siginfo_to_lsiginfo(&ksi->ksi_info, &sf.sf_si, sig); 607 608 /* Copy the sigframe out to the user's stack. */ 609 if (copyout(&sf, sfp, sizeof(*sfp)) != 0) { 610 uprintf("pid %d comm %s has trashed its stack, killing\n", 611 p->p_pid, p->p_comm); 612 PROC_LOCK(p); 613 sigexit(td, SIGILL); 614 } 615 616 fpstate_drop(td); 617 /* Build the argument list for the signal handler. */ 618 regs->tf_rdi = sig; /* arg 1 in %rdi */ 619 regs->tf_rax = 0; 620 if (issiginfo) { 621 regs->tf_rsi = (register_t)&sfp->sf_si; /* arg 2 in %rsi */ 622 regs->tf_rdx = (register_t)&sfp->sf_uc; /* arg 3 in %rdx */ 623 } else { 624 regs->tf_rsi = 0; 625 regs->tf_rdx = 0; 626 } 627 regs->tf_rcx = (register_t)catcher; 628 regs->tf_rsp = (long)sfp; 629 regs->tf_rip = linux_rt_sigcode; 630 regs->tf_rflags &= ~(PSL_T | PSL_D); 631 regs->tf_cs = _ucodesel; 632 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 633 PROC_LOCK(p); 634 mtx_lock(&psp->ps_mtx); 635 } 636 637 #define LINUX_VSYSCALL_START (-10UL << 20) 638 #define LINUX_VSYSCALL_SZ 1024 639 640 const unsigned long linux_vsyscall_vector[] = { 641 LINUX_SYS_gettimeofday, 642 LINUX_SYS_linux_time, 643 LINUX_SYS_linux_getcpu, 644 }; 645 646 static int 647 linux_vsyscall(struct thread *td) 648 { 649 struct trapframe *frame; 650 uint64_t retqaddr; 651 int code, traced; 652 int error; 653 654 frame = td->td_frame; 655 656 /* Check %rip for vsyscall area. */ 657 if (__predict_true(frame->tf_rip < LINUX_VSYSCALL_START)) 658 return (EINVAL); 659 if ((frame->tf_rip & (LINUX_VSYSCALL_SZ - 1)) != 0) 660 return (EINVAL); 661 code = (frame->tf_rip - LINUX_VSYSCALL_START) / LINUX_VSYSCALL_SZ; 662 if (code >= nitems(linux_vsyscall_vector)) 663 return (EINVAL); 664 665 /* 666 * vsyscall called as callq *(%rax), so we must 667 * use return address from %rsp and also fixup %rsp. 668 */ 669 error = copyin((void *)frame->tf_rsp, &retqaddr, sizeof(retqaddr)); 670 if (error) 671 return (error); 672 673 frame->tf_rip = retqaddr; 674 frame->tf_rax = linux_vsyscall_vector[code]; 675 frame->tf_rsp += 8; 676 677 traced = (frame->tf_flags & PSL_T); 678 679 amd64_syscall(td, traced); 680 681 return (0); 682 } 683 684 struct sysentvec elf_linux_sysvec = { 685 .sv_size = LINUX_SYS_MAXSYSCALL, 686 .sv_table = linux_sysent, 687 .sv_fixup = __elfN(freebsd_fixup), 688 .sv_sendsig = linux_rt_sendsig, 689 .sv_sigcode = &_binary_linux_vdso_so_o_start, 690 .sv_szsigcode = &linux_szsigcode, 691 .sv_name = "Linux ELF64", 692 .sv_coredump = elf64_coredump, 693 .sv_elf_core_osabi = ELFOSABI_NONE, 694 .sv_elf_core_abi_vendor = LINUX_ABI_VENDOR, 695 .sv_elf_core_prepare_notes = linux64_prepare_notes, 696 .sv_minsigstksz = LINUX_MINSIGSTKSZ, 697 .sv_minuser = VM_MIN_ADDRESS, 698 .sv_maxuser = VM_MAXUSER_ADDRESS_LA48, 699 .sv_usrstack = LINUX_USRSTACK_LA48, 700 .sv_psstrings = LINUX_PS_STRINGS_LA48, 701 .sv_psstringssz = sizeof(struct ps_strings), 702 .sv_stackprot = VM_PROT_ALL, 703 .sv_copyout_auxargs = __linuxN(copyout_auxargs), 704 .sv_copyout_strings = __linuxN(copyout_strings), 705 .sv_setregs = linux_exec_setregs, 706 .sv_fixlimit = NULL, 707 .sv_maxssiz = NULL, 708 .sv_flags = SV_ABI_LINUX | SV_LP64 | SV_SHP | SV_SIG_DISCIGN | 709 SV_SIG_WAITNDQ | SV_TIMEKEEP, 710 .sv_set_syscall_retval = linux_set_syscall_retval, 711 .sv_fetch_syscall_args = linux_fetch_syscall_args, 712 .sv_syscallnames = linux_syscallnames, 713 .sv_shared_page_base = LINUX_SHAREDPAGE_LA48, 714 .sv_shared_page_len = PAGE_SIZE, 715 .sv_schedtail = linux_schedtail, 716 .sv_thread_detach = linux_thread_detach, 717 .sv_trap = linux_vsyscall, 718 .sv_hwcap = NULL, 719 .sv_hwcap2 = 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 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 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 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 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 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 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