Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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sys/amd64/ia32/ia32_signal.c
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1 /*- 2 * Copyright (c) 2003 Peter Wemm 3 * Copyright (c) 1982, 1987, 1990 The Regents of the University of California. 4 * All rights reserved. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * William Jolitz. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #include <sys/cdefs.h> 35 __FBSDID("$FreeBSD: releng/8.4/sys/amd64/ia32/ia32_signal.c 237009 2012-06-13 15:25:52Z jhb $"); 36 37 #include "opt_compat.h" 38 39 #include <sys/param.h> 40 #include <sys/exec.h> 41 #include <sys/fcntl.h> 42 #include <sys/imgact.h> 43 #include <sys/kernel.h> 44 #include <sys/lock.h> 45 #include <sys/malloc.h> 46 #include <sys/mutex.h> 47 #include <sys/mman.h> 48 #include <sys/namei.h> 49 #include <sys/pioctl.h> 50 #include <sys/proc.h> 51 #include <sys/procfs.h> 52 #include <sys/resourcevar.h> 53 #include <sys/systm.h> 54 #include <sys/signalvar.h> 55 #include <sys/stat.h> 56 #include <sys/sx.h> 57 #include <sys/syscall.h> 58 #include <sys/syscallsubr.h> 59 #include <sys/sysctl.h> 60 #include <sys/sysent.h> 61 #include <sys/vnode.h> 62 63 #include <vm/vm.h> 64 #include <vm/vm_kern.h> 65 #include <vm/vm_param.h> 66 #include <vm/pmap.h> 67 #include <vm/vm_map.h> 68 #include <vm/vm_object.h> 69 #include <vm/vm_extern.h> 70 71 #include <compat/freebsd32/freebsd32_signal.h> 72 #include <compat/freebsd32/freebsd32_util.h> 73 #include <compat/freebsd32/freebsd32_proto.h> 74 #include <compat/freebsd32/freebsd32.h> 75 #include <compat/ia32/ia32_signal.h> 76 #include <machine/psl.h> 77 #include <machine/segments.h> 78 #include <machine/specialreg.h> 79 #include <machine/frame.h> 80 #include <machine/md_var.h> 81 #include <machine/pcb.h> 82 #include <machine/cpufunc.h> 83 84 #ifdef COMPAT_FREEBSD4 85 static void freebsd4_ia32_sendsig(sig_t, ksiginfo_t *, sigset_t *); 86 #endif 87 88 #define CS_SECURE(cs) (ISPL(cs) == SEL_UPL) 89 #define EFL_SECURE(ef, oef) ((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0) 90 91 static void 92 ia32_get_fpcontext(struct thread *td, struct ia32_mcontext *mcp, 93 char *xfpusave, size_t xfpusave_len) 94 { 95 size_t max_len, len; 96 97 /* 98 * XXX Format of 64bit and 32bit FXSAVE areas differs. FXSAVE 99 * in 32bit mode saves %cs and %ds, while on 64bit it saves 100 * 64bit instruction and data pointers. Ignore the difference 101 * for now, it should be irrelevant for most applications. 102 */ 103 mcp->mc_ownedfp = fpugetregs(td); 104 bcopy(get_pcb_user_save_td(td), &mcp->mc_fpstate, 105 sizeof(mcp->mc_fpstate)); 106 mcp->mc_fpformat = fpuformat(); 107 if (!use_xsave || xfpusave_len == 0) 108 return; 109 max_len = cpu_max_ext_state_size - sizeof(struct savefpu); 110 len = xfpusave_len; 111 if (len > max_len) { 112 len = max_len; 113 bzero(xfpusave + max_len, len - max_len); 114 } 115 mcp->mc_flags |= _MC_HASFPXSTATE; 116 mcp->mc_xfpustate_len = len; 117 bcopy(get_pcb_user_save_td(td) + 1, xfpusave, len); 118 } 119 120 static int 121 ia32_set_fpcontext(struct thread *td, const struct ia32_mcontext *mcp, 122 char *xfpustate, size_t xfpustate_len) 123 { 124 int error; 125 126 if (mcp->mc_fpformat == _MC_FPFMT_NODEV) 127 return (0); 128 else if (mcp->mc_fpformat != _MC_FPFMT_XMM) 129 return (EINVAL); 130 else if (mcp->mc_ownedfp == _MC_FPOWNED_NONE) { 131 /* We don't care what state is left in the FPU or PCB. */ 132 fpstate_drop(td); 133 error = 0; 134 } else if (mcp->mc_ownedfp == _MC_FPOWNED_FPU || 135 mcp->mc_ownedfp == _MC_FPOWNED_PCB) { 136 error = fpusetregs(td, (struct savefpu *)&mcp->mc_fpstate, 137 xfpustate, xfpustate_len); 138 } else 139 return (EINVAL); 140 return (error); 141 } 142 143 /* 144 * Get machine context. 145 */ 146 static int 147 ia32_get_mcontext(struct thread *td, struct ia32_mcontext *mcp, int flags) 148 { 149 struct pcb *pcb; 150 struct trapframe *tp; 151 152 pcb = td->td_pcb; 153 tp = td->td_frame; 154 155 PROC_LOCK(curthread->td_proc); 156 mcp->mc_onstack = sigonstack(tp->tf_rsp); 157 PROC_UNLOCK(curthread->td_proc); 158 /* Entry into kernel always sets TF_HASSEGS */ 159 mcp->mc_gs = tp->tf_gs; 160 mcp->mc_fs = tp->tf_fs; 161 mcp->mc_es = tp->tf_es; 162 mcp->mc_ds = tp->tf_ds; 163 mcp->mc_edi = tp->tf_rdi; 164 mcp->mc_esi = tp->tf_rsi; 165 mcp->mc_ebp = tp->tf_rbp; 166 mcp->mc_isp = tp->tf_rsp; 167 mcp->mc_eflags = tp->tf_rflags; 168 if (flags & GET_MC_CLEAR_RET) { 169 mcp->mc_eax = 0; 170 mcp->mc_edx = 0; 171 mcp->mc_eflags &= ~PSL_C; 172 } else { 173 mcp->mc_eax = tp->tf_rax; 174 mcp->mc_edx = tp->tf_rdx; 175 } 176 mcp->mc_ebx = tp->tf_rbx; 177 mcp->mc_ecx = tp->tf_rcx; 178 mcp->mc_eip = tp->tf_rip; 179 mcp->mc_cs = tp->tf_cs; 180 mcp->mc_esp = tp->tf_rsp; 181 mcp->mc_ss = tp->tf_ss; 182 mcp->mc_len = sizeof(*mcp); 183 mcp->mc_flags = tp->tf_flags; 184 ia32_get_fpcontext(td, mcp, NULL, 0); 185 mcp->mc_fsbase = pcb->pcb_fsbase; 186 mcp->mc_gsbase = pcb->pcb_gsbase; 187 mcp->mc_xfpustate = 0; 188 mcp->mc_xfpustate_len = 0; 189 bzero(mcp->mc_spare2, sizeof(mcp->mc_spare2)); 190 set_pcb_flags(pcb, PCB_FULL_IRET); 191 return (0); 192 } 193 194 /* 195 * Set machine context. 196 * 197 * However, we don't set any but the user modifiable flags, and we won't 198 * touch the cs selector. 199 */ 200 static int 201 ia32_set_mcontext(struct thread *td, const struct ia32_mcontext *mcp) 202 { 203 struct trapframe *tp; 204 char *xfpustate; 205 long rflags; 206 int ret; 207 208 tp = td->td_frame; 209 if (mcp->mc_len != sizeof(*mcp)) 210 return (EINVAL); 211 rflags = (mcp->mc_eflags & PSL_USERCHANGE) | 212 (tp->tf_rflags & ~PSL_USERCHANGE); 213 if (mcp->mc_flags & _MC_IA32_HASFPXSTATE) { 214 if (mcp->mc_xfpustate_len > cpu_max_ext_state_size - 215 sizeof(struct savefpu)) 216 return (EINVAL); 217 xfpustate = __builtin_alloca(mcp->mc_xfpustate_len); 218 ret = copyin(PTRIN(mcp->mc_xfpustate), xfpustate, 219 mcp->mc_xfpustate_len); 220 if (ret != 0) 221 return (ret); 222 } else 223 xfpustate = NULL; 224 ret = ia32_set_fpcontext(td, mcp, xfpustate, mcp->mc_xfpustate_len); 225 if (ret != 0) 226 return (ret); 227 tp->tf_gs = mcp->mc_gs; 228 tp->tf_fs = mcp->mc_fs; 229 tp->tf_es = mcp->mc_es; 230 tp->tf_ds = mcp->mc_ds; 231 tp->tf_flags = TF_HASSEGS; 232 tp->tf_rdi = mcp->mc_edi; 233 tp->tf_rsi = mcp->mc_esi; 234 tp->tf_rbp = mcp->mc_ebp; 235 tp->tf_rbx = mcp->mc_ebx; 236 tp->tf_rdx = mcp->mc_edx; 237 tp->tf_rcx = mcp->mc_ecx; 238 tp->tf_rax = mcp->mc_eax; 239 /* trapno, err */ 240 tp->tf_rip = mcp->mc_eip; 241 tp->tf_rflags = rflags; 242 tp->tf_rsp = mcp->mc_esp; 243 tp->tf_ss = mcp->mc_ss; 244 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 245 return (0); 246 } 247 248 /* 249 * The first two fields of a ucontext_t are the signal mask and 250 * the machine context. The next field is uc_link; we want to 251 * avoid destroying the link when copying out contexts. 252 */ 253 #define UC_COPY_SIZE offsetof(struct ia32_ucontext, uc_link) 254 255 int 256 freebsd32_getcontext(struct thread *td, struct freebsd32_getcontext_args *uap) 257 { 258 struct ia32_ucontext uc; 259 int ret; 260 261 if (uap->ucp == NULL) 262 ret = EINVAL; 263 else { 264 ia32_get_mcontext(td, &uc.uc_mcontext, GET_MC_CLEAR_RET); 265 PROC_LOCK(td->td_proc); 266 uc.uc_sigmask = td->td_sigmask; 267 PROC_UNLOCK(td->td_proc); 268 bzero(&uc.__spare__, sizeof(uc.__spare__)); 269 ret = copyout(&uc, uap->ucp, UC_COPY_SIZE); 270 } 271 return (ret); 272 } 273 274 int 275 freebsd32_setcontext(struct thread *td, struct freebsd32_setcontext_args *uap) 276 { 277 struct ia32_ucontext uc; 278 int ret; 279 280 if (uap->ucp == NULL) 281 ret = EINVAL; 282 else { 283 ret = copyin(uap->ucp, &uc, UC_COPY_SIZE); 284 if (ret == 0) { 285 ret = ia32_set_mcontext(td, &uc.uc_mcontext); 286 if (ret == 0) { 287 kern_sigprocmask(td, SIG_SETMASK, 288 &uc.uc_sigmask, NULL, 0); 289 } 290 } 291 } 292 return (ret == 0 ? EJUSTRETURN : ret); 293 } 294 295 int 296 freebsd32_swapcontext(struct thread *td, struct freebsd32_swapcontext_args *uap) 297 { 298 struct ia32_ucontext uc; 299 int ret; 300 301 if (uap->oucp == NULL || uap->ucp == NULL) 302 ret = EINVAL; 303 else { 304 ia32_get_mcontext(td, &uc.uc_mcontext, GET_MC_CLEAR_RET); 305 PROC_LOCK(td->td_proc); 306 uc.uc_sigmask = td->td_sigmask; 307 PROC_UNLOCK(td->td_proc); 308 ret = copyout(&uc, uap->oucp, UC_COPY_SIZE); 309 if (ret == 0) { 310 ret = copyin(uap->ucp, &uc, UC_COPY_SIZE); 311 if (ret == 0) { 312 ret = ia32_set_mcontext(td, &uc.uc_mcontext); 313 if (ret == 0) { 314 kern_sigprocmask(td, SIG_SETMASK, 315 &uc.uc_sigmask, NULL, 0); 316 } 317 } 318 } 319 } 320 return (ret == 0 ? EJUSTRETURN : ret); 321 } 322 323 /* 324 * Send an interrupt to process. 325 * 326 * Stack is set up to allow sigcode stored 327 * at top to call routine, followed by kcall 328 * to sigreturn routine below. After sigreturn 329 * resets the signal mask, the stack, and the 330 * frame pointer, it returns to the user 331 * specified pc, psl. 332 */ 333 #ifdef COMPAT_FREEBSD4 334 static void 335 freebsd4_ia32_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask) 336 { 337 struct ia32_sigframe4 sf, *sfp; 338 struct siginfo32 siginfo; 339 struct proc *p; 340 struct thread *td; 341 struct sigacts *psp; 342 struct trapframe *regs; 343 int oonstack; 344 int sig; 345 346 td = curthread; 347 p = td->td_proc; 348 siginfo_to_siginfo32(&ksi->ksi_info, &siginfo); 349 350 PROC_LOCK_ASSERT(p, MA_OWNED); 351 sig = siginfo.si_signo; 352 psp = p->p_sigacts; 353 mtx_assert(&psp->ps_mtx, MA_OWNED); 354 regs = td->td_frame; 355 oonstack = sigonstack(regs->tf_rsp); 356 357 /* Save user context. */ 358 bzero(&sf, sizeof(sf)); 359 sf.sf_uc.uc_sigmask = *mask; 360 sf.sf_uc.uc_stack.ss_sp = (uintptr_t)td->td_sigstk.ss_sp; 361 sf.sf_uc.uc_stack.ss_size = td->td_sigstk.ss_size; 362 sf.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK) 363 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 364 sf.sf_uc.uc_mcontext.mc_onstack = (oonstack) ? 1 : 0; 365 sf.sf_uc.uc_mcontext.mc_edi = regs->tf_rdi; 366 sf.sf_uc.uc_mcontext.mc_esi = regs->tf_rsi; 367 sf.sf_uc.uc_mcontext.mc_ebp = regs->tf_rbp; 368 sf.sf_uc.uc_mcontext.mc_isp = regs->tf_rsp; /* XXX */ 369 sf.sf_uc.uc_mcontext.mc_ebx = regs->tf_rbx; 370 sf.sf_uc.uc_mcontext.mc_edx = regs->tf_rdx; 371 sf.sf_uc.uc_mcontext.mc_ecx = regs->tf_rcx; 372 sf.sf_uc.uc_mcontext.mc_eax = regs->tf_rax; 373 sf.sf_uc.uc_mcontext.mc_trapno = regs->tf_trapno; 374 sf.sf_uc.uc_mcontext.mc_err = regs->tf_err; 375 sf.sf_uc.uc_mcontext.mc_eip = regs->tf_rip; 376 sf.sf_uc.uc_mcontext.mc_cs = regs->tf_cs; 377 sf.sf_uc.uc_mcontext.mc_eflags = regs->tf_rflags; 378 sf.sf_uc.uc_mcontext.mc_esp = regs->tf_rsp; 379 sf.sf_uc.uc_mcontext.mc_ss = regs->tf_ss; 380 sf.sf_uc.uc_mcontext.mc_ds = regs->tf_ds; 381 sf.sf_uc.uc_mcontext.mc_es = regs->tf_es; 382 sf.sf_uc.uc_mcontext.mc_fs = regs->tf_fs; 383 sf.sf_uc.uc_mcontext.mc_gs = regs->tf_gs; 384 bzero(sf.sf_uc.uc_mcontext.mc_fpregs, 385 sizeof(sf.sf_uc.uc_mcontext.mc_fpregs)); 386 bzero(sf.sf_uc.uc_mcontext.__spare__, 387 sizeof(sf.sf_uc.uc_mcontext.__spare__)); 388 bzero(sf.sf_uc.__spare__, sizeof(sf.sf_uc.__spare__)); 389 390 /* Allocate space for the signal handler context. */ 391 if ((td->td_pflags & TDP_ALTSTACK) != 0 && !oonstack && 392 SIGISMEMBER(psp->ps_sigonstack, sig)) { 393 sfp = (struct ia32_sigframe4 *)(td->td_sigstk.ss_sp + 394 td->td_sigstk.ss_size - sizeof(sf)); 395 } else 396 sfp = (struct ia32_sigframe4 *)regs->tf_rsp - 1; 397 PROC_UNLOCK(p); 398 399 /* Translate the signal if appropriate. */ 400 if (p->p_sysent->sv_sigtbl && sig <= p->p_sysent->sv_sigsize) 401 sig = p->p_sysent->sv_sigtbl[_SIG_IDX(sig)]; 402 403 /* Build the argument list for the signal handler. */ 404 sf.sf_signum = sig; 405 sf.sf_ucontext = (register_t)&sfp->sf_uc; 406 bzero(&sf.sf_si, sizeof(sf.sf_si)); 407 if (SIGISMEMBER(psp->ps_siginfo, sig)) { 408 /* Signal handler installed with SA_SIGINFO. */ 409 sf.sf_siginfo = (u_int32_t)(uintptr_t)&sfp->sf_si; 410 sf.sf_ah = (u_int32_t)(uintptr_t)catcher; 411 412 /* Fill in POSIX parts */ 413 sf.sf_si = siginfo; 414 sf.sf_si.si_signo = sig; 415 } else { 416 /* Old FreeBSD-style arguments. */ 417 sf.sf_siginfo = siginfo.si_code; 418 sf.sf_addr = (u_int32_t)siginfo.si_addr; 419 sf.sf_ah = (u_int32_t)(uintptr_t)catcher; 420 } 421 mtx_unlock(&psp->ps_mtx); 422 423 /* 424 * Copy the sigframe out to the user's stack. 425 */ 426 if (copyout(&sf, sfp, sizeof(*sfp)) != 0) { 427 #ifdef DEBUG 428 printf("process %ld has trashed its stack\n", (long)p->p_pid); 429 #endif 430 PROC_LOCK(p); 431 sigexit(td, SIGILL); 432 } 433 434 regs->tf_rsp = (uintptr_t)sfp; 435 regs->tf_rip = p->p_sysent->sv_psstrings - sz_freebsd4_ia32_sigcode; 436 regs->tf_rflags &= ~(PSL_T | PSL_D); 437 regs->tf_cs = _ucode32sel; 438 regs->tf_ss = _udatasel; 439 regs->tf_ds = _udatasel; 440 regs->tf_es = _udatasel; 441 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 442 /* leave user %fs and %gs untouched */ 443 PROC_LOCK(p); 444 mtx_lock(&psp->ps_mtx); 445 } 446 #endif /* COMPAT_FREEBSD4 */ 447 448 void 449 ia32_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask) 450 { 451 struct ia32_sigframe sf, *sfp; 452 struct siginfo32 siginfo; 453 struct proc *p; 454 struct thread *td; 455 struct sigacts *psp; 456 char *sp; 457 struct trapframe *regs; 458 char *xfpusave; 459 size_t xfpusave_len; 460 int oonstack; 461 int sig; 462 463 siginfo_to_siginfo32(&ksi->ksi_info, &siginfo); 464 td = curthread; 465 p = td->td_proc; 466 PROC_LOCK_ASSERT(p, MA_OWNED); 467 sig = siginfo.si_signo; 468 psp = p->p_sigacts; 469 #ifdef COMPAT_FREEBSD4 470 if (SIGISMEMBER(psp->ps_freebsd4, sig)) { 471 freebsd4_ia32_sendsig(catcher, ksi, mask); 472 return; 473 } 474 #endif 475 mtx_assert(&psp->ps_mtx, MA_OWNED); 476 regs = td->td_frame; 477 oonstack = sigonstack(regs->tf_rsp); 478 479 if (cpu_max_ext_state_size > sizeof(struct savefpu) && use_xsave) { 480 xfpusave_len = cpu_max_ext_state_size - sizeof(struct savefpu); 481 xfpusave = __builtin_alloca(xfpusave_len); 482 } else { 483 xfpusave_len = 0; 484 xfpusave = NULL; 485 } 486 487 /* Save user context. */ 488 bzero(&sf, sizeof(sf)); 489 sf.sf_uc.uc_sigmask = *mask; 490 sf.sf_uc.uc_stack.ss_sp = (uintptr_t)td->td_sigstk.ss_sp; 491 sf.sf_uc.uc_stack.ss_size = td->td_sigstk.ss_size; 492 sf.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK) 493 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 494 sf.sf_uc.uc_mcontext.mc_onstack = (oonstack) ? 1 : 0; 495 sf.sf_uc.uc_mcontext.mc_edi = regs->tf_rdi; 496 sf.sf_uc.uc_mcontext.mc_esi = regs->tf_rsi; 497 sf.sf_uc.uc_mcontext.mc_ebp = regs->tf_rbp; 498 sf.sf_uc.uc_mcontext.mc_isp = regs->tf_rsp; /* XXX */ 499 sf.sf_uc.uc_mcontext.mc_ebx = regs->tf_rbx; 500 sf.sf_uc.uc_mcontext.mc_edx = regs->tf_rdx; 501 sf.sf_uc.uc_mcontext.mc_ecx = regs->tf_rcx; 502 sf.sf_uc.uc_mcontext.mc_eax = regs->tf_rax; 503 sf.sf_uc.uc_mcontext.mc_trapno = regs->tf_trapno; 504 sf.sf_uc.uc_mcontext.mc_err = regs->tf_err; 505 sf.sf_uc.uc_mcontext.mc_eip = regs->tf_rip; 506 sf.sf_uc.uc_mcontext.mc_cs = regs->tf_cs; 507 sf.sf_uc.uc_mcontext.mc_eflags = regs->tf_rflags; 508 sf.sf_uc.uc_mcontext.mc_esp = regs->tf_rsp; 509 sf.sf_uc.uc_mcontext.mc_ss = regs->tf_ss; 510 sf.sf_uc.uc_mcontext.mc_ds = regs->tf_ds; 511 sf.sf_uc.uc_mcontext.mc_es = regs->tf_es; 512 sf.sf_uc.uc_mcontext.mc_fs = regs->tf_fs; 513 sf.sf_uc.uc_mcontext.mc_gs = regs->tf_gs; 514 sf.sf_uc.uc_mcontext.mc_len = sizeof(sf.sf_uc.uc_mcontext); /* magic */ 515 ia32_get_fpcontext(td, &sf.sf_uc.uc_mcontext, xfpusave, xfpusave_len); 516 fpstate_drop(td); 517 sf.sf_uc.uc_mcontext.mc_fsbase = td->td_pcb->pcb_fsbase; 518 sf.sf_uc.uc_mcontext.mc_gsbase = td->td_pcb->pcb_gsbase; 519 bzero(sf.sf_uc.__spare__, sizeof(sf.sf_uc.__spare__)); 520 521 /* Allocate space for the signal handler context. */ 522 if ((td->td_pflags & TDP_ALTSTACK) != 0 && !oonstack && 523 SIGISMEMBER(psp->ps_sigonstack, sig)) 524 sp = td->td_sigstk.ss_sp + td->td_sigstk.ss_size; 525 else 526 sp = (char *)regs->tf_rsp; 527 if (xfpusave != NULL) { 528 sp -= xfpusave_len; 529 sp = (char *)((unsigned long)sp & ~0x3Ful); 530 sf.sf_uc.uc_mcontext.mc_xfpustate = (register_t)sp; 531 } 532 sp -= sizeof(sf); 533 /* Align to 16 bytes. */ 534 sfp = (struct ia32_sigframe *)((uintptr_t)sp & ~0xF); 535 PROC_UNLOCK(p); 536 537 /* Translate the signal if appropriate. */ 538 if (p->p_sysent->sv_sigtbl && sig <= p->p_sysent->sv_sigsize) 539 sig = p->p_sysent->sv_sigtbl[_SIG_IDX(sig)]; 540 541 /* Build the argument list for the signal handler. */ 542 sf.sf_signum = sig; 543 sf.sf_ucontext = (register_t)&sfp->sf_uc; 544 bzero(&sf.sf_si, sizeof(sf.sf_si)); 545 if (SIGISMEMBER(psp->ps_siginfo, sig)) { 546 /* Signal handler installed with SA_SIGINFO. */ 547 sf.sf_siginfo = (u_int32_t)(uintptr_t)&sfp->sf_si; 548 sf.sf_ah = (u_int32_t)(uintptr_t)catcher; 549 550 /* Fill in POSIX parts */ 551 sf.sf_si = siginfo; 552 sf.sf_si.si_signo = sig; 553 } else { 554 /* Old FreeBSD-style arguments. */ 555 sf.sf_siginfo = siginfo.si_code; 556 sf.sf_addr = (u_int32_t)siginfo.si_addr; 557 sf.sf_ah = (u_int32_t)(uintptr_t)catcher; 558 } 559 mtx_unlock(&psp->ps_mtx); 560 561 /* 562 * Copy the sigframe out to the user's stack. 563 */ 564 if (copyout(&sf, sfp, sizeof(*sfp)) != 0 || 565 (xfpusave != NULL && copyout(xfpusave, 566 PTRIN(sf.sf_uc.uc_mcontext.mc_xfpustate), xfpusave_len) 567 != 0)) { 568 #ifdef DEBUG 569 printf("process %ld has trashed its stack\n", (long)p->p_pid); 570 #endif 571 PROC_LOCK(p); 572 sigexit(td, SIGILL); 573 } 574 575 regs->tf_rsp = (uintptr_t)sfp; 576 regs->tf_rip = p->p_sysent->sv_psstrings - *(p->p_sysent->sv_szsigcode); 577 regs->tf_rflags &= ~(PSL_T | PSL_D); 578 regs->tf_cs = _ucode32sel; 579 regs->tf_ss = _udatasel; 580 regs->tf_ds = _udatasel; 581 regs->tf_es = _udatasel; 582 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 583 /* XXXKIB leave user %fs and %gs untouched */ 584 PROC_LOCK(p); 585 mtx_lock(&psp->ps_mtx); 586 } 587 588 /* 589 * System call to cleanup state after a signal 590 * has been taken. Reset signal mask and 591 * stack state from context left by sendsig (above). 592 * Return to previous pc and psl as specified by 593 * context left by sendsig. Check carefully to 594 * make sure that the user has not modified the 595 * state to gain improper privileges. 596 */ 597 #ifdef COMPAT_FREEBSD4 598 /* 599 * MPSAFE 600 */ 601 int 602 freebsd4_freebsd32_sigreturn(td, uap) 603 struct thread *td; 604 struct freebsd4_freebsd32_sigreturn_args /* { 605 const struct freebsd4_freebsd32_ucontext *sigcntxp; 606 } */ *uap; 607 { 608 struct ia32_ucontext4 uc; 609 struct trapframe *regs; 610 struct ia32_ucontext4 *ucp; 611 int cs, eflags, error; 612 ksiginfo_t ksi; 613 614 error = copyin(uap->sigcntxp, &uc, sizeof(uc)); 615 if (error != 0) 616 return (error); 617 ucp = &uc; 618 regs = td->td_frame; 619 eflags = ucp->uc_mcontext.mc_eflags; 620 /* 621 * Don't allow users to change privileged or reserved flags. 622 */ 623 /* 624 * XXX do allow users to change the privileged flag PSL_RF. 625 * The cpu sets PSL_RF in tf_eflags for faults. Debuggers 626 * should sometimes set it there too. tf_eflags is kept in 627 * the signal context during signal handling and there is no 628 * other place to remember it, so the PSL_RF bit may be 629 * corrupted by the signal handler without us knowing. 630 * Corruption of the PSL_RF bit at worst causes one more or 631 * one less debugger trap, so allowing it is fairly harmless. 632 */ 633 if (!EFL_SECURE(eflags & ~PSL_RF, regs->tf_rflags & ~PSL_RF)) { 634 uprintf("pid %d (%s): freebsd4_freebsd32_sigreturn eflags = 0x%x\n", 635 td->td_proc->p_pid, td->td_name, eflags); 636 return (EINVAL); 637 } 638 639 /* 640 * Don't allow users to load a valid privileged %cs. Let the 641 * hardware check for invalid selectors, excess privilege in 642 * other selectors, invalid %eip's and invalid %esp's. 643 */ 644 cs = ucp->uc_mcontext.mc_cs; 645 if (!CS_SECURE(cs)) { 646 uprintf("pid %d (%s): freebsd4_sigreturn cs = 0x%x\n", 647 td->td_proc->p_pid, td->td_name, cs); 648 ksiginfo_init_trap(&ksi); 649 ksi.ksi_signo = SIGBUS; 650 ksi.ksi_code = BUS_OBJERR; 651 ksi.ksi_trapno = T_PROTFLT; 652 ksi.ksi_addr = (void *)regs->tf_rip; 653 trapsignal(td, &ksi); 654 return (EINVAL); 655 } 656 657 regs->tf_rdi = ucp->uc_mcontext.mc_edi; 658 regs->tf_rsi = ucp->uc_mcontext.mc_esi; 659 regs->tf_rbp = ucp->uc_mcontext.mc_ebp; 660 regs->tf_rbx = ucp->uc_mcontext.mc_ebx; 661 regs->tf_rdx = ucp->uc_mcontext.mc_edx; 662 regs->tf_rcx = ucp->uc_mcontext.mc_ecx; 663 regs->tf_rax = ucp->uc_mcontext.mc_eax; 664 regs->tf_trapno = ucp->uc_mcontext.mc_trapno; 665 regs->tf_err = ucp->uc_mcontext.mc_err; 666 regs->tf_rip = ucp->uc_mcontext.mc_eip; 667 regs->tf_cs = cs; 668 regs->tf_rflags = ucp->uc_mcontext.mc_eflags; 669 regs->tf_rsp = ucp->uc_mcontext.mc_esp; 670 regs->tf_ss = ucp->uc_mcontext.mc_ss; 671 regs->tf_ds = ucp->uc_mcontext.mc_ds; 672 regs->tf_es = ucp->uc_mcontext.mc_es; 673 regs->tf_fs = ucp->uc_mcontext.mc_fs; 674 regs->tf_gs = ucp->uc_mcontext.mc_gs; 675 676 kern_sigprocmask(td, SIG_SETMASK, &ucp->uc_sigmask, NULL, 0); 677 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 678 return (EJUSTRETURN); 679 } 680 #endif /* COMPAT_FREEBSD4 */ 681 682 /* 683 * MPSAFE 684 */ 685 int 686 freebsd32_sigreturn(td, uap) 687 struct thread *td; 688 struct freebsd32_sigreturn_args /* { 689 const struct freebsd32_ucontext *sigcntxp; 690 } */ *uap; 691 { 692 struct ia32_ucontext uc; 693 struct trapframe *regs; 694 struct ia32_ucontext *ucp; 695 char *xfpustate; 696 size_t xfpustate_len; 697 int cs, eflags, error, ret; 698 ksiginfo_t ksi; 699 700 error = copyin(uap->sigcntxp, &uc, sizeof(uc)); 701 if (error != 0) 702 return (error); 703 ucp = &uc; 704 regs = td->td_frame; 705 eflags = ucp->uc_mcontext.mc_eflags; 706 /* 707 * Don't allow users to change privileged or reserved flags. 708 */ 709 /* 710 * XXX do allow users to change the privileged flag PSL_RF. 711 * The cpu sets PSL_RF in tf_eflags for faults. Debuggers 712 * should sometimes set it there too. tf_eflags is kept in 713 * the signal context during signal handling and there is no 714 * other place to remember it, so the PSL_RF bit may be 715 * corrupted by the signal handler without us knowing. 716 * Corruption of the PSL_RF bit at worst causes one more or 717 * one less debugger trap, so allowing it is fairly harmless. 718 */ 719 if (!EFL_SECURE(eflags & ~PSL_RF, regs->tf_rflags & ~PSL_RF)) { 720 uprintf("pid %d (%s): freebsd32_sigreturn eflags = 0x%x\n", 721 td->td_proc->p_pid, td->td_name, eflags); 722 return (EINVAL); 723 } 724 725 /* 726 * Don't allow users to load a valid privileged %cs. Let the 727 * hardware check for invalid selectors, excess privilege in 728 * other selectors, invalid %eip's and invalid %esp's. 729 */ 730 cs = ucp->uc_mcontext.mc_cs; 731 if (!CS_SECURE(cs)) { 732 uprintf("pid %d (%s): sigreturn cs = 0x%x\n", 733 td->td_proc->p_pid, td->td_name, cs); 734 ksiginfo_init_trap(&ksi); 735 ksi.ksi_signo = SIGBUS; 736 ksi.ksi_code = BUS_OBJERR; 737 ksi.ksi_trapno = T_PROTFLT; 738 ksi.ksi_addr = (void *)regs->tf_rip; 739 trapsignal(td, &ksi); 740 return (EINVAL); 741 } 742 743 if ((ucp->uc_mcontext.mc_flags & _MC_HASFPXSTATE) != 0) { 744 xfpustate_len = uc.uc_mcontext.mc_xfpustate_len; 745 if (xfpustate_len > cpu_max_ext_state_size - 746 sizeof(struct savefpu)) { 747 uprintf("pid %d (%s): sigreturn xfpusave_len = 0x%zx\n", 748 td->td_proc->p_pid, td->td_name, xfpustate_len); 749 return (EINVAL); 750 } 751 xfpustate = __builtin_alloca(xfpustate_len); 752 error = copyin(PTRIN(ucp->uc_mcontext.mc_xfpustate), 753 xfpustate, xfpustate_len); 754 if (error != 0) { 755 uprintf( 756 "pid %d (%s): sigreturn copying xfpustate failed\n", 757 td->td_proc->p_pid, td->td_name); 758 return (error); 759 } 760 } else { 761 xfpustate = NULL; 762 xfpustate_len = 0; 763 } 764 ret = ia32_set_fpcontext(td, &ucp->uc_mcontext, xfpustate, 765 xfpustate_len); 766 if (ret != 0) { 767 uprintf("pid %d (%s): sigreturn set_fpcontext err %d\n", 768 td->td_proc->p_pid, td->td_name, ret); 769 return (ret); 770 } 771 772 regs->tf_rdi = ucp->uc_mcontext.mc_edi; 773 regs->tf_rsi = ucp->uc_mcontext.mc_esi; 774 regs->tf_rbp = ucp->uc_mcontext.mc_ebp; 775 regs->tf_rbx = ucp->uc_mcontext.mc_ebx; 776 regs->tf_rdx = ucp->uc_mcontext.mc_edx; 777 regs->tf_rcx = ucp->uc_mcontext.mc_ecx; 778 regs->tf_rax = ucp->uc_mcontext.mc_eax; 779 regs->tf_trapno = ucp->uc_mcontext.mc_trapno; 780 regs->tf_err = ucp->uc_mcontext.mc_err; 781 regs->tf_rip = ucp->uc_mcontext.mc_eip; 782 regs->tf_cs = cs; 783 regs->tf_rflags = ucp->uc_mcontext.mc_eflags; 784 regs->tf_rsp = ucp->uc_mcontext.mc_esp; 785 regs->tf_ss = ucp->uc_mcontext.mc_ss; 786 regs->tf_ds = ucp->uc_mcontext.mc_ds; 787 regs->tf_es = ucp->uc_mcontext.mc_es; 788 regs->tf_fs = ucp->uc_mcontext.mc_fs; 789 regs->tf_gs = ucp->uc_mcontext.mc_gs; 790 regs->tf_flags = TF_HASSEGS; 791 792 kern_sigprocmask(td, SIG_SETMASK, &ucp->uc_sigmask, NULL, 0); 793 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 794 return (EJUSTRETURN); 795 } 796 797 /* 798 * Clear registers on exec 799 */ 800 void 801 ia32_setregs(td, entry, stack, ps_strings) 802 struct thread *td; 803 u_long entry; 804 u_long stack; 805 u_long ps_strings; 806 { 807 struct trapframe *regs = td->td_frame; 808 struct pcb *pcb = td->td_pcb; 809 810 mtx_lock(&dt_lock); 811 if (td->td_proc->p_md.md_ldt != NULL) 812 user_ldt_free(td); 813 else 814 mtx_unlock(&dt_lock); 815 816 pcb->pcb_fsbase = 0; 817 pcb->pcb_gsbase = 0; 818 pcb->pcb_initial_fpucw = __INITIAL_FPUCW_I386__; 819 820 bzero((char *)regs, sizeof(struct trapframe)); 821 regs->tf_rip = entry; 822 regs->tf_rsp = stack; 823 regs->tf_rflags = PSL_USER | (regs->tf_rflags & PSL_T); 824 regs->tf_ss = _udatasel; 825 regs->tf_cs = _ucode32sel; 826 regs->tf_rbx = ps_strings; 827 regs->tf_ds = _udatasel; 828 regs->tf_es = _udatasel; 829 regs->tf_fs = _ufssel; 830 regs->tf_gs = _ugssel; 831 regs->tf_flags = TF_HASSEGS; 832 833 fpstate_drop(td); 834 835 /* Return via doreti so that we can change to a different %cs */ 836 set_pcb_flags(pcb, PCB_32BIT | PCB_FULL_IRET); 837 clear_pcb_flags(pcb, PCB_GS32BIT); 838 td->td_retval[1] = 0; 839 }
Cache object: 965df09611cbc6b058c02beb8375e6f4
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