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("$FreeBSD$"); 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/sysctl.h> 59 #include <sys/sysent.h> 60 #include <sys/vnode.h> 61 62 #include <vm/vm.h> 63 #include <vm/vm_kern.h> 64 #include <vm/vm_param.h> 65 #include <vm/pmap.h> 66 #include <vm/vm_map.h> 67 #include <vm/vm_object.h> 68 #include <vm/vm_extern.h> 69 70 #include <compat/freebsd32/freebsd32_signal.h> 71 #include <compat/freebsd32/freebsd32_util.h> 72 #include <compat/freebsd32/freebsd32_proto.h> 73 #include <compat/ia32/ia32_signal.h> 74 #include <machine/psl.h> 75 #include <machine/segments.h> 76 #include <machine/specialreg.h> 77 #include <machine/frame.h> 78 #include <machine/md_var.h> 79 #include <machine/pcb.h> 80 #include <machine/cpufunc.h> 81 82 #ifdef COMPAT_FREEBSD4 83 static void freebsd4_ia32_sendsig(sig_t, ksiginfo_t *, sigset_t *); 84 #endif 85 static void ia32_get_fpcontext(struct thread *td, struct ia32_mcontext *mcp); 86 static int ia32_set_fpcontext(struct thread *td, const struct ia32_mcontext *mcp); 87 88 extern int _ucode32sel, _udatasel; 89 90 #define CS_SECURE(cs) (ISPL(cs) == SEL_UPL) 91 #define EFL_SECURE(ef, oef) ((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0) 92 93 static void 94 ia32_get_fpcontext(struct thread *td, struct ia32_mcontext *mcp) 95 { 96 97 mcp->mc_ownedfp = fpugetregs(td, (struct savefpu *)&mcp->mc_fpstate); 98 mcp->mc_fpformat = fpuformat(); 99 } 100 101 static int 102 ia32_set_fpcontext(struct thread *td, const struct ia32_mcontext *mcp) 103 { 104 105 if (mcp->mc_fpformat == _MC_FPFMT_NODEV) 106 return (0); 107 else if (mcp->mc_fpformat != _MC_FPFMT_XMM) 108 return (EINVAL); 109 else if (mcp->mc_ownedfp == _MC_FPOWNED_NONE) 110 /* We don't care what state is left in the FPU or PCB. */ 111 fpstate_drop(td); 112 else if (mcp->mc_ownedfp == _MC_FPOWNED_FPU || 113 mcp->mc_ownedfp == _MC_FPOWNED_PCB) { 114 /* 115 * XXX we violate the dubious requirement that fpusetregs() 116 * be called with interrupts disabled. 117 */ 118 fpusetregs(td, (struct savefpu *)&mcp->mc_fpstate); 119 } else 120 return (EINVAL); 121 return (0); 122 } 123 124 /* 125 * Get machine context. 126 */ 127 static int 128 ia32_get_mcontext(struct thread *td, struct ia32_mcontext *mcp, int flags) 129 { 130 struct trapframe *tp; 131 132 tp = td->td_frame; 133 134 PROC_LOCK(curthread->td_proc); 135 mcp->mc_onstack = sigonstack(tp->tf_rsp); 136 PROC_UNLOCK(curthread->td_proc); 137 mcp->mc_gs = td->td_pcb->pcb_gs; 138 mcp->mc_fs = td->td_pcb->pcb_fs; 139 mcp->mc_es = td->td_pcb->pcb_es; 140 mcp->mc_ds = td->td_pcb->pcb_ds; 141 mcp->mc_edi = tp->tf_rdi; 142 mcp->mc_esi = tp->tf_rsi; 143 mcp->mc_ebp = tp->tf_rbp; 144 mcp->mc_isp = tp->tf_rsp; 145 if (flags & GET_MC_CLEAR_RET) { 146 mcp->mc_eax = 0; 147 mcp->mc_edx = 0; 148 } else { 149 mcp->mc_eax = tp->tf_rax; 150 mcp->mc_edx = tp->tf_rdx; 151 } 152 mcp->mc_ebx = tp->tf_rbx; 153 mcp->mc_ecx = tp->tf_rcx; 154 mcp->mc_eip = tp->tf_rip; 155 mcp->mc_cs = tp->tf_cs; 156 mcp->mc_eflags = tp->tf_rflags; 157 mcp->mc_esp = tp->tf_rsp; 158 mcp->mc_ss = tp->tf_ss; 159 mcp->mc_len = sizeof(*mcp); 160 ia32_get_fpcontext(td, mcp); 161 return (0); 162 } 163 164 /* 165 * Set machine context. 166 * 167 * However, we don't set any but the user modifiable flags, and we won't 168 * touch the cs selector. 169 */ 170 static int 171 ia32_set_mcontext(struct thread *td, const struct ia32_mcontext *mcp) 172 { 173 struct trapframe *tp; 174 long rflags; 175 int ret; 176 177 tp = td->td_frame; 178 if (mcp->mc_len != sizeof(*mcp)) 179 return (EINVAL); 180 rflags = (mcp->mc_eflags & PSL_USERCHANGE) | 181 (tp->tf_rflags & ~PSL_USERCHANGE); 182 ret = ia32_set_fpcontext(td, mcp); 183 if (ret != 0) 184 return (ret); 185 #if 0 /* XXX deal with load_fs() and friends */ 186 tp->tf_fs = mcp->mc_fs; 187 tp->tf_es = mcp->mc_es; 188 tp->tf_ds = mcp->mc_ds; 189 #endif 190 tp->tf_rdi = mcp->mc_edi; 191 tp->tf_rsi = mcp->mc_esi; 192 tp->tf_rbp = mcp->mc_ebp; 193 tp->tf_rbx = mcp->mc_ebx; 194 tp->tf_rdx = mcp->mc_edx; 195 tp->tf_rcx = mcp->mc_ecx; 196 tp->tf_rax = mcp->mc_eax; 197 /* trapno, err */ 198 tp->tf_rip = mcp->mc_eip; 199 tp->tf_rflags = rflags; 200 tp->tf_rsp = mcp->mc_esp; 201 tp->tf_ss = mcp->mc_ss; 202 #if 0 /* XXX deal with load_gs() and friends */ 203 td->td_pcb->pcb_gs = mcp->mc_gs; 204 #endif 205 td->td_pcb->pcb_flags |= PCB_FULLCTX; 206 return (0); 207 } 208 209 /* 210 * The first two fields of a ucontext_t are the signal mask and 211 * the machine context. The next field is uc_link; we want to 212 * avoid destroying the link when copying out contexts. 213 */ 214 #define UC_COPY_SIZE offsetof(struct ia32_ucontext, uc_link) 215 216 int 217 freebsd32_getcontext(struct thread *td, struct freebsd32_getcontext_args *uap) 218 { 219 struct ia32_ucontext uc; 220 int ret; 221 222 if (uap->ucp == NULL) 223 ret = EINVAL; 224 else { 225 ia32_get_mcontext(td, &uc.uc_mcontext, GET_MC_CLEAR_RET); 226 PROC_LOCK(td->td_proc); 227 uc.uc_sigmask = td->td_sigmask; 228 PROC_UNLOCK(td->td_proc); 229 ret = copyout(&uc, uap->ucp, UC_COPY_SIZE); 230 } 231 return (ret); 232 } 233 234 int 235 freebsd32_setcontext(struct thread *td, struct freebsd32_setcontext_args *uap) 236 { 237 struct ia32_ucontext uc; 238 int ret; 239 240 if (uap->ucp == NULL) 241 ret = EINVAL; 242 else { 243 ret = copyin(uap->ucp, &uc, UC_COPY_SIZE); 244 if (ret == 0) { 245 ret = ia32_set_mcontext(td, &uc.uc_mcontext); 246 if (ret == 0) { 247 SIG_CANTMASK(uc.uc_sigmask); 248 PROC_LOCK(td->td_proc); 249 td->td_sigmask = uc.uc_sigmask; 250 PROC_UNLOCK(td->td_proc); 251 } 252 } 253 } 254 return (ret == 0 ? EJUSTRETURN : ret); 255 } 256 257 int 258 freebsd32_swapcontext(struct thread *td, struct freebsd32_swapcontext_args *uap) 259 { 260 struct ia32_ucontext uc; 261 int ret; 262 263 if (uap->oucp == NULL || uap->ucp == NULL) 264 ret = EINVAL; 265 else { 266 ia32_get_mcontext(td, &uc.uc_mcontext, GET_MC_CLEAR_RET); 267 PROC_LOCK(td->td_proc); 268 uc.uc_sigmask = td->td_sigmask; 269 PROC_UNLOCK(td->td_proc); 270 ret = copyout(&uc, uap->oucp, UC_COPY_SIZE); 271 if (ret == 0) { 272 ret = copyin(uap->ucp, &uc, UC_COPY_SIZE); 273 if (ret == 0) { 274 ret = ia32_set_mcontext(td, &uc.uc_mcontext); 275 if (ret == 0) { 276 SIG_CANTMASK(uc.uc_sigmask); 277 PROC_LOCK(td->td_proc); 278 td->td_sigmask = uc.uc_sigmask; 279 PROC_UNLOCK(td->td_proc); 280 } 281 } 282 } 283 } 284 return (ret == 0 ? EJUSTRETURN : ret); 285 } 286 287 /* 288 * Send an interrupt to process. 289 * 290 * Stack is set up to allow sigcode stored 291 * at top to call routine, followed by kcall 292 * to sigreturn routine below. After sigreturn 293 * resets the signal mask, the stack, and the 294 * frame pointer, it returns to the user 295 * specified pc, psl. 296 */ 297 #ifdef COMPAT_FREEBSD4 298 static void 299 freebsd4_ia32_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask) 300 { 301 struct ia32_sigframe4 sf, *sfp; 302 struct siginfo32 siginfo; 303 struct proc *p; 304 struct thread *td; 305 struct sigacts *psp; 306 struct trapframe *regs; 307 int oonstack; 308 int sig; 309 310 td = curthread; 311 p = td->td_proc; 312 siginfo_to_siginfo32(&ksi->ksi_info, &siginfo); 313 314 PROC_LOCK_ASSERT(p, MA_OWNED); 315 sig = siginfo.si_signo; 316 psp = p->p_sigacts; 317 mtx_assert(&psp->ps_mtx, MA_OWNED); 318 regs = td->td_frame; 319 oonstack = sigonstack(regs->tf_rsp); 320 321 /* Save user context. */ 322 bzero(&sf, sizeof(sf)); 323 sf.sf_uc.uc_sigmask = *mask; 324 sf.sf_uc.uc_stack.ss_sp = (uintptr_t)td->td_sigstk.ss_sp; 325 sf.sf_uc.uc_stack.ss_size = td->td_sigstk.ss_size; 326 sf.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK) 327 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 328 sf.sf_uc.uc_mcontext.mc_onstack = (oonstack) ? 1 : 0; 329 sf.sf_uc.uc_mcontext.mc_gs = rgs(); 330 sf.sf_uc.uc_mcontext.mc_fs = rfs(); 331 __asm __volatile("movl %%es,%0" : "=rm" (sf.sf_uc.uc_mcontext.mc_es)); 332 __asm __volatile("movl %%ds,%0" : "=rm" (sf.sf_uc.uc_mcontext.mc_ds)); 333 sf.sf_uc.uc_mcontext.mc_edi = regs->tf_rdi; 334 sf.sf_uc.uc_mcontext.mc_esi = regs->tf_rsi; 335 sf.sf_uc.uc_mcontext.mc_ebp = regs->tf_rbp; 336 sf.sf_uc.uc_mcontext.mc_isp = regs->tf_rsp; /* XXX */ 337 sf.sf_uc.uc_mcontext.mc_ebx = regs->tf_rbx; 338 sf.sf_uc.uc_mcontext.mc_edx = regs->tf_rdx; 339 sf.sf_uc.uc_mcontext.mc_ecx = regs->tf_rcx; 340 sf.sf_uc.uc_mcontext.mc_eax = regs->tf_rax; 341 sf.sf_uc.uc_mcontext.mc_trapno = regs->tf_trapno; 342 sf.sf_uc.uc_mcontext.mc_err = regs->tf_err; 343 sf.sf_uc.uc_mcontext.mc_eip = regs->tf_rip; 344 sf.sf_uc.uc_mcontext.mc_cs = regs->tf_cs; 345 sf.sf_uc.uc_mcontext.mc_eflags = regs->tf_rflags; 346 sf.sf_uc.uc_mcontext.mc_esp = regs->tf_rsp; 347 sf.sf_uc.uc_mcontext.mc_ss = regs->tf_ss; 348 349 /* Allocate space for the signal handler context. */ 350 if ((td->td_pflags & TDP_ALTSTACK) != 0 && !oonstack && 351 SIGISMEMBER(psp->ps_sigonstack, sig)) { 352 sfp = (struct ia32_sigframe4 *)(td->td_sigstk.ss_sp + 353 td->td_sigstk.ss_size - sizeof(sf)); 354 } else 355 sfp = (struct ia32_sigframe4 *)regs->tf_rsp - 1; 356 PROC_UNLOCK(p); 357 358 /* Translate the signal if appropriate. */ 359 if (p->p_sysent->sv_sigtbl && sig <= p->p_sysent->sv_sigsize) 360 sig = p->p_sysent->sv_sigtbl[_SIG_IDX(sig)]; 361 362 /* Build the argument list for the signal handler. */ 363 sf.sf_signum = sig; 364 sf.sf_ucontext = (register_t)&sfp->sf_uc; 365 if (SIGISMEMBER(psp->ps_siginfo, sig)) { 366 /* Signal handler installed with SA_SIGINFO. */ 367 sf.sf_siginfo = (u_int32_t)(uintptr_t)&sfp->sf_si; 368 sf.sf_ah = (u_int32_t)(uintptr_t)catcher; 369 370 /* Fill in POSIX parts */ 371 sf.sf_si = siginfo; 372 sf.sf_si.si_signo = sig; 373 } else { 374 /* Old FreeBSD-style arguments. */ 375 sf.sf_siginfo = siginfo.si_code; 376 sf.sf_addr = (u_int32_t)siginfo.si_addr; 377 sf.sf_ah = (u_int32_t)(uintptr_t)catcher; 378 } 379 mtx_unlock(&psp->ps_mtx); 380 381 /* 382 * Copy the sigframe out to the user's stack. 383 */ 384 if (copyout(&sf, sfp, sizeof(*sfp)) != 0) { 385 #ifdef DEBUG 386 printf("process %ld has trashed its stack\n", (long)p->p_pid); 387 #endif 388 PROC_LOCK(p); 389 sigexit(td, SIGILL); 390 } 391 392 regs->tf_rsp = (uintptr_t)sfp; 393 regs->tf_rip = FREEBSD32_PS_STRINGS - sz_freebsd4_ia32_sigcode; 394 regs->tf_rflags &= ~(PSL_T | PSL_D); 395 regs->tf_cs = _ucode32sel; 396 regs->tf_ss = _udatasel; 397 load_ds(_udatasel); 398 td->td_pcb->pcb_ds = _udatasel; 399 load_es(_udatasel); 400 td->td_pcb->pcb_es = _udatasel; 401 /* leave user %fs and %gs untouched */ 402 PROC_LOCK(p); 403 mtx_lock(&psp->ps_mtx); 404 } 405 #endif /* COMPAT_FREEBSD4 */ 406 407 void 408 ia32_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask) 409 { 410 struct ia32_sigframe sf, *sfp; 411 struct siginfo32 siginfo; 412 struct proc *p; 413 struct thread *td; 414 struct sigacts *psp; 415 char *sp; 416 struct trapframe *regs; 417 int oonstack; 418 int sig; 419 420 siginfo_to_siginfo32(&ksi->ksi_info, &siginfo); 421 td = curthread; 422 p = td->td_proc; 423 PROC_LOCK_ASSERT(p, MA_OWNED); 424 sig = siginfo.si_signo; 425 psp = p->p_sigacts; 426 #ifdef COMPAT_FREEBSD4 427 if (SIGISMEMBER(psp->ps_freebsd4, sig)) { 428 freebsd4_ia32_sendsig(catcher, ksi, mask); 429 return; 430 } 431 #endif 432 mtx_assert(&psp->ps_mtx, MA_OWNED); 433 regs = td->td_frame; 434 oonstack = sigonstack(regs->tf_rsp); 435 436 /* Save user context. */ 437 bzero(&sf, sizeof(sf)); 438 sf.sf_uc.uc_sigmask = *mask; 439 sf.sf_uc.uc_stack.ss_sp = (uintptr_t)td->td_sigstk.ss_sp; 440 sf.sf_uc.uc_stack.ss_size = td->td_sigstk.ss_size; 441 sf.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK) 442 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 443 sf.sf_uc.uc_mcontext.mc_onstack = (oonstack) ? 1 : 0; 444 sf.sf_uc.uc_mcontext.mc_gs = rgs(); 445 sf.sf_uc.uc_mcontext.mc_fs = rfs(); 446 __asm __volatile("movl %%es,%0" : "=rm" (sf.sf_uc.uc_mcontext.mc_es)); 447 __asm __volatile("movl %%ds,%0" : "=rm" (sf.sf_uc.uc_mcontext.mc_ds)); 448 sf.sf_uc.uc_mcontext.mc_edi = regs->tf_rdi; 449 sf.sf_uc.uc_mcontext.mc_esi = regs->tf_rsi; 450 sf.sf_uc.uc_mcontext.mc_ebp = regs->tf_rbp; 451 sf.sf_uc.uc_mcontext.mc_isp = regs->tf_rsp; /* XXX */ 452 sf.sf_uc.uc_mcontext.mc_ebx = regs->tf_rbx; 453 sf.sf_uc.uc_mcontext.mc_edx = regs->tf_rdx; 454 sf.sf_uc.uc_mcontext.mc_ecx = regs->tf_rcx; 455 sf.sf_uc.uc_mcontext.mc_eax = regs->tf_rax; 456 sf.sf_uc.uc_mcontext.mc_trapno = regs->tf_trapno; 457 sf.sf_uc.uc_mcontext.mc_err = regs->tf_err; 458 sf.sf_uc.uc_mcontext.mc_eip = regs->tf_rip; 459 sf.sf_uc.uc_mcontext.mc_cs = regs->tf_cs; 460 sf.sf_uc.uc_mcontext.mc_eflags = regs->tf_rflags; 461 sf.sf_uc.uc_mcontext.mc_esp = regs->tf_rsp; 462 sf.sf_uc.uc_mcontext.mc_ss = regs->tf_ss; 463 sf.sf_uc.uc_mcontext.mc_len = sizeof(sf.sf_uc.uc_mcontext); /* magic */ 464 ia32_get_fpcontext(td, &sf.sf_uc.uc_mcontext); 465 fpstate_drop(td); 466 467 /* Allocate space for the signal handler context. */ 468 if ((td->td_pflags & TDP_ALTSTACK) != 0 && !oonstack && 469 SIGISMEMBER(psp->ps_sigonstack, sig)) { 470 sp = td->td_sigstk.ss_sp + 471 td->td_sigstk.ss_size - sizeof(sf); 472 } else 473 sp = (char *)regs->tf_rsp - sizeof(sf); 474 /* Align to 16 bytes. */ 475 sfp = (struct ia32_sigframe *)((uintptr_t)sp & ~0xF); 476 PROC_UNLOCK(p); 477 478 /* Translate the signal if appropriate. */ 479 if (p->p_sysent->sv_sigtbl && sig <= p->p_sysent->sv_sigsize) 480 sig = p->p_sysent->sv_sigtbl[_SIG_IDX(sig)]; 481 482 /* Build the argument list for the signal handler. */ 483 sf.sf_signum = sig; 484 sf.sf_ucontext = (register_t)&sfp->sf_uc; 485 if (SIGISMEMBER(psp->ps_siginfo, sig)) { 486 /* Signal handler installed with SA_SIGINFO. */ 487 sf.sf_siginfo = (u_int32_t)(uintptr_t)&sfp->sf_si; 488 sf.sf_ah = (u_int32_t)(uintptr_t)catcher; 489 490 /* Fill in POSIX parts */ 491 sf.sf_si = siginfo; 492 sf.sf_si.si_signo = sig; 493 } else { 494 /* Old FreeBSD-style arguments. */ 495 sf.sf_siginfo = siginfo.si_code; 496 sf.sf_addr = (u_int32_t)siginfo.si_addr; 497 sf.sf_ah = (u_int32_t)(uintptr_t)catcher; 498 } 499 mtx_unlock(&psp->ps_mtx); 500 501 /* 502 * Copy the sigframe out to the user's stack. 503 */ 504 if (copyout(&sf, sfp, sizeof(*sfp)) != 0) { 505 #ifdef DEBUG 506 printf("process %ld has trashed its stack\n", (long)p->p_pid); 507 #endif 508 PROC_LOCK(p); 509 sigexit(td, SIGILL); 510 } 511 512 regs->tf_rsp = (uintptr_t)sfp; 513 regs->tf_rip = FREEBSD32_PS_STRINGS - *(p->p_sysent->sv_szsigcode); 514 regs->tf_rflags &= ~(PSL_T | PSL_D); 515 regs->tf_cs = _ucode32sel; 516 regs->tf_ss = _udatasel; 517 load_ds(_udatasel); 518 td->td_pcb->pcb_ds = _udatasel; 519 load_es(_udatasel); 520 td->td_pcb->pcb_es = _udatasel; 521 /* leave user %fs and %gs untouched */ 522 PROC_LOCK(p); 523 mtx_lock(&psp->ps_mtx); 524 } 525 526 /* 527 * System call to cleanup state after a signal 528 * has been taken. Reset signal mask and 529 * stack state from context left by sendsig (above). 530 * Return to previous pc and psl as specified by 531 * context left by sendsig. Check carefully to 532 * make sure that the user has not modified the 533 * state to gain improper privileges. 534 */ 535 #ifdef COMPAT_FREEBSD4 536 /* 537 * MPSAFE 538 */ 539 int 540 freebsd4_freebsd32_sigreturn(td, uap) 541 struct thread *td; 542 struct freebsd4_freebsd32_sigreturn_args /* { 543 const struct freebsd4_freebsd32_ucontext *sigcntxp; 544 } */ *uap; 545 { 546 struct ia32_ucontext4 uc; 547 struct proc *p = td->td_proc; 548 struct trapframe *regs; 549 const struct ia32_ucontext4 *ucp; 550 int cs, eflags, error; 551 ksiginfo_t ksi; 552 553 error = copyin(uap->sigcntxp, &uc, sizeof(uc)); 554 if (error != 0) 555 return (error); 556 ucp = &uc; 557 regs = td->td_frame; 558 eflags = ucp->uc_mcontext.mc_eflags; 559 /* 560 * Don't allow users to change privileged or reserved flags. 561 */ 562 /* 563 * XXX do allow users to change the privileged flag PSL_RF. 564 * The cpu sets PSL_RF in tf_eflags for faults. Debuggers 565 * should sometimes set it there too. tf_eflags is kept in 566 * the signal context during signal handling and there is no 567 * other place to remember it, so the PSL_RF bit may be 568 * corrupted by the signal handler without us knowing. 569 * Corruption of the PSL_RF bit at worst causes one more or 570 * one less debugger trap, so allowing it is fairly harmless. 571 */ 572 if (!EFL_SECURE(eflags & ~PSL_RF, regs->tf_rflags & ~PSL_RF)) { 573 printf("freebsd4_freebsd32_sigreturn: eflags = 0x%x\n", eflags); 574 return (EINVAL); 575 } 576 577 /* 578 * Don't allow users to load a valid privileged %cs. Let the 579 * hardware check for invalid selectors, excess privilege in 580 * other selectors, invalid %eip's and invalid %esp's. 581 */ 582 cs = ucp->uc_mcontext.mc_cs; 583 if (!CS_SECURE(cs)) { 584 printf("freebsd4_sigreturn: cs = 0x%x\n", cs); 585 ksiginfo_init_trap(&ksi); 586 ksi.ksi_signo = SIGBUS; 587 ksi.ksi_code = BUS_OBJERR; 588 ksi.ksi_trapno = T_PROTFLT; 589 ksi.ksi_addr = (void *)regs->tf_rip; 590 trapsignal(td, &ksi); 591 return (EINVAL); 592 } 593 594 /* Segment selectors restored by sigtramp.S */ 595 regs->tf_rdi = ucp->uc_mcontext.mc_edi; 596 regs->tf_rsi = ucp->uc_mcontext.mc_esi; 597 regs->tf_rbp = ucp->uc_mcontext.mc_ebp; 598 regs->tf_rbx = ucp->uc_mcontext.mc_ebx; 599 regs->tf_rdx = ucp->uc_mcontext.mc_edx; 600 regs->tf_rcx = ucp->uc_mcontext.mc_ecx; 601 regs->tf_rax = ucp->uc_mcontext.mc_eax; 602 regs->tf_trapno = ucp->uc_mcontext.mc_trapno; 603 regs->tf_err = ucp->uc_mcontext.mc_err; 604 regs->tf_rip = ucp->uc_mcontext.mc_eip; 605 regs->tf_cs = cs; 606 regs->tf_rflags = ucp->uc_mcontext.mc_eflags; 607 regs->tf_rsp = ucp->uc_mcontext.mc_esp; 608 regs->tf_ss = ucp->uc_mcontext.mc_ss; 609 610 PROC_LOCK(p); 611 td->td_sigmask = ucp->uc_sigmask; 612 SIG_CANTMASK(td->td_sigmask); 613 signotify(td); 614 PROC_UNLOCK(p); 615 return (EJUSTRETURN); 616 } 617 #endif /* COMPAT_FREEBSD4 */ 618 619 /* 620 * MPSAFE 621 */ 622 int 623 freebsd32_sigreturn(td, uap) 624 struct thread *td; 625 struct freebsd32_sigreturn_args /* { 626 const struct freebsd32_ucontext *sigcntxp; 627 } */ *uap; 628 { 629 struct ia32_ucontext uc; 630 struct proc *p = td->td_proc; 631 struct trapframe *regs; 632 const struct ia32_ucontext *ucp; 633 int cs, eflags, error, ret; 634 ksiginfo_t ksi; 635 636 error = copyin(uap->sigcntxp, &uc, sizeof(uc)); 637 if (error != 0) 638 return (error); 639 ucp = &uc; 640 regs = td->td_frame; 641 eflags = ucp->uc_mcontext.mc_eflags; 642 /* 643 * Don't allow users to change privileged or reserved flags. 644 */ 645 /* 646 * XXX do allow users to change the privileged flag PSL_RF. 647 * The cpu sets PSL_RF in tf_eflags for faults. Debuggers 648 * should sometimes set it there too. tf_eflags is kept in 649 * the signal context during signal handling and there is no 650 * other place to remember it, so the PSL_RF bit may be 651 * corrupted by the signal handler without us knowing. 652 * Corruption of the PSL_RF bit at worst causes one more or 653 * one less debugger trap, so allowing it is fairly harmless. 654 */ 655 if (!EFL_SECURE(eflags & ~PSL_RF, regs->tf_rflags & ~PSL_RF)) { 656 printf("freebsd32_sigreturn: eflags = 0x%x\n", eflags); 657 return (EINVAL); 658 } 659 660 /* 661 * Don't allow users to load a valid privileged %cs. Let the 662 * hardware check for invalid selectors, excess privilege in 663 * other selectors, invalid %eip's and invalid %esp's. 664 */ 665 cs = ucp->uc_mcontext.mc_cs; 666 if (!CS_SECURE(cs)) { 667 printf("sigreturn: cs = 0x%x\n", cs); 668 ksiginfo_init_trap(&ksi); 669 ksi.ksi_signo = SIGBUS; 670 ksi.ksi_code = BUS_OBJERR; 671 ksi.ksi_trapno = T_PROTFLT; 672 ksi.ksi_addr = (void *)regs->tf_rip; 673 trapsignal(td, &ksi); 674 return (EINVAL); 675 } 676 677 ret = ia32_set_fpcontext(td, &ucp->uc_mcontext); 678 if (ret != 0) 679 return (ret); 680 681 /* Segment selectors restored by sigtramp.S */ 682 regs->tf_rdi = ucp->uc_mcontext.mc_edi; 683 regs->tf_rsi = ucp->uc_mcontext.mc_esi; 684 regs->tf_rbp = ucp->uc_mcontext.mc_ebp; 685 regs->tf_rbx = ucp->uc_mcontext.mc_ebx; 686 regs->tf_rdx = ucp->uc_mcontext.mc_edx; 687 regs->tf_rcx = ucp->uc_mcontext.mc_ecx; 688 regs->tf_rax = ucp->uc_mcontext.mc_eax; 689 regs->tf_trapno = ucp->uc_mcontext.mc_trapno; 690 regs->tf_err = ucp->uc_mcontext.mc_err; 691 regs->tf_rip = ucp->uc_mcontext.mc_eip; 692 regs->tf_cs = cs; 693 regs->tf_rflags = ucp->uc_mcontext.mc_eflags; 694 regs->tf_rsp = ucp->uc_mcontext.mc_esp; 695 regs->tf_ss = ucp->uc_mcontext.mc_ss; 696 697 PROC_LOCK(p); 698 td->td_sigmask = ucp->uc_sigmask; 699 SIG_CANTMASK(td->td_sigmask); 700 signotify(td); 701 PROC_UNLOCK(p); 702 return (EJUSTRETURN); 703 } 704 705 /* 706 * Clear registers on exec 707 */ 708 void 709 ia32_setregs(td, entry, stack, ps_strings) 710 struct thread *td; 711 u_long entry; 712 u_long stack; 713 u_long ps_strings; 714 { 715 struct trapframe *regs = td->td_frame; 716 struct pcb *pcb = td->td_pcb; 717 718 critical_enter(); 719 wrmsr(MSR_FSBASE, 0); 720 wrmsr(MSR_KGSBASE, 0); /* User value while we're in the kernel */ 721 pcb->pcb_fsbase = 0; 722 pcb->pcb_gsbase = 0; 723 critical_exit(); 724 load_ds(_udatasel); 725 load_es(_udatasel); 726 load_fs(_udatasel); 727 load_gs(_udatasel); 728 pcb->pcb_ds = _udatasel; 729 pcb->pcb_es = _udatasel; 730 pcb->pcb_fs = _udatasel; 731 pcb->pcb_gs = _udatasel; 732 733 bzero((char *)regs, sizeof(struct trapframe)); 734 regs->tf_rip = entry; 735 regs->tf_rsp = stack; 736 regs->tf_rflags = PSL_USER | (regs->tf_rflags & PSL_T); 737 regs->tf_ss = _udatasel; 738 regs->tf_cs = _ucode32sel; 739 regs->tf_rbx = ps_strings; 740 load_cr0(rcr0() | CR0_MP | CR0_TS); 741 fpstate_drop(td); 742 743 /* Return via doreti so that we can change to a different %cs */ 744 pcb->pcb_flags |= PCB_FULLCTX | PCB_32BIT; 745 td->td_retval[1] = 0; 746 } 747