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 #include <linux/syscalls.h> 28 29 #include <asm/sigcontext.h> 30 #include <asm/ucontext.h> 31 #include <linux/uaccess.h> 32 #include <asm/pgtable.h> 33 #include <asm/unistd.h> 34 #include <asm/cacheflush.h> 35 #include <asm/syscalls.h> 36 #include <asm/vdso.h> 37 #include <asm/switch_to.h> 38 #include <asm/tm.h> 39 #include <asm/asm-prototypes.h> 40 41 #include "signal.h" 42 43 44 #define GP_REGS_SIZE min(sizeof(elf_gregset_t), sizeof(struct pt_regs)) 45 #define FP_REGS_SIZE sizeof(elf_fpregset_t) 46 47 #define TRAMP_TRACEBACK 3 48 #define TRAMP_SIZE 6 49 50 /* 51 * When we have signals to deliver, we set up on the user stack, 52 * going down from the original stack pointer: 53 * 1) a rt_sigframe struct which contains the ucontext 54 * 2) a gap of __SIGNAL_FRAMESIZE bytes which acts as a dummy caller 55 * frame for the signal handler. 56 */ 57 58 struct rt_sigframe { 59 /* sys_rt_sigreturn requires the ucontext be the first field */ 60 struct ucontext uc; 61 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 62 struct ucontext uc_transact; 63 #endif 64 unsigned long _unused[2]; 65 unsigned int tramp[TRAMP_SIZE]; 66 struct siginfo __user *pinfo; 67 void __user *puc; 68 struct siginfo info; 69 /* New 64 bit little-endian ABI allows redzone of 512 bytes below sp */ 70 char abigap[USER_REDZONE_SIZE]; 71 } __attribute__ ((aligned (16))); 72 73 static const char fmt32[] = KERN_INFO \ 74 "%s[%d]: bad frame in %s: %08lx nip %08lx lr %08lx\n"; 75 static const char fmt64[] = KERN_INFO \ 76 "%s[%d]: bad frame in %s: %016lx nip %016lx lr %016lx\n"; 77 78 /* 79 * This computes a quad word aligned pointer inside the vmx_reserve array 80 * element. For historical reasons sigcontext might not be quad word aligned, 81 * but the location we write the VMX regs to must be. See the comment in 82 * sigcontext for more detail. 83 */ 84 #ifdef CONFIG_ALTIVEC 85 static elf_vrreg_t __user *sigcontext_vmx_regs(struct sigcontext __user *sc) 86 { 87 return (elf_vrreg_t __user *) (((unsigned long)sc->vmx_reserve + 15) & ~0xful); 88 } 89 #endif 90 91 /* 92 * Set up the sigcontext for the signal frame. 93 */ 94 95 static long setup_sigcontext(struct sigcontext __user *sc, 96 struct task_struct *tsk, int signr, sigset_t *set, 97 unsigned long handler, int ctx_has_vsx_region) 98 { 99 /* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the 100 * process never used altivec yet (MSR_VEC is zero in pt_regs of 101 * the context). This is very important because we must ensure we 102 * don't lose the VRSAVE content that may have been set prior to 103 * the process doing its first vector operation 104 * Userland shall check AT_HWCAP to know whether it can rely on the 105 * v_regs pointer or not 106 */ 107 #ifdef CONFIG_ALTIVEC 108 elf_vrreg_t __user *v_regs = sigcontext_vmx_regs(sc); 109 unsigned long vrsave; 110 #endif 111 struct pt_regs *regs = tsk->thread.regs; 112 unsigned long msr = regs->msr; 113 long err = 0; 114 /* Force usr to alway see softe as 1 (interrupts enabled) */ 115 unsigned long softe = 0x1; 116 117 BUG_ON(tsk != current); 118 119 #ifdef CONFIG_ALTIVEC 120 err |= __put_user(v_regs, &sc->v_regs); 121 122 /* save altivec registers */ 123 if (tsk->thread.used_vr) { 124 flush_altivec_to_thread(tsk); 125 /* Copy 33 vec registers (vr0..31 and vscr) to the stack */ 126 err |= __copy_to_user(v_regs, &tsk->thread.vr_state, 127 33 * sizeof(vector128)); 128 /* set MSR_VEC in the MSR value in the frame to indicate that sc->v_reg) 129 * contains valid data. 130 */ 131 msr |= MSR_VEC; 132 } 133 /* We always copy to/from vrsave, it's 0 if we don't have or don't 134 * use altivec. 135 */ 136 vrsave = 0; 137 if (cpu_has_feature(CPU_FTR_ALTIVEC)) { 138 vrsave = mfspr(SPRN_VRSAVE); 139 tsk->thread.vrsave = vrsave; 140 } 141 142 err |= __put_user(vrsave, (u32 __user *)&v_regs[33]); 143 #else /* CONFIG_ALTIVEC */ 144 err |= __put_user(0, &sc->v_regs); 145 #endif /* CONFIG_ALTIVEC */ 146 flush_fp_to_thread(tsk); 147 /* copy fpr regs and fpscr */ 148 err |= copy_fpr_to_user(&sc->fp_regs, tsk); 149 150 /* 151 * Clear the MSR VSX bit to indicate there is no valid state attached 152 * to this context, except in the specific case below where we set it. 153 */ 154 msr &= ~MSR_VSX; 155 #ifdef CONFIG_VSX 156 /* 157 * Copy VSX low doubleword to local buffer for formatting, 158 * then out to userspace. Update v_regs to point after the 159 * VMX data. 160 */ 161 if (tsk->thread.used_vsr && ctx_has_vsx_region) { 162 flush_vsx_to_thread(tsk); 163 v_regs += ELF_NVRREG; 164 err |= copy_vsx_to_user(v_regs, tsk); 165 /* set MSR_VSX in the MSR value in the frame to 166 * indicate that sc->vs_reg) contains valid data. 167 */ 168 msr |= MSR_VSX; 169 } 170 #endif /* CONFIG_VSX */ 171 err |= __put_user(&sc->gp_regs, &sc->regs); 172 WARN_ON(!FULL_REGS(regs)); 173 err |= __copy_to_user(&sc->gp_regs, regs, GP_REGS_SIZE); 174 err |= __put_user(msr, &sc->gp_regs[PT_MSR]); 175 err |= __put_user(softe, &sc->gp_regs[PT_SOFTE]); 176 err |= __put_user(signr, &sc->signal); 177 err |= __put_user(handler, &sc->handler); 178 if (set != NULL) 179 err |= __put_user(set->sig[0], &sc->oldmask); 180 181 return err; 182 } 183 184 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 185 /* 186 * As above, but Transactional Memory is in use, so deliver sigcontexts 187 * containing checkpointed and transactional register states. 188 * 189 * To do this, we treclaim (done before entering here) to gather both sets of 190 * registers and set up the 'normal' sigcontext registers with rolled-back 191 * register values such that a simple signal handler sees a correct 192 * checkpointed register state. If interested, a TM-aware sighandler can 193 * examine the transactional registers in the 2nd sigcontext to determine the 194 * real origin of the signal. 195 */ 196 static long setup_tm_sigcontexts(struct sigcontext __user *sc, 197 struct sigcontext __user *tm_sc, 198 struct task_struct *tsk, 199 int signr, sigset_t *set, unsigned long handler) 200 { 201 /* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the 202 * process never used altivec yet (MSR_VEC is zero in pt_regs of 203 * the context). This is very important because we must ensure we 204 * don't lose the VRSAVE content that may have been set prior to 205 * the process doing its first vector operation 206 * Userland shall check AT_HWCAP to know wether it can rely on the 207 * v_regs pointer or not. 208 */ 209 #ifdef CONFIG_ALTIVEC 210 elf_vrreg_t __user *v_regs = sigcontext_vmx_regs(sc); 211 elf_vrreg_t __user *tm_v_regs = sigcontext_vmx_regs(tm_sc); 212 #endif 213 struct pt_regs *regs = tsk->thread.regs; 214 unsigned long msr = tsk->thread.regs->msr; 215 long err = 0; 216 217 BUG_ON(tsk != current); 218 219 BUG_ON(!MSR_TM_ACTIVE(regs->msr)); 220 221 WARN_ON(tm_suspend_disabled); 222 223 /* Restore checkpointed FP, VEC, and VSX bits from ckpt_regs as 224 * it contains the correct FP, VEC, VSX state after we treclaimed 225 * the transaction and giveup_all() was called on reclaiming. 226 */ 227 msr |= tsk->thread.ckpt_regs.msr & (MSR_FP | MSR_VEC | MSR_VSX); 228 229 /* Remove TM bits from thread's MSR. The MSR in the sigcontext 230 * just indicates to userland that we were doing a transaction, but we 231 * don't want to return in transactional state. This also ensures 232 * that flush_fp_to_thread won't set TIF_RESTORE_TM again. 233 */ 234 regs->msr &= ~MSR_TS_MASK; 235 236 #ifdef CONFIG_ALTIVEC 237 err |= __put_user(v_regs, &sc->v_regs); 238 err |= __put_user(tm_v_regs, &tm_sc->v_regs); 239 240 /* save altivec registers */ 241 if (tsk->thread.used_vr) { 242 /* Copy 33 vec registers (vr0..31 and vscr) to the stack */ 243 err |= __copy_to_user(v_regs, &tsk->thread.ckvr_state, 244 33 * sizeof(vector128)); 245 /* If VEC was enabled there are transactional VRs valid too, 246 * else they're a copy of the checkpointed VRs. 247 */ 248 if (msr & MSR_VEC) 249 err |= __copy_to_user(tm_v_regs, 250 &tsk->thread.vr_state, 251 33 * sizeof(vector128)); 252 else 253 err |= __copy_to_user(tm_v_regs, 254 &tsk->thread.ckvr_state, 255 33 * sizeof(vector128)); 256 257 /* set MSR_VEC in the MSR value in the frame to indicate 258 * that sc->v_reg contains valid data. 259 */ 260 msr |= MSR_VEC; 261 } 262 /* We always copy to/from vrsave, it's 0 if we don't have or don't 263 * use altivec. 264 */ 265 if (cpu_has_feature(CPU_FTR_ALTIVEC)) 266 tsk->thread.ckvrsave = mfspr(SPRN_VRSAVE); 267 err |= __put_user(tsk->thread.ckvrsave, (u32 __user *)&v_regs[33]); 268 if (msr & MSR_VEC) 269 err |= __put_user(tsk->thread.vrsave, 270 (u32 __user *)&tm_v_regs[33]); 271 else 272 err |= __put_user(tsk->thread.ckvrsave, 273 (u32 __user *)&tm_v_regs[33]); 274 275 #else /* CONFIG_ALTIVEC */ 276 err |= __put_user(0, &sc->v_regs); 277 err |= __put_user(0, &tm_sc->v_regs); 278 #endif /* CONFIG_ALTIVEC */ 279 280 /* copy fpr regs and fpscr */ 281 err |= copy_ckfpr_to_user(&sc->fp_regs, tsk); 282 if (msr & MSR_FP) 283 err |= copy_fpr_to_user(&tm_sc->fp_regs, tsk); 284 else 285 err |= copy_ckfpr_to_user(&tm_sc->fp_regs, tsk); 286 287 #ifdef CONFIG_VSX 288 /* 289 * Copy VSX low doubleword to local buffer for formatting, 290 * then out to userspace. Update v_regs to point after the 291 * VMX data. 292 */ 293 if (tsk->thread.used_vsr) { 294 v_regs += ELF_NVRREG; 295 tm_v_regs += ELF_NVRREG; 296 297 err |= copy_ckvsx_to_user(v_regs, tsk); 298 299 if (msr & MSR_VSX) 300 err |= copy_vsx_to_user(tm_v_regs, tsk); 301 else 302 err |= copy_ckvsx_to_user(tm_v_regs, tsk); 303 304 /* set MSR_VSX in the MSR value in the frame to 305 * indicate that sc->vs_reg) contains valid data. 306 */ 307 msr |= MSR_VSX; 308 } 309 #endif /* CONFIG_VSX */ 310 311 err |= __put_user(&sc->gp_regs, &sc->regs); 312 err |= __put_user(&tm_sc->gp_regs, &tm_sc->regs); 313 WARN_ON(!FULL_REGS(regs)); 314 err |= __copy_to_user(&tm_sc->gp_regs, regs, GP_REGS_SIZE); 315 err |= __copy_to_user(&sc->gp_regs, 316 &tsk->thread.ckpt_regs, GP_REGS_SIZE); 317 err |= __put_user(msr, &tm_sc->gp_regs[PT_MSR]); 318 err |= __put_user(msr, &sc->gp_regs[PT_MSR]); 319 err |= __put_user(signr, &sc->signal); 320 err |= __put_user(handler, &sc->handler); 321 if (set != NULL) 322 err |= __put_user(set->sig[0], &sc->oldmask); 323 324 return err; 325 } 326 #endif 327 328 /* 329 * Restore the sigcontext from the signal frame. 330 */ 331 332 static long restore_sigcontext(struct task_struct *tsk, sigset_t *set, int sig, 333 struct sigcontext __user *sc) 334 { 335 #ifdef CONFIG_ALTIVEC 336 elf_vrreg_t __user *v_regs; 337 #endif 338 unsigned long err = 0; 339 unsigned long save_r13 = 0; 340 unsigned long msr; 341 struct pt_regs *regs = tsk->thread.regs; 342 #ifdef CONFIG_VSX 343 int i; 344 #endif 345 346 BUG_ON(tsk != current); 347 348 /* If this is not a signal return, we preserve the TLS in r13 */ 349 if (!sig) 350 save_r13 = regs->gpr[13]; 351 352 /* copy the GPRs */ 353 err |= __copy_from_user(regs->gpr, sc->gp_regs, sizeof(regs->gpr)); 354 err |= __get_user(regs->nip, &sc->gp_regs[PT_NIP]); 355 /* get MSR separately, transfer the LE bit if doing signal return */ 356 err |= __get_user(msr, &sc->gp_regs[PT_MSR]); 357 if (sig) 358 regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE); 359 err |= __get_user(regs->orig_gpr3, &sc->gp_regs[PT_ORIG_R3]); 360 err |= __get_user(regs->ctr, &sc->gp_regs[PT_CTR]); 361 err |= __get_user(regs->link, &sc->gp_regs[PT_LNK]); 362 err |= __get_user(regs->xer, &sc->gp_regs[PT_XER]); 363 err |= __get_user(regs->ccr, &sc->gp_regs[PT_CCR]); 364 /* skip SOFTE */ 365 regs->trap = 0; 366 err |= __get_user(regs->dar, &sc->gp_regs[PT_DAR]); 367 err |= __get_user(regs->dsisr, &sc->gp_regs[PT_DSISR]); 368 err |= __get_user(regs->result, &sc->gp_regs[PT_RESULT]); 369 370 if (!sig) 371 regs->gpr[13] = save_r13; 372 if (set != NULL) 373 err |= __get_user(set->sig[0], &sc->oldmask); 374 375 /* 376 * Force reload of FP/VEC. 377 * This has to be done before copying stuff into tsk->thread.fpr/vr 378 * for the reasons explained in the previous comment. 379 */ 380 regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC | MSR_VSX); 381 382 #ifdef CONFIG_ALTIVEC 383 err |= __get_user(v_regs, &sc->v_regs); 384 if (err) 385 return err; 386 if (v_regs && !access_ok(VERIFY_READ, v_regs, 34 * sizeof(vector128))) 387 return -EFAULT; 388 /* Copy 33 vec registers (vr0..31 and vscr) from the stack */ 389 if (v_regs != NULL && (msr & MSR_VEC) != 0) { 390 err |= __copy_from_user(&tsk->thread.vr_state, v_regs, 391 33 * sizeof(vector128)); 392 tsk->thread.used_vr = true; 393 } else if (tsk->thread.used_vr) { 394 memset(&tsk->thread.vr_state, 0, 33 * sizeof(vector128)); 395 } 396 /* Always get VRSAVE back */ 397 if (v_regs != NULL) 398 err |= __get_user(tsk->thread.vrsave, (u32 __user *)&v_regs[33]); 399 else 400 tsk->thread.vrsave = 0; 401 if (cpu_has_feature(CPU_FTR_ALTIVEC)) 402 mtspr(SPRN_VRSAVE, tsk->thread.vrsave); 403 #endif /* CONFIG_ALTIVEC */ 404 /* restore floating point */ 405 err |= copy_fpr_from_user(tsk, &sc->fp_regs); 406 #ifdef CONFIG_VSX 407 /* 408 * Get additional VSX data. Update v_regs to point after the 409 * VMX data. Copy VSX low doubleword from userspace to local 410 * buffer for formatting, then into the taskstruct. 411 */ 412 v_regs += ELF_NVRREG; 413 if ((msr & MSR_VSX) != 0) { 414 err |= copy_vsx_from_user(tsk, v_regs); 415 tsk->thread.used_vsr = true; 416 } else { 417 for (i = 0; i < 32 ; i++) 418 tsk->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0; 419 } 420 #endif 421 return err; 422 } 423 424 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 425 /* 426 * Restore the two sigcontexts from the frame of a transactional processes. 427 */ 428 429 static long restore_tm_sigcontexts(struct task_struct *tsk, 430 struct sigcontext __user *sc, 431 struct sigcontext __user *tm_sc) 432 { 433 #ifdef CONFIG_ALTIVEC 434 elf_vrreg_t __user *v_regs, *tm_v_regs; 435 #endif 436 unsigned long err = 0; 437 unsigned long msr; 438 struct pt_regs *regs = tsk->thread.regs; 439 #ifdef CONFIG_VSX 440 int i; 441 #endif 442 443 BUG_ON(tsk != current); 444 445 if (tm_suspend_disabled) 446 return -EINVAL; 447 448 /* copy the GPRs */ 449 err |= __copy_from_user(regs->gpr, tm_sc->gp_regs, sizeof(regs->gpr)); 450 err |= __copy_from_user(&tsk->thread.ckpt_regs, sc->gp_regs, 451 sizeof(regs->gpr)); 452 453 /* 454 * TFHAR is restored from the checkpointed 'wound-back' ucontext's NIP. 455 * TEXASR was set by the signal delivery reclaim, as was TFIAR. 456 * Users doing anything abhorrent like thread-switching w/ signals for 457 * TM-Suspended code will have to back TEXASR/TFIAR up themselves. 458 * For the case of getting a signal and simply returning from it, 459 * we don't need to re-copy them here. 460 */ 461 err |= __get_user(regs->nip, &tm_sc->gp_regs[PT_NIP]); 462 err |= __get_user(tsk->thread.tm_tfhar, &sc->gp_regs[PT_NIP]); 463 464 /* get MSR separately, transfer the LE bit if doing signal return */ 465 err |= __get_user(msr, &sc->gp_regs[PT_MSR]); 466 /* Don't allow reserved mode. */ 467 if (MSR_TM_RESV(msr)) 468 return -EINVAL; 469 470 /* pull in MSR TS bits from user context */ 471 regs->msr = (regs->msr & ~MSR_TS_MASK) | (msr & MSR_TS_MASK); 472 473 /* 474 * Ensure that TM is enabled in regs->msr before we leave the signal 475 * handler. It could be the case that (a) user disabled the TM bit 476 * through the manipulation of the MSR bits in uc_mcontext or (b) the 477 * TM bit was disabled because a sufficient number of context switches 478 * happened whilst in the signal handler and load_tm overflowed, 479 * disabling the TM bit. In either case we can end up with an illegal 480 * TM state leading to a TM Bad Thing when we return to userspace. 481 */ 482 regs->msr |= MSR_TM; 483 484 /* pull in MSR LE from user context */ 485 regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE); 486 487 /* The following non-GPR non-FPR non-VR state is also checkpointed: */ 488 err |= __get_user(regs->ctr, &tm_sc->gp_regs[PT_CTR]); 489 err |= __get_user(regs->link, &tm_sc->gp_regs[PT_LNK]); 490 err |= __get_user(regs->xer, &tm_sc->gp_regs[PT_XER]); 491 err |= __get_user(regs->ccr, &tm_sc->gp_regs[PT_CCR]); 492 err |= __get_user(tsk->thread.ckpt_regs.ctr, 493 &sc->gp_regs[PT_CTR]); 494 err |= __get_user(tsk->thread.ckpt_regs.link, 495 &sc->gp_regs[PT_LNK]); 496 err |= __get_user(tsk->thread.ckpt_regs.xer, 497 &sc->gp_regs[PT_XER]); 498 err |= __get_user(tsk->thread.ckpt_regs.ccr, 499 &sc->gp_regs[PT_CCR]); 500 501 /* These regs are not checkpointed; they can go in 'regs'. */ 502 err |= __get_user(regs->trap, &sc->gp_regs[PT_TRAP]); 503 err |= __get_user(regs->dar, &sc->gp_regs[PT_DAR]); 504 err |= __get_user(regs->dsisr, &sc->gp_regs[PT_DSISR]); 505 err |= __get_user(regs->result, &sc->gp_regs[PT_RESULT]); 506 507 /* 508 * Force reload of FP/VEC. 509 * This has to be done before copying stuff into tsk->thread.fpr/vr 510 * for the reasons explained in the previous comment. 511 */ 512 regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC | MSR_VSX); 513 514 #ifdef CONFIG_ALTIVEC 515 err |= __get_user(v_regs, &sc->v_regs); 516 err |= __get_user(tm_v_regs, &tm_sc->v_regs); 517 if (err) 518 return err; 519 if (v_regs && !access_ok(VERIFY_READ, v_regs, 34 * sizeof(vector128))) 520 return -EFAULT; 521 if (tm_v_regs && !access_ok(VERIFY_READ, 522 tm_v_regs, 34 * sizeof(vector128))) 523 return -EFAULT; 524 /* Copy 33 vec registers (vr0..31 and vscr) from the stack */ 525 if (v_regs != NULL && tm_v_regs != NULL && (msr & MSR_VEC) != 0) { 526 err |= __copy_from_user(&tsk->thread.ckvr_state, v_regs, 527 33 * sizeof(vector128)); 528 err |= __copy_from_user(&tsk->thread.vr_state, tm_v_regs, 529 33 * sizeof(vector128)); 530 current->thread.used_vr = true; 531 } 532 else if (tsk->thread.used_vr) { 533 memset(&tsk->thread.vr_state, 0, 33 * sizeof(vector128)); 534 memset(&tsk->thread.ckvr_state, 0, 33 * sizeof(vector128)); 535 } 536 /* Always get VRSAVE back */ 537 if (v_regs != NULL && tm_v_regs != NULL) { 538 err |= __get_user(tsk->thread.ckvrsave, 539 (u32 __user *)&v_regs[33]); 540 err |= __get_user(tsk->thread.vrsave, 541 (u32 __user *)&tm_v_regs[33]); 542 } 543 else { 544 tsk->thread.vrsave = 0; 545 tsk->thread.ckvrsave = 0; 546 } 547 if (cpu_has_feature(CPU_FTR_ALTIVEC)) 548 mtspr(SPRN_VRSAVE, tsk->thread.vrsave); 549 #endif /* CONFIG_ALTIVEC */ 550 /* restore floating point */ 551 err |= copy_fpr_from_user(tsk, &tm_sc->fp_regs); 552 err |= copy_ckfpr_from_user(tsk, &sc->fp_regs); 553 #ifdef CONFIG_VSX 554 /* 555 * Get additional VSX data. Update v_regs to point after the 556 * VMX data. Copy VSX low doubleword from userspace to local 557 * buffer for formatting, then into the taskstruct. 558 */ 559 if (v_regs && ((msr & MSR_VSX) != 0)) { 560 v_regs += ELF_NVRREG; 561 tm_v_regs += ELF_NVRREG; 562 err |= copy_vsx_from_user(tsk, tm_v_regs); 563 err |= copy_ckvsx_from_user(tsk, v_regs); 564 tsk->thread.used_vsr = true; 565 } else { 566 for (i = 0; i < 32 ; i++) { 567 tsk->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0; 568 tsk->thread.ckfp_state.fpr[i][TS_VSRLOWOFFSET] = 0; 569 } 570 } 571 #endif 572 tm_enable(); 573 /* Make sure the transaction is marked as failed */ 574 tsk->thread.tm_texasr |= TEXASR_FS; 575 /* This loads the checkpointed FP/VEC state, if used */ 576 tm_recheckpoint(&tsk->thread); 577 578 msr_check_and_set(msr & (MSR_FP | MSR_VEC)); 579 if (msr & MSR_FP) { 580 load_fp_state(&tsk->thread.fp_state); 581 regs->msr |= (MSR_FP | tsk->thread.fpexc_mode); 582 } 583 if (msr & MSR_VEC) { 584 load_vr_state(&tsk->thread.vr_state); 585 regs->msr |= MSR_VEC; 586 } 587 588 return err; 589 } 590 #endif 591 592 /* 593 * Setup the trampoline code on the stack 594 */ 595 static long setup_trampoline(unsigned int syscall, unsigned int __user *tramp) 596 { 597 int i; 598 long err = 0; 599 600 /* addi r1, r1, __SIGNAL_FRAMESIZE # Pop the dummy stackframe */ 601 err |= __put_user(0x38210000UL | (__SIGNAL_FRAMESIZE & 0xffff), &tramp[0]); 602 /* li r0, __NR_[rt_]sigreturn| */ 603 err |= __put_user(0x38000000UL | (syscall & 0xffff), &tramp[1]); 604 /* sc */ 605 err |= __put_user(0x44000002UL, &tramp[2]); 606 607 /* Minimal traceback info */ 608 for (i=TRAMP_TRACEBACK; i < TRAMP_SIZE ;i++) 609 err |= __put_user(0, &tramp[i]); 610 611 if (!err) 612 flush_icache_range((unsigned long) &tramp[0], 613 (unsigned long) &tramp[TRAMP_SIZE]); 614 615 return err; 616 } 617 618 /* 619 * Userspace code may pass a ucontext which doesn't include VSX added 620 * at the end. We need to check for this case. 621 */ 622 #define UCONTEXTSIZEWITHOUTVSX \ 623 (sizeof(struct ucontext) - 32*sizeof(long)) 624 625 /* 626 * Handle {get,set,swap}_context operations 627 */ 628 SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx, 629 struct ucontext __user *, new_ctx, long, ctx_size) 630 { 631 unsigned char tmp; 632 sigset_t set; 633 unsigned long new_msr = 0; 634 int ctx_has_vsx_region = 0; 635 636 if (new_ctx && 637 get_user(new_msr, &new_ctx->uc_mcontext.gp_regs[PT_MSR])) 638 return -EFAULT; 639 /* 640 * Check that the context is not smaller than the original 641 * size (with VMX but without VSX) 642 */ 643 if (ctx_size < UCONTEXTSIZEWITHOUTVSX) 644 return -EINVAL; 645 /* 646 * If the new context state sets the MSR VSX bits but 647 * it doesn't provide VSX state. 648 */ 649 if ((ctx_size < sizeof(struct ucontext)) && 650 (new_msr & MSR_VSX)) 651 return -EINVAL; 652 /* Does the context have enough room to store VSX data? */ 653 if (ctx_size >= sizeof(struct ucontext)) 654 ctx_has_vsx_region = 1; 655 656 if (old_ctx != NULL) { 657 if (!access_ok(VERIFY_WRITE, old_ctx, ctx_size) 658 || setup_sigcontext(&old_ctx->uc_mcontext, current, 0, NULL, 0, 659 ctx_has_vsx_region) 660 || __copy_to_user(&old_ctx->uc_sigmask, 661 ¤t->blocked, sizeof(sigset_t))) 662 return -EFAULT; 663 } 664 if (new_ctx == NULL) 665 return 0; 666 if (!access_ok(VERIFY_READ, new_ctx, ctx_size) 667 || __get_user(tmp, (u8 __user *) new_ctx) 668 || __get_user(tmp, (u8 __user *) new_ctx + ctx_size - 1)) 669 return -EFAULT; 670 671 /* 672 * If we get a fault copying the context into the kernel's 673 * image of the user's registers, we can't just return -EFAULT 674 * because the user's registers will be corrupted. For instance 675 * the NIP value may have been updated but not some of the 676 * other registers. Given that we have done the access_ok 677 * and successfully read the first and last bytes of the region 678 * above, this should only happen in an out-of-memory situation 679 * or if another thread unmaps the region containing the context. 680 * We kill the task with a SIGSEGV in this situation. 681 */ 682 683 if (__copy_from_user(&set, &new_ctx->uc_sigmask, sizeof(set))) 684 do_exit(SIGSEGV); 685 set_current_blocked(&set); 686 if (restore_sigcontext(current, NULL, 0, &new_ctx->uc_mcontext)) 687 do_exit(SIGSEGV); 688 689 /* This returns like rt_sigreturn */ 690 set_thread_flag(TIF_RESTOREALL); 691 return 0; 692 } 693 694 695 /* 696 * Do a signal return; undo the signal stack. 697 */ 698 699 SYSCALL_DEFINE0(rt_sigreturn) 700 { 701 struct pt_regs *regs = current_pt_regs(); 702 struct ucontext __user *uc = (struct ucontext __user *)regs->gpr[1]; 703 sigset_t set; 704 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 705 unsigned long msr; 706 #endif 707 708 /* Always make any pending restarted system calls return -EINTR */ 709 current->restart_block.fn = do_no_restart_syscall; 710 711 if (!access_ok(VERIFY_READ, uc, sizeof(*uc))) 712 goto badframe; 713 714 if (__copy_from_user(&set, &uc->uc_sigmask, sizeof(set))) 715 goto badframe; 716 set_current_blocked(&set); 717 718 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 719 /* 720 * If there is a transactional state then throw it away. 721 * The purpose of a sigreturn is to destroy all traces of the 722 * signal frame, this includes any transactional state created 723 * within in. We only check for suspended as we can never be 724 * active in the kernel, we are active, there is nothing better to 725 * do than go ahead and Bad Thing later. 726 * The cause is not important as there will never be a 727 * recheckpoint so it's not user visible. 728 */ 729 if (MSR_TM_SUSPENDED(mfmsr())) 730 tm_reclaim_current(0); 731 732 if (__get_user(msr, &uc->uc_mcontext.gp_regs[PT_MSR])) 733 goto badframe; 734 if (MSR_TM_ACTIVE(msr)) { 735 /* We recheckpoint on return. */ 736 struct ucontext __user *uc_transact; 737 if (__get_user(uc_transact, &uc->uc_link)) 738 goto badframe; 739 if (restore_tm_sigcontexts(current, &uc->uc_mcontext, 740 &uc_transact->uc_mcontext)) 741 goto badframe; 742 } 743 else 744 /* Fall through, for non-TM restore */ 745 #endif 746 if (restore_sigcontext(current, NULL, 1, &uc->uc_mcontext)) 747 goto badframe; 748 749 if (restore_altstack(&uc->uc_stack)) 750 goto badframe; 751 752 set_thread_flag(TIF_RESTOREALL); 753 return 0; 754 755 badframe: 756 if (show_unhandled_signals) 757 printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32, 758 current->comm, current->pid, "rt_sigreturn", 759 (long)uc, regs->nip, regs->link); 760 761 force_sig(SIGSEGV, current); 762 return 0; 763 } 764 765 int handle_rt_signal64(struct ksignal *ksig, sigset_t *set, 766 struct task_struct *tsk) 767 { 768 struct rt_sigframe __user *frame; 769 unsigned long newsp = 0; 770 long err = 0; 771 struct pt_regs *regs = tsk->thread.regs; 772 773 BUG_ON(tsk != current); 774 775 frame = get_sigframe(ksig, get_tm_stackpointer(tsk), sizeof(*frame), 0); 776 if (unlikely(frame == NULL)) 777 goto badframe; 778 779 err |= __put_user(&frame->info, &frame->pinfo); 780 err |= __put_user(&frame->uc, &frame->puc); 781 err |= copy_siginfo_to_user(&frame->info, &ksig->info); 782 if (err) 783 goto badframe; 784 785 /* Create the ucontext. */ 786 err |= __put_user(0, &frame->uc.uc_flags); 787 err |= __save_altstack(&frame->uc.uc_stack, regs->gpr[1]); 788 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 789 if (MSR_TM_ACTIVE(regs->msr)) { 790 /* The ucontext_t passed to userland points to the second 791 * ucontext_t (for transactional state) with its uc_link ptr. 792 */ 793 err |= __put_user(&frame->uc_transact, &frame->uc.uc_link); 794 err |= setup_tm_sigcontexts(&frame->uc.uc_mcontext, 795 &frame->uc_transact.uc_mcontext, 796 tsk, ksig->sig, NULL, 797 (unsigned long)ksig->ka.sa.sa_handler); 798 } else 799 #endif 800 { 801 err |= __put_user(0, &frame->uc.uc_link); 802 err |= setup_sigcontext(&frame->uc.uc_mcontext, tsk, ksig->sig, 803 NULL, (unsigned long)ksig->ka.sa.sa_handler, 804 1); 805 } 806 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); 807 if (err) 808 goto badframe; 809 810 /* Make sure signal handler doesn't get spurious FP exceptions */ 811 tsk->thread.fp_state.fpscr = 0; 812 813 /* Set up to return from userspace. */ 814 if (vdso64_rt_sigtramp && tsk->mm->context.vdso_base) { 815 regs->link = tsk->mm->context.vdso_base + vdso64_rt_sigtramp; 816 } else { 817 err |= setup_trampoline(__NR_rt_sigreturn, &frame->tramp[0]); 818 if (err) 819 goto badframe; 820 regs->link = (unsigned long) &frame->tramp[0]; 821 } 822 823 /* Allocate a dummy caller frame for the signal handler. */ 824 newsp = ((unsigned long)frame) - __SIGNAL_FRAMESIZE; 825 err |= put_user(regs->gpr[1], (unsigned long __user *)newsp); 826 827 /* Set up "regs" so we "return" to the signal handler. */ 828 if (is_elf2_task()) { 829 regs->nip = (unsigned long) ksig->ka.sa.sa_handler; 830 regs->gpr[12] = regs->nip; 831 } else { 832 /* Handler is *really* a pointer to the function descriptor for 833 * the signal routine. The first entry in the function 834 * descriptor is the entry address of signal and the second 835 * entry is the TOC value we need to use. 836 */ 837 func_descr_t __user *funct_desc_ptr = 838 (func_descr_t __user *) ksig->ka.sa.sa_handler; 839 840 err |= get_user(regs->nip, &funct_desc_ptr->entry); 841 err |= get_user(regs->gpr[2], &funct_desc_ptr->toc); 842 } 843 844 /* enter the signal handler in native-endian mode */ 845 regs->msr &= ~MSR_LE; 846 regs->msr |= (MSR_KERNEL & MSR_LE); 847 regs->gpr[1] = newsp; 848 regs->gpr[3] = ksig->sig; 849 regs->result = 0; 850 if (ksig->ka.sa.sa_flags & SA_SIGINFO) { 851 err |= get_user(regs->gpr[4], (unsigned long __user *)&frame->pinfo); 852 err |= get_user(regs->gpr[5], (unsigned long __user *)&frame->puc); 853 regs->gpr[6] = (unsigned long) frame; 854 } else { 855 regs->gpr[4] = (unsigned long)&frame->uc.uc_mcontext; 856 } 857 if (err) 858 goto badframe; 859 860 return 0; 861 862 badframe: 863 if (show_unhandled_signals) 864 printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32, 865 tsk->comm, tsk->pid, "setup_rt_frame", 866 (long)frame, regs->nip, regs->link); 867 868 return 1; 869 } 870