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 <linux/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 #include <asm/asm-prototypes.h> 39 40 #include "signal.h" 41 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 /* New 64 bit little-endian ABI allows redzone of 512 bytes below sp */ 69 char abigap[USER_REDZONE_SIZE]; 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 * This computes a quad word aligned pointer inside the vmx_reserve array 79 * element. For historical reasons sigcontext might not be quad word aligned, 80 * but the location we write the VMX regs to must be. See the comment in 81 * sigcontext for more detail. 82 */ 83 #ifdef CONFIG_ALTIVEC 84 static elf_vrreg_t __user *sigcontext_vmx_regs(struct sigcontext __user *sc) 85 { 86 return (elf_vrreg_t __user *) (((unsigned long)sc->vmx_reserve + 15) & ~0xful); 87 } 88 #endif 89 90 /* 91 * Set up the sigcontext for the signal frame. 92 */ 93 94 static long setup_sigcontext(struct sigcontext __user *sc, 95 struct task_struct *tsk, int signr, sigset_t *set, 96 unsigned long handler, int ctx_has_vsx_region) 97 { 98 /* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the 99 * process never used altivec yet (MSR_VEC is zero in pt_regs of 100 * the context). This is very important because we must ensure we 101 * don't lose the VRSAVE content that may have been set prior to 102 * the process doing its first vector operation 103 * Userland shall check AT_HWCAP to know whether it can rely on the 104 * v_regs pointer or not 105 */ 106 #ifdef CONFIG_ALTIVEC 107 elf_vrreg_t __user *v_regs = sigcontext_vmx_regs(sc); 108 unsigned long vrsave; 109 #endif 110 struct pt_regs *regs = tsk->thread.regs; 111 unsigned long msr = regs->msr; 112 long err = 0; 113 114 BUG_ON(tsk != current); 115 116 #ifdef CONFIG_ALTIVEC 117 err |= __put_user(v_regs, &sc->v_regs); 118 119 /* save altivec registers */ 120 if (tsk->thread.used_vr) { 121 flush_altivec_to_thread(tsk); 122 /* Copy 33 vec registers (vr0..31 and vscr) to the stack */ 123 err |= __copy_to_user(v_regs, &tsk->thread.vr_state, 124 33 * sizeof(vector128)); 125 /* set MSR_VEC in the MSR value in the frame to indicate that sc->v_reg) 126 * contains valid data. 127 */ 128 msr |= MSR_VEC; 129 } 130 /* We always copy to/from vrsave, it's 0 if we don't have or don't 131 * use altivec. 132 */ 133 vrsave = 0; 134 if (cpu_has_feature(CPU_FTR_ALTIVEC)) { 135 vrsave = mfspr(SPRN_VRSAVE); 136 tsk->thread.vrsave = vrsave; 137 } 138 139 err |= __put_user(vrsave, (u32 __user *)&v_regs[33]); 140 #else /* CONFIG_ALTIVEC */ 141 err |= __put_user(0, &sc->v_regs); 142 #endif /* CONFIG_ALTIVEC */ 143 flush_fp_to_thread(tsk); 144 /* copy fpr regs and fpscr */ 145 err |= copy_fpr_to_user(&sc->fp_regs, tsk); 146 147 /* 148 * Clear the MSR VSX bit to indicate there is no valid state attached 149 * to this context, except in the specific case below where we set it. 150 */ 151 msr &= ~MSR_VSX; 152 #ifdef CONFIG_VSX 153 /* 154 * Copy VSX low doubleword to local buffer for formatting, 155 * then out to userspace. Update v_regs to point after the 156 * VMX data. 157 */ 158 if (tsk->thread.used_vsr && ctx_has_vsx_region) { 159 flush_vsx_to_thread(tsk); 160 v_regs += ELF_NVRREG; 161 err |= copy_vsx_to_user(v_regs, tsk); 162 /* set MSR_VSX in the MSR value in the frame to 163 * indicate that sc->vs_reg) contains valid data. 164 */ 165 msr |= MSR_VSX; 166 } 167 #endif /* CONFIG_VSX */ 168 err |= __put_user(&sc->gp_regs, &sc->regs); 169 WARN_ON(!FULL_REGS(regs)); 170 err |= __copy_to_user(&sc->gp_regs, regs, GP_REGS_SIZE); 171 err |= __put_user(msr, &sc->gp_regs[PT_MSR]); 172 err |= __put_user(signr, &sc->signal); 173 err |= __put_user(handler, &sc->handler); 174 if (set != NULL) 175 err |= __put_user(set->sig[0], &sc->oldmask); 176 177 return err; 178 } 179 180 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 181 /* 182 * As above, but Transactional Memory is in use, so deliver sigcontexts 183 * containing checkpointed and transactional register states. 184 * 185 * To do this, we treclaim (done before entering here) to gather both sets of 186 * registers and set up the 'normal' sigcontext registers with rolled-back 187 * register values such that a simple signal handler sees a correct 188 * checkpointed register state. If interested, a TM-aware sighandler can 189 * examine the transactional registers in the 2nd sigcontext to determine the 190 * real origin of the signal. 191 */ 192 static long setup_tm_sigcontexts(struct sigcontext __user *sc, 193 struct sigcontext __user *tm_sc, 194 struct task_struct *tsk, 195 int signr, sigset_t *set, unsigned long handler) 196 { 197 /* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the 198 * process never used altivec yet (MSR_VEC is zero in pt_regs of 199 * the context). This is very important because we must ensure we 200 * don't lose the VRSAVE content that may have been set prior to 201 * the process doing its first vector operation 202 * Userland shall check AT_HWCAP to know wether it can rely on the 203 * v_regs pointer or not. 204 */ 205 #ifdef CONFIG_ALTIVEC 206 elf_vrreg_t __user *v_regs = sigcontext_vmx_regs(sc); 207 elf_vrreg_t __user *tm_v_regs = sigcontext_vmx_regs(tm_sc); 208 #endif 209 struct pt_regs *regs = tsk->thread.regs; 210 unsigned long msr = tsk->thread.ckpt_regs.msr; 211 long err = 0; 212 213 BUG_ON(tsk != current); 214 215 BUG_ON(!MSR_TM_ACTIVE(regs->msr)); 216 217 /* Remove TM bits from thread's MSR. The MSR in the sigcontext 218 * just indicates to userland that we were doing a transaction, but we 219 * don't want to return in transactional state. This also ensures 220 * that flush_fp_to_thread won't set TIF_RESTORE_TM again. 221 */ 222 regs->msr &= ~MSR_TS_MASK; 223 224 #ifdef CONFIG_ALTIVEC 225 err |= __put_user(v_regs, &sc->v_regs); 226 err |= __put_user(tm_v_regs, &tm_sc->v_regs); 227 228 /* save altivec registers */ 229 if (tsk->thread.used_vr) { 230 /* Copy 33 vec registers (vr0..31 and vscr) to the stack */ 231 err |= __copy_to_user(v_regs, &tsk->thread.ckvr_state, 232 33 * sizeof(vector128)); 233 /* If VEC was enabled there are transactional VRs valid too, 234 * else they're a copy of the checkpointed VRs. 235 */ 236 if (msr & MSR_VEC) 237 err |= __copy_to_user(tm_v_regs, 238 &tsk->thread.vr_state, 239 33 * sizeof(vector128)); 240 else 241 err |= __copy_to_user(tm_v_regs, 242 &tsk->thread.ckvr_state, 243 33 * sizeof(vector128)); 244 245 /* set MSR_VEC in the MSR value in the frame to indicate 246 * that sc->v_reg contains valid data. 247 */ 248 msr |= MSR_VEC; 249 } 250 /* We always copy to/from vrsave, it's 0 if we don't have or don't 251 * use altivec. 252 */ 253 if (cpu_has_feature(CPU_FTR_ALTIVEC)) 254 tsk->thread.ckvrsave = mfspr(SPRN_VRSAVE); 255 err |= __put_user(tsk->thread.ckvrsave, (u32 __user *)&v_regs[33]); 256 if (msr & MSR_VEC) 257 err |= __put_user(tsk->thread.vrsave, 258 (u32 __user *)&tm_v_regs[33]); 259 else 260 err |= __put_user(tsk->thread.ckvrsave, 261 (u32 __user *)&tm_v_regs[33]); 262 263 #else /* CONFIG_ALTIVEC */ 264 err |= __put_user(0, &sc->v_regs); 265 err |= __put_user(0, &tm_sc->v_regs); 266 #endif /* CONFIG_ALTIVEC */ 267 268 /* copy fpr regs and fpscr */ 269 err |= copy_ckfpr_to_user(&sc->fp_regs, tsk); 270 if (msr & MSR_FP) 271 err |= copy_fpr_to_user(&tm_sc->fp_regs, tsk); 272 else 273 err |= copy_ckfpr_to_user(&tm_sc->fp_regs, tsk); 274 275 #ifdef CONFIG_VSX 276 /* 277 * Copy VSX low doubleword to local buffer for formatting, 278 * then out to userspace. Update v_regs to point after the 279 * VMX data. 280 */ 281 if (tsk->thread.used_vsr) { 282 v_regs += ELF_NVRREG; 283 tm_v_regs += ELF_NVRREG; 284 285 err |= copy_ckvsx_to_user(v_regs, tsk); 286 287 if (msr & MSR_VSX) 288 err |= copy_vsx_to_user(tm_v_regs, tsk); 289 else 290 err |= copy_ckvsx_to_user(tm_v_regs, tsk); 291 292 /* set MSR_VSX in the MSR value in the frame to 293 * indicate that sc->vs_reg) contains valid data. 294 */ 295 msr |= MSR_VSX; 296 } 297 #endif /* CONFIG_VSX */ 298 299 err |= __put_user(&sc->gp_regs, &sc->regs); 300 err |= __put_user(&tm_sc->gp_regs, &tm_sc->regs); 301 WARN_ON(!FULL_REGS(regs)); 302 err |= __copy_to_user(&tm_sc->gp_regs, regs, GP_REGS_SIZE); 303 err |= __copy_to_user(&sc->gp_regs, 304 &tsk->thread.ckpt_regs, GP_REGS_SIZE); 305 err |= __put_user(msr, &tm_sc->gp_regs[PT_MSR]); 306 err |= __put_user(msr, &sc->gp_regs[PT_MSR]); 307 err |= __put_user(signr, &sc->signal); 308 err |= __put_user(handler, &sc->handler); 309 if (set != NULL) 310 err |= __put_user(set->sig[0], &sc->oldmask); 311 312 return err; 313 } 314 #endif 315 316 /* 317 * Restore the sigcontext from the signal frame. 318 */ 319 320 static long restore_sigcontext(struct task_struct *tsk, sigset_t *set, int sig, 321 struct sigcontext __user *sc) 322 { 323 #ifdef CONFIG_ALTIVEC 324 elf_vrreg_t __user *v_regs; 325 #endif 326 unsigned long err = 0; 327 unsigned long save_r13 = 0; 328 unsigned long msr; 329 struct pt_regs *regs = tsk->thread.regs; 330 #ifdef CONFIG_VSX 331 int i; 332 #endif 333 334 BUG_ON(tsk != current); 335 336 /* If this is not a signal return, we preserve the TLS in r13 */ 337 if (!sig) 338 save_r13 = regs->gpr[13]; 339 340 /* copy the GPRs */ 341 err |= __copy_from_user(regs->gpr, sc->gp_regs, sizeof(regs->gpr)); 342 err |= __get_user(regs->nip, &sc->gp_regs[PT_NIP]); 343 /* get MSR separately, transfer the LE bit if doing signal return */ 344 err |= __get_user(msr, &sc->gp_regs[PT_MSR]); 345 if (sig) 346 regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE); 347 err |= __get_user(regs->orig_gpr3, &sc->gp_regs[PT_ORIG_R3]); 348 err |= __get_user(regs->ctr, &sc->gp_regs[PT_CTR]); 349 err |= __get_user(regs->link, &sc->gp_regs[PT_LNK]); 350 err |= __get_user(regs->xer, &sc->gp_regs[PT_XER]); 351 err |= __get_user(regs->ccr, &sc->gp_regs[PT_CCR]); 352 /* skip SOFTE */ 353 regs->trap = 0; 354 err |= __get_user(regs->dar, &sc->gp_regs[PT_DAR]); 355 err |= __get_user(regs->dsisr, &sc->gp_regs[PT_DSISR]); 356 err |= __get_user(regs->result, &sc->gp_regs[PT_RESULT]); 357 358 if (!sig) 359 regs->gpr[13] = save_r13; 360 if (set != NULL) 361 err |= __get_user(set->sig[0], &sc->oldmask); 362 363 /* 364 * Force reload of FP/VEC. 365 * This has to be done before copying stuff into tsk->thread.fpr/vr 366 * for the reasons explained in the previous comment. 367 */ 368 regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC | MSR_VSX); 369 370 #ifdef CONFIG_ALTIVEC 371 err |= __get_user(v_regs, &sc->v_regs); 372 if (err) 373 return err; 374 if (v_regs && !access_ok(VERIFY_READ, v_regs, 34 * sizeof(vector128))) 375 return -EFAULT; 376 /* Copy 33 vec registers (vr0..31 and vscr) from the stack */ 377 if (v_regs != NULL && (msr & MSR_VEC) != 0) { 378 err |= __copy_from_user(&tsk->thread.vr_state, v_regs, 379 33 * sizeof(vector128)); 380 tsk->thread.used_vr = true; 381 } else if (tsk->thread.used_vr) { 382 memset(&tsk->thread.vr_state, 0, 33 * sizeof(vector128)); 383 } 384 /* Always get VRSAVE back */ 385 if (v_regs != NULL) 386 err |= __get_user(tsk->thread.vrsave, (u32 __user *)&v_regs[33]); 387 else 388 tsk->thread.vrsave = 0; 389 if (cpu_has_feature(CPU_FTR_ALTIVEC)) 390 mtspr(SPRN_VRSAVE, tsk->thread.vrsave); 391 #endif /* CONFIG_ALTIVEC */ 392 /* restore floating point */ 393 err |= copy_fpr_from_user(tsk, &sc->fp_regs); 394 #ifdef CONFIG_VSX 395 /* 396 * Get additional VSX data. Update v_regs to point after the 397 * VMX data. Copy VSX low doubleword from userspace to local 398 * buffer for formatting, then into the taskstruct. 399 */ 400 v_regs += ELF_NVRREG; 401 if ((msr & MSR_VSX) != 0) { 402 err |= copy_vsx_from_user(tsk, v_regs); 403 tsk->thread.used_vsr = true; 404 } else { 405 for (i = 0; i < 32 ; i++) 406 tsk->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0; 407 } 408 #endif 409 return err; 410 } 411 412 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 413 /* 414 * Restore the two sigcontexts from the frame of a transactional processes. 415 */ 416 417 static long restore_tm_sigcontexts(struct task_struct *tsk, 418 struct sigcontext __user *sc, 419 struct sigcontext __user *tm_sc) 420 { 421 #ifdef CONFIG_ALTIVEC 422 elf_vrreg_t __user *v_regs, *tm_v_regs; 423 #endif 424 unsigned long err = 0; 425 unsigned long msr; 426 struct pt_regs *regs = tsk->thread.regs; 427 #ifdef CONFIG_VSX 428 int i; 429 #endif 430 431 BUG_ON(tsk != current); 432 433 /* copy the GPRs */ 434 err |= __copy_from_user(regs->gpr, tm_sc->gp_regs, sizeof(regs->gpr)); 435 err |= __copy_from_user(&tsk->thread.ckpt_regs, sc->gp_regs, 436 sizeof(regs->gpr)); 437 438 /* 439 * TFHAR is restored from the checkpointed 'wound-back' ucontext's NIP. 440 * TEXASR was set by the signal delivery reclaim, as was TFIAR. 441 * Users doing anything abhorrent like thread-switching w/ signals for 442 * TM-Suspended code will have to back TEXASR/TFIAR up themselves. 443 * For the case of getting a signal and simply returning from it, 444 * we don't need to re-copy them here. 445 */ 446 err |= __get_user(regs->nip, &tm_sc->gp_regs[PT_NIP]); 447 err |= __get_user(tsk->thread.tm_tfhar, &sc->gp_regs[PT_NIP]); 448 449 /* get MSR separately, transfer the LE bit if doing signal return */ 450 err |= __get_user(msr, &sc->gp_regs[PT_MSR]); 451 /* Don't allow reserved mode. */ 452 if (MSR_TM_RESV(msr)) 453 return -EINVAL; 454 455 /* pull in MSR TS bits from user context */ 456 regs->msr = (regs->msr & ~MSR_TS_MASK) | (msr & MSR_TS_MASK); 457 458 /* 459 * Ensure that TM is enabled in regs->msr before we leave the signal 460 * handler. It could be the case that (a) user disabled the TM bit 461 * through the manipulation of the MSR bits in uc_mcontext or (b) the 462 * TM bit was disabled because a sufficient number of context switches 463 * happened whilst in the signal handler and load_tm overflowed, 464 * disabling the TM bit. In either case we can end up with an illegal 465 * TM state leading to a TM Bad Thing when we return to userspace. 466 */ 467 regs->msr |= MSR_TM; 468 469 /* pull in MSR LE from user context */ 470 regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE); 471 472 /* The following non-GPR non-FPR non-VR state is also checkpointed: */ 473 err |= __get_user(regs->ctr, &tm_sc->gp_regs[PT_CTR]); 474 err |= __get_user(regs->link, &tm_sc->gp_regs[PT_LNK]); 475 err |= __get_user(regs->xer, &tm_sc->gp_regs[PT_XER]); 476 err |= __get_user(regs->ccr, &tm_sc->gp_regs[PT_CCR]); 477 err |= __get_user(tsk->thread.ckpt_regs.ctr, 478 &sc->gp_regs[PT_CTR]); 479 err |= __get_user(tsk->thread.ckpt_regs.link, 480 &sc->gp_regs[PT_LNK]); 481 err |= __get_user(tsk->thread.ckpt_regs.xer, 482 &sc->gp_regs[PT_XER]); 483 err |= __get_user(tsk->thread.ckpt_regs.ccr, 484 &sc->gp_regs[PT_CCR]); 485 486 /* These regs are not checkpointed; they can go in 'regs'. */ 487 err |= __get_user(regs->trap, &sc->gp_regs[PT_TRAP]); 488 err |= __get_user(regs->dar, &sc->gp_regs[PT_DAR]); 489 err |= __get_user(regs->dsisr, &sc->gp_regs[PT_DSISR]); 490 err |= __get_user(regs->result, &sc->gp_regs[PT_RESULT]); 491 492 /* 493 * Force reload of FP/VEC. 494 * This has to be done before copying stuff into tsk->thread.fpr/vr 495 * for the reasons explained in the previous comment. 496 */ 497 regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC | MSR_VSX); 498 499 #ifdef CONFIG_ALTIVEC 500 err |= __get_user(v_regs, &sc->v_regs); 501 err |= __get_user(tm_v_regs, &tm_sc->v_regs); 502 if (err) 503 return err; 504 if (v_regs && !access_ok(VERIFY_READ, v_regs, 34 * sizeof(vector128))) 505 return -EFAULT; 506 if (tm_v_regs && !access_ok(VERIFY_READ, 507 tm_v_regs, 34 * sizeof(vector128))) 508 return -EFAULT; 509 /* Copy 33 vec registers (vr0..31 and vscr) from the stack */ 510 if (v_regs != NULL && tm_v_regs != NULL && (msr & MSR_VEC) != 0) { 511 err |= __copy_from_user(&tsk->thread.ckvr_state, v_regs, 512 33 * sizeof(vector128)); 513 err |= __copy_from_user(&tsk->thread.vr_state, tm_v_regs, 514 33 * sizeof(vector128)); 515 current->thread.used_vr = true; 516 } 517 else if (tsk->thread.used_vr) { 518 memset(&tsk->thread.vr_state, 0, 33 * sizeof(vector128)); 519 memset(&tsk->thread.ckvr_state, 0, 33 * sizeof(vector128)); 520 } 521 /* Always get VRSAVE back */ 522 if (v_regs != NULL && tm_v_regs != NULL) { 523 err |= __get_user(tsk->thread.ckvrsave, 524 (u32 __user *)&v_regs[33]); 525 err |= __get_user(tsk->thread.vrsave, 526 (u32 __user *)&tm_v_regs[33]); 527 } 528 else { 529 tsk->thread.vrsave = 0; 530 tsk->thread.ckvrsave = 0; 531 } 532 if (cpu_has_feature(CPU_FTR_ALTIVEC)) 533 mtspr(SPRN_VRSAVE, tsk->thread.vrsave); 534 #endif /* CONFIG_ALTIVEC */ 535 /* restore floating point */ 536 err |= copy_fpr_from_user(tsk, &tm_sc->fp_regs); 537 err |= copy_ckfpr_from_user(tsk, &sc->fp_regs); 538 #ifdef CONFIG_VSX 539 /* 540 * Get additional VSX data. Update v_regs to point after the 541 * VMX data. Copy VSX low doubleword from userspace to local 542 * buffer for formatting, then into the taskstruct. 543 */ 544 if (v_regs && ((msr & MSR_VSX) != 0)) { 545 v_regs += ELF_NVRREG; 546 tm_v_regs += ELF_NVRREG; 547 err |= copy_vsx_from_user(tsk, tm_v_regs); 548 err |= copy_ckvsx_from_user(tsk, v_regs); 549 tsk->thread.used_vsr = true; 550 } else { 551 for (i = 0; i < 32 ; i++) { 552 tsk->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0; 553 tsk->thread.ckfp_state.fpr[i][TS_VSRLOWOFFSET] = 0; 554 } 555 } 556 #endif 557 tm_enable(); 558 /* Make sure the transaction is marked as failed */ 559 tsk->thread.tm_texasr |= TEXASR_FS; 560 /* This loads the checkpointed FP/VEC state, if used */ 561 tm_recheckpoint(&tsk->thread, msr); 562 563 msr_check_and_set(msr & (MSR_FP | MSR_VEC)); 564 if (msr & MSR_FP) { 565 load_fp_state(&tsk->thread.fp_state); 566 regs->msr |= (MSR_FP | tsk->thread.fpexc_mode); 567 } 568 if (msr & MSR_VEC) { 569 load_vr_state(&tsk->thread.vr_state); 570 regs->msr |= MSR_VEC; 571 } 572 573 return err; 574 } 575 #endif 576 577 /* 578 * Setup the trampoline code on the stack 579 */ 580 static long setup_trampoline(unsigned int syscall, unsigned int __user *tramp) 581 { 582 int i; 583 long err = 0; 584 585 /* addi r1, r1, __SIGNAL_FRAMESIZE # Pop the dummy stackframe */ 586 err |= __put_user(0x38210000UL | (__SIGNAL_FRAMESIZE & 0xffff), &tramp[0]); 587 /* li r0, __NR_[rt_]sigreturn| */ 588 err |= __put_user(0x38000000UL | (syscall & 0xffff), &tramp[1]); 589 /* sc */ 590 err |= __put_user(0x44000002UL, &tramp[2]); 591 592 /* Minimal traceback info */ 593 for (i=TRAMP_TRACEBACK; i < TRAMP_SIZE ;i++) 594 err |= __put_user(0, &tramp[i]); 595 596 if (!err) 597 flush_icache_range((unsigned long) &tramp[0], 598 (unsigned long) &tramp[TRAMP_SIZE]); 599 600 return err; 601 } 602 603 /* 604 * Userspace code may pass a ucontext which doesn't include VSX added 605 * at the end. We need to check for this case. 606 */ 607 #define UCONTEXTSIZEWITHOUTVSX \ 608 (sizeof(struct ucontext) - 32*sizeof(long)) 609 610 /* 611 * Handle {get,set,swap}_context operations 612 */ 613 int sys_swapcontext(struct ucontext __user *old_ctx, 614 struct ucontext __user *new_ctx, 615 long ctx_size, long r6, long r7, long r8, struct pt_regs *regs) 616 { 617 unsigned char tmp; 618 sigset_t set; 619 unsigned long new_msr = 0; 620 int ctx_has_vsx_region = 0; 621 622 BUG_ON(regs != current->thread.regs); 623 624 if (new_ctx && 625 get_user(new_msr, &new_ctx->uc_mcontext.gp_regs[PT_MSR])) 626 return -EFAULT; 627 /* 628 * Check that the context is not smaller than the original 629 * size (with VMX but without VSX) 630 */ 631 if (ctx_size < UCONTEXTSIZEWITHOUTVSX) 632 return -EINVAL; 633 /* 634 * If the new context state sets the MSR VSX bits but 635 * it doesn't provide VSX state. 636 */ 637 if ((ctx_size < sizeof(struct ucontext)) && 638 (new_msr & MSR_VSX)) 639 return -EINVAL; 640 /* Does the context have enough room to store VSX data? */ 641 if (ctx_size >= sizeof(struct ucontext)) 642 ctx_has_vsx_region = 1; 643 644 if (old_ctx != NULL) { 645 if (!access_ok(VERIFY_WRITE, old_ctx, ctx_size) 646 || setup_sigcontext(&old_ctx->uc_mcontext, current, 0, NULL, 0, 647 ctx_has_vsx_region) 648 || __copy_to_user(&old_ctx->uc_sigmask, 649 ¤t->blocked, sizeof(sigset_t))) 650 return -EFAULT; 651 } 652 if (new_ctx == NULL) 653 return 0; 654 if (!access_ok(VERIFY_READ, new_ctx, ctx_size) 655 || __get_user(tmp, (u8 __user *) new_ctx) 656 || __get_user(tmp, (u8 __user *) new_ctx + ctx_size - 1)) 657 return -EFAULT; 658 659 /* 660 * If we get a fault copying the context into the kernel's 661 * image of the user's registers, we can't just return -EFAULT 662 * because the user's registers will be corrupted. For instance 663 * the NIP value may have been updated but not some of the 664 * other registers. Given that we have done the access_ok 665 * and successfully read the first and last bytes of the region 666 * above, this should only happen in an out-of-memory situation 667 * or if another thread unmaps the region containing the context. 668 * We kill the task with a SIGSEGV in this situation. 669 */ 670 671 if (__copy_from_user(&set, &new_ctx->uc_sigmask, sizeof(set))) 672 do_exit(SIGSEGV); 673 set_current_blocked(&set); 674 if (restore_sigcontext(current, NULL, 0, &new_ctx->uc_mcontext)) 675 do_exit(SIGSEGV); 676 677 /* This returns like rt_sigreturn */ 678 set_thread_flag(TIF_RESTOREALL); 679 return 0; 680 } 681 682 683 /* 684 * Do a signal return; undo the signal stack. 685 */ 686 687 int sys_rt_sigreturn(unsigned long r3, unsigned long r4, unsigned long r5, 688 unsigned long r6, unsigned long r7, unsigned long r8, 689 struct pt_regs *regs) 690 { 691 struct ucontext __user *uc = (struct ucontext __user *)regs->gpr[1]; 692 sigset_t set; 693 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 694 unsigned long msr; 695 #endif 696 697 BUG_ON(current->thread.regs != regs); 698 699 /* Always make any pending restarted system calls return -EINTR */ 700 current->restart_block.fn = do_no_restart_syscall; 701 702 if (!access_ok(VERIFY_READ, uc, sizeof(*uc))) 703 goto badframe; 704 705 if (__copy_from_user(&set, &uc->uc_sigmask, sizeof(set))) 706 goto badframe; 707 set_current_blocked(&set); 708 709 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 710 /* 711 * If there is a transactional state then throw it away. 712 * The purpose of a sigreturn is to destroy all traces of the 713 * signal frame, this includes any transactional state created 714 * within in. We only check for suspended as we can never be 715 * active in the kernel, we are active, there is nothing better to 716 * do than go ahead and Bad Thing later. 717 * The cause is not important as there will never be a 718 * recheckpoint so it's not user visible. 719 */ 720 if (MSR_TM_SUSPENDED(mfmsr())) 721 tm_reclaim_current(0); 722 723 if (__get_user(msr, &uc->uc_mcontext.gp_regs[PT_MSR])) 724 goto badframe; 725 if (MSR_TM_ACTIVE(msr)) { 726 /* We recheckpoint on return. */ 727 struct ucontext __user *uc_transact; 728 if (__get_user(uc_transact, &uc->uc_link)) 729 goto badframe; 730 if (restore_tm_sigcontexts(current, &uc->uc_mcontext, 731 &uc_transact->uc_mcontext)) 732 goto badframe; 733 } 734 else 735 /* Fall through, for non-TM restore */ 736 #endif 737 if (restore_sigcontext(current, NULL, 1, &uc->uc_mcontext)) 738 goto badframe; 739 740 if (restore_altstack(&uc->uc_stack)) 741 goto badframe; 742 743 set_thread_flag(TIF_RESTOREALL); 744 return 0; 745 746 badframe: 747 if (show_unhandled_signals) 748 printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32, 749 current->comm, current->pid, "rt_sigreturn", 750 (long)uc, regs->nip, regs->link); 751 752 force_sig(SIGSEGV, current); 753 return 0; 754 } 755 756 int handle_rt_signal64(struct ksignal *ksig, sigset_t *set, 757 struct task_struct *tsk) 758 { 759 struct rt_sigframe __user *frame; 760 unsigned long newsp = 0; 761 long err = 0; 762 struct pt_regs *regs = tsk->thread.regs; 763 764 BUG_ON(tsk != current); 765 766 frame = get_sigframe(ksig, get_tm_stackpointer(tsk), sizeof(*frame), 0); 767 if (unlikely(frame == NULL)) 768 goto badframe; 769 770 err |= __put_user(&frame->info, &frame->pinfo); 771 err |= __put_user(&frame->uc, &frame->puc); 772 err |= copy_siginfo_to_user(&frame->info, &ksig->info); 773 if (err) 774 goto badframe; 775 776 /* Create the ucontext. */ 777 err |= __put_user(0, &frame->uc.uc_flags); 778 err |= __save_altstack(&frame->uc.uc_stack, regs->gpr[1]); 779 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 780 if (MSR_TM_ACTIVE(regs->msr)) { 781 /* The ucontext_t passed to userland points to the second 782 * ucontext_t (for transactional state) with its uc_link ptr. 783 */ 784 err |= __put_user(&frame->uc_transact, &frame->uc.uc_link); 785 err |= setup_tm_sigcontexts(&frame->uc.uc_mcontext, 786 &frame->uc_transact.uc_mcontext, 787 tsk, ksig->sig, NULL, 788 (unsigned long)ksig->ka.sa.sa_handler); 789 } else 790 #endif 791 { 792 err |= __put_user(0, &frame->uc.uc_link); 793 err |= setup_sigcontext(&frame->uc.uc_mcontext, tsk, ksig->sig, 794 NULL, (unsigned long)ksig->ka.sa.sa_handler, 795 1); 796 } 797 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); 798 if (err) 799 goto badframe; 800 801 /* Make sure signal handler doesn't get spurious FP exceptions */ 802 tsk->thread.fp_state.fpscr = 0; 803 804 /* Set up to return from userspace. */ 805 if (vdso64_rt_sigtramp && tsk->mm->context.vdso_base) { 806 regs->link = tsk->mm->context.vdso_base + vdso64_rt_sigtramp; 807 } else { 808 err |= setup_trampoline(__NR_rt_sigreturn, &frame->tramp[0]); 809 if (err) 810 goto badframe; 811 regs->link = (unsigned long) &frame->tramp[0]; 812 } 813 814 /* Allocate a dummy caller frame for the signal handler. */ 815 newsp = ((unsigned long)frame) - __SIGNAL_FRAMESIZE; 816 err |= put_user(regs->gpr[1], (unsigned long __user *)newsp); 817 818 /* Set up "regs" so we "return" to the signal handler. */ 819 if (is_elf2_task()) { 820 regs->nip = (unsigned long) ksig->ka.sa.sa_handler; 821 regs->gpr[12] = regs->nip; 822 } else { 823 /* Handler is *really* a pointer to the function descriptor for 824 * the signal routine. The first entry in the function 825 * descriptor is the entry address of signal and the second 826 * entry is the TOC value we need to use. 827 */ 828 func_descr_t __user *funct_desc_ptr = 829 (func_descr_t __user *) ksig->ka.sa.sa_handler; 830 831 err |= get_user(regs->nip, &funct_desc_ptr->entry); 832 err |= get_user(regs->gpr[2], &funct_desc_ptr->toc); 833 } 834 835 /* enter the signal handler in native-endian mode */ 836 regs->msr &= ~MSR_LE; 837 regs->msr |= (MSR_KERNEL & MSR_LE); 838 regs->gpr[1] = newsp; 839 regs->gpr[3] = ksig->sig; 840 regs->result = 0; 841 if (ksig->ka.sa.sa_flags & SA_SIGINFO) { 842 err |= get_user(regs->gpr[4], (unsigned long __user *)&frame->pinfo); 843 err |= get_user(regs->gpr[5], (unsigned long __user *)&frame->puc); 844 regs->gpr[6] = (unsigned long) frame; 845 } else { 846 regs->gpr[4] = (unsigned long)&frame->uc.uc_mcontext; 847 } 848 if (err) 849 goto badframe; 850 851 return 0; 852 853 badframe: 854 if (show_unhandled_signals) 855 printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32, 856 tsk->comm, tsk->pid, "setup_rt_frame", 857 (long)frame, regs->nip, regs->link); 858 859 return 1; 860 } 861