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 42 #define GP_REGS_SIZE min(sizeof(elf_gregset_t), sizeof(struct pt_regs)) 43 #define FP_REGS_SIZE sizeof(elf_fpregset_t) 44 45 #define TRAMP_TRACEBACK 3 46 #define TRAMP_SIZE 6 47 48 /* 49 * When we have signals to deliver, we set up on the user stack, 50 * going down from the original stack pointer: 51 * 1) a rt_sigframe struct which contains the ucontext 52 * 2) a gap of __SIGNAL_FRAMESIZE bytes which acts as a dummy caller 53 * frame for the signal handler. 54 */ 55 56 struct rt_sigframe { 57 /* sys_rt_sigreturn requires the ucontext be the first field */ 58 struct ucontext uc; 59 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 60 struct ucontext uc_transact; 61 #endif 62 unsigned long _unused[2]; 63 unsigned int tramp[TRAMP_SIZE]; 64 struct siginfo __user *pinfo; 65 void __user *puc; 66 struct siginfo info; 67 /* New 64 bit little-endian ABI allows redzone of 512 bytes below sp */ 68 char abigap[USER_REDZONE_SIZE]; 69 } __attribute__ ((aligned (16))); 70 71 static const char fmt32[] = KERN_INFO \ 72 "%s[%d]: bad frame in %s: %08lx nip %08lx lr %08lx\n"; 73 static const char fmt64[] = KERN_INFO \ 74 "%s[%d]: bad frame in %s: %016lx nip %016lx lr %016lx\n"; 75 76 /* 77 * This computes a quad word aligned pointer inside the vmx_reserve array 78 * element. For historical reasons sigcontext might not be quad word aligned, 79 * but the location we write the VMX regs to must be. See the comment in 80 * sigcontext for more detail. 81 */ 82 #ifdef CONFIG_ALTIVEC 83 static elf_vrreg_t __user *sigcontext_vmx_regs(struct sigcontext __user *sc) 84 { 85 return (elf_vrreg_t __user *) (((unsigned long)sc->vmx_reserve + 15) & ~0xful); 86 } 87 #endif 88 89 /* 90 * Set up the sigcontext for the signal frame. 91 */ 92 93 static long setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, 94 int signr, sigset_t *set, unsigned long handler, 95 int ctx_has_vsx_region) 96 { 97 /* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the 98 * process never used altivec yet (MSR_VEC is zero in pt_regs of 99 * the context). This is very important because we must ensure we 100 * don't lose the VRSAVE content that may have been set prior to 101 * the process doing its first vector operation 102 * Userland shall check AT_HWCAP to know whether it can rely on the 103 * v_regs pointer or not 104 */ 105 #ifdef CONFIG_ALTIVEC 106 elf_vrreg_t __user *v_regs = sigcontext_vmx_regs(sc); 107 #endif 108 unsigned long msr = regs->msr; 109 long err = 0; 110 111 #ifdef CONFIG_ALTIVEC 112 err |= __put_user(v_regs, &sc->v_regs); 113 114 /* save altivec registers */ 115 if (current->thread.used_vr) { 116 flush_altivec_to_thread(current); 117 /* Copy 33 vec registers (vr0..31 and vscr) to the stack */ 118 err |= __copy_to_user(v_regs, ¤t->thread.vr_state, 119 33 * sizeof(vector128)); 120 /* set MSR_VEC in the MSR value in the frame to indicate that sc->v_reg) 121 * contains valid data. 122 */ 123 msr |= MSR_VEC; 124 } 125 /* We always copy to/from vrsave, it's 0 if we don't have or don't 126 * use altivec. 127 */ 128 if (cpu_has_feature(CPU_FTR_ALTIVEC)) 129 current->thread.vrsave = mfspr(SPRN_VRSAVE); 130 err |= __put_user(current->thread.vrsave, (u32 __user *)&v_regs[33]); 131 #else /* CONFIG_ALTIVEC */ 132 err |= __put_user(0, &sc->v_regs); 133 #endif /* CONFIG_ALTIVEC */ 134 flush_fp_to_thread(current); 135 /* copy fpr regs and fpscr */ 136 err |= copy_fpr_to_user(&sc->fp_regs, current); 137 138 /* 139 * Clear the MSR VSX bit to indicate there is no valid state attached 140 * to this context, except in the specific case below where we set it. 141 */ 142 msr &= ~MSR_VSX; 143 #ifdef CONFIG_VSX 144 /* 145 * Copy VSX low doubleword to local buffer for formatting, 146 * then out to userspace. Update v_regs to point after the 147 * VMX data. 148 */ 149 if (current->thread.used_vsr && ctx_has_vsx_region) { 150 __giveup_vsx(current); 151 v_regs += ELF_NVRREG; 152 err |= copy_vsx_to_user(v_regs, current); 153 /* set MSR_VSX in the MSR value in the frame to 154 * indicate that sc->vs_reg) contains valid data. 155 */ 156 msr |= MSR_VSX; 157 } 158 #endif /* CONFIG_VSX */ 159 err |= __put_user(&sc->gp_regs, &sc->regs); 160 WARN_ON(!FULL_REGS(regs)); 161 err |= __copy_to_user(&sc->gp_regs, regs, GP_REGS_SIZE); 162 err |= __put_user(msr, &sc->gp_regs[PT_MSR]); 163 err |= __put_user(signr, &sc->signal); 164 err |= __put_user(handler, &sc->handler); 165 if (set != NULL) 166 err |= __put_user(set->sig[0], &sc->oldmask); 167 168 return err; 169 } 170 171 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 172 /* 173 * As above, but Transactional Memory is in use, so deliver sigcontexts 174 * containing checkpointed and transactional register states. 175 * 176 * To do this, we treclaim (done before entering here) to gather both sets of 177 * registers and set up the 'normal' sigcontext registers with rolled-back 178 * register values such that a simple signal handler sees a correct 179 * checkpointed register state. If interested, a TM-aware sighandler can 180 * examine the transactional registers in the 2nd sigcontext to determine the 181 * real origin of the signal. 182 */ 183 static long setup_tm_sigcontexts(struct sigcontext __user *sc, 184 struct sigcontext __user *tm_sc, 185 struct pt_regs *regs, 186 int signr, sigset_t *set, unsigned long handler) 187 { 188 /* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the 189 * process never used altivec yet (MSR_VEC is zero in pt_regs of 190 * the context). This is very important because we must ensure we 191 * don't lose the VRSAVE content that may have been set prior to 192 * the process doing its first vector operation 193 * Userland shall check AT_HWCAP to know wether it can rely on the 194 * v_regs pointer or not. 195 */ 196 #ifdef CONFIG_ALTIVEC 197 elf_vrreg_t __user *v_regs = sigcontext_vmx_regs(sc); 198 elf_vrreg_t __user *tm_v_regs = sigcontext_vmx_regs(tm_sc); 199 #endif 200 unsigned long msr = regs->msr; 201 long err = 0; 202 203 BUG_ON(!MSR_TM_ACTIVE(regs->msr)); 204 205 /* Remove TM bits from thread's MSR. The MSR in the sigcontext 206 * just indicates to userland that we were doing a transaction, but we 207 * don't want to return in transactional state. This also ensures 208 * that flush_fp_to_thread won't set TIF_RESTORE_TM again. 209 */ 210 regs->msr &= ~MSR_TS_MASK; 211 212 flush_fp_to_thread(current); 213 214 #ifdef CONFIG_ALTIVEC 215 err |= __put_user(v_regs, &sc->v_regs); 216 err |= __put_user(tm_v_regs, &tm_sc->v_regs); 217 218 /* save altivec registers */ 219 if (current->thread.used_vr) { 220 flush_altivec_to_thread(current); 221 /* Copy 33 vec registers (vr0..31 and vscr) to the stack */ 222 err |= __copy_to_user(v_regs, ¤t->thread.vr_state, 223 33 * sizeof(vector128)); 224 /* If VEC was enabled there are transactional VRs valid too, 225 * else they're a copy of the checkpointed VRs. 226 */ 227 if (msr & MSR_VEC) 228 err |= __copy_to_user(tm_v_regs, 229 ¤t->thread.transact_vr, 230 33 * sizeof(vector128)); 231 else 232 err |= __copy_to_user(tm_v_regs, 233 ¤t->thread.vr_state, 234 33 * sizeof(vector128)); 235 236 /* set MSR_VEC in the MSR value in the frame to indicate 237 * that sc->v_reg contains valid data. 238 */ 239 msr |= MSR_VEC; 240 } 241 /* We always copy to/from vrsave, it's 0 if we don't have or don't 242 * use altivec. 243 */ 244 if (cpu_has_feature(CPU_FTR_ALTIVEC)) 245 current->thread.vrsave = mfspr(SPRN_VRSAVE); 246 err |= __put_user(current->thread.vrsave, (u32 __user *)&v_regs[33]); 247 if (msr & MSR_VEC) 248 err |= __put_user(current->thread.transact_vrsave, 249 (u32 __user *)&tm_v_regs[33]); 250 else 251 err |= __put_user(current->thread.vrsave, 252 (u32 __user *)&tm_v_regs[33]); 253 254 #else /* CONFIG_ALTIVEC */ 255 err |= __put_user(0, &sc->v_regs); 256 err |= __put_user(0, &tm_sc->v_regs); 257 #endif /* CONFIG_ALTIVEC */ 258 259 /* copy fpr regs and fpscr */ 260 err |= copy_fpr_to_user(&sc->fp_regs, current); 261 if (msr & MSR_FP) 262 err |= copy_transact_fpr_to_user(&tm_sc->fp_regs, current); 263 else 264 err |= copy_fpr_to_user(&tm_sc->fp_regs, current); 265 266 #ifdef CONFIG_VSX 267 /* 268 * Copy VSX low doubleword to local buffer for formatting, 269 * then out to userspace. Update v_regs to point after the 270 * VMX data. 271 */ 272 if (current->thread.used_vsr) { 273 __giveup_vsx(current); 274 v_regs += ELF_NVRREG; 275 tm_v_regs += ELF_NVRREG; 276 277 err |= copy_vsx_to_user(v_regs, current); 278 279 if (msr & MSR_VSX) 280 err |= copy_transact_vsx_to_user(tm_v_regs, current); 281 else 282 err |= copy_vsx_to_user(tm_v_regs, current); 283 284 /* set MSR_VSX in the MSR value in the frame to 285 * indicate that sc->vs_reg) contains valid data. 286 */ 287 msr |= MSR_VSX; 288 } 289 #endif /* CONFIG_VSX */ 290 291 err |= __put_user(&sc->gp_regs, &sc->regs); 292 err |= __put_user(&tm_sc->gp_regs, &tm_sc->regs); 293 WARN_ON(!FULL_REGS(regs)); 294 err |= __copy_to_user(&tm_sc->gp_regs, regs, GP_REGS_SIZE); 295 err |= __copy_to_user(&sc->gp_regs, 296 ¤t->thread.ckpt_regs, GP_REGS_SIZE); 297 err |= __put_user(msr, &tm_sc->gp_regs[PT_MSR]); 298 err |= __put_user(msr, &sc->gp_regs[PT_MSR]); 299 err |= __put_user(signr, &sc->signal); 300 err |= __put_user(handler, &sc->handler); 301 if (set != NULL) 302 err |= __put_user(set->sig[0], &sc->oldmask); 303 304 return err; 305 } 306 #endif 307 308 /* 309 * Restore the sigcontext from the signal frame. 310 */ 311 312 static long restore_sigcontext(struct pt_regs *regs, sigset_t *set, int sig, 313 struct sigcontext __user *sc) 314 { 315 #ifdef CONFIG_ALTIVEC 316 elf_vrreg_t __user *v_regs; 317 #endif 318 unsigned long err = 0; 319 unsigned long save_r13 = 0; 320 unsigned long msr; 321 #ifdef CONFIG_VSX 322 int i; 323 #endif 324 325 /* If this is not a signal return, we preserve the TLS in r13 */ 326 if (!sig) 327 save_r13 = regs->gpr[13]; 328 329 /* copy the GPRs */ 330 err |= __copy_from_user(regs->gpr, sc->gp_regs, sizeof(regs->gpr)); 331 err |= __get_user(regs->nip, &sc->gp_regs[PT_NIP]); 332 /* get MSR separately, transfer the LE bit if doing signal return */ 333 err |= __get_user(msr, &sc->gp_regs[PT_MSR]); 334 if (sig) 335 regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE); 336 err |= __get_user(regs->orig_gpr3, &sc->gp_regs[PT_ORIG_R3]); 337 err |= __get_user(regs->ctr, &sc->gp_regs[PT_CTR]); 338 err |= __get_user(regs->link, &sc->gp_regs[PT_LNK]); 339 err |= __get_user(regs->xer, &sc->gp_regs[PT_XER]); 340 err |= __get_user(regs->ccr, &sc->gp_regs[PT_CCR]); 341 /* skip SOFTE */ 342 regs->trap = 0; 343 err |= __get_user(regs->dar, &sc->gp_regs[PT_DAR]); 344 err |= __get_user(regs->dsisr, &sc->gp_regs[PT_DSISR]); 345 err |= __get_user(regs->result, &sc->gp_regs[PT_RESULT]); 346 347 if (!sig) 348 regs->gpr[13] = save_r13; 349 if (set != NULL) 350 err |= __get_user(set->sig[0], &sc->oldmask); 351 352 /* 353 * Do this before updating the thread state in 354 * current->thread.fpr/vr. That way, if we get preempted 355 * and another task grabs the FPU/Altivec, it won't be 356 * tempted to save the current CPU state into the thread_struct 357 * and corrupt what we are writing there. 358 */ 359 discard_lazy_cpu_state(); 360 361 /* 362 * Force reload of FP/VEC. 363 * This has to be done before copying stuff into current->thread.fpr/vr 364 * for the reasons explained in the previous comment. 365 */ 366 regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC | MSR_VSX); 367 368 #ifdef CONFIG_ALTIVEC 369 err |= __get_user(v_regs, &sc->v_regs); 370 if (err) 371 return err; 372 if (v_regs && !access_ok(VERIFY_READ, v_regs, 34 * sizeof(vector128))) 373 return -EFAULT; 374 /* Copy 33 vec registers (vr0..31 and vscr) from the stack */ 375 if (v_regs != NULL && (msr & MSR_VEC) != 0) 376 err |= __copy_from_user(¤t->thread.vr_state, v_regs, 377 33 * sizeof(vector128)); 378 else if (current->thread.used_vr) 379 memset(¤t->thread.vr_state, 0, 33 * sizeof(vector128)); 380 /* Always get VRSAVE back */ 381 if (v_regs != NULL) 382 err |= __get_user(current->thread.vrsave, (u32 __user *)&v_regs[33]); 383 else 384 current->thread.vrsave = 0; 385 if (cpu_has_feature(CPU_FTR_ALTIVEC)) 386 mtspr(SPRN_VRSAVE, current->thread.vrsave); 387 #endif /* CONFIG_ALTIVEC */ 388 /* restore floating point */ 389 err |= copy_fpr_from_user(current, &sc->fp_regs); 390 #ifdef CONFIG_VSX 391 /* 392 * Get additional VSX data. Update v_regs to point after the 393 * VMX data. Copy VSX low doubleword from userspace to local 394 * buffer for formatting, then into the taskstruct. 395 */ 396 v_regs += ELF_NVRREG; 397 if ((msr & MSR_VSX) != 0) 398 err |= copy_vsx_from_user(current, v_regs); 399 else 400 for (i = 0; i < 32 ; i++) 401 current->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0; 402 #endif 403 return err; 404 } 405 406 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 407 /* 408 * Restore the two sigcontexts from the frame of a transactional processes. 409 */ 410 411 static long restore_tm_sigcontexts(struct pt_regs *regs, 412 struct sigcontext __user *sc, 413 struct sigcontext __user *tm_sc) 414 { 415 #ifdef CONFIG_ALTIVEC 416 elf_vrreg_t __user *v_regs, *tm_v_regs; 417 #endif 418 unsigned long err = 0; 419 unsigned long msr; 420 #ifdef CONFIG_VSX 421 int i; 422 #endif 423 /* copy the GPRs */ 424 err |= __copy_from_user(regs->gpr, tm_sc->gp_regs, sizeof(regs->gpr)); 425 err |= __copy_from_user(¤t->thread.ckpt_regs, sc->gp_regs, 426 sizeof(regs->gpr)); 427 428 /* 429 * TFHAR is restored from the checkpointed 'wound-back' ucontext's NIP. 430 * TEXASR was set by the signal delivery reclaim, as was TFIAR. 431 * Users doing anything abhorrent like thread-switching w/ signals for 432 * TM-Suspended code will have to back TEXASR/TFIAR up themselves. 433 * For the case of getting a signal and simply returning from it, 434 * we don't need to re-copy them here. 435 */ 436 err |= __get_user(regs->nip, &tm_sc->gp_regs[PT_NIP]); 437 err |= __get_user(current->thread.tm_tfhar, &sc->gp_regs[PT_NIP]); 438 439 /* get MSR separately, transfer the LE bit if doing signal return */ 440 err |= __get_user(msr, &sc->gp_regs[PT_MSR]); 441 /* Don't allow reserved mode. */ 442 if (MSR_TM_RESV(msr)) 443 return -EINVAL; 444 445 /* pull in MSR TM from user context */ 446 regs->msr = (regs->msr & ~MSR_TS_MASK) | (msr & MSR_TS_MASK); 447 448 /* pull in MSR LE from user context */ 449 regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE); 450 451 /* The following non-GPR non-FPR non-VR state is also checkpointed: */ 452 err |= __get_user(regs->ctr, &tm_sc->gp_regs[PT_CTR]); 453 err |= __get_user(regs->link, &tm_sc->gp_regs[PT_LNK]); 454 err |= __get_user(regs->xer, &tm_sc->gp_regs[PT_XER]); 455 err |= __get_user(regs->ccr, &tm_sc->gp_regs[PT_CCR]); 456 err |= __get_user(current->thread.ckpt_regs.ctr, 457 &sc->gp_regs[PT_CTR]); 458 err |= __get_user(current->thread.ckpt_regs.link, 459 &sc->gp_regs[PT_LNK]); 460 err |= __get_user(current->thread.ckpt_regs.xer, 461 &sc->gp_regs[PT_XER]); 462 err |= __get_user(current->thread.ckpt_regs.ccr, 463 &sc->gp_regs[PT_CCR]); 464 465 /* These regs are not checkpointed; they can go in 'regs'. */ 466 err |= __get_user(regs->trap, &sc->gp_regs[PT_TRAP]); 467 err |= __get_user(regs->dar, &sc->gp_regs[PT_DAR]); 468 err |= __get_user(regs->dsisr, &sc->gp_regs[PT_DSISR]); 469 err |= __get_user(regs->result, &sc->gp_regs[PT_RESULT]); 470 471 /* 472 * Do this before updating the thread state in 473 * current->thread.fpr/vr. That way, if we get preempted 474 * and another task grabs the FPU/Altivec, it won't be 475 * tempted to save the current CPU state into the thread_struct 476 * and corrupt what we are writing there. 477 */ 478 discard_lazy_cpu_state(); 479 480 /* 481 * Force reload of FP/VEC. 482 * This has to be done before copying stuff into current->thread.fpr/vr 483 * for the reasons explained in the previous comment. 484 */ 485 regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC | MSR_VSX); 486 487 #ifdef CONFIG_ALTIVEC 488 err |= __get_user(v_regs, &sc->v_regs); 489 err |= __get_user(tm_v_regs, &tm_sc->v_regs); 490 if (err) 491 return err; 492 if (v_regs && !access_ok(VERIFY_READ, v_regs, 34 * sizeof(vector128))) 493 return -EFAULT; 494 if (tm_v_regs && !access_ok(VERIFY_READ, 495 tm_v_regs, 34 * sizeof(vector128))) 496 return -EFAULT; 497 /* Copy 33 vec registers (vr0..31 and vscr) from the stack */ 498 if (v_regs != NULL && tm_v_regs != NULL && (msr & MSR_VEC) != 0) { 499 err |= __copy_from_user(¤t->thread.vr_state, v_regs, 500 33 * sizeof(vector128)); 501 err |= __copy_from_user(¤t->thread.transact_vr, tm_v_regs, 502 33 * sizeof(vector128)); 503 } 504 else if (current->thread.used_vr) { 505 memset(¤t->thread.vr_state, 0, 33 * sizeof(vector128)); 506 memset(¤t->thread.transact_vr, 0, 33 * sizeof(vector128)); 507 } 508 /* Always get VRSAVE back */ 509 if (v_regs != NULL && tm_v_regs != NULL) { 510 err |= __get_user(current->thread.vrsave, 511 (u32 __user *)&v_regs[33]); 512 err |= __get_user(current->thread.transact_vrsave, 513 (u32 __user *)&tm_v_regs[33]); 514 } 515 else { 516 current->thread.vrsave = 0; 517 current->thread.transact_vrsave = 0; 518 } 519 if (cpu_has_feature(CPU_FTR_ALTIVEC)) 520 mtspr(SPRN_VRSAVE, current->thread.vrsave); 521 #endif /* CONFIG_ALTIVEC */ 522 /* restore floating point */ 523 err |= copy_fpr_from_user(current, &sc->fp_regs); 524 err |= copy_transact_fpr_from_user(current, &tm_sc->fp_regs); 525 #ifdef CONFIG_VSX 526 /* 527 * Get additional VSX data. Update v_regs to point after the 528 * VMX data. Copy VSX low doubleword from userspace to local 529 * buffer for formatting, then into the taskstruct. 530 */ 531 if (v_regs && ((msr & MSR_VSX) != 0)) { 532 v_regs += ELF_NVRREG; 533 tm_v_regs += ELF_NVRREG; 534 err |= copy_vsx_from_user(current, v_regs); 535 err |= copy_transact_vsx_from_user(current, tm_v_regs); 536 } else { 537 for (i = 0; i < 32 ; i++) { 538 current->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0; 539 current->thread.transact_fp.fpr[i][TS_VSRLOWOFFSET] = 0; 540 } 541 } 542 #endif 543 tm_enable(); 544 /* Make sure the transaction is marked as failed */ 545 current->thread.tm_texasr |= TEXASR_FS; 546 /* This loads the checkpointed FP/VEC state, if used */ 547 tm_recheckpoint(¤t->thread, msr); 548 549 /* This loads the speculative FP/VEC state, if used */ 550 if (msr & MSR_FP) { 551 do_load_up_transact_fpu(¤t->thread); 552 regs->msr |= (MSR_FP | current->thread.fpexc_mode); 553 } 554 #ifdef CONFIG_ALTIVEC 555 if (msr & MSR_VEC) { 556 do_load_up_transact_altivec(¤t->thread); 557 regs->msr |= MSR_VEC; 558 } 559 #endif 560 561 return err; 562 } 563 #endif 564 565 /* 566 * Setup the trampoline code on the stack 567 */ 568 static long setup_trampoline(unsigned int syscall, unsigned int __user *tramp) 569 { 570 int i; 571 long err = 0; 572 573 /* addi r1, r1, __SIGNAL_FRAMESIZE # Pop the dummy stackframe */ 574 err |= __put_user(0x38210000UL | (__SIGNAL_FRAMESIZE & 0xffff), &tramp[0]); 575 /* li r0, __NR_[rt_]sigreturn| */ 576 err |= __put_user(0x38000000UL | (syscall & 0xffff), &tramp[1]); 577 /* sc */ 578 err |= __put_user(0x44000002UL, &tramp[2]); 579 580 /* Minimal traceback info */ 581 for (i=TRAMP_TRACEBACK; i < TRAMP_SIZE ;i++) 582 err |= __put_user(0, &tramp[i]); 583 584 if (!err) 585 flush_icache_range((unsigned long) &tramp[0], 586 (unsigned long) &tramp[TRAMP_SIZE]); 587 588 return err; 589 } 590 591 /* 592 * Userspace code may pass a ucontext which doesn't include VSX added 593 * at the end. We need to check for this case. 594 */ 595 #define UCONTEXTSIZEWITHOUTVSX \ 596 (sizeof(struct ucontext) - 32*sizeof(long)) 597 598 /* 599 * Handle {get,set,swap}_context operations 600 */ 601 int sys_swapcontext(struct ucontext __user *old_ctx, 602 struct ucontext __user *new_ctx, 603 long ctx_size, long r6, long r7, long r8, struct pt_regs *regs) 604 { 605 unsigned char tmp; 606 sigset_t set; 607 unsigned long new_msr = 0; 608 int ctx_has_vsx_region = 0; 609 610 if (new_ctx && 611 get_user(new_msr, &new_ctx->uc_mcontext.gp_regs[PT_MSR])) 612 return -EFAULT; 613 /* 614 * Check that the context is not smaller than the original 615 * size (with VMX but without VSX) 616 */ 617 if (ctx_size < UCONTEXTSIZEWITHOUTVSX) 618 return -EINVAL; 619 /* 620 * If the new context state sets the MSR VSX bits but 621 * it doesn't provide VSX state. 622 */ 623 if ((ctx_size < sizeof(struct ucontext)) && 624 (new_msr & MSR_VSX)) 625 return -EINVAL; 626 /* Does the context have enough room to store VSX data? */ 627 if (ctx_size >= sizeof(struct ucontext)) 628 ctx_has_vsx_region = 1; 629 630 if (old_ctx != NULL) { 631 if (!access_ok(VERIFY_WRITE, old_ctx, ctx_size) 632 || setup_sigcontext(&old_ctx->uc_mcontext, regs, 0, NULL, 0, 633 ctx_has_vsx_region) 634 || __copy_to_user(&old_ctx->uc_sigmask, 635 ¤t->blocked, sizeof(sigset_t))) 636 return -EFAULT; 637 } 638 if (new_ctx == NULL) 639 return 0; 640 if (!access_ok(VERIFY_READ, new_ctx, ctx_size) 641 || __get_user(tmp, (u8 __user *) new_ctx) 642 || __get_user(tmp, (u8 __user *) new_ctx + ctx_size - 1)) 643 return -EFAULT; 644 645 /* 646 * If we get a fault copying the context into the kernel's 647 * image of the user's registers, we can't just return -EFAULT 648 * because the user's registers will be corrupted. For instance 649 * the NIP value may have been updated but not some of the 650 * other registers. Given that we have done the access_ok 651 * and successfully read the first and last bytes of the region 652 * above, this should only happen in an out-of-memory situation 653 * or if another thread unmaps the region containing the context. 654 * We kill the task with a SIGSEGV in this situation. 655 */ 656 657 if (__copy_from_user(&set, &new_ctx->uc_sigmask, sizeof(set))) 658 do_exit(SIGSEGV); 659 set_current_blocked(&set); 660 if (restore_sigcontext(regs, NULL, 0, &new_ctx->uc_mcontext)) 661 do_exit(SIGSEGV); 662 663 /* This returns like rt_sigreturn */ 664 set_thread_flag(TIF_RESTOREALL); 665 return 0; 666 } 667 668 669 /* 670 * Do a signal return; undo the signal stack. 671 */ 672 673 int sys_rt_sigreturn(unsigned long r3, unsigned long r4, unsigned long r5, 674 unsigned long r6, unsigned long r7, unsigned long r8, 675 struct pt_regs *regs) 676 { 677 struct ucontext __user *uc = (struct ucontext __user *)regs->gpr[1]; 678 sigset_t set; 679 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 680 unsigned long msr; 681 #endif 682 683 /* Always make any pending restarted system calls return -EINTR */ 684 current->restart_block.fn = do_no_restart_syscall; 685 686 if (!access_ok(VERIFY_READ, uc, sizeof(*uc))) 687 goto badframe; 688 689 if (__copy_from_user(&set, &uc->uc_sigmask, sizeof(set))) 690 goto badframe; 691 set_current_blocked(&set); 692 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 693 if (__get_user(msr, &uc->uc_mcontext.gp_regs[PT_MSR])) 694 goto badframe; 695 if (MSR_TM_ACTIVE(msr)) { 696 /* We recheckpoint on return. */ 697 struct ucontext __user *uc_transact; 698 if (__get_user(uc_transact, &uc->uc_link)) 699 goto badframe; 700 if (restore_tm_sigcontexts(regs, &uc->uc_mcontext, 701 &uc_transact->uc_mcontext)) 702 goto badframe; 703 } 704 else 705 /* Fall through, for non-TM restore */ 706 #endif 707 if (restore_sigcontext(regs, NULL, 1, &uc->uc_mcontext)) 708 goto badframe; 709 710 if (restore_altstack(&uc->uc_stack)) 711 goto badframe; 712 713 set_thread_flag(TIF_RESTOREALL); 714 return 0; 715 716 badframe: 717 if (show_unhandled_signals) 718 printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32, 719 current->comm, current->pid, "rt_sigreturn", 720 (long)uc, regs->nip, regs->link); 721 722 force_sig(SIGSEGV, current); 723 return 0; 724 } 725 726 int handle_rt_signal64(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs) 727 { 728 struct rt_sigframe __user *frame; 729 unsigned long newsp = 0; 730 long err = 0; 731 732 frame = get_sigframe(ksig, get_tm_stackpointer(regs), sizeof(*frame), 0); 733 if (unlikely(frame == NULL)) 734 goto badframe; 735 736 err |= __put_user(&frame->info, &frame->pinfo); 737 err |= __put_user(&frame->uc, &frame->puc); 738 err |= copy_siginfo_to_user(&frame->info, &ksig->info); 739 if (err) 740 goto badframe; 741 742 /* Create the ucontext. */ 743 err |= __put_user(0, &frame->uc.uc_flags); 744 err |= __save_altstack(&frame->uc.uc_stack, regs->gpr[1]); 745 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 746 if (MSR_TM_ACTIVE(regs->msr)) { 747 /* The ucontext_t passed to userland points to the second 748 * ucontext_t (for transactional state) with its uc_link ptr. 749 */ 750 err |= __put_user(&frame->uc_transact, &frame->uc.uc_link); 751 err |= setup_tm_sigcontexts(&frame->uc.uc_mcontext, 752 &frame->uc_transact.uc_mcontext, 753 regs, ksig->sig, 754 NULL, 755 (unsigned long)ksig->ka.sa.sa_handler); 756 } else 757 #endif 758 { 759 err |= __put_user(0, &frame->uc.uc_link); 760 err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, ksig->sig, 761 NULL, (unsigned long)ksig->ka.sa.sa_handler, 762 1); 763 } 764 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); 765 if (err) 766 goto badframe; 767 768 /* Make sure signal handler doesn't get spurious FP exceptions */ 769 current->thread.fp_state.fpscr = 0; 770 771 /* Set up to return from userspace. */ 772 if (vdso64_rt_sigtramp && current->mm->context.vdso_base) { 773 regs->link = current->mm->context.vdso_base + vdso64_rt_sigtramp; 774 } else { 775 err |= setup_trampoline(__NR_rt_sigreturn, &frame->tramp[0]); 776 if (err) 777 goto badframe; 778 regs->link = (unsigned long) &frame->tramp[0]; 779 } 780 781 /* Allocate a dummy caller frame for the signal handler. */ 782 newsp = ((unsigned long)frame) - __SIGNAL_FRAMESIZE; 783 err |= put_user(regs->gpr[1], (unsigned long __user *)newsp); 784 785 /* Set up "regs" so we "return" to the signal handler. */ 786 if (is_elf2_task()) { 787 regs->nip = (unsigned long) ksig->ka.sa.sa_handler; 788 regs->gpr[12] = regs->nip; 789 } else { 790 /* Handler is *really* a pointer to the function descriptor for 791 * the signal routine. The first entry in the function 792 * descriptor is the entry address of signal and the second 793 * entry is the TOC value we need to use. 794 */ 795 func_descr_t __user *funct_desc_ptr = 796 (func_descr_t __user *) ksig->ka.sa.sa_handler; 797 798 err |= get_user(regs->nip, &funct_desc_ptr->entry); 799 err |= get_user(regs->gpr[2], &funct_desc_ptr->toc); 800 } 801 802 /* enter the signal handler in native-endian mode */ 803 regs->msr &= ~MSR_LE; 804 regs->msr |= (MSR_KERNEL & MSR_LE); 805 regs->gpr[1] = newsp; 806 regs->gpr[3] = ksig->sig; 807 regs->result = 0; 808 if (ksig->ka.sa.sa_flags & SA_SIGINFO) { 809 err |= get_user(regs->gpr[4], (unsigned long __user *)&frame->pinfo); 810 err |= get_user(regs->gpr[5], (unsigned long __user *)&frame->puc); 811 regs->gpr[6] = (unsigned long) frame; 812 } else { 813 regs->gpr[4] = (unsigned long)&frame->uc.uc_mcontext; 814 } 815 if (err) 816 goto badframe; 817 818 return 0; 819 820 badframe: 821 if (show_unhandled_signals) 822 printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32, 823 current->comm, current->pid, "setup_rt_frame", 824 (long)frame, regs->nip, regs->link); 825 826 return 1; 827 } 828