1 /* 2 * PowerPC version 3 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) 4 * 5 * Derived from "arch/i386/kernel/signal.c" 6 * Copyright (C) 1991, 1992 Linus Torvalds 7 * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson 8 * 9 * This program is free software; you can redistribute it and/or 10 * modify it under the terms of the GNU General Public License 11 * as published by the Free Software Foundation; either version 12 * 2 of the License, or (at your option) any later version. 13 */ 14 15 #include <linux/sched.h> 16 #include <linux/mm.h> 17 #include <linux/smp.h> 18 #include <linux/kernel.h> 19 #include <linux/signal.h> 20 #include <linux/errno.h> 21 #include <linux/wait.h> 22 #include <linux/unistd.h> 23 #include <linux/stddef.h> 24 #include <linux/elf.h> 25 #include <linux/ptrace.h> 26 #include <linux/ratelimit.h> 27 28 #include <asm/sigcontext.h> 29 #include <asm/ucontext.h> 30 #include <asm/uaccess.h> 31 #include <asm/pgtable.h> 32 #include <asm/unistd.h> 33 #include <asm/cacheflush.h> 34 #include <asm/syscalls.h> 35 #include <asm/vdso.h> 36 #include <asm/switch_to.h> 37 #include <asm/tm.h> 38 39 #include "signal.h" 40 41 #define DEBUG_SIG 0 42 43 #define GP_REGS_SIZE min(sizeof(elf_gregset_t), sizeof(struct pt_regs)) 44 #define FP_REGS_SIZE sizeof(elf_fpregset_t) 45 46 #define TRAMP_TRACEBACK 3 47 #define TRAMP_SIZE 6 48 49 /* 50 * When we have signals to deliver, we set up on the user stack, 51 * going down from the original stack pointer: 52 * 1) a rt_sigframe struct which contains the ucontext 53 * 2) a gap of __SIGNAL_FRAMESIZE bytes which acts as a dummy caller 54 * frame for the signal handler. 55 */ 56 57 struct rt_sigframe { 58 /* sys_rt_sigreturn requires the ucontext be the first field */ 59 struct ucontext uc; 60 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 61 struct ucontext uc_transact; 62 #endif 63 unsigned long _unused[2]; 64 unsigned int tramp[TRAMP_SIZE]; 65 struct siginfo __user *pinfo; 66 void __user *puc; 67 struct siginfo info; 68 /* 64 bit ABI allows for 288 bytes below sp before decrementing it. */ 69 char abigap[288]; 70 } __attribute__ ((aligned (16))); 71 72 static const char fmt32[] = KERN_INFO \ 73 "%s[%d]: bad frame in %s: %08lx nip %08lx lr %08lx\n"; 74 static const char fmt64[] = KERN_INFO \ 75 "%s[%d]: bad frame in %s: %016lx nip %016lx lr %016lx\n"; 76 77 /* 78 * Set up the sigcontext for the signal frame. 79 */ 80 81 static long setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, 82 int signr, sigset_t *set, unsigned long handler, 83 int ctx_has_vsx_region) 84 { 85 /* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the 86 * process never used altivec yet (MSR_VEC is zero in pt_regs of 87 * the context). This is very important because we must ensure we 88 * don't lose the VRSAVE content that may have been set prior to 89 * the process doing its first vector operation 90 * Userland shall check AT_HWCAP to know whether it can rely on the 91 * v_regs pointer or not 92 */ 93 #ifdef CONFIG_ALTIVEC 94 elf_vrreg_t __user *v_regs = (elf_vrreg_t __user *)(((unsigned long)sc->vmx_reserve + 15) & ~0xful); 95 #endif 96 unsigned long msr = regs->msr; 97 long err = 0; 98 99 flush_fp_to_thread(current); 100 101 #ifdef CONFIG_ALTIVEC 102 err |= __put_user(v_regs, &sc->v_regs); 103 104 /* save altivec registers */ 105 if (current->thread.used_vr) { 106 flush_altivec_to_thread(current); 107 /* Copy 33 vec registers (vr0..31 and vscr) to the stack */ 108 err |= __copy_to_user(v_regs, current->thread.vr, 33 * sizeof(vector128)); 109 /* set MSR_VEC in the MSR value in the frame to indicate that sc->v_reg) 110 * contains valid data. 111 */ 112 msr |= MSR_VEC; 113 } 114 /* We always copy to/from vrsave, it's 0 if we don't have or don't 115 * use altivec. 116 */ 117 err |= __put_user(current->thread.vrsave, (u32 __user *)&v_regs[33]); 118 #else /* CONFIG_ALTIVEC */ 119 err |= __put_user(0, &sc->v_regs); 120 #endif /* CONFIG_ALTIVEC */ 121 flush_fp_to_thread(current); 122 /* copy fpr regs and fpscr */ 123 err |= copy_fpr_to_user(&sc->fp_regs, current); 124 #ifdef CONFIG_VSX 125 /* 126 * Copy VSX low doubleword to local buffer for formatting, 127 * then out to userspace. Update v_regs to point after the 128 * VMX data. 129 */ 130 if (current->thread.used_vsr && ctx_has_vsx_region) { 131 __giveup_vsx(current); 132 v_regs += ELF_NVRREG; 133 err |= copy_vsx_to_user(v_regs, current); 134 /* set MSR_VSX in the MSR value in the frame to 135 * indicate that sc->vs_reg) contains valid data. 136 */ 137 msr |= MSR_VSX; 138 } 139 #endif /* CONFIG_VSX */ 140 err |= __put_user(&sc->gp_regs, &sc->regs); 141 WARN_ON(!FULL_REGS(regs)); 142 err |= __copy_to_user(&sc->gp_regs, regs, GP_REGS_SIZE); 143 err |= __put_user(msr, &sc->gp_regs[PT_MSR]); 144 err |= __put_user(signr, &sc->signal); 145 err |= __put_user(handler, &sc->handler); 146 if (set != NULL) 147 err |= __put_user(set->sig[0], &sc->oldmask); 148 149 return err; 150 } 151 152 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 153 /* 154 * As above, but Transactional Memory is in use, so deliver sigcontexts 155 * containing checkpointed and transactional register states. 156 * 157 * To do this, we treclaim (done before entering here) to gather both sets of 158 * registers and set up the 'normal' sigcontext registers with rolled-back 159 * register values such that a simple signal handler sees a correct 160 * checkpointed register state. If interested, a TM-aware sighandler can 161 * examine the transactional registers in the 2nd sigcontext to determine the 162 * real origin of the signal. 163 */ 164 static long setup_tm_sigcontexts(struct sigcontext __user *sc, 165 struct sigcontext __user *tm_sc, 166 struct pt_regs *regs, 167 int signr, sigset_t *set, unsigned long handler) 168 { 169 /* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the 170 * process never used altivec yet (MSR_VEC is zero in pt_regs of 171 * the context). This is very important because we must ensure we 172 * don't lose the VRSAVE content that may have been set prior to 173 * the process doing its first vector operation 174 * Userland shall check AT_HWCAP to know wether it can rely on the 175 * v_regs pointer or not. 176 */ 177 #ifdef CONFIG_ALTIVEC 178 elf_vrreg_t __user *v_regs = (elf_vrreg_t __user *) 179 (((unsigned long)sc->vmx_reserve + 15) & ~0xful); 180 elf_vrreg_t __user *tm_v_regs = (elf_vrreg_t __user *) 181 (((unsigned long)tm_sc->vmx_reserve + 15) & ~0xful); 182 #endif 183 unsigned long msr = regs->msr; 184 long err = 0; 185 186 BUG_ON(!MSR_TM_ACTIVE(regs->msr)); 187 188 flush_fp_to_thread(current); 189 190 #ifdef CONFIG_ALTIVEC 191 err |= __put_user(v_regs, &sc->v_regs); 192 err |= __put_user(tm_v_regs, &tm_sc->v_regs); 193 194 /* save altivec registers */ 195 if (current->thread.used_vr) { 196 flush_altivec_to_thread(current); 197 /* Copy 33 vec registers (vr0..31 and vscr) to the stack */ 198 err |= __copy_to_user(v_regs, current->thread.vr, 199 33 * sizeof(vector128)); 200 /* If VEC was enabled there are transactional VRs valid too, 201 * else they're a copy of the checkpointed VRs. 202 */ 203 if (msr & MSR_VEC) 204 err |= __copy_to_user(tm_v_regs, 205 current->thread.transact_vr, 206 33 * sizeof(vector128)); 207 else 208 err |= __copy_to_user(tm_v_regs, 209 current->thread.vr, 210 33 * sizeof(vector128)); 211 212 /* set MSR_VEC in the MSR value in the frame to indicate 213 * that sc->v_reg contains valid data. 214 */ 215 msr |= MSR_VEC; 216 } 217 /* We always copy to/from vrsave, it's 0 if we don't have or don't 218 * use altivec. 219 */ 220 err |= __put_user(current->thread.vrsave, (u32 __user *)&v_regs[33]); 221 if (msr & MSR_VEC) 222 err |= __put_user(current->thread.transact_vrsave, 223 (u32 __user *)&tm_v_regs[33]); 224 else 225 err |= __put_user(current->thread.vrsave, 226 (u32 __user *)&tm_v_regs[33]); 227 228 #else /* CONFIG_ALTIVEC */ 229 err |= __put_user(0, &sc->v_regs); 230 err |= __put_user(0, &tm_sc->v_regs); 231 #endif /* CONFIG_ALTIVEC */ 232 233 /* copy fpr regs and fpscr */ 234 err |= copy_fpr_to_user(&sc->fp_regs, current); 235 if (msr & MSR_FP) 236 err |= copy_transact_fpr_to_user(&tm_sc->fp_regs, current); 237 else 238 err |= copy_fpr_to_user(&tm_sc->fp_regs, current); 239 240 #ifdef CONFIG_VSX 241 /* 242 * Copy VSX low doubleword to local buffer for formatting, 243 * then out to userspace. Update v_regs to point after the 244 * VMX data. 245 */ 246 if (current->thread.used_vsr) { 247 __giveup_vsx(current); 248 v_regs += ELF_NVRREG; 249 tm_v_regs += ELF_NVRREG; 250 251 err |= copy_vsx_to_user(v_regs, current); 252 253 if (msr & MSR_VSX) 254 err |= copy_transact_vsx_to_user(tm_v_regs, current); 255 else 256 err |= copy_vsx_to_user(tm_v_regs, current); 257 258 /* set MSR_VSX in the MSR value in the frame to 259 * indicate that sc->vs_reg) contains valid data. 260 */ 261 msr |= MSR_VSX; 262 } 263 #endif /* CONFIG_VSX */ 264 265 err |= __put_user(&sc->gp_regs, &sc->regs); 266 err |= __put_user(&tm_sc->gp_regs, &tm_sc->regs); 267 WARN_ON(!FULL_REGS(regs)); 268 err |= __copy_to_user(&tm_sc->gp_regs, regs, GP_REGS_SIZE); 269 err |= __copy_to_user(&sc->gp_regs, 270 ¤t->thread.ckpt_regs, GP_REGS_SIZE); 271 err |= __put_user(msr, &tm_sc->gp_regs[PT_MSR]); 272 err |= __put_user(msr, &sc->gp_regs[PT_MSR]); 273 err |= __put_user(signr, &sc->signal); 274 err |= __put_user(handler, &sc->handler); 275 if (set != NULL) 276 err |= __put_user(set->sig[0], &sc->oldmask); 277 278 return err; 279 } 280 #endif 281 282 /* 283 * Restore the sigcontext from the signal frame. 284 */ 285 286 static long restore_sigcontext(struct pt_regs *regs, sigset_t *set, int sig, 287 struct sigcontext __user *sc) 288 { 289 #ifdef CONFIG_ALTIVEC 290 elf_vrreg_t __user *v_regs; 291 #endif 292 unsigned long err = 0; 293 unsigned long save_r13 = 0; 294 unsigned long msr; 295 #ifdef CONFIG_VSX 296 int i; 297 #endif 298 299 /* If this is not a signal return, we preserve the TLS in r13 */ 300 if (!sig) 301 save_r13 = regs->gpr[13]; 302 303 /* copy the GPRs */ 304 err |= __copy_from_user(regs->gpr, sc->gp_regs, sizeof(regs->gpr)); 305 err |= __get_user(regs->nip, &sc->gp_regs[PT_NIP]); 306 /* get MSR separately, transfer the LE bit if doing signal return */ 307 err |= __get_user(msr, &sc->gp_regs[PT_MSR]); 308 if (sig) 309 regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE); 310 err |= __get_user(regs->orig_gpr3, &sc->gp_regs[PT_ORIG_R3]); 311 err |= __get_user(regs->ctr, &sc->gp_regs[PT_CTR]); 312 err |= __get_user(regs->link, &sc->gp_regs[PT_LNK]); 313 err |= __get_user(regs->xer, &sc->gp_regs[PT_XER]); 314 err |= __get_user(regs->ccr, &sc->gp_regs[PT_CCR]); 315 /* skip SOFTE */ 316 regs->trap = 0; 317 err |= __get_user(regs->dar, &sc->gp_regs[PT_DAR]); 318 err |= __get_user(regs->dsisr, &sc->gp_regs[PT_DSISR]); 319 err |= __get_user(regs->result, &sc->gp_regs[PT_RESULT]); 320 321 if (!sig) 322 regs->gpr[13] = save_r13; 323 if (set != NULL) 324 err |= __get_user(set->sig[0], &sc->oldmask); 325 326 /* 327 * Do this before updating the thread state in 328 * current->thread.fpr/vr. That way, if we get preempted 329 * and another task grabs the FPU/Altivec, it won't be 330 * tempted to save the current CPU state into the thread_struct 331 * and corrupt what we are writing there. 332 */ 333 discard_lazy_cpu_state(); 334 335 /* 336 * Force reload of FP/VEC. 337 * This has to be done before copying stuff into current->thread.fpr/vr 338 * for the reasons explained in the previous comment. 339 */ 340 regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC | MSR_VSX); 341 342 #ifdef CONFIG_ALTIVEC 343 err |= __get_user(v_regs, &sc->v_regs); 344 if (err) 345 return err; 346 if (v_regs && !access_ok(VERIFY_READ, v_regs, 34 * sizeof(vector128))) 347 return -EFAULT; 348 /* Copy 33 vec registers (vr0..31 and vscr) from the stack */ 349 if (v_regs != 0 && (msr & MSR_VEC) != 0) 350 err |= __copy_from_user(current->thread.vr, v_regs, 351 33 * sizeof(vector128)); 352 else if (current->thread.used_vr) 353 memset(current->thread.vr, 0, 33 * sizeof(vector128)); 354 /* Always get VRSAVE back */ 355 if (v_regs != 0) 356 err |= __get_user(current->thread.vrsave, (u32 __user *)&v_regs[33]); 357 else 358 current->thread.vrsave = 0; 359 #endif /* CONFIG_ALTIVEC */ 360 /* restore floating point */ 361 err |= copy_fpr_from_user(current, &sc->fp_regs); 362 #ifdef CONFIG_VSX 363 /* 364 * Get additional VSX data. Update v_regs to point after the 365 * VMX data. Copy VSX low doubleword from userspace to local 366 * buffer for formatting, then into the taskstruct. 367 */ 368 v_regs += ELF_NVRREG; 369 if ((msr & MSR_VSX) != 0) 370 err |= copy_vsx_from_user(current, v_regs); 371 else 372 for (i = 0; i < 32 ; i++) 373 current->thread.fpr[i][TS_VSRLOWOFFSET] = 0; 374 #endif 375 return err; 376 } 377 378 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 379 /* 380 * Restore the two sigcontexts from the frame of a transactional processes. 381 */ 382 383 static long restore_tm_sigcontexts(struct pt_regs *regs, 384 struct sigcontext __user *sc, 385 struct sigcontext __user *tm_sc) 386 { 387 #ifdef CONFIG_ALTIVEC 388 elf_vrreg_t __user *v_regs, *tm_v_regs; 389 #endif 390 unsigned long err = 0; 391 unsigned long msr; 392 #ifdef CONFIG_VSX 393 int i; 394 #endif 395 /* copy the GPRs */ 396 err |= __copy_from_user(regs->gpr, tm_sc->gp_regs, sizeof(regs->gpr)); 397 err |= __copy_from_user(¤t->thread.ckpt_regs, sc->gp_regs, 398 sizeof(regs->gpr)); 399 400 /* 401 * TFHAR is restored from the checkpointed 'wound-back' ucontext's NIP. 402 * TEXASR was set by the signal delivery reclaim, as was TFIAR. 403 * Users doing anything abhorrent like thread-switching w/ signals for 404 * TM-Suspended code will have to back TEXASR/TFIAR up themselves. 405 * For the case of getting a signal and simply returning from it, 406 * we don't need to re-copy them here. 407 */ 408 err |= __get_user(regs->nip, &tm_sc->gp_regs[PT_NIP]); 409 err |= __get_user(current->thread.tm_tfhar, &sc->gp_regs[PT_NIP]); 410 411 /* get MSR separately, transfer the LE bit if doing signal return */ 412 err |= __get_user(msr, &sc->gp_regs[PT_MSR]); 413 /* pull in MSR TM from user context */ 414 regs->msr = (regs->msr & ~MSR_TS_MASK) | (msr & MSR_TS_MASK); 415 416 /* pull in MSR LE from user context */ 417 regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE); 418 419 /* The following non-GPR non-FPR non-VR state is also checkpointed: */ 420 err |= __get_user(regs->ctr, &tm_sc->gp_regs[PT_CTR]); 421 err |= __get_user(regs->link, &tm_sc->gp_regs[PT_LNK]); 422 err |= __get_user(regs->xer, &tm_sc->gp_regs[PT_XER]); 423 err |= __get_user(regs->ccr, &tm_sc->gp_regs[PT_CCR]); 424 err |= __get_user(current->thread.ckpt_regs.ctr, 425 &sc->gp_regs[PT_CTR]); 426 err |= __get_user(current->thread.ckpt_regs.link, 427 &sc->gp_regs[PT_LNK]); 428 err |= __get_user(current->thread.ckpt_regs.xer, 429 &sc->gp_regs[PT_XER]); 430 err |= __get_user(current->thread.ckpt_regs.ccr, 431 &sc->gp_regs[PT_CCR]); 432 433 /* These regs are not checkpointed; they can go in 'regs'. */ 434 err |= __get_user(regs->trap, &sc->gp_regs[PT_TRAP]); 435 err |= __get_user(regs->dar, &sc->gp_regs[PT_DAR]); 436 err |= __get_user(regs->dsisr, &sc->gp_regs[PT_DSISR]); 437 err |= __get_user(regs->result, &sc->gp_regs[PT_RESULT]); 438 439 /* 440 * Do this before updating the thread state in 441 * current->thread.fpr/vr. That way, if we get preempted 442 * and another task grabs the FPU/Altivec, it won't be 443 * tempted to save the current CPU state into the thread_struct 444 * and corrupt what we are writing there. 445 */ 446 discard_lazy_cpu_state(); 447 448 /* 449 * Force reload of FP/VEC. 450 * This has to be done before copying stuff into current->thread.fpr/vr 451 * for the reasons explained in the previous comment. 452 */ 453 regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC | MSR_VSX); 454 455 #ifdef CONFIG_ALTIVEC 456 err |= __get_user(v_regs, &sc->v_regs); 457 err |= __get_user(tm_v_regs, &tm_sc->v_regs); 458 if (err) 459 return err; 460 if (v_regs && !access_ok(VERIFY_READ, v_regs, 34 * sizeof(vector128))) 461 return -EFAULT; 462 if (tm_v_regs && !access_ok(VERIFY_READ, 463 tm_v_regs, 34 * sizeof(vector128))) 464 return -EFAULT; 465 /* Copy 33 vec registers (vr0..31 and vscr) from the stack */ 466 if (v_regs != 0 && tm_v_regs != 0 && (msr & MSR_VEC) != 0) { 467 err |= __copy_from_user(current->thread.vr, v_regs, 468 33 * sizeof(vector128)); 469 err |= __copy_from_user(current->thread.transact_vr, tm_v_regs, 470 33 * sizeof(vector128)); 471 } 472 else if (current->thread.used_vr) { 473 memset(current->thread.vr, 0, 33 * sizeof(vector128)); 474 memset(current->thread.transact_vr, 0, 33 * sizeof(vector128)); 475 } 476 /* Always get VRSAVE back */ 477 if (v_regs != 0 && tm_v_regs != 0) { 478 err |= __get_user(current->thread.vrsave, 479 (u32 __user *)&v_regs[33]); 480 err |= __get_user(current->thread.transact_vrsave, 481 (u32 __user *)&tm_v_regs[33]); 482 } 483 else { 484 current->thread.vrsave = 0; 485 current->thread.transact_vrsave = 0; 486 } 487 #endif /* CONFIG_ALTIVEC */ 488 /* restore floating point */ 489 err |= copy_fpr_from_user(current, &sc->fp_regs); 490 err |= copy_transact_fpr_from_user(current, &tm_sc->fp_regs); 491 #ifdef CONFIG_VSX 492 /* 493 * Get additional VSX data. Update v_regs to point after the 494 * VMX data. Copy VSX low doubleword from userspace to local 495 * buffer for formatting, then into the taskstruct. 496 */ 497 if (v_regs && ((msr & MSR_VSX) != 0)) { 498 v_regs += ELF_NVRREG; 499 tm_v_regs += ELF_NVRREG; 500 err |= copy_vsx_from_user(current, v_regs); 501 err |= copy_transact_vsx_from_user(current, tm_v_regs); 502 } else { 503 for (i = 0; i < 32 ; i++) { 504 current->thread.fpr[i][TS_VSRLOWOFFSET] = 0; 505 current->thread.transact_fpr[i][TS_VSRLOWOFFSET] = 0; 506 } 507 } 508 #endif 509 tm_enable(); 510 /* This loads the checkpointed FP/VEC state, if used */ 511 tm_recheckpoint(¤t->thread, msr); 512 513 /* This loads the speculative FP/VEC state, if used */ 514 if (msr & MSR_FP) { 515 do_load_up_transact_fpu(¤t->thread); 516 regs->msr |= (MSR_FP | current->thread.fpexc_mode); 517 } 518 #ifdef CONFIG_ALTIVEC 519 if (msr & MSR_VEC) { 520 do_load_up_transact_altivec(¤t->thread); 521 regs->msr |= MSR_VEC; 522 } 523 #endif 524 525 return err; 526 } 527 #endif 528 529 /* 530 * Setup the trampoline code on the stack 531 */ 532 static long setup_trampoline(unsigned int syscall, unsigned int __user *tramp) 533 { 534 int i; 535 long err = 0; 536 537 /* addi r1, r1, __SIGNAL_FRAMESIZE # Pop the dummy stackframe */ 538 err |= __put_user(0x38210000UL | (__SIGNAL_FRAMESIZE & 0xffff), &tramp[0]); 539 /* li r0, __NR_[rt_]sigreturn| */ 540 err |= __put_user(0x38000000UL | (syscall & 0xffff), &tramp[1]); 541 /* sc */ 542 err |= __put_user(0x44000002UL, &tramp[2]); 543 544 /* Minimal traceback info */ 545 for (i=TRAMP_TRACEBACK; i < TRAMP_SIZE ;i++) 546 err |= __put_user(0, &tramp[i]); 547 548 if (!err) 549 flush_icache_range((unsigned long) &tramp[0], 550 (unsigned long) &tramp[TRAMP_SIZE]); 551 552 return err; 553 } 554 555 /* 556 * Userspace code may pass a ucontext which doesn't include VSX added 557 * at the end. We need to check for this case. 558 */ 559 #define UCONTEXTSIZEWITHOUTVSX \ 560 (sizeof(struct ucontext) - 32*sizeof(long)) 561 562 /* 563 * Handle {get,set,swap}_context operations 564 */ 565 int sys_swapcontext(struct ucontext __user *old_ctx, 566 struct ucontext __user *new_ctx, 567 long ctx_size, long r6, long r7, long r8, struct pt_regs *regs) 568 { 569 unsigned char tmp; 570 sigset_t set; 571 unsigned long new_msr = 0; 572 int ctx_has_vsx_region = 0; 573 574 if (new_ctx && 575 get_user(new_msr, &new_ctx->uc_mcontext.gp_regs[PT_MSR])) 576 return -EFAULT; 577 /* 578 * Check that the context is not smaller than the original 579 * size (with VMX but without VSX) 580 */ 581 if (ctx_size < UCONTEXTSIZEWITHOUTVSX) 582 return -EINVAL; 583 /* 584 * If the new context state sets the MSR VSX bits but 585 * it doesn't provide VSX state. 586 */ 587 if ((ctx_size < sizeof(struct ucontext)) && 588 (new_msr & MSR_VSX)) 589 return -EINVAL; 590 /* Does the context have enough room to store VSX data? */ 591 if (ctx_size >= sizeof(struct ucontext)) 592 ctx_has_vsx_region = 1; 593 594 if (old_ctx != NULL) { 595 if (!access_ok(VERIFY_WRITE, old_ctx, ctx_size) 596 || setup_sigcontext(&old_ctx->uc_mcontext, regs, 0, NULL, 0, 597 ctx_has_vsx_region) 598 || __copy_to_user(&old_ctx->uc_sigmask, 599 ¤t->blocked, sizeof(sigset_t))) 600 return -EFAULT; 601 } 602 if (new_ctx == NULL) 603 return 0; 604 if (!access_ok(VERIFY_READ, new_ctx, ctx_size) 605 || __get_user(tmp, (u8 __user *) new_ctx) 606 || __get_user(tmp, (u8 __user *) new_ctx + ctx_size - 1)) 607 return -EFAULT; 608 609 /* 610 * If we get a fault copying the context into the kernel's 611 * image of the user's registers, we can't just return -EFAULT 612 * because the user's registers will be corrupted. For instance 613 * the NIP value may have been updated but not some of the 614 * other registers. Given that we have done the access_ok 615 * and successfully read the first and last bytes of the region 616 * above, this should only happen in an out-of-memory situation 617 * or if another thread unmaps the region containing the context. 618 * We kill the task with a SIGSEGV in this situation. 619 */ 620 621 if (__copy_from_user(&set, &new_ctx->uc_sigmask, sizeof(set))) 622 do_exit(SIGSEGV); 623 set_current_blocked(&set); 624 if (restore_sigcontext(regs, NULL, 0, &new_ctx->uc_mcontext)) 625 do_exit(SIGSEGV); 626 627 /* This returns like rt_sigreturn */ 628 set_thread_flag(TIF_RESTOREALL); 629 return 0; 630 } 631 632 633 /* 634 * Do a signal return; undo the signal stack. 635 */ 636 637 int sys_rt_sigreturn(unsigned long r3, unsigned long r4, unsigned long r5, 638 unsigned long r6, unsigned long r7, unsigned long r8, 639 struct pt_regs *regs) 640 { 641 struct ucontext __user *uc = (struct ucontext __user *)regs->gpr[1]; 642 sigset_t set; 643 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 644 unsigned long msr; 645 #endif 646 647 /* Always make any pending restarted system calls return -EINTR */ 648 current_thread_info()->restart_block.fn = do_no_restart_syscall; 649 650 if (!access_ok(VERIFY_READ, uc, sizeof(*uc))) 651 goto badframe; 652 653 if (__copy_from_user(&set, &uc->uc_sigmask, sizeof(set))) 654 goto badframe; 655 set_current_blocked(&set); 656 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 657 if (__get_user(msr, &uc->uc_mcontext.gp_regs[PT_MSR])) 658 goto badframe; 659 if (MSR_TM_ACTIVE(msr)) { 660 /* We recheckpoint on return. */ 661 struct ucontext __user *uc_transact; 662 if (__get_user(uc_transact, &uc->uc_link)) 663 goto badframe; 664 if (restore_tm_sigcontexts(regs, &uc->uc_mcontext, 665 &uc_transact->uc_mcontext)) 666 goto badframe; 667 } 668 else 669 /* Fall through, for non-TM restore */ 670 #endif 671 if (restore_sigcontext(regs, NULL, 1, &uc->uc_mcontext)) 672 goto badframe; 673 674 if (restore_altstack(&uc->uc_stack)) 675 goto badframe; 676 677 set_thread_flag(TIF_RESTOREALL); 678 return 0; 679 680 badframe: 681 #if DEBUG_SIG 682 printk("badframe in sys_rt_sigreturn, regs=%p uc=%p &uc->uc_mcontext=%p\n", 683 regs, uc, &uc->uc_mcontext); 684 #endif 685 if (show_unhandled_signals) 686 printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32, 687 current->comm, current->pid, "rt_sigreturn", 688 (long)uc, regs->nip, regs->link); 689 690 force_sig(SIGSEGV, current); 691 return 0; 692 } 693 694 int handle_rt_signal64(int signr, struct k_sigaction *ka, siginfo_t *info, 695 sigset_t *set, struct pt_regs *regs) 696 { 697 /* Handler is *really* a pointer to the function descriptor for 698 * the signal routine. The first entry in the function 699 * descriptor is the entry address of signal and the second 700 * entry is the TOC value we need to use. 701 */ 702 func_descr_t __user *funct_desc_ptr; 703 struct rt_sigframe __user *frame; 704 unsigned long newsp = 0; 705 long err = 0; 706 707 frame = get_sigframe(ka, get_tm_stackpointer(regs), sizeof(*frame), 0); 708 if (unlikely(frame == NULL)) 709 goto badframe; 710 711 err |= __put_user(&frame->info, &frame->pinfo); 712 err |= __put_user(&frame->uc, &frame->puc); 713 err |= copy_siginfo_to_user(&frame->info, info); 714 if (err) 715 goto badframe; 716 717 /* Create the ucontext. */ 718 err |= __put_user(0, &frame->uc.uc_flags); 719 err |= __save_altstack(&frame->uc.uc_stack, regs->gpr[1]); 720 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 721 if (MSR_TM_ACTIVE(regs->msr)) { 722 /* The ucontext_t passed to userland points to the second 723 * ucontext_t (for transactional state) with its uc_link ptr. 724 */ 725 err |= __put_user(&frame->uc_transact, &frame->uc.uc_link); 726 err |= setup_tm_sigcontexts(&frame->uc.uc_mcontext, 727 &frame->uc_transact.uc_mcontext, 728 regs, signr, 729 NULL, 730 (unsigned long)ka->sa.sa_handler); 731 } else 732 #endif 733 { 734 err |= __put_user(0, &frame->uc.uc_link); 735 err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, signr, 736 NULL, (unsigned long)ka->sa.sa_handler, 737 1); 738 } 739 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); 740 if (err) 741 goto badframe; 742 743 /* Make sure signal handler doesn't get spurious FP exceptions */ 744 current->thread.fpscr.val = 0; 745 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 746 /* Remove TM bits from thread's MSR. The MSR in the sigcontext 747 * just indicates to userland that we were doing a transaction, but we 748 * don't want to return in transactional state: 749 */ 750 regs->msr &= ~MSR_TS_MASK; 751 #endif 752 753 /* Set up to return from userspace. */ 754 if (vdso64_rt_sigtramp && current->mm->context.vdso_base) { 755 regs->link = current->mm->context.vdso_base + vdso64_rt_sigtramp; 756 } else { 757 err |= setup_trampoline(__NR_rt_sigreturn, &frame->tramp[0]); 758 if (err) 759 goto badframe; 760 regs->link = (unsigned long) &frame->tramp[0]; 761 } 762 funct_desc_ptr = (func_descr_t __user *) ka->sa.sa_handler; 763 764 /* Allocate a dummy caller frame for the signal handler. */ 765 newsp = ((unsigned long)frame) - __SIGNAL_FRAMESIZE; 766 err |= put_user(regs->gpr[1], (unsigned long __user *)newsp); 767 768 /* Set up "regs" so we "return" to the signal handler. */ 769 err |= get_user(regs->nip, &funct_desc_ptr->entry); 770 /* enter the signal handler in big-endian mode */ 771 regs->msr &= ~MSR_LE; 772 regs->gpr[1] = newsp; 773 err |= get_user(regs->gpr[2], &funct_desc_ptr->toc); 774 regs->gpr[3] = signr; 775 regs->result = 0; 776 if (ka->sa.sa_flags & SA_SIGINFO) { 777 err |= get_user(regs->gpr[4], (unsigned long __user *)&frame->pinfo); 778 err |= get_user(regs->gpr[5], (unsigned long __user *)&frame->puc); 779 regs->gpr[6] = (unsigned long) frame; 780 } else { 781 regs->gpr[4] = (unsigned long)&frame->uc.uc_mcontext; 782 } 783 if (err) 784 goto badframe; 785 786 return 1; 787 788 badframe: 789 #if DEBUG_SIG 790 printk("badframe in setup_rt_frame, regs=%p frame=%p newsp=%lx\n", 791 regs, frame, newsp); 792 #endif 793 if (show_unhandled_signals) 794 printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32, 795 current->comm, current->pid, "setup_rt_frame", 796 (long)frame, regs->nip, regs->link); 797 798 force_sigsegv(signr, current); 799 return 0; 800 } 801