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 #include <sys/cdefs.h> 35 __FBSDID("$FreeBSD$"); 36 37 #define __ELF_WORD_SIZE 64 38 39 #include <sys/param.h> 40 #include <sys/exec.h> 41 #include <sys/imgact.h> 42 #include <sys/imgact_elf.h> 43 #include <sys/kernel.h> 44 #include <sys/ktr.h> 45 #include <sys/lock.h> 46 #include <sys/malloc.h> 47 #include <sys/module.h> 48 #include <sys/mutex.h> 49 #include <sys/proc.h> 50 #include <sys/stddef.h> 51 #include <sys/syscallsubr.h> 52 #include <sys/sysctl.h> 53 #include <sys/sysent.h> 54 55 #include <vm/pmap.h> 56 #include <vm/vm.h> 57 #include <vm/vm_map.h> 58 #include <vm/vm_page.h> 59 60 #include <machine/cpu.h> 61 #include <machine/md_var.h> 62 #include <machine/pcb.h> 63 #include <machine/specialreg.h> 64 #include <machine/trap.h> 65 66 #include <x86/linux/linux_x86.h> 67 #include <amd64/linux/linux.h> 68 #include <amd64/linux/linux_proto.h> 69 #include <compat/linux/linux_elf.h> 70 #include <compat/linux/linux_emul.h> 71 #include <compat/linux/linux_fork.h> 72 #include <compat/linux/linux_ioctl.h> 73 #include <compat/linux/linux_mib.h> 74 #include <compat/linux/linux_misc.h> 75 #include <compat/linux/linux_signal.h> 76 #include <compat/linux/linux_sysproto.h> 77 #include <compat/linux/linux_util.h> 78 #include <compat/linux/linux_vdso.h> 79 80 #include <x86/linux/linux_x86_sigframe.h> 81 82 MODULE_VERSION(linux64, 1); 83 84 #define LINUX_VDSOPAGE_SIZE PAGE_SIZE * 2 85 #define LINUX_VDSOPAGE_LA48 (VM_MAXUSER_ADDRESS_LA48 - \ 86 LINUX_VDSOPAGE_SIZE) 87 #define LINUX_SHAREDPAGE_LA48 (LINUX_VDSOPAGE_LA48 - PAGE_SIZE) 88 /* 89 * PAGE_SIZE - the size 90 * of the native SHAREDPAGE 91 */ 92 #define LINUX_USRSTACK_LA48 LINUX_SHAREDPAGE_LA48 93 #define LINUX_PS_STRINGS_LA48 (LINUX_USRSTACK_LA48 - \ 94 sizeof(struct ps_strings)) 95 96 static int linux_szsigcode; 97 static vm_object_t linux_vdso_obj; 98 static char *linux_vdso_mapping; 99 extern char _binary_linux_vdso_so_o_start; 100 extern char _binary_linux_vdso_so_o_end; 101 static vm_offset_t linux_vdso_base; 102 103 extern struct sysent linux_sysent[LINUX_SYS_MAXSYSCALL]; 104 extern const char *linux_syscallnames[]; 105 106 SET_DECLARE(linux_ioctl_handler_set, struct linux_ioctl_handler); 107 108 static void linux_vdso_install(const void *param); 109 static void linux_vdso_deinstall(const void *param); 110 static void linux_vdso_reloc(char *mapping, Elf_Addr offset); 111 static void linux_set_syscall_retval(struct thread *td, int error); 112 static int linux_fetch_syscall_args(struct thread *td); 113 static void linux_exec_setregs(struct thread *td, struct image_params *imgp, 114 uintptr_t stack); 115 static void linux_exec_sysvec_init(void *param); 116 static int linux_on_exec_vmspace(struct proc *p, 117 struct image_params *imgp); 118 static void linux_set_fork_retval(struct thread *td); 119 static int linux_vsyscall(struct thread *td); 120 121 LINUX_VDSO_SYM_INTPTR(linux_rt_sigcode); 122 LINUX_VDSO_SYM_CHAR(linux_platform); 123 LINUX_VDSO_SYM_INTPTR(kern_timekeep_base); 124 LINUX_VDSO_SYM_INTPTR(kern_tsc_selector); 125 LINUX_VDSO_SYM_INTPTR(kern_cpu_selector); 126 127 static int 128 linux_fetch_syscall_args(struct thread *td) 129 { 130 struct proc *p; 131 struct trapframe *frame; 132 struct syscall_args *sa; 133 134 p = td->td_proc; 135 frame = td->td_frame; 136 sa = &td->td_sa; 137 138 sa->args[0] = frame->tf_rdi; 139 sa->args[1] = frame->tf_rsi; 140 sa->args[2] = frame->tf_rdx; 141 sa->args[3] = frame->tf_rcx; 142 sa->args[4] = frame->tf_r8; 143 sa->args[5] = frame->tf_r9; 144 sa->code = frame->tf_rax; 145 sa->original_code = sa->code; 146 147 if (sa->code >= p->p_sysent->sv_size) 148 /* nosys */ 149 sa->callp = &p->p_sysent->sv_table[p->p_sysent->sv_size - 1]; 150 else 151 sa->callp = &p->p_sysent->sv_table[sa->code]; 152 153 td->td_retval[0] = 0; 154 return (0); 155 } 156 157 static void 158 linux_set_syscall_retval(struct thread *td, int error) 159 { 160 struct trapframe *frame; 161 162 frame = td->td_frame; 163 164 switch (error) { 165 case 0: 166 frame->tf_rax = td->td_retval[0]; 167 frame->tf_r10 = frame->tf_rcx; 168 break; 169 170 case ERESTART: 171 /* 172 * Reconstruct pc, we know that 'syscall' is 2 bytes, 173 * lcall $X,y is 7 bytes, int 0x80 is 2 bytes. 174 * We saved this in tf_err. 175 * 176 */ 177 frame->tf_rip -= frame->tf_err; 178 frame->tf_r10 = frame->tf_rcx; 179 break; 180 181 case EJUSTRETURN: 182 break; 183 184 default: 185 frame->tf_rax = bsd_to_linux_errno(error); 186 frame->tf_r10 = frame->tf_rcx; 187 break; 188 } 189 190 /* 191 * Differently from FreeBSD native ABI, on Linux only %rcx 192 * and %r11 values are not preserved across the syscall. 193 * Require full context restore to get all registers except 194 * those two restored at return to usermode. 195 * 196 * XXX: Would be great to be able to avoid PCB_FULL_IRET 197 * for the error == 0 case. 198 */ 199 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 200 } 201 202 static void 203 linux_set_fork_retval(struct thread *td) 204 { 205 struct trapframe *frame = td->td_frame; 206 207 frame->tf_rax = 0; 208 } 209 210 void 211 linux64_arch_copyout_auxargs(struct image_params *imgp, Elf_Auxinfo **pos) 212 { 213 214 AUXARGS_ENTRY((*pos), LINUX_AT_SYSINFO_EHDR, linux_vdso_base); 215 AUXARGS_ENTRY((*pos), LINUX_AT_HWCAP, cpu_feature); 216 AUXARGS_ENTRY((*pos), LINUX_AT_HWCAP2, 0); 217 AUXARGS_ENTRY((*pos), LINUX_AT_PLATFORM, PTROUT(linux_platform)); 218 } 219 220 /* 221 * Reset registers to default values on exec. 222 */ 223 static void 224 linux_exec_setregs(struct thread *td, struct image_params *imgp, 225 uintptr_t stack) 226 { 227 struct trapframe *regs; 228 struct pcb *pcb; 229 register_t saved_rflags; 230 231 regs = td->td_frame; 232 pcb = td->td_pcb; 233 234 if (td->td_proc->p_md.md_ldt != NULL) 235 user_ldt_free(td); 236 237 pcb->pcb_fsbase = 0; 238 pcb->pcb_gsbase = 0; 239 clear_pcb_flags(pcb, PCB_32BIT); 240 pcb->pcb_initial_fpucw = __LINUX_NPXCW__; 241 set_pcb_flags(pcb, PCB_FULL_IRET); 242 243 saved_rflags = regs->tf_rflags & PSL_T; 244 bzero((char *)regs, sizeof(struct trapframe)); 245 regs->tf_rip = imgp->entry_addr; 246 regs->tf_rsp = stack; 247 regs->tf_rflags = PSL_USER | saved_rflags; 248 regs->tf_ss = _udatasel; 249 regs->tf_cs = _ucodesel; 250 regs->tf_ds = _udatasel; 251 regs->tf_es = _udatasel; 252 regs->tf_fs = _ufssel; 253 regs->tf_gs = _ugssel; 254 regs->tf_flags = TF_HASSEGS; 255 256 x86_clear_dbregs(pcb); 257 258 /* 259 * Drop the FP state if we hold it, so that the process gets a 260 * clean FP state if it uses the FPU again. 261 */ 262 fpstate_drop(td); 263 } 264 265 /* 266 * Copied from amd64/amd64/machdep.c 267 */ 268 int 269 linux_rt_sigreturn(struct thread *td, struct linux_rt_sigreturn_args *args) 270 { 271 struct proc *p; 272 struct l_rt_sigframe sf; 273 struct l_sigcontext *context; 274 struct trapframe *regs; 275 mcontext_t mc; 276 unsigned long rflags; 277 sigset_t bmask; 278 int error, i; 279 ksiginfo_t ksi; 280 281 regs = td->td_frame; 282 error = copyin((void *)regs->tf_rbx, &sf, sizeof(sf)); 283 if (error != 0) 284 return (error); 285 286 p = td->td_proc; 287 context = &sf.sf_uc.uc_mcontext; 288 rflags = context->sc_rflags; 289 290 /* 291 * Don't allow users to change privileged or reserved flags. 292 */ 293 /* 294 * XXX do allow users to change the privileged flag PSL_RF. 295 * The cpu sets PSL_RF in tf_rflags for faults. Debuggers 296 * should sometimes set it there too. tf_rflags is kept in 297 * the signal context during signal handling and there is no 298 * other place to remember it, so the PSL_RF bit may be 299 * corrupted by the signal handler without us knowing. 300 * Corruption of the PSL_RF bit at worst causes one more or 301 * one less debugger trap, so allowing it is fairly harmless. 302 */ 303 if (!EFL_SECURE(rflags & ~PSL_RF, regs->tf_rflags & ~PSL_RF)) { 304 uprintf("pid %d comm %s linux mangled rflags %#lx\n", 305 p->p_pid, p->p_comm, rflags); 306 return (EINVAL); 307 } 308 309 /* 310 * Don't allow users to load a valid privileged %cs. Let the 311 * hardware check for invalid selectors, excess privilege in 312 * other selectors, invalid %eip's and invalid %esp's. 313 */ 314 if (!CS_SECURE(context->sc_cs)) { 315 uprintf("pid %d comm %s linux mangled cs %#x\n", 316 p->p_pid, p->p_comm, context->sc_cs); 317 ksiginfo_init_trap(&ksi); 318 ksi.ksi_signo = SIGBUS; 319 ksi.ksi_code = BUS_OBJERR; 320 ksi.ksi_trapno = T_PROTFLT; 321 ksi.ksi_addr = (void *)regs->tf_rip; 322 trapsignal(td, &ksi); 323 return (EINVAL); 324 } 325 326 linux_to_bsd_sigset(&sf.sf_uc.uc_sigmask, &bmask); 327 kern_sigprocmask(td, SIG_SETMASK, &bmask, NULL, 0); 328 329 regs->tf_rdi = context->sc_rdi; 330 regs->tf_rsi = context->sc_rsi; 331 regs->tf_rdx = context->sc_rdx; 332 regs->tf_rbp = context->sc_rbp; 333 regs->tf_rbx = context->sc_rbx; 334 regs->tf_rcx = context->sc_rcx; 335 regs->tf_rax = context->sc_rax; 336 regs->tf_rip = context->sc_rip; 337 regs->tf_rsp = context->sc_rsp; 338 regs->tf_r8 = context->sc_r8; 339 regs->tf_r9 = context->sc_r9; 340 regs->tf_r10 = context->sc_r10; 341 regs->tf_r11 = context->sc_r11; 342 regs->tf_r12 = context->sc_r12; 343 regs->tf_r13 = context->sc_r13; 344 regs->tf_r14 = context->sc_r14; 345 regs->tf_r15 = context->sc_r15; 346 regs->tf_cs = context->sc_cs; 347 regs->tf_err = context->sc_err; 348 regs->tf_rflags = rflags; 349 350 if (sf.sf_uc.uc_mcontext.sc_fpstate != NULL) { 351 struct savefpu *svfp = (struct savefpu *)mc.mc_fpstate; 352 353 bzero(&mc, sizeof(mc)); 354 mc.mc_ownedfp = _MC_FPOWNED_FPU; 355 mc.mc_fpformat = _MC_FPFMT_XMM; 356 357 svfp->sv_env.en_cw = sf.sf_fs.cwd; 358 svfp->sv_env.en_sw = sf.sf_fs.swd; 359 svfp->sv_env.en_tw = sf.sf_fs.twd; 360 svfp->sv_env.en_opcode = sf.sf_fs.fop; 361 svfp->sv_env.en_rip = sf.sf_fs.rip; 362 svfp->sv_env.en_rdp = sf.sf_fs.rdp; 363 svfp->sv_env.en_mxcsr = sf.sf_fs.mxcsr; 364 svfp->sv_env.en_mxcsr_mask = sf.sf_fs.mxcsr_mask; 365 /* FPU registers */ 366 for (i = 0; i < nitems(svfp->sv_fp); ++i) 367 bcopy(&sf.sf_fs.st[i], svfp->sv_fp[i].fp_acc.fp_bytes, 368 sizeof(svfp->sv_fp[i].fp_acc.fp_bytes)); 369 /* SSE registers */ 370 for (i = 0; i < nitems(svfp->sv_xmm); ++i) 371 bcopy(&sf.sf_fs.xmm[i], svfp->sv_xmm[i].xmm_bytes, 372 sizeof(svfp->sv_xmm[i].xmm_bytes)); 373 error = set_fpcontext(td, &mc, NULL, 0); 374 if (error != 0) { 375 uprintf("pid %d comm %s linux can't restore fpu state %d\n", 376 p->p_pid, p->p_comm, error); 377 return (error); 378 } 379 } 380 381 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 382 return (EJUSTRETURN); 383 } 384 385 /* 386 * copied from amd64/amd64/machdep.c 387 * 388 * Send an interrupt to process. 389 */ 390 static void 391 linux_rt_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask) 392 { 393 struct l_rt_sigframe sf, *sfp; 394 struct proc *p; 395 struct thread *td; 396 struct sigacts *psp; 397 caddr_t sp; 398 struct trapframe *regs; 399 struct savefpu *svfp; 400 mcontext_t mc; 401 int sig, code; 402 int oonstack, issiginfo, i; 403 404 td = curthread; 405 p = td->td_proc; 406 PROC_LOCK_ASSERT(p, MA_OWNED); 407 sig = linux_translate_traps(ksi->ksi_signo, ksi->ksi_trapno); 408 psp = p->p_sigacts; 409 issiginfo = SIGISMEMBER(psp->ps_siginfo, sig); 410 code = ksi->ksi_code; 411 mtx_assert(&psp->ps_mtx, MA_OWNED); 412 regs = td->td_frame; 413 oonstack = sigonstack(regs->tf_rsp); 414 415 LINUX_CTR4(rt_sendsig, "%p, %d, %p, %u", 416 catcher, sig, mask, code); 417 418 bzero(&sf, sizeof(sf)); 419 sf.sf_uc.uc_stack.ss_sp = PTROUT(td->td_sigstk.ss_sp); 420 sf.sf_uc.uc_stack.ss_size = td->td_sigstk.ss_size; 421 sf.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK) 422 ? ((oonstack) ? LINUX_SS_ONSTACK : 0) : LINUX_SS_DISABLE; 423 424 /* Allocate space for the signal handler context. */ 425 if ((td->td_pflags & TDP_ALTSTACK) != 0 && !oonstack && 426 SIGISMEMBER(psp->ps_sigonstack, sig)) { 427 sp = (caddr_t)td->td_sigstk.ss_sp + td->td_sigstk.ss_size; 428 } else 429 sp = (caddr_t)regs->tf_rsp - 128; 430 431 mtx_unlock(&psp->ps_mtx); 432 PROC_UNLOCK(p); 433 434 /* Make room, keeping the stack aligned. */ 435 sp -= sizeof(struct l_rt_sigframe); 436 sfp = (struct l_rt_sigframe *)((unsigned long)sp & ~0xFul); 437 438 /* Save user context. */ 439 bsd_to_linux_sigset(mask, &sf.sf_uc.uc_sigmask); 440 sf.sf_uc.uc_mcontext.sc_mask = sf.sf_uc.uc_sigmask; 441 sf.sf_uc.uc_mcontext.sc_rdi = regs->tf_rdi; 442 sf.sf_uc.uc_mcontext.sc_rsi = regs->tf_rsi; 443 sf.sf_uc.uc_mcontext.sc_rdx = regs->tf_rdx; 444 sf.sf_uc.uc_mcontext.sc_rbp = regs->tf_rbp; 445 sf.sf_uc.uc_mcontext.sc_rbx = regs->tf_rbx; 446 sf.sf_uc.uc_mcontext.sc_rcx = regs->tf_rcx; 447 sf.sf_uc.uc_mcontext.sc_rax = regs->tf_rax; 448 sf.sf_uc.uc_mcontext.sc_rip = regs->tf_rip; 449 sf.sf_uc.uc_mcontext.sc_rsp = regs->tf_rsp; 450 sf.sf_uc.uc_mcontext.sc_r8 = regs->tf_r8; 451 sf.sf_uc.uc_mcontext.sc_r9 = regs->tf_r9; 452 sf.sf_uc.uc_mcontext.sc_r10 = regs->tf_r10; 453 sf.sf_uc.uc_mcontext.sc_r11 = regs->tf_r11; 454 sf.sf_uc.uc_mcontext.sc_r12 = regs->tf_r12; 455 sf.sf_uc.uc_mcontext.sc_r13 = regs->tf_r13; 456 sf.sf_uc.uc_mcontext.sc_r14 = regs->tf_r14; 457 sf.sf_uc.uc_mcontext.sc_r15 = regs->tf_r15; 458 sf.sf_uc.uc_mcontext.sc_cs = regs->tf_cs; 459 sf.sf_uc.uc_mcontext.sc_rflags = regs->tf_rflags; 460 sf.sf_uc.uc_mcontext.sc_err = regs->tf_err; 461 sf.sf_uc.uc_mcontext.sc_trapno = bsd_to_linux_trapcode(code); 462 sf.sf_uc.uc_mcontext.sc_cr2 = (register_t)ksi->ksi_addr; 463 464 get_fpcontext(td, &mc, NULL, NULL); 465 KASSERT(mc.mc_fpformat != _MC_FPFMT_NODEV, ("fpu not present")); 466 svfp = (struct savefpu *)mc.mc_fpstate; 467 468 sf.sf_fs.cwd = svfp->sv_env.en_cw; 469 sf.sf_fs.swd = svfp->sv_env.en_sw; 470 sf.sf_fs.twd = svfp->sv_env.en_tw; 471 sf.sf_fs.fop = svfp->sv_env.en_opcode; 472 sf.sf_fs.rip = svfp->sv_env.en_rip; 473 sf.sf_fs.rdp = svfp->sv_env.en_rdp; 474 sf.sf_fs.mxcsr = svfp->sv_env.en_mxcsr; 475 sf.sf_fs.mxcsr_mask = svfp->sv_env.en_mxcsr_mask; 476 /* FPU registers */ 477 for (i = 0; i < nitems(svfp->sv_fp); ++i) 478 bcopy(svfp->sv_fp[i].fp_acc.fp_bytes, &sf.sf_fs.st[i], 479 sizeof(svfp->sv_fp[i].fp_acc.fp_bytes)); 480 /* SSE registers */ 481 for (i = 0; i < nitems(svfp->sv_xmm); ++i) 482 bcopy(svfp->sv_xmm[i].xmm_bytes, &sf.sf_fs.xmm[i], 483 sizeof(svfp->sv_xmm[i].xmm_bytes)); 484 sf.sf_uc.uc_mcontext.sc_fpstate = (struct l_fpstate *)((caddr_t)sfp + 485 offsetof(struct l_rt_sigframe, sf_fs)); 486 487 /* Translate the signal. */ 488 sig = bsd_to_linux_signal(sig); 489 /* Fill in POSIX parts. */ 490 siginfo_to_lsiginfo(&ksi->ksi_info, &sf.sf_si, sig); 491 492 /* Copy the sigframe out to the user's stack. */ 493 if (copyout(&sf, sfp, sizeof(*sfp)) != 0) { 494 uprintf("pid %d comm %s has trashed its stack, killing\n", 495 p->p_pid, p->p_comm); 496 PROC_LOCK(p); 497 sigexit(td, SIGILL); 498 } 499 500 fpstate_drop(td); 501 /* Build the argument list for the signal handler. */ 502 regs->tf_rdi = sig; /* arg 1 in %rdi */ 503 regs->tf_rax = 0; 504 if (issiginfo) { 505 regs->tf_rsi = (register_t)&sfp->sf_si; /* arg 2 in %rsi */ 506 regs->tf_rdx = (register_t)&sfp->sf_uc; /* arg 3 in %rdx */ 507 } else { 508 regs->tf_rsi = 0; 509 regs->tf_rdx = 0; 510 } 511 regs->tf_rcx = (register_t)catcher; 512 regs->tf_rsp = (long)sfp; 513 regs->tf_rip = linux_rt_sigcode; 514 regs->tf_rflags &= ~(PSL_T | PSL_D); 515 regs->tf_cs = _ucodesel; 516 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 517 PROC_LOCK(p); 518 mtx_lock(&psp->ps_mtx); 519 } 520 521 #define LINUX_VSYSCALL_START (-10UL << 20) 522 #define LINUX_VSYSCALL_SZ 1024 523 524 const unsigned long linux_vsyscall_vector[] = { 525 LINUX_SYS_gettimeofday, 526 LINUX_SYS_linux_time, 527 LINUX_SYS_linux_getcpu, 528 }; 529 530 static int 531 linux_vsyscall(struct thread *td) 532 { 533 struct trapframe *frame; 534 uint64_t retqaddr; 535 int code, traced; 536 int error; 537 538 frame = td->td_frame; 539 540 /* Check %rip for vsyscall area. */ 541 if (__predict_true(frame->tf_rip < LINUX_VSYSCALL_START)) 542 return (EINVAL); 543 if ((frame->tf_rip & (LINUX_VSYSCALL_SZ - 1)) != 0) 544 return (EINVAL); 545 code = (frame->tf_rip - LINUX_VSYSCALL_START) / LINUX_VSYSCALL_SZ; 546 if (code >= nitems(linux_vsyscall_vector)) 547 return (EINVAL); 548 549 /* 550 * vsyscall called as callq *(%rax), so we must 551 * use return address from %rsp and also fixup %rsp. 552 */ 553 error = copyin((void *)frame->tf_rsp, &retqaddr, sizeof(retqaddr)); 554 if (error) 555 return (error); 556 557 frame->tf_rip = retqaddr; 558 frame->tf_rax = linux_vsyscall_vector[code]; 559 frame->tf_rsp += 8; 560 561 traced = (frame->tf_flags & PSL_T); 562 563 amd64_syscall(td, traced); 564 565 return (0); 566 } 567 568 struct sysentvec elf_linux_sysvec = { 569 .sv_size = LINUX_SYS_MAXSYSCALL, 570 .sv_table = linux_sysent, 571 .sv_fixup = __elfN(freebsd_fixup), 572 .sv_sendsig = linux_rt_sendsig, 573 .sv_sigcode = &_binary_linux_vdso_so_o_start, 574 .sv_szsigcode = &linux_szsigcode, 575 .sv_name = "Linux ELF64", 576 .sv_coredump = elf64_coredump, 577 .sv_elf_core_osabi = ELFOSABI_NONE, 578 .sv_elf_core_abi_vendor = LINUX_ABI_VENDOR, 579 .sv_elf_core_prepare_notes = linux64_prepare_notes, 580 .sv_imgact_try = linux_exec_imgact_try, 581 .sv_minsigstksz = LINUX_MINSIGSTKSZ, 582 .sv_minuser = VM_MIN_ADDRESS, 583 .sv_maxuser = VM_MAXUSER_ADDRESS_LA48, 584 .sv_usrstack = LINUX_USRSTACK_LA48, 585 .sv_psstrings = LINUX_PS_STRINGS_LA48, 586 .sv_psstringssz = sizeof(struct ps_strings), 587 .sv_stackprot = VM_PROT_ALL, 588 .sv_copyout_auxargs = __linuxN(copyout_auxargs), 589 .sv_copyout_strings = __linuxN(copyout_strings), 590 .sv_setregs = linux_exec_setregs, 591 .sv_fixlimit = NULL, 592 .sv_maxssiz = NULL, 593 .sv_flags = SV_ABI_LINUX | SV_LP64 | SV_SHP | SV_SIG_DISCIGN | 594 SV_SIG_WAITNDQ | SV_TIMEKEEP, 595 .sv_set_syscall_retval = linux_set_syscall_retval, 596 .sv_fetch_syscall_args = linux_fetch_syscall_args, 597 .sv_syscallnames = linux_syscallnames, 598 .sv_shared_page_base = LINUX_SHAREDPAGE_LA48, 599 .sv_shared_page_len = PAGE_SIZE, 600 .sv_schedtail = linux_schedtail, 601 .sv_thread_detach = linux_thread_detach, 602 .sv_trap = linux_vsyscall, 603 .sv_hwcap = NULL, 604 .sv_hwcap2 = NULL, 605 .sv_onexec = linux_on_exec_vmspace, 606 .sv_onexit = linux_on_exit, 607 .sv_ontdexit = linux_thread_dtor, 608 .sv_setid_allowed = &linux_setid_allowed_query, 609 .sv_set_fork_retval = linux_set_fork_retval, 610 }; 611 612 static int 613 linux_on_exec_vmspace(struct proc *p, struct image_params *imgp) 614 { 615 int error; 616 617 error = linux_map_vdso(p, linux_vdso_obj, linux_vdso_base, 618 LINUX_VDSOPAGE_SIZE, imgp); 619 if (error == 0) 620 linux_on_exec(p, imgp); 621 return (error); 622 } 623 624 /* 625 * linux_vdso_install() and linux_exec_sysvec_init() must be called 626 * after exec_sysvec_init() which is SI_SUB_EXEC (SI_ORDER_ANY). 627 */ 628 static void 629 linux_exec_sysvec_init(void *param) 630 { 631 l_uintptr_t *ktimekeep_base, *ktsc_selector; 632 struct sysentvec *sv; 633 ptrdiff_t tkoff; 634 635 sv = param; 636 amd64_lower_shared_page(sv); 637 /* Fill timekeep_base */ 638 exec_sysvec_init(sv); 639 640 tkoff = kern_timekeep_base - linux_vdso_base; 641 ktimekeep_base = (l_uintptr_t *)(linux_vdso_mapping + tkoff); 642 *ktimekeep_base = sv->sv_shared_page_base + sv->sv_timekeep_offset; 643 644 tkoff = kern_tsc_selector - linux_vdso_base; 645 ktsc_selector = (l_uintptr_t *)(linux_vdso_mapping + tkoff); 646 *ktsc_selector = linux_vdso_tsc_selector_idx(); 647 if (bootverbose) 648 printf("Linux x86-64 vDSO tsc_selector: %lu\n", *ktsc_selector); 649 650 tkoff = kern_cpu_selector - linux_vdso_base; 651 ktsc_selector = (l_uintptr_t *)(linux_vdso_mapping + tkoff); 652 *ktsc_selector = linux_vdso_cpu_selector_idx(); 653 if (bootverbose) 654 printf("Linux x86-64 vDSO cpu_selector: %lu\n", *ktsc_selector); 655 } 656 SYSINIT(elf_linux_exec_sysvec_init, SI_SUB_EXEC + 1, SI_ORDER_ANY, 657 linux_exec_sysvec_init, &elf_linux_sysvec); 658 659 static void 660 linux_vdso_install(const void *param) 661 { 662 char *vdso_start = &_binary_linux_vdso_so_o_start; 663 char *vdso_end = &_binary_linux_vdso_so_o_end; 664 665 linux_szsigcode = vdso_end - vdso_start; 666 MPASS(linux_szsigcode <= LINUX_VDSOPAGE_SIZE); 667 668 linux_vdso_base = LINUX_VDSOPAGE_LA48; 669 if (hw_lower_amd64_sharedpage != 0) 670 linux_vdso_base -= PAGE_SIZE; 671 672 __elfN(linux_vdso_fixup)(vdso_start, linux_vdso_base); 673 674 linux_vdso_obj = __elfN(linux_shared_page_init) 675 (&linux_vdso_mapping, LINUX_VDSOPAGE_SIZE); 676 bcopy(vdso_start, linux_vdso_mapping, linux_szsigcode); 677 678 linux_vdso_reloc(linux_vdso_mapping, linux_vdso_base); 679 } 680 SYSINIT(elf_linux_vdso_init, SI_SUB_EXEC + 1, SI_ORDER_FIRST, 681 linux_vdso_install, NULL); 682 683 static void 684 linux_vdso_deinstall(const void *param) 685 { 686 687 __elfN(linux_shared_page_fini)(linux_vdso_obj, 688 linux_vdso_mapping, LINUX_VDSOPAGE_SIZE); 689 } 690 SYSUNINIT(elf_linux_vdso_uninit, SI_SUB_EXEC, SI_ORDER_FIRST, 691 linux_vdso_deinstall, NULL); 692 693 static void 694 linux_vdso_reloc(char *mapping, Elf_Addr offset) 695 { 696 const Elf_Ehdr *ehdr; 697 const Elf_Shdr *shdr; 698 Elf64_Addr *where, val; 699 Elf_Size rtype, symidx; 700 const Elf_Rela *rela; 701 Elf_Addr addr, addend; 702 int relacnt; 703 int i, j; 704 705 MPASS(offset != 0); 706 707 relacnt = 0; 708 ehdr = (const Elf_Ehdr *)mapping; 709 shdr = (const Elf_Shdr *)(mapping + ehdr->e_shoff); 710 for (i = 0; i < ehdr->e_shnum; i++) 711 { 712 switch (shdr[i].sh_type) { 713 case SHT_REL: 714 printf("Linux x86_64 vDSO: unexpected Rel section\n"); 715 break; 716 case SHT_RELA: 717 rela = (const Elf_Rela *)(mapping + shdr[i].sh_offset); 718 relacnt = shdr[i].sh_size / sizeof(*rela); 719 } 720 } 721 722 for (j = 0; j < relacnt; j++, rela++) { 723 where = (Elf_Addr *)(mapping + rela->r_offset); 724 addend = rela->r_addend; 725 rtype = ELF_R_TYPE(rela->r_info); 726 symidx = ELF_R_SYM(rela->r_info); 727 728 switch (rtype) { 729 case R_X86_64_NONE: /* none */ 730 break; 731 732 case R_X86_64_RELATIVE: /* B + A */ 733 addr = (Elf_Addr)(offset + addend); 734 val = addr; 735 if (*where != val) 736 *where = val; 737 break; 738 case R_X86_64_IRELATIVE: 739 printf("Linux x86_64 vDSO: unexpected ifunc relocation, " 740 "symbol index %ld\n", symidx); 741 break; 742 default: 743 printf("Linux x86_64 vDSO: unexpected relocation type %ld, " 744 "symbol index %ld\n", rtype, symidx); 745 } 746 } 747 } 748 749 static Elf_Brandnote linux64_brandnote = { 750 .hdr.n_namesz = sizeof(GNU_ABI_VENDOR), 751 .hdr.n_descsz = 16, 752 .hdr.n_type = 1, 753 .vendor = GNU_ABI_VENDOR, 754 .flags = BN_TRANSLATE_OSREL, 755 .trans_osrel = linux_trans_osrel 756 }; 757 758 static Elf64_Brandinfo linux_glibc2brand = { 759 .brand = ELFOSABI_LINUX, 760 .machine = EM_X86_64, 761 .compat_3_brand = "Linux", 762 .emul_path = linux_emul_path, 763 .interp_path = "/lib64/ld-linux-x86-64.so.2", 764 .sysvec = &elf_linux_sysvec, 765 .interp_newpath = NULL, 766 .brand_note = &linux64_brandnote, 767 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 768 }; 769 770 static Elf64_Brandinfo linux_glibc2brandshort = { 771 .brand = ELFOSABI_LINUX, 772 .machine = EM_X86_64, 773 .compat_3_brand = "Linux", 774 .emul_path = linux_emul_path, 775 .interp_path = "/lib64/ld-linux.so.2", 776 .sysvec = &elf_linux_sysvec, 777 .interp_newpath = NULL, 778 .brand_note = &linux64_brandnote, 779 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 780 }; 781 782 static Elf64_Brandinfo linux_muslbrand = { 783 .brand = ELFOSABI_LINUX, 784 .machine = EM_X86_64, 785 .compat_3_brand = "Linux", 786 .emul_path = linux_emul_path, 787 .interp_path = "/lib/ld-musl-x86_64.so.1", 788 .sysvec = &elf_linux_sysvec, 789 .interp_newpath = NULL, 790 .brand_note = &linux64_brandnote, 791 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE | 792 LINUX_BI_FUTEX_REQUEUE 793 }; 794 795 Elf64_Brandinfo *linux_brandlist[] = { 796 &linux_glibc2brand, 797 &linux_glibc2brandshort, 798 &linux_muslbrand, 799 NULL 800 }; 801 802 static int 803 linux64_elf_modevent(module_t mod, int type, void *data) 804 { 805 Elf64_Brandinfo **brandinfo; 806 int error; 807 struct linux_ioctl_handler **lihp; 808 809 error = 0; 810 811 switch(type) { 812 case MOD_LOAD: 813 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL; 814 ++brandinfo) 815 if (elf64_insert_brand_entry(*brandinfo) < 0) 816 error = EINVAL; 817 if (error == 0) { 818 SET_FOREACH(lihp, linux_ioctl_handler_set) 819 linux_ioctl_register_handler(*lihp); 820 stclohz = (stathz ? stathz : hz); 821 if (bootverbose) 822 printf("Linux x86-64 ELF exec handler installed\n"); 823 } else 824 printf("cannot insert Linux x86-64 ELF brand handler\n"); 825 break; 826 case MOD_UNLOAD: 827 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL; 828 ++brandinfo) 829 if (elf64_brand_inuse(*brandinfo)) 830 error = EBUSY; 831 if (error == 0) { 832 for (brandinfo = &linux_brandlist[0]; 833 *brandinfo != NULL; ++brandinfo) 834 if (elf64_remove_brand_entry(*brandinfo) < 0) 835 error = EINVAL; 836 } 837 if (error == 0) { 838 SET_FOREACH(lihp, linux_ioctl_handler_set) 839 linux_ioctl_unregister_handler(*lihp); 840 if (bootverbose) 841 printf("Linux x86_64 ELF exec handler removed\n"); 842 } else 843 printf("Could not deinstall Linux x86_64 ELF interpreter entry\n"); 844 break; 845 default: 846 return (EOPNOTSUPP); 847 } 848 return (error); 849 } 850 851 static moduledata_t linux64_elf_mod = { 852 "linux64elf", 853 linux64_elf_modevent, 854 0 855 }; 856 857 DECLARE_MODULE_TIED(linux64elf, linux64_elf_mod, SI_SUB_EXEC, SI_ORDER_ANY); 858 MODULE_DEPEND(linux64elf, linux_common, 1, 1, 1); 859 FEATURE(linux64, "Linux 64bit support"); 860