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_proto.h> 61 #include <compat/linux/linux_elf.h> 62 #include <compat/linux/linux_emul.h> 63 #include <compat/linux/linux_fork.h> 64 #include <compat/linux/linux_ioctl.h> 65 #include <compat/linux/linux_mib.h> 66 #include <compat/linux/linux_misc.h> 67 #include <compat/linux/linux_signal.h> 68 #include <compat/linux/linux_util.h> 69 #include <compat/linux/linux_vdso.h> 70 71 #include <x86/linux/linux_x86_sigframe.h> 72 73 _Static_assert(sizeof(struct l_fpstate) == 74 sizeof(__typeof(((mcontext_t *)0)->mc_fpstate)), 75 "fxsave area size incorrect"); 76 77 MODULE_VERSION(linux64, 1); 78 79 #define LINUX_VDSOPAGE_SIZE PAGE_SIZE * 2 80 #define LINUX_VDSOPAGE_LA48 (VM_MAXUSER_ADDRESS_LA48 - \ 81 LINUX_VDSOPAGE_SIZE) 82 #define LINUX_SHAREDPAGE_LA48 (LINUX_VDSOPAGE_LA48 - PAGE_SIZE) 83 /* 84 * PAGE_SIZE - the size 85 * of the native SHAREDPAGE 86 */ 87 #define LINUX_USRSTACK_LA48 LINUX_SHAREDPAGE_LA48 88 #define LINUX_PS_STRINGS_LA48 (LINUX_USRSTACK_LA48 - \ 89 sizeof(struct ps_strings)) 90 91 static int linux_szsigcode; 92 static vm_object_t linux_vdso_obj; 93 static char *linux_vdso_mapping; 94 extern char _binary_linux_vdso_so_o_start; 95 extern char _binary_linux_vdso_so_o_end; 96 static vm_offset_t linux_vdso_base; 97 98 extern struct sysent linux_sysent[LINUX_SYS_MAXSYSCALL]; 99 extern const char *linux_syscallnames[]; 100 101 SET_DECLARE(linux_ioctl_handler_set, struct linux_ioctl_handler); 102 103 static void linux_vdso_install(const void *param); 104 static void linux_vdso_deinstall(const void *param); 105 static void linux_vdso_reloc(char *mapping, Elf_Addr offset); 106 static void linux_set_syscall_retval(struct thread *td, int error); 107 static int linux_fetch_syscall_args(struct thread *td); 108 static void linux_exec_setregs(struct thread *td, struct image_params *imgp, 109 uintptr_t stack); 110 static void linux_exec_sysvec_init(void *param); 111 static int linux_on_exec_vmspace(struct proc *p, 112 struct image_params *imgp); 113 static void linux_set_fork_retval(struct thread *td); 114 static int linux_vsyscall(struct thread *td); 115 116 LINUX_VDSO_SYM_INTPTR(linux_rt_sigcode); 117 LINUX_VDSO_SYM_CHAR(linux_platform); 118 LINUX_VDSO_SYM_INTPTR(kern_timekeep_base); 119 LINUX_VDSO_SYM_INTPTR(kern_tsc_selector); 120 LINUX_VDSO_SYM_INTPTR(kern_cpu_selector); 121 122 /* 123 * According to the Intel x86 ISA 64-bit syscall 124 * saves %rip to %rcx and rflags to %r11. Registers on syscall entry: 125 * %rax system call number 126 * %rcx return address 127 * %r11 saved rflags 128 * %rdi arg1 129 * %rsi arg2 130 * %rdx arg3 131 * %r10 arg4 132 * %r8 arg5 133 * %r9 arg6 134 * 135 * Then FreeBSD fast_syscall() move registers: 136 * %rcx -> trapframe.tf_rip 137 * %r10 -> trapframe.tf_rcx 138 */ 139 static int 140 linux_fetch_syscall_args(struct thread *td) 141 { 142 struct proc *p; 143 struct trapframe *frame; 144 struct syscall_args *sa; 145 146 p = td->td_proc; 147 frame = td->td_frame; 148 sa = &td->td_sa; 149 150 sa->args[0] = frame->tf_rdi; 151 sa->args[1] = frame->tf_rsi; 152 sa->args[2] = frame->tf_rdx; 153 sa->args[3] = frame->tf_rcx; 154 sa->args[4] = frame->tf_r8; 155 sa->args[5] = frame->tf_r9; 156 sa->code = frame->tf_rax; 157 sa->original_code = sa->code; 158 159 if (sa->code >= p->p_sysent->sv_size) 160 /* nosys */ 161 sa->callp = &nosys_sysent; 162 else 163 sa->callp = &p->p_sysent->sv_table[sa->code]; 164 165 /* Restore r10 earlier to avoid doing this multiply times. */ 166 frame->tf_r10 = frame->tf_rcx; 167 /* Restore %rcx for machine context. */ 168 frame->tf_rcx = frame->tf_rip; 169 170 td->td_retval[0] = 0; 171 return (0); 172 } 173 174 static void 175 linux_set_syscall_retval(struct thread *td, int error) 176 { 177 struct trapframe *frame; 178 179 frame = td->td_frame; 180 181 switch (error) { 182 case 0: 183 frame->tf_rax = td->td_retval[0]; 184 break; 185 186 case ERESTART: 187 /* 188 * Reconstruct pc, we know that 'syscall' is 2 bytes, 189 * lcall $X,y is 7 bytes, int 0x80 is 2 bytes. 190 * We saved this in tf_err. 191 * 192 */ 193 frame->tf_rip -= frame->tf_err; 194 break; 195 196 case EJUSTRETURN: 197 break; 198 199 default: 200 frame->tf_rax = bsd_to_linux_errno(error); 201 break; 202 } 203 204 /* 205 * Differently from FreeBSD native ABI, on Linux only %rcx 206 * and %r11 values are not preserved across the syscall. 207 * Require full context restore to get all registers except 208 * those two restored at return to usermode. 209 */ 210 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 211 } 212 213 static void 214 linux_set_fork_retval(struct thread *td) 215 { 216 struct trapframe *frame = td->td_frame; 217 218 frame->tf_rax = 0; 219 } 220 221 void 222 linux64_arch_copyout_auxargs(struct image_params *imgp, Elf_Auxinfo **pos) 223 { 224 225 AUXARGS_ENTRY((*pos), LINUX_AT_SYSINFO_EHDR, linux_vdso_base); 226 AUXARGS_ENTRY((*pos), LINUX_AT_HWCAP, cpu_feature); 227 AUXARGS_ENTRY((*pos), LINUX_AT_HWCAP2, linux_x86_elf_hwcap2()); 228 AUXARGS_ENTRY((*pos), LINUX_AT_PLATFORM, PTROUT(linux_platform)); 229 } 230 231 /* 232 * Reset registers to default values on exec. 233 */ 234 static void 235 linux_exec_setregs(struct thread *td, struct image_params *imgp, 236 uintptr_t stack) 237 { 238 struct trapframe *regs; 239 struct pcb *pcb; 240 register_t saved_rflags; 241 242 regs = td->td_frame; 243 pcb = td->td_pcb; 244 245 if (td->td_proc->p_md.md_ldt != NULL) 246 user_ldt_free(td); 247 248 pcb->pcb_fsbase = 0; 249 pcb->pcb_gsbase = 0; 250 clear_pcb_flags(pcb, PCB_32BIT); 251 pcb->pcb_initial_fpucw = __LINUX_NPXCW__; 252 set_pcb_flags(pcb, PCB_FULL_IRET); 253 254 saved_rflags = regs->tf_rflags & PSL_T; 255 bzero((char *)regs, sizeof(struct trapframe)); 256 regs->tf_rip = imgp->entry_addr; 257 regs->tf_rsp = stack; 258 regs->tf_rflags = PSL_USER | saved_rflags; 259 regs->tf_ss = _udatasel; 260 regs->tf_cs = _ucodesel; 261 regs->tf_ds = _udatasel; 262 regs->tf_es = _udatasel; 263 regs->tf_fs = _ufssel; 264 regs->tf_gs = _ugssel; 265 regs->tf_flags = TF_HASSEGS; 266 267 x86_clear_dbregs(pcb); 268 269 /* 270 * Drop the FP state if we hold it, so that the process gets a 271 * clean FP state if it uses the FPU again. 272 */ 273 fpstate_drop(td); 274 } 275 276 static int 277 linux_fxrstor(struct thread *td, mcontext_t *mcp, struct l_sigcontext *sc) 278 { 279 struct savefpu *fp = (struct savefpu *)&mcp->mc_fpstate[0]; 280 int error; 281 282 error = copyin(PTRIN(sc->sc_fpstate), fp, sizeof(mcp->mc_fpstate)); 283 if (error != 0) 284 return (error); 285 bzero(&fp->sv_pad[0], sizeof(fp->sv_pad)); 286 return (set_fpcontext(td, mcp, NULL, 0)); 287 } 288 289 static int 290 linux_xrstor(struct thread *td, mcontext_t *mcp, struct l_sigcontext *sc) 291 { 292 struct savefpu *fp = (struct savefpu *)&mcp->mc_fpstate[0]; 293 char *xfpustate; 294 struct proc *p; 295 uint32_t magic2; 296 int error; 297 298 p = td->td_proc; 299 mcp->mc_xfpustate_len = cpu_max_ext_state_size - sizeof(struct savefpu); 300 301 /* Legacy region of an xsave area. */ 302 error = copyin(PTRIN(sc->sc_fpstate), fp, sizeof(mcp->mc_fpstate)); 303 if (error != 0) 304 return (error); 305 bzero(&fp->sv_pad[0], sizeof(fp->sv_pad)); 306 307 /* Extended region of an xsave area. */ 308 sc->sc_fpstate += sizeof(mcp->mc_fpstate); 309 xfpustate = (char *)fpu_save_area_alloc(); 310 error = copyin(PTRIN(sc->sc_fpstate), xfpustate, mcp->mc_xfpustate_len); 311 if (error != 0) { 312 fpu_save_area_free((struct savefpu *)xfpustate); 313 uprintf("pid %d (%s): linux xrstor failed\n", p->p_pid, 314 td->td_name); 315 return (error); 316 } 317 318 /* Linux specific end of xsave area marker. */ 319 sc->sc_fpstate += mcp->mc_xfpustate_len; 320 error = copyin(PTRIN(sc->sc_fpstate), &magic2, LINUX_FP_XSTATE_MAGIC2_SIZE); 321 if (error != 0 || magic2 != LINUX_FP_XSTATE_MAGIC2) { 322 fpu_save_area_free((struct savefpu *)xfpustate); 323 uprintf("pid %d (%s): sigreturn magic2 0x%x error %d\n", 324 p->p_pid, td->td_name, magic2, error); 325 return (error); 326 } 327 328 error = set_fpcontext(td, mcp, xfpustate, mcp->mc_xfpustate_len); 329 fpu_save_area_free((struct savefpu *)xfpustate); 330 if (error != 0) { 331 uprintf("pid %d (%s): sigreturn set_fpcontext error %d\n", 332 p->p_pid, td->td_name, error); 333 } 334 return (error); 335 } 336 337 static int 338 linux_copyin_fpstate(struct thread *td, struct l_ucontext *uc) 339 { 340 mcontext_t mc; 341 342 bzero(&mc, sizeof(mc)); 343 mc.mc_ownedfp = _MC_FPOWNED_FPU; 344 mc.mc_fpformat = _MC_FPFMT_XMM; 345 346 if ((uc->uc_flags & LINUX_UC_FP_XSTATE) != 0) 347 return (linux_xrstor(td, &mc, &uc->uc_mcontext)); 348 else 349 return (linux_fxrstor(td, &mc, &uc->uc_mcontext)); 350 } 351 352 /* 353 * Copied from amd64/amd64/machdep.c 354 */ 355 int 356 linux_rt_sigreturn(struct thread *td, struct linux_rt_sigreturn_args *args) 357 { 358 struct proc *p; 359 struct l_rt_sigframe sf; 360 struct l_sigcontext *context; 361 struct trapframe *regs; 362 unsigned long rflags; 363 sigset_t bmask; 364 int error; 365 ksiginfo_t ksi; 366 367 regs = td->td_frame; 368 error = copyin((void *)regs->tf_rbx, &sf, sizeof(sf)); 369 if (error != 0) 370 return (error); 371 372 p = td->td_proc; 373 context = &sf.sf_uc.uc_mcontext; 374 rflags = context->sc_rflags; 375 376 /* 377 * Don't allow users to change privileged or reserved flags. 378 */ 379 /* 380 * XXX do allow users to change the privileged flag PSL_RF. 381 * The cpu sets PSL_RF in tf_rflags for faults. Debuggers 382 * should sometimes set it there too. tf_rflags is kept in 383 * the signal context during signal handling and there is no 384 * other place to remember it, so the PSL_RF bit may be 385 * corrupted by the signal handler without us knowing. 386 * Corruption of the PSL_RF bit at worst causes one more or 387 * one less debugger trap, so allowing it is fairly harmless. 388 */ 389 if (!EFL_SECURE(rflags & ~PSL_RF, regs->tf_rflags & ~PSL_RF)) { 390 uprintf("pid %d comm %s linux mangled rflags %#lx\n", 391 p->p_pid, p->p_comm, rflags); 392 return (EINVAL); 393 } 394 395 /* 396 * Don't allow users to load a valid privileged %cs. Let the 397 * hardware check for invalid selectors, excess privilege in 398 * other selectors, invalid %eip's and invalid %esp's. 399 */ 400 if (!CS_SECURE(context->sc_cs)) { 401 uprintf("pid %d comm %s linux mangled cs %#x\n", 402 p->p_pid, p->p_comm, context->sc_cs); 403 ksiginfo_init_trap(&ksi); 404 ksi.ksi_signo = SIGBUS; 405 ksi.ksi_code = BUS_OBJERR; 406 ksi.ksi_trapno = T_PROTFLT; 407 ksi.ksi_addr = (void *)regs->tf_rip; 408 trapsignal(td, &ksi); 409 return (EINVAL); 410 } 411 412 linux_to_bsd_sigset(&sf.sf_uc.uc_sigmask, &bmask); 413 kern_sigprocmask(td, SIG_SETMASK, &bmask, NULL, 0); 414 415 regs->tf_rdi = context->sc_rdi; 416 regs->tf_rsi = context->sc_rsi; 417 regs->tf_rdx = context->sc_rdx; 418 regs->tf_rbp = context->sc_rbp; 419 regs->tf_rbx = context->sc_rbx; 420 regs->tf_rcx = context->sc_rcx; 421 regs->tf_rax = context->sc_rax; 422 regs->tf_rip = context->sc_rip; 423 regs->tf_rsp = context->sc_rsp; 424 regs->tf_r8 = context->sc_r8; 425 regs->tf_r9 = context->sc_r9; 426 regs->tf_r10 = context->sc_r10; 427 regs->tf_r11 = context->sc_r11; 428 regs->tf_r12 = context->sc_r12; 429 regs->tf_r13 = context->sc_r13; 430 regs->tf_r14 = context->sc_r14; 431 regs->tf_r15 = context->sc_r15; 432 regs->tf_cs = context->sc_cs; 433 regs->tf_err = context->sc_err; 434 regs->tf_rflags = rflags; 435 436 error = linux_copyin_fpstate(td, &sf.sf_uc); 437 if (error != 0) { 438 uprintf("pid %d comm %s linux can't restore fpu state %d\n", 439 p->p_pid, p->p_comm, error); 440 return (error); 441 } 442 443 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 444 return (EJUSTRETURN); 445 } 446 447 static int 448 linux_fxsave(mcontext_t *mcp, void *ufp) 449 { 450 struct l_fpstate *fx = (struct l_fpstate *)&mcp->mc_fpstate[0]; 451 452 bzero(&fx->reserved2[0], sizeof(fx->reserved2)); 453 return (copyout(fx, ufp, sizeof(*fx))); 454 } 455 456 static int 457 linux_xsave(mcontext_t *mcp, char *xfpusave, char *ufp) 458 { 459 struct l_fpstate *fx = (struct l_fpstate *)&mcp->mc_fpstate[0]; 460 uint32_t magic2; 461 int error; 462 463 /* Legacy region of an xsave area. */ 464 fx->sw_reserved.magic1 = LINUX_FP_XSTATE_MAGIC1; 465 fx->sw_reserved.xstate_size = mcp->mc_xfpustate_len + sizeof(*fx); 466 fx->sw_reserved.extended_size = fx->sw_reserved.xstate_size + 467 LINUX_FP_XSTATE_MAGIC2_SIZE; 468 fx->sw_reserved.xfeatures = xsave_mask; 469 470 error = copyout(fx, ufp, sizeof(*fx)); 471 if (error != 0) 472 return (error); 473 ufp += sizeof(*fx); 474 475 /* Extended region of an xsave area. */ 476 error = copyout(xfpusave, ufp, mcp->mc_xfpustate_len); 477 if (error != 0) 478 return (error); 479 480 /* Linux specific end of xsave area marker. */ 481 ufp += mcp->mc_xfpustate_len; 482 magic2 = LINUX_FP_XSTATE_MAGIC2; 483 return (copyout(&magic2, ufp, LINUX_FP_XSTATE_MAGIC2_SIZE)); 484 } 485 486 static int 487 linux_copyout_fpstate(struct thread *td, struct l_ucontext *uc, char **sp) 488 { 489 size_t xfpusave_len; 490 char *xfpusave; 491 mcontext_t mc; 492 char *ufp = *sp; 493 494 get_fpcontext(td, &mc, &xfpusave, &xfpusave_len); 495 KASSERT(mc.mc_fpformat != _MC_FPFMT_NODEV, ("fpu not present")); 496 497 /* Room for fxsave area. */ 498 ufp -= sizeof(struct l_fpstate); 499 if (xfpusave != NULL) { 500 /* Room for xsave area. */ 501 ufp -= (xfpusave_len + LINUX_FP_XSTATE_MAGIC2_SIZE); 502 uc->uc_flags |= LINUX_UC_FP_XSTATE; 503 } 504 *sp = ufp = (char *)((unsigned long)ufp & ~0x3Ful); 505 506 if (xfpusave != NULL) 507 return (linux_xsave(&mc, xfpusave, ufp)); 508 else 509 return (linux_fxsave(&mc, ufp)); 510 } 511 512 /* 513 * copied from amd64/amd64/machdep.c 514 * 515 * Send an interrupt to process. 516 */ 517 static void 518 linux_rt_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask) 519 { 520 struct l_rt_sigframe sf, *sfp; 521 struct proc *p; 522 struct thread *td; 523 struct sigacts *psp; 524 char *sp; 525 struct trapframe *regs; 526 int sig, code; 527 int oonstack, issiginfo; 528 529 td = curthread; 530 p = td->td_proc; 531 PROC_LOCK_ASSERT(p, MA_OWNED); 532 sig = linux_translate_traps(ksi->ksi_signo, ksi->ksi_trapno); 533 psp = p->p_sigacts; 534 issiginfo = SIGISMEMBER(psp->ps_siginfo, sig); 535 code = ksi->ksi_code; 536 mtx_assert(&psp->ps_mtx, MA_OWNED); 537 regs = td->td_frame; 538 oonstack = sigonstack(regs->tf_rsp); 539 540 LINUX_CTR4(rt_sendsig, "%p, %d, %p, %u", 541 catcher, sig, mask, code); 542 543 bzero(&sf, sizeof(sf)); 544 sf.sf_uc.uc_stack.ss_sp = PTROUT(td->td_sigstk.ss_sp); 545 sf.sf_uc.uc_stack.ss_size = td->td_sigstk.ss_size; 546 sf.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK) 547 ? ((oonstack) ? LINUX_SS_ONSTACK : 0) : LINUX_SS_DISABLE; 548 549 /* Allocate space for the signal handler context. */ 550 if ((td->td_pflags & TDP_ALTSTACK) != 0 && !oonstack && 551 SIGISMEMBER(psp->ps_sigonstack, sig)) { 552 sp = (char *)td->td_sigstk.ss_sp + td->td_sigstk.ss_size; 553 } else 554 sp = (char *)regs->tf_rsp - 128; 555 556 mtx_unlock(&psp->ps_mtx); 557 PROC_UNLOCK(p); 558 559 if (linux_copyout_fpstate(td, &sf.sf_uc, &sp) != 0) { 560 uprintf("pid %d comm %s linux can't save fpu state, killing\n", 561 p->p_pid, p->p_comm); 562 PROC_LOCK(p); 563 sigexit(td, SIGILL); 564 } 565 sf.sf_uc.uc_mcontext.sc_fpstate = (register_t)sp; 566 567 /* Make room, keeping the stack aligned. */ 568 sp -= sizeof(struct l_rt_sigframe); 569 sfp = (struct l_rt_sigframe *)((unsigned long)sp & ~0xFul); 570 571 /* Save user context. */ 572 bsd_to_linux_sigset(mask, &sf.sf_uc.uc_sigmask); 573 sf.sf_uc.uc_mcontext.sc_mask = sf.sf_uc.uc_sigmask; 574 sf.sf_uc.uc_mcontext.sc_rdi = regs->tf_rdi; 575 sf.sf_uc.uc_mcontext.sc_rsi = regs->tf_rsi; 576 sf.sf_uc.uc_mcontext.sc_rdx = regs->tf_rdx; 577 sf.sf_uc.uc_mcontext.sc_rbp = regs->tf_rbp; 578 sf.sf_uc.uc_mcontext.sc_rbx = regs->tf_rbx; 579 sf.sf_uc.uc_mcontext.sc_rcx = regs->tf_rcx; 580 sf.sf_uc.uc_mcontext.sc_rax = regs->tf_rax; 581 sf.sf_uc.uc_mcontext.sc_rip = regs->tf_rip; 582 sf.sf_uc.uc_mcontext.sc_rsp = regs->tf_rsp; 583 sf.sf_uc.uc_mcontext.sc_r8 = regs->tf_r8; 584 sf.sf_uc.uc_mcontext.sc_r9 = regs->tf_r9; 585 sf.sf_uc.uc_mcontext.sc_r10 = regs->tf_r10; 586 sf.sf_uc.uc_mcontext.sc_r11 = regs->tf_r11; 587 sf.sf_uc.uc_mcontext.sc_r12 = regs->tf_r12; 588 sf.sf_uc.uc_mcontext.sc_r13 = regs->tf_r13; 589 sf.sf_uc.uc_mcontext.sc_r14 = regs->tf_r14; 590 sf.sf_uc.uc_mcontext.sc_r15 = regs->tf_r15; 591 sf.sf_uc.uc_mcontext.sc_cs = regs->tf_cs; 592 sf.sf_uc.uc_mcontext.sc_rflags = regs->tf_rflags; 593 sf.sf_uc.uc_mcontext.sc_err = regs->tf_err; 594 sf.sf_uc.uc_mcontext.sc_trapno = bsd_to_linux_trapcode(code); 595 sf.sf_uc.uc_mcontext.sc_cr2 = (register_t)ksi->ksi_addr; 596 597 /* Translate the signal. */ 598 sig = bsd_to_linux_signal(sig); 599 /* Fill in POSIX parts. */ 600 siginfo_to_lsiginfo(&ksi->ksi_info, &sf.sf_si, sig); 601 602 /* Copy the sigframe out to the user's stack. */ 603 if (copyout(&sf, sfp, sizeof(*sfp)) != 0) { 604 uprintf("pid %d comm %s has trashed its stack, killing\n", 605 p->p_pid, p->p_comm); 606 PROC_LOCK(p); 607 sigexit(td, SIGILL); 608 } 609 610 fpstate_drop(td); 611 /* Build the argument list for the signal handler. */ 612 regs->tf_rdi = sig; /* arg 1 in %rdi */ 613 regs->tf_rax = 0; 614 if (issiginfo) { 615 regs->tf_rsi = (register_t)&sfp->sf_si; /* arg 2 in %rsi */ 616 regs->tf_rdx = (register_t)&sfp->sf_uc; /* arg 3 in %rdx */ 617 } else { 618 regs->tf_rsi = 0; 619 regs->tf_rdx = 0; 620 } 621 regs->tf_rcx = (register_t)catcher; 622 regs->tf_rsp = (long)sfp; 623 regs->tf_rip = linux_rt_sigcode; 624 regs->tf_rflags &= ~(PSL_T | PSL_D); 625 regs->tf_cs = _ucodesel; 626 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 627 PROC_LOCK(p); 628 mtx_lock(&psp->ps_mtx); 629 } 630 631 #define LINUX_VSYSCALL_START (-10UL << 20) 632 #define LINUX_VSYSCALL_SZ 1024 633 634 const unsigned long linux_vsyscall_vector[] = { 635 LINUX_SYS_gettimeofday, 636 LINUX_SYS_linux_time, 637 LINUX_SYS_linux_getcpu, 638 }; 639 640 static int 641 linux_vsyscall(struct thread *td) 642 { 643 struct trapframe *frame; 644 uint64_t retqaddr; 645 int code, traced; 646 int error; 647 648 frame = td->td_frame; 649 650 /* Check %rip for vsyscall area. */ 651 if (__predict_true(frame->tf_rip < LINUX_VSYSCALL_START)) 652 return (EINVAL); 653 if ((frame->tf_rip & (LINUX_VSYSCALL_SZ - 1)) != 0) 654 return (EINVAL); 655 code = (frame->tf_rip - LINUX_VSYSCALL_START) / LINUX_VSYSCALL_SZ; 656 if (code >= nitems(linux_vsyscall_vector)) 657 return (EINVAL); 658 659 /* 660 * vsyscall called as callq *(%rax), so we must 661 * use return address from %rsp and also fixup %rsp. 662 */ 663 error = copyin((void *)frame->tf_rsp, &retqaddr, sizeof(retqaddr)); 664 if (error) 665 return (error); 666 667 frame->tf_rip = retqaddr; 668 frame->tf_rax = linux_vsyscall_vector[code]; 669 frame->tf_rsp += 8; 670 671 traced = (frame->tf_flags & PSL_T); 672 673 amd64_syscall(td, traced); 674 675 return (0); 676 } 677 678 struct sysentvec elf_linux_sysvec = { 679 .sv_size = LINUX_SYS_MAXSYSCALL, 680 .sv_table = linux_sysent, 681 .sv_fixup = __elfN(freebsd_fixup), 682 .sv_sendsig = linux_rt_sendsig, 683 .sv_sigcode = &_binary_linux_vdso_so_o_start, 684 .sv_szsigcode = &linux_szsigcode, 685 .sv_name = "Linux ELF64", 686 .sv_coredump = elf64_coredump, 687 .sv_elf_core_osabi = ELFOSABI_NONE, 688 .sv_elf_core_abi_vendor = LINUX_ABI_VENDOR, 689 .sv_elf_core_prepare_notes = linux64_prepare_notes, 690 .sv_minsigstksz = LINUX_MINSIGSTKSZ, 691 .sv_minuser = VM_MIN_ADDRESS, 692 .sv_maxuser = VM_MAXUSER_ADDRESS_LA48, 693 .sv_usrstack = LINUX_USRSTACK_LA48, 694 .sv_psstrings = LINUX_PS_STRINGS_LA48, 695 .sv_psstringssz = sizeof(struct ps_strings), 696 .sv_stackprot = VM_PROT_ALL, 697 .sv_copyout_auxargs = __linuxN(copyout_auxargs), 698 .sv_copyout_strings = __linuxN(copyout_strings), 699 .sv_setregs = linux_exec_setregs, 700 .sv_fixlimit = NULL, 701 .sv_maxssiz = NULL, 702 .sv_flags = SV_ABI_LINUX | SV_LP64 | SV_SHP | SV_SIG_DISCIGN | 703 SV_SIG_WAITNDQ | SV_TIMEKEEP, 704 .sv_set_syscall_retval = linux_set_syscall_retval, 705 .sv_fetch_syscall_args = linux_fetch_syscall_args, 706 .sv_syscallnames = linux_syscallnames, 707 .sv_shared_page_base = LINUX_SHAREDPAGE_LA48, 708 .sv_shared_page_len = PAGE_SIZE, 709 .sv_schedtail = linux_schedtail, 710 .sv_thread_detach = linux_thread_detach, 711 .sv_trap = linux_vsyscall, 712 .sv_hwcap = NULL, 713 .sv_hwcap2 = NULL, 714 .sv_onexec = linux_on_exec_vmspace, 715 .sv_onexit = linux_on_exit, 716 .sv_ontdexit = linux_thread_dtor, 717 .sv_setid_allowed = &linux_setid_allowed_query, 718 .sv_set_fork_retval = linux_set_fork_retval, 719 }; 720 721 static int 722 linux_on_exec_vmspace(struct proc *p, struct image_params *imgp) 723 { 724 int error; 725 726 error = linux_map_vdso(p, linux_vdso_obj, linux_vdso_base, 727 LINUX_VDSOPAGE_SIZE, imgp); 728 if (error == 0) 729 error = linux_on_exec(p, imgp); 730 return (error); 731 } 732 733 /* 734 * linux_vdso_install() and linux_exec_sysvec_init() must be called 735 * after exec_sysvec_init() which is SI_SUB_EXEC (SI_ORDER_ANY). 736 */ 737 static void 738 linux_exec_sysvec_init(void *param) 739 { 740 l_uintptr_t *ktimekeep_base, *ktsc_selector; 741 struct sysentvec *sv; 742 ptrdiff_t tkoff; 743 744 sv = param; 745 amd64_lower_shared_page(sv); 746 /* Fill timekeep_base */ 747 exec_sysvec_init(sv); 748 749 tkoff = kern_timekeep_base - linux_vdso_base; 750 ktimekeep_base = (l_uintptr_t *)(linux_vdso_mapping + tkoff); 751 *ktimekeep_base = sv->sv_shared_page_base + sv->sv_timekeep_offset; 752 753 tkoff = kern_tsc_selector - linux_vdso_base; 754 ktsc_selector = (l_uintptr_t *)(linux_vdso_mapping + tkoff); 755 *ktsc_selector = linux_vdso_tsc_selector_idx(); 756 if (bootverbose) 757 printf("Linux x86-64 vDSO tsc_selector: %lu\n", *ktsc_selector); 758 759 tkoff = kern_cpu_selector - linux_vdso_base; 760 ktsc_selector = (l_uintptr_t *)(linux_vdso_mapping + tkoff); 761 *ktsc_selector = linux_vdso_cpu_selector_idx(); 762 if (bootverbose) 763 printf("Linux x86-64 vDSO cpu_selector: %lu\n", *ktsc_selector); 764 } 765 SYSINIT(elf_linux_exec_sysvec_init, SI_SUB_EXEC + 1, SI_ORDER_ANY, 766 linux_exec_sysvec_init, &elf_linux_sysvec); 767 768 static void 769 linux_vdso_install(const void *param) 770 { 771 char *vdso_start = &_binary_linux_vdso_so_o_start; 772 char *vdso_end = &_binary_linux_vdso_so_o_end; 773 774 linux_szsigcode = vdso_end - vdso_start; 775 MPASS(linux_szsigcode <= LINUX_VDSOPAGE_SIZE); 776 777 linux_vdso_base = LINUX_VDSOPAGE_LA48; 778 if (hw_lower_amd64_sharedpage != 0) 779 linux_vdso_base -= PAGE_SIZE; 780 781 __elfN(linux_vdso_fixup)(vdso_start, linux_vdso_base); 782 783 linux_vdso_obj = __elfN(linux_shared_page_init) 784 (&linux_vdso_mapping, LINUX_VDSOPAGE_SIZE); 785 bcopy(vdso_start, linux_vdso_mapping, linux_szsigcode); 786 787 linux_vdso_reloc(linux_vdso_mapping, linux_vdso_base); 788 } 789 SYSINIT(elf_linux_vdso_init, SI_SUB_EXEC + 1, SI_ORDER_FIRST, 790 linux_vdso_install, NULL); 791 792 static void 793 linux_vdso_deinstall(const void *param) 794 { 795 796 __elfN(linux_shared_page_fini)(linux_vdso_obj, 797 linux_vdso_mapping, LINUX_VDSOPAGE_SIZE); 798 } 799 SYSUNINIT(elf_linux_vdso_uninit, SI_SUB_EXEC, SI_ORDER_FIRST, 800 linux_vdso_deinstall, NULL); 801 802 static void 803 linux_vdso_reloc(char *mapping, Elf_Addr offset) 804 { 805 const Elf_Ehdr *ehdr; 806 const Elf_Shdr *shdr; 807 Elf64_Addr *where, val; 808 Elf_Size rtype, symidx; 809 const Elf_Rela *rela; 810 Elf_Addr addr, addend; 811 int relacnt; 812 int i, j; 813 814 MPASS(offset != 0); 815 816 relacnt = 0; 817 ehdr = (const Elf_Ehdr *)mapping; 818 shdr = (const Elf_Shdr *)(mapping + ehdr->e_shoff); 819 for (i = 0; i < ehdr->e_shnum; i++) 820 { 821 switch (shdr[i].sh_type) { 822 case SHT_REL: 823 printf("Linux x86_64 vDSO: unexpected Rel section\n"); 824 break; 825 case SHT_RELA: 826 rela = (const Elf_Rela *)(mapping + shdr[i].sh_offset); 827 relacnt = shdr[i].sh_size / sizeof(*rela); 828 } 829 } 830 831 for (j = 0; j < relacnt; j++, rela++) { 832 where = (Elf_Addr *)(mapping + rela->r_offset); 833 addend = rela->r_addend; 834 rtype = ELF_R_TYPE(rela->r_info); 835 symidx = ELF_R_SYM(rela->r_info); 836 837 switch (rtype) { 838 case R_X86_64_NONE: /* none */ 839 break; 840 841 case R_X86_64_RELATIVE: /* B + A */ 842 addr = (Elf_Addr)(offset + addend); 843 val = addr; 844 if (*where != val) 845 *where = val; 846 break; 847 case R_X86_64_IRELATIVE: 848 printf("Linux x86_64 vDSO: unexpected ifunc relocation, " 849 "symbol index %ld\n", symidx); 850 break; 851 default: 852 printf("Linux x86_64 vDSO: unexpected relocation type %ld, " 853 "symbol index %ld\n", rtype, symidx); 854 } 855 } 856 } 857 858 static Elf_Brandnote linux64_brandnote = { 859 .hdr.n_namesz = sizeof(GNU_ABI_VENDOR), 860 .hdr.n_descsz = 16, 861 .hdr.n_type = 1, 862 .vendor = GNU_ABI_VENDOR, 863 .flags = BN_TRANSLATE_OSREL, 864 .trans_osrel = linux_trans_osrel 865 }; 866 867 static Elf64_Brandinfo linux_glibc2brand = { 868 .brand = ELFOSABI_LINUX, 869 .machine = EM_X86_64, 870 .compat_3_brand = "Linux", 871 .interp_path = "/lib64/ld-linux-x86-64.so.2", 872 .sysvec = &elf_linux_sysvec, 873 .interp_newpath = NULL, 874 .brand_note = &linux64_brandnote, 875 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 876 }; 877 878 static Elf64_Brandinfo linux_glibc2brandshort = { 879 .brand = ELFOSABI_LINUX, 880 .machine = EM_X86_64, 881 .compat_3_brand = "Linux", 882 .interp_path = "/lib64/ld-linux.so.2", 883 .sysvec = &elf_linux_sysvec, 884 .interp_newpath = NULL, 885 .brand_note = &linux64_brandnote, 886 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 887 }; 888 889 static Elf64_Brandinfo linux_muslbrand = { 890 .brand = ELFOSABI_LINUX, 891 .machine = EM_X86_64, 892 .compat_3_brand = "Linux", 893 .interp_path = "/lib/ld-musl-x86_64.so.1", 894 .sysvec = &elf_linux_sysvec, 895 .interp_newpath = NULL, 896 .brand_note = &linux64_brandnote, 897 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE | 898 LINUX_BI_FUTEX_REQUEUE 899 }; 900 901 static Elf64_Brandinfo *linux_brandlist[] = { 902 &linux_glibc2brand, 903 &linux_glibc2brandshort, 904 &linux_muslbrand, 905 NULL 906 }; 907 908 static int 909 linux64_elf_modevent(module_t mod, int type, void *data) 910 { 911 Elf64_Brandinfo **brandinfo; 912 int error; 913 struct linux_ioctl_handler **lihp; 914 915 error = 0; 916 917 switch(type) { 918 case MOD_LOAD: 919 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL; 920 ++brandinfo) 921 if (elf64_insert_brand_entry(*brandinfo) < 0) 922 error = EINVAL; 923 if (error == 0) { 924 SET_FOREACH(lihp, linux_ioctl_handler_set) 925 linux_ioctl_register_handler(*lihp); 926 stclohz = (stathz ? stathz : hz); 927 if (bootverbose) 928 printf("Linux x86-64 ELF exec handler installed\n"); 929 } else 930 printf("cannot insert Linux x86-64 ELF brand handler\n"); 931 break; 932 case MOD_UNLOAD: 933 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL; 934 ++brandinfo) 935 if (elf64_brand_inuse(*brandinfo)) 936 error = EBUSY; 937 if (error == 0) { 938 for (brandinfo = &linux_brandlist[0]; 939 *brandinfo != NULL; ++brandinfo) 940 if (elf64_remove_brand_entry(*brandinfo) < 0) 941 error = EINVAL; 942 } 943 if (error == 0) { 944 SET_FOREACH(lihp, linux_ioctl_handler_set) 945 linux_ioctl_unregister_handler(*lihp); 946 if (bootverbose) 947 printf("Linux x86_64 ELF exec handler removed\n"); 948 } else 949 printf("Could not deinstall Linux x86_64 ELF interpreter entry\n"); 950 break; 951 default: 952 return (EOPNOTSUPP); 953 } 954 return (error); 955 } 956 957 static moduledata_t linux64_elf_mod = { 958 "linux64elf", 959 linux64_elf_modevent, 960 0 961 }; 962 963 DECLARE_MODULE_TIED(linux64elf, linux64_elf_mod, SI_SUB_EXEC, SI_ORDER_ANY); 964 MODULE_DEPEND(linux64elf, linux_common, 1, 1, 1); 965 FEATURE(linux64, "Linux 64bit support"); 966