1 /* 2 * arch/sparc64/kernel/signal.c 3 * 4 * Copyright (C) 1991, 1992 Linus Torvalds 5 * Copyright (C) 1995, 2008 David S. Miller (davem@davemloft.net) 6 * Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx) 7 * Copyright (C) 1997 Eddie C. Dost (ecd@skynet.be) 8 * Copyright (C) 1997,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz) 9 */ 10 11 #ifdef CONFIG_COMPAT 12 #include <linux/compat.h> /* for compat_old_sigset_t */ 13 #endif 14 #include <linux/sched.h> 15 #include <linux/kernel.h> 16 #include <linux/signal.h> 17 #include <linux/errno.h> 18 #include <linux/wait.h> 19 #include <linux/ptrace.h> 20 #include <linux/tracehook.h> 21 #include <linux/unistd.h> 22 #include <linux/mm.h> 23 #include <linux/tty.h> 24 #include <linux/binfmts.h> 25 #include <linux/bitops.h> 26 27 #include <asm/uaccess.h> 28 #include <asm/ptrace.h> 29 #include <asm/pgtable.h> 30 #include <asm/fpumacro.h> 31 #include <asm/uctx.h> 32 #include <asm/siginfo.h> 33 #include <asm/visasm.h> 34 #include <asm/switch_to.h> 35 #include <asm/cacheflush.h> 36 37 #include "entry.h" 38 #include "systbls.h" 39 #include "sigutil.h" 40 41 /* {set, get}context() needed for 64-bit SparcLinux userland. */ 42 asmlinkage void sparc64_set_context(struct pt_regs *regs) 43 { 44 struct ucontext __user *ucp = (struct ucontext __user *) 45 regs->u_regs[UREG_I0]; 46 mc_gregset_t __user *grp; 47 unsigned long pc, npc, tstate; 48 unsigned long fp, i7; 49 unsigned char fenab; 50 int err; 51 52 flush_user_windows(); 53 if (get_thread_wsaved() || 54 (((unsigned long)ucp) & (sizeof(unsigned long)-1)) || 55 (!__access_ok(ucp, sizeof(*ucp)))) 56 goto do_sigsegv; 57 grp = &ucp->uc_mcontext.mc_gregs; 58 err = __get_user(pc, &((*grp)[MC_PC])); 59 err |= __get_user(npc, &((*grp)[MC_NPC])); 60 if (err || ((pc | npc) & 3)) 61 goto do_sigsegv; 62 if (regs->u_regs[UREG_I1]) { 63 sigset_t set; 64 65 if (_NSIG_WORDS == 1) { 66 if (__get_user(set.sig[0], &ucp->uc_sigmask.sig[0])) 67 goto do_sigsegv; 68 } else { 69 if (__copy_from_user(&set, &ucp->uc_sigmask, sizeof(sigset_t))) 70 goto do_sigsegv; 71 } 72 set_current_blocked(&set); 73 } 74 if (test_thread_flag(TIF_32BIT)) { 75 pc &= 0xffffffff; 76 npc &= 0xffffffff; 77 } 78 regs->tpc = pc; 79 regs->tnpc = npc; 80 err |= __get_user(regs->y, &((*grp)[MC_Y])); 81 err |= __get_user(tstate, &((*grp)[MC_TSTATE])); 82 regs->tstate &= ~(TSTATE_ASI | TSTATE_ICC | TSTATE_XCC); 83 regs->tstate |= (tstate & (TSTATE_ASI | TSTATE_ICC | TSTATE_XCC)); 84 err |= __get_user(regs->u_regs[UREG_G1], (&(*grp)[MC_G1])); 85 err |= __get_user(regs->u_regs[UREG_G2], (&(*grp)[MC_G2])); 86 err |= __get_user(regs->u_regs[UREG_G3], (&(*grp)[MC_G3])); 87 err |= __get_user(regs->u_regs[UREG_G4], (&(*grp)[MC_G4])); 88 err |= __get_user(regs->u_regs[UREG_G5], (&(*grp)[MC_G5])); 89 err |= __get_user(regs->u_regs[UREG_G6], (&(*grp)[MC_G6])); 90 91 /* Skip %g7 as that's the thread register in userspace. */ 92 93 err |= __get_user(regs->u_regs[UREG_I0], (&(*grp)[MC_O0])); 94 err |= __get_user(regs->u_regs[UREG_I1], (&(*grp)[MC_O1])); 95 err |= __get_user(regs->u_regs[UREG_I2], (&(*grp)[MC_O2])); 96 err |= __get_user(regs->u_regs[UREG_I3], (&(*grp)[MC_O3])); 97 err |= __get_user(regs->u_regs[UREG_I4], (&(*grp)[MC_O4])); 98 err |= __get_user(regs->u_regs[UREG_I5], (&(*grp)[MC_O5])); 99 err |= __get_user(regs->u_regs[UREG_I6], (&(*grp)[MC_O6])); 100 err |= __get_user(regs->u_regs[UREG_I7], (&(*grp)[MC_O7])); 101 102 err |= __get_user(fp, &(ucp->uc_mcontext.mc_fp)); 103 err |= __get_user(i7, &(ucp->uc_mcontext.mc_i7)); 104 err |= __put_user(fp, 105 (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[6]))); 106 err |= __put_user(i7, 107 (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[7]))); 108 109 err |= __get_user(fenab, &(ucp->uc_mcontext.mc_fpregs.mcfpu_enab)); 110 if (fenab) { 111 unsigned long *fpregs = current_thread_info()->fpregs; 112 unsigned long fprs; 113 114 fprs_write(0); 115 err |= __get_user(fprs, &(ucp->uc_mcontext.mc_fpregs.mcfpu_fprs)); 116 if (fprs & FPRS_DL) 117 err |= copy_from_user(fpregs, 118 &(ucp->uc_mcontext.mc_fpregs.mcfpu_fregs), 119 (sizeof(unsigned int) * 32)); 120 if (fprs & FPRS_DU) 121 err |= copy_from_user(fpregs+16, 122 ((unsigned long __user *)&(ucp->uc_mcontext.mc_fpregs.mcfpu_fregs))+16, 123 (sizeof(unsigned int) * 32)); 124 err |= __get_user(current_thread_info()->xfsr[0], 125 &(ucp->uc_mcontext.mc_fpregs.mcfpu_fsr)); 126 err |= __get_user(current_thread_info()->gsr[0], 127 &(ucp->uc_mcontext.mc_fpregs.mcfpu_gsr)); 128 regs->tstate &= ~TSTATE_PEF; 129 } 130 if (err) 131 goto do_sigsegv; 132 133 return; 134 do_sigsegv: 135 force_sig(SIGSEGV, current); 136 } 137 138 asmlinkage void sparc64_get_context(struct pt_regs *regs) 139 { 140 struct ucontext __user *ucp = (struct ucontext __user *) 141 regs->u_regs[UREG_I0]; 142 mc_gregset_t __user *grp; 143 mcontext_t __user *mcp; 144 unsigned long fp, i7; 145 unsigned char fenab; 146 int err; 147 148 synchronize_user_stack(); 149 if (get_thread_wsaved() || clear_user(ucp, sizeof(*ucp))) 150 goto do_sigsegv; 151 152 #if 1 153 fenab = 0; /* IMO get_context is like any other system call, thus modifies FPU state -jj */ 154 #else 155 fenab = (current_thread_info()->fpsaved[0] & FPRS_FEF); 156 #endif 157 158 mcp = &ucp->uc_mcontext; 159 grp = &mcp->mc_gregs; 160 161 /* Skip over the trap instruction, first. */ 162 if (test_thread_flag(TIF_32BIT)) { 163 regs->tpc = (regs->tnpc & 0xffffffff); 164 regs->tnpc = (regs->tnpc + 4) & 0xffffffff; 165 } else { 166 regs->tpc = regs->tnpc; 167 regs->tnpc += 4; 168 } 169 err = 0; 170 if (_NSIG_WORDS == 1) 171 err |= __put_user(current->blocked.sig[0], 172 (unsigned long __user *)&ucp->uc_sigmask); 173 else 174 err |= __copy_to_user(&ucp->uc_sigmask, ¤t->blocked, 175 sizeof(sigset_t)); 176 177 err |= __put_user(regs->tstate, &((*grp)[MC_TSTATE])); 178 err |= __put_user(regs->tpc, &((*grp)[MC_PC])); 179 err |= __put_user(regs->tnpc, &((*grp)[MC_NPC])); 180 err |= __put_user(regs->y, &((*grp)[MC_Y])); 181 err |= __put_user(regs->u_regs[UREG_G1], &((*grp)[MC_G1])); 182 err |= __put_user(regs->u_regs[UREG_G2], &((*grp)[MC_G2])); 183 err |= __put_user(regs->u_regs[UREG_G3], &((*grp)[MC_G3])); 184 err |= __put_user(regs->u_regs[UREG_G4], &((*grp)[MC_G4])); 185 err |= __put_user(regs->u_regs[UREG_G5], &((*grp)[MC_G5])); 186 err |= __put_user(regs->u_regs[UREG_G6], &((*grp)[MC_G6])); 187 err |= __put_user(regs->u_regs[UREG_G7], &((*grp)[MC_G7])); 188 err |= __put_user(regs->u_regs[UREG_I0], &((*grp)[MC_O0])); 189 err |= __put_user(regs->u_regs[UREG_I1], &((*grp)[MC_O1])); 190 err |= __put_user(regs->u_regs[UREG_I2], &((*grp)[MC_O2])); 191 err |= __put_user(regs->u_regs[UREG_I3], &((*grp)[MC_O3])); 192 err |= __put_user(regs->u_regs[UREG_I4], &((*grp)[MC_O4])); 193 err |= __put_user(regs->u_regs[UREG_I5], &((*grp)[MC_O5])); 194 err |= __put_user(regs->u_regs[UREG_I6], &((*grp)[MC_O6])); 195 err |= __put_user(regs->u_regs[UREG_I7], &((*grp)[MC_O7])); 196 197 err |= __get_user(fp, 198 (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[6]))); 199 err |= __get_user(i7, 200 (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[7]))); 201 err |= __put_user(fp, &(mcp->mc_fp)); 202 err |= __put_user(i7, &(mcp->mc_i7)); 203 204 err |= __put_user(fenab, &(mcp->mc_fpregs.mcfpu_enab)); 205 if (fenab) { 206 unsigned long *fpregs = current_thread_info()->fpregs; 207 unsigned long fprs; 208 209 fprs = current_thread_info()->fpsaved[0]; 210 if (fprs & FPRS_DL) 211 err |= copy_to_user(&(mcp->mc_fpregs.mcfpu_fregs), fpregs, 212 (sizeof(unsigned int) * 32)); 213 if (fprs & FPRS_DU) 214 err |= copy_to_user( 215 ((unsigned long __user *)&(mcp->mc_fpregs.mcfpu_fregs))+16, fpregs+16, 216 (sizeof(unsigned int) * 32)); 217 err |= __put_user(current_thread_info()->xfsr[0], &(mcp->mc_fpregs.mcfpu_fsr)); 218 err |= __put_user(current_thread_info()->gsr[0], &(mcp->mc_fpregs.mcfpu_gsr)); 219 err |= __put_user(fprs, &(mcp->mc_fpregs.mcfpu_fprs)); 220 } 221 if (err) 222 goto do_sigsegv; 223 224 return; 225 do_sigsegv: 226 force_sig(SIGSEGV, current); 227 } 228 229 struct rt_signal_frame { 230 struct sparc_stackf ss; 231 siginfo_t info; 232 struct pt_regs regs; 233 __siginfo_fpu_t __user *fpu_save; 234 stack_t stack; 235 sigset_t mask; 236 __siginfo_rwin_t *rwin_save; 237 }; 238 239 void do_rt_sigreturn(struct pt_regs *regs) 240 { 241 struct rt_signal_frame __user *sf; 242 unsigned long tpc, tnpc, tstate; 243 __siginfo_fpu_t __user *fpu_save; 244 __siginfo_rwin_t __user *rwin_save; 245 sigset_t set; 246 int err; 247 248 /* Always make any pending restarted system calls return -EINTR */ 249 current_thread_info()->restart_block.fn = do_no_restart_syscall; 250 251 synchronize_user_stack (); 252 sf = (struct rt_signal_frame __user *) 253 (regs->u_regs [UREG_FP] + STACK_BIAS); 254 255 /* 1. Make sure we are not getting garbage from the user */ 256 if (((unsigned long) sf) & 3) 257 goto segv; 258 259 err = get_user(tpc, &sf->regs.tpc); 260 err |= __get_user(tnpc, &sf->regs.tnpc); 261 if (test_thread_flag(TIF_32BIT)) { 262 tpc &= 0xffffffff; 263 tnpc &= 0xffffffff; 264 } 265 err |= ((tpc | tnpc) & 3); 266 267 /* 2. Restore the state */ 268 err |= __get_user(regs->y, &sf->regs.y); 269 err |= __get_user(tstate, &sf->regs.tstate); 270 err |= copy_from_user(regs->u_regs, sf->regs.u_regs, sizeof(regs->u_regs)); 271 272 /* User can only change condition codes and %asi in %tstate. */ 273 regs->tstate &= ~(TSTATE_ASI | TSTATE_ICC | TSTATE_XCC); 274 regs->tstate |= (tstate & (TSTATE_ASI | TSTATE_ICC | TSTATE_XCC)); 275 276 err |= __get_user(fpu_save, &sf->fpu_save); 277 if (!err && fpu_save) 278 err |= restore_fpu_state(regs, fpu_save); 279 280 err |= __copy_from_user(&set, &sf->mask, sizeof(sigset_t)); 281 err |= restore_altstack(&sf->stack); 282 if (err) 283 goto segv; 284 285 err |= __get_user(rwin_save, &sf->rwin_save); 286 if (!err && rwin_save) { 287 if (restore_rwin_state(rwin_save)) 288 goto segv; 289 } 290 291 regs->tpc = tpc; 292 regs->tnpc = tnpc; 293 294 /* Prevent syscall restart. */ 295 pt_regs_clear_syscall(regs); 296 297 set_current_blocked(&set); 298 return; 299 segv: 300 force_sig(SIGSEGV, current); 301 } 302 303 /* Checks if the fp is valid */ 304 static int invalid_frame_pointer(void __user *fp) 305 { 306 if (((unsigned long) fp) & 15) 307 return 1; 308 return 0; 309 } 310 311 static inline void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs, unsigned long framesize) 312 { 313 unsigned long sp = regs->u_regs[UREG_FP] + STACK_BIAS; 314 315 /* 316 * If we are on the alternate signal stack and would overflow it, don't. 317 * Return an always-bogus address instead so we will die with SIGSEGV. 318 */ 319 if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize))) 320 return (void __user *) -1L; 321 322 /* This is the X/Open sanctioned signal stack switching. */ 323 sp = sigsp(sp, ksig) - framesize; 324 325 /* Always align the stack frame. This handles two cases. First, 326 * sigaltstack need not be mindful of platform specific stack 327 * alignment. Second, if we took this signal because the stack 328 * is not aligned properly, we'd like to take the signal cleanly 329 * and report that. 330 */ 331 sp &= ~15UL; 332 333 return (void __user *) sp; 334 } 335 336 static inline int 337 setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs) 338 { 339 struct rt_signal_frame __user *sf; 340 int wsaved, err, sf_size; 341 void __user *tail; 342 343 /* 1. Make sure everything is clean */ 344 synchronize_user_stack(); 345 save_and_clear_fpu(); 346 347 wsaved = get_thread_wsaved(); 348 349 sf_size = sizeof(struct rt_signal_frame); 350 if (current_thread_info()->fpsaved[0] & FPRS_FEF) 351 sf_size += sizeof(__siginfo_fpu_t); 352 if (wsaved) 353 sf_size += sizeof(__siginfo_rwin_t); 354 sf = (struct rt_signal_frame __user *) 355 get_sigframe(ksig, regs, sf_size); 356 357 if (invalid_frame_pointer (sf)) { 358 do_exit(SIGILL); /* won't return, actually */ 359 return -EINVAL; 360 } 361 362 tail = (sf + 1); 363 364 /* 2. Save the current process state */ 365 err = copy_to_user(&sf->regs, regs, sizeof (*regs)); 366 367 if (current_thread_info()->fpsaved[0] & FPRS_FEF) { 368 __siginfo_fpu_t __user *fpu_save = tail; 369 tail += sizeof(__siginfo_fpu_t); 370 err |= save_fpu_state(regs, fpu_save); 371 err |= __put_user((u64)fpu_save, &sf->fpu_save); 372 } else { 373 err |= __put_user(0, &sf->fpu_save); 374 } 375 if (wsaved) { 376 __siginfo_rwin_t __user *rwin_save = tail; 377 tail += sizeof(__siginfo_rwin_t); 378 err |= save_rwin_state(wsaved, rwin_save); 379 err |= __put_user((u64)rwin_save, &sf->rwin_save); 380 set_thread_wsaved(0); 381 } else { 382 err |= __put_user(0, &sf->rwin_save); 383 } 384 385 /* Setup sigaltstack */ 386 err |= __save_altstack(&sf->stack, regs->u_regs[UREG_FP]); 387 388 err |= copy_to_user(&sf->mask, sigmask_to_save(), sizeof(sigset_t)); 389 390 if (!wsaved) { 391 err |= copy_in_user((u64 __user *)sf, 392 (u64 __user *)(regs->u_regs[UREG_FP] + 393 STACK_BIAS), 394 sizeof(struct reg_window)); 395 } else { 396 struct reg_window *rp; 397 398 rp = ¤t_thread_info()->reg_window[wsaved - 1]; 399 err |= copy_to_user(sf, rp, sizeof(struct reg_window)); 400 } 401 if (ksig->ka.sa.sa_flags & SA_SIGINFO) 402 err |= copy_siginfo_to_user(&sf->info, &ksig->info); 403 else { 404 err |= __put_user(ksig->sig, &sf->info.si_signo); 405 err |= __put_user(SI_NOINFO, &sf->info.si_code); 406 } 407 if (err) 408 return err; 409 410 /* 3. signal handler back-trampoline and parameters */ 411 regs->u_regs[UREG_FP] = ((unsigned long) sf) - STACK_BIAS; 412 regs->u_regs[UREG_I0] = ksig->sig; 413 regs->u_regs[UREG_I1] = (unsigned long) &sf->info; 414 415 /* The sigcontext is passed in this way because of how it 416 * is defined in GLIBC's /usr/include/bits/sigcontext.h 417 * for sparc64. It includes the 128 bytes of siginfo_t. 418 */ 419 regs->u_regs[UREG_I2] = (unsigned long) &sf->info; 420 421 /* 5. signal handler */ 422 regs->tpc = (unsigned long) ksig->ka.sa.sa_handler; 423 regs->tnpc = (regs->tpc + 4); 424 if (test_thread_flag(TIF_32BIT)) { 425 regs->tpc &= 0xffffffff; 426 regs->tnpc &= 0xffffffff; 427 } 428 /* 4. return to kernel instructions */ 429 regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer; 430 return 0; 431 } 432 433 static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs, 434 struct sigaction *sa) 435 { 436 switch (regs->u_regs[UREG_I0]) { 437 case ERESTART_RESTARTBLOCK: 438 case ERESTARTNOHAND: 439 no_system_call_restart: 440 regs->u_regs[UREG_I0] = EINTR; 441 regs->tstate |= (TSTATE_ICARRY|TSTATE_XCARRY); 442 break; 443 case ERESTARTSYS: 444 if (!(sa->sa_flags & SA_RESTART)) 445 goto no_system_call_restart; 446 /* fallthrough */ 447 case ERESTARTNOINTR: 448 regs->u_regs[UREG_I0] = orig_i0; 449 regs->tpc -= 4; 450 regs->tnpc -= 4; 451 } 452 } 453 454 /* Note that 'init' is a special process: it doesn't get signals it doesn't 455 * want to handle. Thus you cannot kill init even with a SIGKILL even by 456 * mistake. 457 */ 458 static void do_signal(struct pt_regs *regs, unsigned long orig_i0) 459 { 460 struct ksignal ksig; 461 int restart_syscall; 462 bool has_handler; 463 464 /* It's a lot of work and synchronization to add a new ptrace 465 * register for GDB to save and restore in order to get 466 * orig_i0 correct for syscall restarts when debugging. 467 * 468 * Although it should be the case that most of the global 469 * registers are volatile across a system call, glibc already 470 * depends upon that fact that we preserve them. So we can't 471 * just use any global register to save away the orig_i0 value. 472 * 473 * In particular %g2, %g3, %g4, and %g5 are all assumed to be 474 * preserved across a system call trap by various pieces of 475 * code in glibc. 476 * 477 * %g7 is used as the "thread register". %g6 is not used in 478 * any fixed manner. %g6 is used as a scratch register and 479 * a compiler temporary, but it's value is never used across 480 * a system call. Therefore %g6 is usable for orig_i0 storage. 481 */ 482 if (pt_regs_is_syscall(regs) && 483 (regs->tstate & (TSTATE_XCARRY | TSTATE_ICARRY))) 484 regs->u_regs[UREG_G6] = orig_i0; 485 486 #ifdef CONFIG_COMPAT 487 if (test_thread_flag(TIF_32BIT)) { 488 extern void do_signal32(struct pt_regs *); 489 do_signal32(regs); 490 return; 491 } 492 #endif 493 494 has_handler = get_signal(&ksig); 495 496 restart_syscall = 0; 497 if (pt_regs_is_syscall(regs) && 498 (regs->tstate & (TSTATE_XCARRY | TSTATE_ICARRY))) { 499 restart_syscall = 1; 500 orig_i0 = regs->u_regs[UREG_G6]; 501 } 502 503 if (has_handler) { 504 if (restart_syscall) 505 syscall_restart(orig_i0, regs, &ksig.ka.sa); 506 signal_setup_done(setup_rt_frame(&ksig, regs), &ksig, 0); 507 } else { 508 if (restart_syscall) { 509 switch (regs->u_regs[UREG_I0]) { 510 case ERESTARTNOHAND: 511 case ERESTARTSYS: 512 case ERESTARTNOINTR: 513 /* replay the system call when we are done */ 514 regs->u_regs[UREG_I0] = orig_i0; 515 regs->tpc -= 4; 516 regs->tnpc -= 4; 517 pt_regs_clear_syscall(regs); 518 case ERESTART_RESTARTBLOCK: 519 regs->u_regs[UREG_G1] = __NR_restart_syscall; 520 regs->tpc -= 4; 521 regs->tnpc -= 4; 522 pt_regs_clear_syscall(regs); 523 } 524 } 525 restore_saved_sigmask(); 526 } 527 } 528 529 void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0, unsigned long thread_info_flags) 530 { 531 if (thread_info_flags & _TIF_SIGPENDING) 532 do_signal(regs, orig_i0); 533 if (thread_info_flags & _TIF_NOTIFY_RESUME) { 534 clear_thread_flag(TIF_NOTIFY_RESUME); 535 tracehook_notify_resume(regs); 536 } 537 } 538 539