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 /* Force usr to alway see softe as 1 (interrupts enabled) */ 114 unsigned long softe = 0x1; 115 116 BUG_ON(tsk != current); 117 118 #ifdef CONFIG_ALTIVEC 119 err |= __put_user(v_regs, &sc->v_regs); 120 121 /* save altivec registers */ 122 if (tsk->thread.used_vr) { 123 flush_altivec_to_thread(tsk); 124 /* Copy 33 vec registers (vr0..31 and vscr) to the stack */ 125 err |= __copy_to_user(v_regs, &tsk->thread.vr_state, 126 33 * sizeof(vector128)); 127 /* set MSR_VEC in the MSR value in the frame to indicate that sc->v_reg) 128 * contains valid data. 129 */ 130 msr |= MSR_VEC; 131 } 132 /* We always copy to/from vrsave, it's 0 if we don't have or don't 133 * use altivec. 134 */ 135 vrsave = 0; 136 if (cpu_has_feature(CPU_FTR_ALTIVEC)) { 137 vrsave = mfspr(SPRN_VRSAVE); 138 tsk->thread.vrsave = vrsave; 139 } 140 141 err |= __put_user(vrsave, (u32 __user *)&v_regs[33]); 142 #else /* CONFIG_ALTIVEC */ 143 err |= __put_user(0, &sc->v_regs); 144 #endif /* CONFIG_ALTIVEC */ 145 flush_fp_to_thread(tsk); 146 /* copy fpr regs and fpscr */ 147 err |= copy_fpr_to_user(&sc->fp_regs, tsk); 148 149 /* 150 * Clear the MSR VSX bit to indicate there is no valid state attached 151 * to this context, except in the specific case below where we set it. 152 */ 153 msr &= ~MSR_VSX; 154 #ifdef CONFIG_VSX 155 /* 156 * Copy VSX low doubleword to local buffer for formatting, 157 * then out to userspace. Update v_regs to point after the 158 * VMX data. 159 */ 160 if (tsk->thread.used_vsr && ctx_has_vsx_region) { 161 flush_vsx_to_thread(tsk); 162 v_regs += ELF_NVRREG; 163 err |= copy_vsx_to_user(v_regs, tsk); 164 /* set MSR_VSX in the MSR value in the frame to 165 * indicate that sc->vs_reg) contains valid data. 166 */ 167 msr |= MSR_VSX; 168 } 169 #endif /* CONFIG_VSX */ 170 err |= __put_user(&sc->gp_regs, &sc->regs); 171 WARN_ON(!FULL_REGS(regs)); 172 err |= __copy_to_user(&sc->gp_regs, regs, GP_REGS_SIZE); 173 err |= __put_user(msr, &sc->gp_regs[PT_MSR]); 174 err |= __put_user(softe, &sc->gp_regs[PT_SOFTE]); 175 err |= __put_user(signr, &sc->signal); 176 err |= __put_user(handler, &sc->handler); 177 if (set != NULL) 178 err |= __put_user(set->sig[0], &sc->oldmask); 179 180 return err; 181 } 182 183 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 184 /* 185 * As above, but Transactional Memory is in use, so deliver sigcontexts 186 * containing checkpointed and transactional register states. 187 * 188 * To do this, we treclaim (done before entering here) to gather both sets of 189 * registers and set up the 'normal' sigcontext registers with rolled-back 190 * register values such that a simple signal handler sees a correct 191 * checkpointed register state. If interested, a TM-aware sighandler can 192 * examine the transactional registers in the 2nd sigcontext to determine the 193 * real origin of the signal. 194 */ 195 static long setup_tm_sigcontexts(struct sigcontext __user *sc, 196 struct sigcontext __user *tm_sc, 197 struct task_struct *tsk, 198 int signr, sigset_t *set, unsigned long handler) 199 { 200 /* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the 201 * process never used altivec yet (MSR_VEC is zero in pt_regs of 202 * the context). This is very important because we must ensure we 203 * don't lose the VRSAVE content that may have been set prior to 204 * the process doing its first vector operation 205 * Userland shall check AT_HWCAP to know wether it can rely on the 206 * v_regs pointer or not. 207 */ 208 #ifdef CONFIG_ALTIVEC 209 elf_vrreg_t __user *v_regs = sigcontext_vmx_regs(sc); 210 elf_vrreg_t __user *tm_v_regs = sigcontext_vmx_regs(tm_sc); 211 #endif 212 struct pt_regs *regs = tsk->thread.regs; 213 unsigned long msr = tsk->thread.regs->msr; 214 long err = 0; 215 216 BUG_ON(tsk != current); 217 218 BUG_ON(!MSR_TM_ACTIVE(regs->msr)); 219 220 WARN_ON(tm_suspend_disabled); 221 222 /* Restore checkpointed FP, VEC, and VSX bits from ckpt_regs as 223 * it contains the correct FP, VEC, VSX state after we treclaimed 224 * the transaction and giveup_all() was called on reclaiming. 225 */ 226 msr |= tsk->thread.ckpt_regs.msr & (MSR_FP | MSR_VEC | MSR_VSX); 227 228 /* Remove TM bits from thread's MSR. The MSR in the sigcontext 229 * just indicates to userland that we were doing a transaction, but we 230 * don't want to return in transactional state. This also ensures 231 * that flush_fp_to_thread won't set TIF_RESTORE_TM again. 232 */ 233 regs->msr &= ~MSR_TS_MASK; 234 235 #ifdef CONFIG_ALTIVEC 236 err |= __put_user(v_regs, &sc->v_regs); 237 err |= __put_user(tm_v_regs, &tm_sc->v_regs); 238 239 /* save altivec registers */ 240 if (tsk->thread.used_vr) { 241 /* Copy 33 vec registers (vr0..31 and vscr) to the stack */ 242 err |= __copy_to_user(v_regs, &tsk->thread.ckvr_state, 243 33 * sizeof(vector128)); 244 /* If VEC was enabled there are transactional VRs valid too, 245 * else they're a copy of the checkpointed VRs. 246 */ 247 if (msr & MSR_VEC) 248 err |= __copy_to_user(tm_v_regs, 249 &tsk->thread.vr_state, 250 33 * sizeof(vector128)); 251 else 252 err |= __copy_to_user(tm_v_regs, 253 &tsk->thread.ckvr_state, 254 33 * sizeof(vector128)); 255 256 /* set MSR_VEC in the MSR value in the frame to indicate 257 * that sc->v_reg contains valid data. 258 */ 259 msr |= MSR_VEC; 260 } 261 /* We always copy to/from vrsave, it's 0 if we don't have or don't 262 * use altivec. 263 */ 264 if (cpu_has_feature(CPU_FTR_ALTIVEC)) 265 tsk->thread.ckvrsave = mfspr(SPRN_VRSAVE); 266 err |= __put_user(tsk->thread.ckvrsave, (u32 __user *)&v_regs[33]); 267 if (msr & MSR_VEC) 268 err |= __put_user(tsk->thread.vrsave, 269 (u32 __user *)&tm_v_regs[33]); 270 else 271 err |= __put_user(tsk->thread.ckvrsave, 272 (u32 __user *)&tm_v_regs[33]); 273 274 #else /* CONFIG_ALTIVEC */ 275 err |= __put_user(0, &sc->v_regs); 276 err |= __put_user(0, &tm_sc->v_regs); 277 #endif /* CONFIG_ALTIVEC */ 278 279 /* copy fpr regs and fpscr */ 280 err |= copy_ckfpr_to_user(&sc->fp_regs, tsk); 281 if (msr & MSR_FP) 282 err |= copy_fpr_to_user(&tm_sc->fp_regs, tsk); 283 else 284 err |= copy_ckfpr_to_user(&tm_sc->fp_regs, tsk); 285 286 #ifdef CONFIG_VSX 287 /* 288 * Copy VSX low doubleword to local buffer for formatting, 289 * then out to userspace. Update v_regs to point after the 290 * VMX data. 291 */ 292 if (tsk->thread.used_vsr) { 293 v_regs += ELF_NVRREG; 294 tm_v_regs += ELF_NVRREG; 295 296 err |= copy_ckvsx_to_user(v_regs, tsk); 297 298 if (msr & MSR_VSX) 299 err |= copy_vsx_to_user(tm_v_regs, tsk); 300 else 301 err |= copy_ckvsx_to_user(tm_v_regs, tsk); 302 303 /* set MSR_VSX in the MSR value in the frame to 304 * indicate that sc->vs_reg) contains valid data. 305 */ 306 msr |= MSR_VSX; 307 } 308 #endif /* CONFIG_VSX */ 309 310 err |= __put_user(&sc->gp_regs, &sc->regs); 311 err |= __put_user(&tm_sc->gp_regs, &tm_sc->regs); 312 WARN_ON(!FULL_REGS(regs)); 313 err |= __copy_to_user(&tm_sc->gp_regs, regs, GP_REGS_SIZE); 314 err |= __copy_to_user(&sc->gp_regs, 315 &tsk->thread.ckpt_regs, GP_REGS_SIZE); 316 err |= __put_user(msr, &tm_sc->gp_regs[PT_MSR]); 317 err |= __put_user(msr, &sc->gp_regs[PT_MSR]); 318 err |= __put_user(signr, &sc->signal); 319 err |= __put_user(handler, &sc->handler); 320 if (set != NULL) 321 err |= __put_user(set->sig[0], &sc->oldmask); 322 323 return err; 324 } 325 #endif 326 327 /* 328 * Restore the sigcontext from the signal frame. 329 */ 330 331 static long restore_sigcontext(struct task_struct *tsk, sigset_t *set, int sig, 332 struct sigcontext __user *sc) 333 { 334 #ifdef CONFIG_ALTIVEC 335 elf_vrreg_t __user *v_regs; 336 #endif 337 unsigned long err = 0; 338 unsigned long save_r13 = 0; 339 unsigned long msr; 340 struct pt_regs *regs = tsk->thread.regs; 341 #ifdef CONFIG_VSX 342 int i; 343 #endif 344 345 BUG_ON(tsk != current); 346 347 /* If this is not a signal return, we preserve the TLS in r13 */ 348 if (!sig) 349 save_r13 = regs->gpr[13]; 350 351 /* copy the GPRs */ 352 err |= __copy_from_user(regs->gpr, sc->gp_regs, sizeof(regs->gpr)); 353 err |= __get_user(regs->nip, &sc->gp_regs[PT_NIP]); 354 /* get MSR separately, transfer the LE bit if doing signal return */ 355 err |= __get_user(msr, &sc->gp_regs[PT_MSR]); 356 if (sig) 357 regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE); 358 err |= __get_user(regs->orig_gpr3, &sc->gp_regs[PT_ORIG_R3]); 359 err |= __get_user(regs->ctr, &sc->gp_regs[PT_CTR]); 360 err |= __get_user(regs->link, &sc->gp_regs[PT_LNK]); 361 err |= __get_user(regs->xer, &sc->gp_regs[PT_XER]); 362 err |= __get_user(regs->ccr, &sc->gp_regs[PT_CCR]); 363 /* skip SOFTE */ 364 regs->trap = 0; 365 err |= __get_user(regs->dar, &sc->gp_regs[PT_DAR]); 366 err |= __get_user(regs->dsisr, &sc->gp_regs[PT_DSISR]); 367 err |= __get_user(regs->result, &sc->gp_regs[PT_RESULT]); 368 369 if (!sig) 370 regs->gpr[13] = save_r13; 371 if (set != NULL) 372 err |= __get_user(set->sig[0], &sc->oldmask); 373 374 /* 375 * Force reload of FP/VEC. 376 * This has to be done before copying stuff into tsk->thread.fpr/vr 377 * for the reasons explained in the previous comment. 378 */ 379 regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC | MSR_VSX); 380 381 #ifdef CONFIG_ALTIVEC 382 err |= __get_user(v_regs, &sc->v_regs); 383 if (err) 384 return err; 385 if (v_regs && !access_ok(VERIFY_READ, v_regs, 34 * sizeof(vector128))) 386 return -EFAULT; 387 /* Copy 33 vec registers (vr0..31 and vscr) from the stack */ 388 if (v_regs != NULL && (msr & MSR_VEC) != 0) { 389 err |= __copy_from_user(&tsk->thread.vr_state, v_regs, 390 33 * sizeof(vector128)); 391 tsk->thread.used_vr = true; 392 } else if (tsk->thread.used_vr) { 393 memset(&tsk->thread.vr_state, 0, 33 * sizeof(vector128)); 394 } 395 /* Always get VRSAVE back */ 396 if (v_regs != NULL) 397 err |= __get_user(tsk->thread.vrsave, (u32 __user *)&v_regs[33]); 398 else 399 tsk->thread.vrsave = 0; 400 if (cpu_has_feature(CPU_FTR_ALTIVEC)) 401 mtspr(SPRN_VRSAVE, tsk->thread.vrsave); 402 #endif /* CONFIG_ALTIVEC */ 403 /* restore floating point */ 404 err |= copy_fpr_from_user(tsk, &sc->fp_regs); 405 #ifdef CONFIG_VSX 406 /* 407 * Get additional VSX data. Update v_regs to point after the 408 * VMX data. Copy VSX low doubleword from userspace to local 409 * buffer for formatting, then into the taskstruct. 410 */ 411 v_regs += ELF_NVRREG; 412 if ((msr & MSR_VSX) != 0) { 413 err |= copy_vsx_from_user(tsk, v_regs); 414 tsk->thread.used_vsr = true; 415 } else { 416 for (i = 0; i < 32 ; i++) 417 tsk->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0; 418 } 419 #endif 420 return err; 421 } 422 423 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 424 /* 425 * Restore the two sigcontexts from the frame of a transactional processes. 426 */ 427 428 static long restore_tm_sigcontexts(struct task_struct *tsk, 429 struct sigcontext __user *sc, 430 struct sigcontext __user *tm_sc) 431 { 432 #ifdef CONFIG_ALTIVEC 433 elf_vrreg_t __user *v_regs, *tm_v_regs; 434 #endif 435 unsigned long err = 0; 436 unsigned long msr; 437 struct pt_regs *regs = tsk->thread.regs; 438 #ifdef CONFIG_VSX 439 int i; 440 #endif 441 442 BUG_ON(tsk != current); 443 444 if (tm_suspend_disabled) 445 return -EINVAL; 446 447 /* copy the GPRs */ 448 err |= __copy_from_user(regs->gpr, tm_sc->gp_regs, sizeof(regs->gpr)); 449 err |= __copy_from_user(&tsk->thread.ckpt_regs, sc->gp_regs, 450 sizeof(regs->gpr)); 451 452 /* 453 * TFHAR is restored from the checkpointed 'wound-back' ucontext's NIP. 454 * TEXASR was set by the signal delivery reclaim, as was TFIAR. 455 * Users doing anything abhorrent like thread-switching w/ signals for 456 * TM-Suspended code will have to back TEXASR/TFIAR up themselves. 457 * For the case of getting a signal and simply returning from it, 458 * we don't need to re-copy them here. 459 */ 460 err |= __get_user(regs->nip, &tm_sc->gp_regs[PT_NIP]); 461 err |= __get_user(tsk->thread.tm_tfhar, &sc->gp_regs[PT_NIP]); 462 463 /* get MSR separately, transfer the LE bit if doing signal return */ 464 err |= __get_user(msr, &sc->gp_regs[PT_MSR]); 465 /* Don't allow reserved mode. */ 466 if (MSR_TM_RESV(msr)) 467 return -EINVAL; 468 469 /* pull in MSR TS bits from user context */ 470 regs->msr = (regs->msr & ~MSR_TS_MASK) | (msr & MSR_TS_MASK); 471 472 /* 473 * Ensure that TM is enabled in regs->msr before we leave the signal 474 * handler. It could be the case that (a) user disabled the TM bit 475 * through the manipulation of the MSR bits in uc_mcontext or (b) the 476 * TM bit was disabled because a sufficient number of context switches 477 * happened whilst in the signal handler and load_tm overflowed, 478 * disabling the TM bit. In either case we can end up with an illegal 479 * TM state leading to a TM Bad Thing when we return to userspace. 480 */ 481 regs->msr |= MSR_TM; 482 483 /* pull in MSR LE from user context */ 484 regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE); 485 486 /* The following non-GPR non-FPR non-VR state is also checkpointed: */ 487 err |= __get_user(regs->ctr, &tm_sc->gp_regs[PT_CTR]); 488 err |= __get_user(regs->link, &tm_sc->gp_regs[PT_LNK]); 489 err |= __get_user(regs->xer, &tm_sc->gp_regs[PT_XER]); 490 err |= __get_user(regs->ccr, &tm_sc->gp_regs[PT_CCR]); 491 err |= __get_user(tsk->thread.ckpt_regs.ctr, 492 &sc->gp_regs[PT_CTR]); 493 err |= __get_user(tsk->thread.ckpt_regs.link, 494 &sc->gp_regs[PT_LNK]); 495 err |= __get_user(tsk->thread.ckpt_regs.xer, 496 &sc->gp_regs[PT_XER]); 497 err |= __get_user(tsk->thread.ckpt_regs.ccr, 498 &sc->gp_regs[PT_CCR]); 499 500 /* These regs are not checkpointed; they can go in 'regs'. */ 501 err |= __get_user(regs->trap, &sc->gp_regs[PT_TRAP]); 502 err |= __get_user(regs->dar, &sc->gp_regs[PT_DAR]); 503 err |= __get_user(regs->dsisr, &sc->gp_regs[PT_DSISR]); 504 err |= __get_user(regs->result, &sc->gp_regs[PT_RESULT]); 505 506 /* 507 * Force reload of FP/VEC. 508 * This has to be done before copying stuff into tsk->thread.fpr/vr 509 * for the reasons explained in the previous comment. 510 */ 511 regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC | MSR_VSX); 512 513 #ifdef CONFIG_ALTIVEC 514 err |= __get_user(v_regs, &sc->v_regs); 515 err |= __get_user(tm_v_regs, &tm_sc->v_regs); 516 if (err) 517 return err; 518 if (v_regs && !access_ok(VERIFY_READ, v_regs, 34 * sizeof(vector128))) 519 return -EFAULT; 520 if (tm_v_regs && !access_ok(VERIFY_READ, 521 tm_v_regs, 34 * sizeof(vector128))) 522 return -EFAULT; 523 /* Copy 33 vec registers (vr0..31 and vscr) from the stack */ 524 if (v_regs != NULL && tm_v_regs != NULL && (msr & MSR_VEC) != 0) { 525 err |= __copy_from_user(&tsk->thread.ckvr_state, v_regs, 526 33 * sizeof(vector128)); 527 err |= __copy_from_user(&tsk->thread.vr_state, tm_v_regs, 528 33 * sizeof(vector128)); 529 current->thread.used_vr = true; 530 } 531 else if (tsk->thread.used_vr) { 532 memset(&tsk->thread.vr_state, 0, 33 * sizeof(vector128)); 533 memset(&tsk->thread.ckvr_state, 0, 33 * sizeof(vector128)); 534 } 535 /* Always get VRSAVE back */ 536 if (v_regs != NULL && tm_v_regs != NULL) { 537 err |= __get_user(tsk->thread.ckvrsave, 538 (u32 __user *)&v_regs[33]); 539 err |= __get_user(tsk->thread.vrsave, 540 (u32 __user *)&tm_v_regs[33]); 541 } 542 else { 543 tsk->thread.vrsave = 0; 544 tsk->thread.ckvrsave = 0; 545 } 546 if (cpu_has_feature(CPU_FTR_ALTIVEC)) 547 mtspr(SPRN_VRSAVE, tsk->thread.vrsave); 548 #endif /* CONFIG_ALTIVEC */ 549 /* restore floating point */ 550 err |= copy_fpr_from_user(tsk, &tm_sc->fp_regs); 551 err |= copy_ckfpr_from_user(tsk, &sc->fp_regs); 552 #ifdef CONFIG_VSX 553 /* 554 * Get additional VSX data. Update v_regs to point after the 555 * VMX data. Copy VSX low doubleword from userspace to local 556 * buffer for formatting, then into the taskstruct. 557 */ 558 if (v_regs && ((msr & MSR_VSX) != 0)) { 559 v_regs += ELF_NVRREG; 560 tm_v_regs += ELF_NVRREG; 561 err |= copy_vsx_from_user(tsk, tm_v_regs); 562 err |= copy_ckvsx_from_user(tsk, v_regs); 563 tsk->thread.used_vsr = true; 564 } else { 565 for (i = 0; i < 32 ; i++) { 566 tsk->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0; 567 tsk->thread.ckfp_state.fpr[i][TS_VSRLOWOFFSET] = 0; 568 } 569 } 570 #endif 571 tm_enable(); 572 /* Make sure the transaction is marked as failed */ 573 tsk->thread.tm_texasr |= TEXASR_FS; 574 /* This loads the checkpointed FP/VEC state, if used */ 575 tm_recheckpoint(&tsk->thread); 576 577 msr_check_and_set(msr & (MSR_FP | MSR_VEC)); 578 if (msr & MSR_FP) { 579 load_fp_state(&tsk->thread.fp_state); 580 regs->msr |= (MSR_FP | tsk->thread.fpexc_mode); 581 } 582 if (msr & MSR_VEC) { 583 load_vr_state(&tsk->thread.vr_state); 584 regs->msr |= MSR_VEC; 585 } 586 587 return err; 588 } 589 #endif 590 591 /* 592 * Setup the trampoline code on the stack 593 */ 594 static long setup_trampoline(unsigned int syscall, unsigned int __user *tramp) 595 { 596 int i; 597 long err = 0; 598 599 /* addi r1, r1, __SIGNAL_FRAMESIZE # Pop the dummy stackframe */ 600 err |= __put_user(0x38210000UL | (__SIGNAL_FRAMESIZE & 0xffff), &tramp[0]); 601 /* li r0, __NR_[rt_]sigreturn| */ 602 err |= __put_user(0x38000000UL | (syscall & 0xffff), &tramp[1]); 603 /* sc */ 604 err |= __put_user(0x44000002UL, &tramp[2]); 605 606 /* Minimal traceback info */ 607 for (i=TRAMP_TRACEBACK; i < TRAMP_SIZE ;i++) 608 err |= __put_user(0, &tramp[i]); 609 610 if (!err) 611 flush_icache_range((unsigned long) &tramp[0], 612 (unsigned long) &tramp[TRAMP_SIZE]); 613 614 return err; 615 } 616 617 /* 618 * Userspace code may pass a ucontext which doesn't include VSX added 619 * at the end. We need to check for this case. 620 */ 621 #define UCONTEXTSIZEWITHOUTVSX \ 622 (sizeof(struct ucontext) - 32*sizeof(long)) 623 624 /* 625 * Handle {get,set,swap}_context operations 626 */ 627 int sys_swapcontext(struct ucontext __user *old_ctx, 628 struct ucontext __user *new_ctx, 629 long ctx_size, long r6, long r7, long r8, struct pt_regs *regs) 630 { 631 unsigned char tmp; 632 sigset_t set; 633 unsigned long new_msr = 0; 634 int ctx_has_vsx_region = 0; 635 636 BUG_ON(regs != current->thread.regs); 637 638 if (new_ctx && 639 get_user(new_msr, &new_ctx->uc_mcontext.gp_regs[PT_MSR])) 640 return -EFAULT; 641 /* 642 * Check that the context is not smaller than the original 643 * size (with VMX but without VSX) 644 */ 645 if (ctx_size < UCONTEXTSIZEWITHOUTVSX) 646 return -EINVAL; 647 /* 648 * If the new context state sets the MSR VSX bits but 649 * it doesn't provide VSX state. 650 */ 651 if ((ctx_size < sizeof(struct ucontext)) && 652 (new_msr & MSR_VSX)) 653 return -EINVAL; 654 /* Does the context have enough room to store VSX data? */ 655 if (ctx_size >= sizeof(struct ucontext)) 656 ctx_has_vsx_region = 1; 657 658 if (old_ctx != NULL) { 659 if (!access_ok(VERIFY_WRITE, old_ctx, ctx_size) 660 || setup_sigcontext(&old_ctx->uc_mcontext, current, 0, NULL, 0, 661 ctx_has_vsx_region) 662 || __copy_to_user(&old_ctx->uc_sigmask, 663 ¤t->blocked, sizeof(sigset_t))) 664 return -EFAULT; 665 } 666 if (new_ctx == NULL) 667 return 0; 668 if (!access_ok(VERIFY_READ, new_ctx, ctx_size) 669 || __get_user(tmp, (u8 __user *) new_ctx) 670 || __get_user(tmp, (u8 __user *) new_ctx + ctx_size - 1)) 671 return -EFAULT; 672 673 /* 674 * If we get a fault copying the context into the kernel's 675 * image of the user's registers, we can't just return -EFAULT 676 * because the user's registers will be corrupted. For instance 677 * the NIP value may have been updated but not some of the 678 * other registers. Given that we have done the access_ok 679 * and successfully read the first and last bytes of the region 680 * above, this should only happen in an out-of-memory situation 681 * or if another thread unmaps the region containing the context. 682 * We kill the task with a SIGSEGV in this situation. 683 */ 684 685 if (__copy_from_user(&set, &new_ctx->uc_sigmask, sizeof(set))) 686 do_exit(SIGSEGV); 687 set_current_blocked(&set); 688 if (restore_sigcontext(current, NULL, 0, &new_ctx->uc_mcontext)) 689 do_exit(SIGSEGV); 690 691 /* This returns like rt_sigreturn */ 692 set_thread_flag(TIF_RESTOREALL); 693 return 0; 694 } 695 696 697 /* 698 * Do a signal return; undo the signal stack. 699 */ 700 701 int sys_rt_sigreturn(unsigned long r3, unsigned long r4, unsigned long r5, 702 unsigned long r6, unsigned long r7, unsigned long r8, 703 struct pt_regs *regs) 704 { 705 struct ucontext __user *uc = (struct ucontext __user *)regs->gpr[1]; 706 sigset_t set; 707 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 708 unsigned long msr; 709 #endif 710 711 BUG_ON(current->thread.regs != regs); 712 713 /* Always make any pending restarted system calls return -EINTR */ 714 current->restart_block.fn = do_no_restart_syscall; 715 716 if (!access_ok(VERIFY_READ, uc, sizeof(*uc))) 717 goto badframe; 718 719 if (__copy_from_user(&set, &uc->uc_sigmask, sizeof(set))) 720 goto badframe; 721 set_current_blocked(&set); 722 723 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 724 /* 725 * If there is a transactional state then throw it away. 726 * The purpose of a sigreturn is to destroy all traces of the 727 * signal frame, this includes any transactional state created 728 * within in. We only check for suspended as we can never be 729 * active in the kernel, we are active, there is nothing better to 730 * do than go ahead and Bad Thing later. 731 * The cause is not important as there will never be a 732 * recheckpoint so it's not user visible. 733 */ 734 if (MSR_TM_SUSPENDED(mfmsr())) 735 tm_reclaim_current(0); 736 737 if (__get_user(msr, &uc->uc_mcontext.gp_regs[PT_MSR])) 738 goto badframe; 739 if (MSR_TM_ACTIVE(msr)) { 740 /* We recheckpoint on return. */ 741 struct ucontext __user *uc_transact; 742 if (__get_user(uc_transact, &uc->uc_link)) 743 goto badframe; 744 if (restore_tm_sigcontexts(current, &uc->uc_mcontext, 745 &uc_transact->uc_mcontext)) 746 goto badframe; 747 } 748 else 749 /* Fall through, for non-TM restore */ 750 #endif 751 if (restore_sigcontext(current, NULL, 1, &uc->uc_mcontext)) 752 goto badframe; 753 754 if (restore_altstack(&uc->uc_stack)) 755 goto badframe; 756 757 set_thread_flag(TIF_RESTOREALL); 758 return 0; 759 760 badframe: 761 if (show_unhandled_signals) 762 printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32, 763 current->comm, current->pid, "rt_sigreturn", 764 (long)uc, regs->nip, regs->link); 765 766 force_sig(SIGSEGV, current); 767 return 0; 768 } 769 770 int handle_rt_signal64(struct ksignal *ksig, sigset_t *set, 771 struct task_struct *tsk) 772 { 773 struct rt_sigframe __user *frame; 774 unsigned long newsp = 0; 775 long err = 0; 776 struct pt_regs *regs = tsk->thread.regs; 777 778 BUG_ON(tsk != current); 779 780 frame = get_sigframe(ksig, get_tm_stackpointer(tsk), sizeof(*frame), 0); 781 if (unlikely(frame == NULL)) 782 goto badframe; 783 784 err |= __put_user(&frame->info, &frame->pinfo); 785 err |= __put_user(&frame->uc, &frame->puc); 786 err |= copy_siginfo_to_user(&frame->info, &ksig->info); 787 if (err) 788 goto badframe; 789 790 /* Create the ucontext. */ 791 err |= __put_user(0, &frame->uc.uc_flags); 792 err |= __save_altstack(&frame->uc.uc_stack, regs->gpr[1]); 793 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 794 if (MSR_TM_ACTIVE(regs->msr)) { 795 /* The ucontext_t passed to userland points to the second 796 * ucontext_t (for transactional state) with its uc_link ptr. 797 */ 798 err |= __put_user(&frame->uc_transact, &frame->uc.uc_link); 799 err |= setup_tm_sigcontexts(&frame->uc.uc_mcontext, 800 &frame->uc_transact.uc_mcontext, 801 tsk, ksig->sig, NULL, 802 (unsigned long)ksig->ka.sa.sa_handler); 803 } else 804 #endif 805 { 806 err |= __put_user(0, &frame->uc.uc_link); 807 err |= setup_sigcontext(&frame->uc.uc_mcontext, tsk, ksig->sig, 808 NULL, (unsigned long)ksig->ka.sa.sa_handler, 809 1); 810 } 811 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); 812 if (err) 813 goto badframe; 814 815 /* Make sure signal handler doesn't get spurious FP exceptions */ 816 tsk->thread.fp_state.fpscr = 0; 817 818 /* Set up to return from userspace. */ 819 if (vdso64_rt_sigtramp && tsk->mm->context.vdso_base) { 820 regs->link = tsk->mm->context.vdso_base + vdso64_rt_sigtramp; 821 } else { 822 err |= setup_trampoline(__NR_rt_sigreturn, &frame->tramp[0]); 823 if (err) 824 goto badframe; 825 regs->link = (unsigned long) &frame->tramp[0]; 826 } 827 828 /* Allocate a dummy caller frame for the signal handler. */ 829 newsp = ((unsigned long)frame) - __SIGNAL_FRAMESIZE; 830 err |= put_user(regs->gpr[1], (unsigned long __user *)newsp); 831 832 /* Set up "regs" so we "return" to the signal handler. */ 833 if (is_elf2_task()) { 834 regs->nip = (unsigned long) ksig->ka.sa.sa_handler; 835 regs->gpr[12] = regs->nip; 836 } else { 837 /* Handler is *really* a pointer to the function descriptor for 838 * the signal routine. The first entry in the function 839 * descriptor is the entry address of signal and the second 840 * entry is the TOC value we need to use. 841 */ 842 func_descr_t __user *funct_desc_ptr = 843 (func_descr_t __user *) ksig->ka.sa.sa_handler; 844 845 err |= get_user(regs->nip, &funct_desc_ptr->entry); 846 err |= get_user(regs->gpr[2], &funct_desc_ptr->toc); 847 } 848 849 /* enter the signal handler in native-endian mode */ 850 regs->msr &= ~MSR_LE; 851 regs->msr |= (MSR_KERNEL & MSR_LE); 852 regs->gpr[1] = newsp; 853 regs->gpr[3] = ksig->sig; 854 regs->result = 0; 855 if (ksig->ka.sa.sa_flags & SA_SIGINFO) { 856 err |= get_user(regs->gpr[4], (unsigned long __user *)&frame->pinfo); 857 err |= get_user(regs->gpr[5], (unsigned long __user *)&frame->puc); 858 regs->gpr[6] = (unsigned long) frame; 859 } else { 860 regs->gpr[4] = (unsigned long)&frame->uc.uc_mcontext; 861 } 862 if (err) 863 goto badframe; 864 865 return 0; 866 867 badframe: 868 if (show_unhandled_signals) 869 printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32, 870 tsk->comm, tsk->pid, "setup_rt_frame", 871 (long)frame, regs->nip, regs->link); 872 873 return 1; 874 } 875