1 /* 2 * PowerPC version 3 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) 4 * 5 * Derived from "arch/i386/kernel/signal.c" 6 * Copyright (C) 1991, 1992 Linus Torvalds 7 * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson 8 * 9 * This program is free software; you can redistribute it and/or 10 * modify it under the terms of the GNU General Public License 11 * as published by the Free Software Foundation; either version 12 * 2 of the License, or (at your option) any later version. 13 */ 14 15 #include <linux/sched.h> 16 #include <linux/mm.h> 17 #include <linux/smp.h> 18 #include <linux/kernel.h> 19 #include <linux/signal.h> 20 #include <linux/errno.h> 21 #include <linux/wait.h> 22 #include <linux/unistd.h> 23 #include <linux/stddef.h> 24 #include <linux/elf.h> 25 #include <linux/ptrace.h> 26 #include <linux/ratelimit.h> 27 28 #include <asm/sigcontext.h> 29 #include <asm/ucontext.h> 30 #include <asm/uaccess.h> 31 #include <asm/pgtable.h> 32 #include <asm/unistd.h> 33 #include <asm/cacheflush.h> 34 #include <asm/syscalls.h> 35 #include <asm/vdso.h> 36 #include <asm/switch_to.h> 37 #include <asm/tm.h> 38 39 #include "signal.h" 40 41 #define DEBUG_SIG 0 42 43 #define GP_REGS_SIZE min(sizeof(elf_gregset_t), sizeof(struct pt_regs)) 44 #define FP_REGS_SIZE sizeof(elf_fpregset_t) 45 46 #define TRAMP_TRACEBACK 3 47 #define TRAMP_SIZE 6 48 49 /* 50 * When we have signals to deliver, we set up on the user stack, 51 * going down from the original stack pointer: 52 * 1) a rt_sigframe struct which contains the ucontext 53 * 2) a gap of __SIGNAL_FRAMESIZE bytes which acts as a dummy caller 54 * frame for the signal handler. 55 */ 56 57 struct rt_sigframe { 58 /* sys_rt_sigreturn requires the ucontext be the first field */ 59 struct ucontext uc; 60 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 61 struct ucontext uc_transact; 62 #endif 63 unsigned long _unused[2]; 64 unsigned int tramp[TRAMP_SIZE]; 65 struct siginfo __user *pinfo; 66 void __user *puc; 67 struct siginfo info; 68 /* 64 bit ABI allows for 288 bytes below sp before decrementing it. */ 69 char abigap[288]; 70 } __attribute__ ((aligned (16))); 71 72 static const char fmt32[] = KERN_INFO \ 73 "%s[%d]: bad frame in %s: %08lx nip %08lx lr %08lx\n"; 74 static const char fmt64[] = KERN_INFO \ 75 "%s[%d]: bad frame in %s: %016lx nip %016lx lr %016lx\n"; 76 77 /* 78 * Set up the sigcontext for the signal frame. 79 */ 80 81 static long setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, 82 int signr, sigset_t *set, unsigned long handler, 83 int ctx_has_vsx_region) 84 { 85 /* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the 86 * process never used altivec yet (MSR_VEC is zero in pt_regs of 87 * the context). This is very important because we must ensure we 88 * don't lose the VRSAVE content that may have been set prior to 89 * the process doing its first vector operation 90 * Userland shall check AT_HWCAP to know whether it can rely on the 91 * v_regs pointer or not 92 */ 93 #ifdef CONFIG_ALTIVEC 94 elf_vrreg_t __user *v_regs = (elf_vrreg_t __user *)(((unsigned long)sc->vmx_reserve + 15) & ~0xful); 95 #endif 96 unsigned long msr = regs->msr; 97 long err = 0; 98 99 #ifdef CONFIG_ALTIVEC 100 err |= __put_user(v_regs, &sc->v_regs); 101 102 /* save altivec registers */ 103 if (current->thread.used_vr) { 104 flush_altivec_to_thread(current); 105 /* Copy 33 vec registers (vr0..31 and vscr) to the stack */ 106 err |= __copy_to_user(v_regs, ¤t->thread.vr_state, 107 33 * sizeof(vector128)); 108 /* set MSR_VEC in the MSR value in the frame to indicate that sc->v_reg) 109 * contains valid data. 110 */ 111 msr |= MSR_VEC; 112 } 113 /* We always copy to/from vrsave, it's 0 if we don't have or don't 114 * use altivec. 115 */ 116 if (cpu_has_feature(CPU_FTR_ALTIVEC)) 117 current->thread.vrsave = mfspr(SPRN_VRSAVE); 118 err |= __put_user(current->thread.vrsave, (u32 __user *)&v_regs[33]); 119 #else /* CONFIG_ALTIVEC */ 120 err |= __put_user(0, &sc->v_regs); 121 #endif /* CONFIG_ALTIVEC */ 122 flush_fp_to_thread(current); 123 /* copy fpr regs and fpscr */ 124 err |= copy_fpr_to_user(&sc->fp_regs, current); 125 126 /* 127 * Clear the MSR VSX bit to indicate there is no valid state attached 128 * to this context, except in the specific case below where we set it. 129 */ 130 msr &= ~MSR_VSX; 131 #ifdef CONFIG_VSX 132 /* 133 * Copy VSX low doubleword to local buffer for formatting, 134 * then out to userspace. Update v_regs to point after the 135 * VMX data. 136 */ 137 if (current->thread.used_vsr && ctx_has_vsx_region) { 138 __giveup_vsx(current); 139 v_regs += ELF_NVRREG; 140 err |= copy_vsx_to_user(v_regs, current); 141 /* set MSR_VSX in the MSR value in the frame to 142 * indicate that sc->vs_reg) contains valid data. 143 */ 144 msr |= MSR_VSX; 145 } 146 #endif /* CONFIG_VSX */ 147 err |= __put_user(&sc->gp_regs, &sc->regs); 148 WARN_ON(!FULL_REGS(regs)); 149 err |= __copy_to_user(&sc->gp_regs, regs, GP_REGS_SIZE); 150 err |= __put_user(msr, &sc->gp_regs[PT_MSR]); 151 err |= __put_user(signr, &sc->signal); 152 err |= __put_user(handler, &sc->handler); 153 if (set != NULL) 154 err |= __put_user(set->sig[0], &sc->oldmask); 155 156 return err; 157 } 158 159 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 160 /* 161 * As above, but Transactional Memory is in use, so deliver sigcontexts 162 * containing checkpointed and transactional register states. 163 * 164 * To do this, we treclaim (done before entering here) to gather both sets of 165 * registers and set up the 'normal' sigcontext registers with rolled-back 166 * register values such that a simple signal handler sees a correct 167 * checkpointed register state. If interested, a TM-aware sighandler can 168 * examine the transactional registers in the 2nd sigcontext to determine the 169 * real origin of the signal. 170 */ 171 static long setup_tm_sigcontexts(struct sigcontext __user *sc, 172 struct sigcontext __user *tm_sc, 173 struct pt_regs *regs, 174 int signr, sigset_t *set, unsigned long handler) 175 { 176 /* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the 177 * process never used altivec yet (MSR_VEC is zero in pt_regs of 178 * the context). This is very important because we must ensure we 179 * don't lose the VRSAVE content that may have been set prior to 180 * the process doing its first vector operation 181 * Userland shall check AT_HWCAP to know wether it can rely on the 182 * v_regs pointer or not. 183 */ 184 #ifdef CONFIG_ALTIVEC 185 elf_vrreg_t __user *v_regs = (elf_vrreg_t __user *) 186 (((unsigned long)sc->vmx_reserve + 15) & ~0xful); 187 elf_vrreg_t __user *tm_v_regs = (elf_vrreg_t __user *) 188 (((unsigned long)tm_sc->vmx_reserve + 15) & ~0xful); 189 #endif 190 unsigned long msr = regs->msr; 191 long err = 0; 192 193 BUG_ON(!MSR_TM_ACTIVE(regs->msr)); 194 195 /* Remove TM bits from thread's MSR. The MSR in the sigcontext 196 * just indicates to userland that we were doing a transaction, but we 197 * don't want to return in transactional state. This also ensures 198 * that flush_fp_to_thread won't set TIF_RESTORE_TM again. 199 */ 200 regs->msr &= ~MSR_TS_MASK; 201 202 flush_fp_to_thread(current); 203 204 #ifdef CONFIG_ALTIVEC 205 err |= __put_user(v_regs, &sc->v_regs); 206 err |= __put_user(tm_v_regs, &tm_sc->v_regs); 207 208 /* save altivec registers */ 209 if (current->thread.used_vr) { 210 flush_altivec_to_thread(current); 211 /* Copy 33 vec registers (vr0..31 and vscr) to the stack */ 212 err |= __copy_to_user(v_regs, ¤t->thread.vr_state, 213 33 * sizeof(vector128)); 214 /* If VEC was enabled there are transactional VRs valid too, 215 * else they're a copy of the checkpointed VRs. 216 */ 217 if (msr & MSR_VEC) 218 err |= __copy_to_user(tm_v_regs, 219 ¤t->thread.transact_vr, 220 33 * sizeof(vector128)); 221 else 222 err |= __copy_to_user(tm_v_regs, 223 ¤t->thread.vr_state, 224 33 * sizeof(vector128)); 225 226 /* set MSR_VEC in the MSR value in the frame to indicate 227 * that sc->v_reg contains valid data. 228 */ 229 msr |= MSR_VEC; 230 } 231 /* We always copy to/from vrsave, it's 0 if we don't have or don't 232 * use altivec. 233 */ 234 if (cpu_has_feature(CPU_FTR_ALTIVEC)) 235 current->thread.vrsave = mfspr(SPRN_VRSAVE); 236 err |= __put_user(current->thread.vrsave, (u32 __user *)&v_regs[33]); 237 if (msr & MSR_VEC) 238 err |= __put_user(current->thread.transact_vrsave, 239 (u32 __user *)&tm_v_regs[33]); 240 else 241 err |= __put_user(current->thread.vrsave, 242 (u32 __user *)&tm_v_regs[33]); 243 244 #else /* CONFIG_ALTIVEC */ 245 err |= __put_user(0, &sc->v_regs); 246 err |= __put_user(0, &tm_sc->v_regs); 247 #endif /* CONFIG_ALTIVEC */ 248 249 /* copy fpr regs and fpscr */ 250 err |= copy_fpr_to_user(&sc->fp_regs, current); 251 if (msr & MSR_FP) 252 err |= copy_transact_fpr_to_user(&tm_sc->fp_regs, current); 253 else 254 err |= copy_fpr_to_user(&tm_sc->fp_regs, current); 255 256 #ifdef CONFIG_VSX 257 /* 258 * Copy VSX low doubleword to local buffer for formatting, 259 * then out to userspace. Update v_regs to point after the 260 * VMX data. 261 */ 262 if (current->thread.used_vsr) { 263 __giveup_vsx(current); 264 v_regs += ELF_NVRREG; 265 tm_v_regs += ELF_NVRREG; 266 267 err |= copy_vsx_to_user(v_regs, current); 268 269 if (msr & MSR_VSX) 270 err |= copy_transact_vsx_to_user(tm_v_regs, current); 271 else 272 err |= copy_vsx_to_user(tm_v_regs, current); 273 274 /* set MSR_VSX in the MSR value in the frame to 275 * indicate that sc->vs_reg) contains valid data. 276 */ 277 msr |= MSR_VSX; 278 } 279 #endif /* CONFIG_VSX */ 280 281 err |= __put_user(&sc->gp_regs, &sc->regs); 282 err |= __put_user(&tm_sc->gp_regs, &tm_sc->regs); 283 WARN_ON(!FULL_REGS(regs)); 284 err |= __copy_to_user(&tm_sc->gp_regs, regs, GP_REGS_SIZE); 285 err |= __copy_to_user(&sc->gp_regs, 286 ¤t->thread.ckpt_regs, GP_REGS_SIZE); 287 err |= __put_user(msr, &tm_sc->gp_regs[PT_MSR]); 288 err |= __put_user(msr, &sc->gp_regs[PT_MSR]); 289 err |= __put_user(signr, &sc->signal); 290 err |= __put_user(handler, &sc->handler); 291 if (set != NULL) 292 err |= __put_user(set->sig[0], &sc->oldmask); 293 294 return err; 295 } 296 #endif 297 298 /* 299 * Restore the sigcontext from the signal frame. 300 */ 301 302 static long restore_sigcontext(struct pt_regs *regs, sigset_t *set, int sig, 303 struct sigcontext __user *sc) 304 { 305 #ifdef CONFIG_ALTIVEC 306 elf_vrreg_t __user *v_regs; 307 #endif 308 unsigned long err = 0; 309 unsigned long save_r13 = 0; 310 unsigned long msr; 311 #ifdef CONFIG_VSX 312 int i; 313 #endif 314 315 /* If this is not a signal return, we preserve the TLS in r13 */ 316 if (!sig) 317 save_r13 = regs->gpr[13]; 318 319 /* copy the GPRs */ 320 err |= __copy_from_user(regs->gpr, sc->gp_regs, sizeof(regs->gpr)); 321 err |= __get_user(regs->nip, &sc->gp_regs[PT_NIP]); 322 /* get MSR separately, transfer the LE bit if doing signal return */ 323 err |= __get_user(msr, &sc->gp_regs[PT_MSR]); 324 if (sig) 325 regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE); 326 err |= __get_user(regs->orig_gpr3, &sc->gp_regs[PT_ORIG_R3]); 327 err |= __get_user(regs->ctr, &sc->gp_regs[PT_CTR]); 328 err |= __get_user(regs->link, &sc->gp_regs[PT_LNK]); 329 err |= __get_user(regs->xer, &sc->gp_regs[PT_XER]); 330 err |= __get_user(regs->ccr, &sc->gp_regs[PT_CCR]); 331 /* skip SOFTE */ 332 regs->trap = 0; 333 err |= __get_user(regs->dar, &sc->gp_regs[PT_DAR]); 334 err |= __get_user(regs->dsisr, &sc->gp_regs[PT_DSISR]); 335 err |= __get_user(regs->result, &sc->gp_regs[PT_RESULT]); 336 337 if (!sig) 338 regs->gpr[13] = save_r13; 339 if (set != NULL) 340 err |= __get_user(set->sig[0], &sc->oldmask); 341 342 /* 343 * Do this before updating the thread state in 344 * current->thread.fpr/vr. That way, if we get preempted 345 * and another task grabs the FPU/Altivec, it won't be 346 * tempted to save the current CPU state into the thread_struct 347 * and corrupt what we are writing there. 348 */ 349 discard_lazy_cpu_state(); 350 351 /* 352 * Force reload of FP/VEC. 353 * This has to be done before copying stuff into current->thread.fpr/vr 354 * for the reasons explained in the previous comment. 355 */ 356 regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC | MSR_VSX); 357 358 #ifdef CONFIG_ALTIVEC 359 err |= __get_user(v_regs, &sc->v_regs); 360 if (err) 361 return err; 362 if (v_regs && !access_ok(VERIFY_READ, v_regs, 34 * sizeof(vector128))) 363 return -EFAULT; 364 /* Copy 33 vec registers (vr0..31 and vscr) from the stack */ 365 if (v_regs != NULL && (msr & MSR_VEC) != 0) 366 err |= __copy_from_user(¤t->thread.vr_state, v_regs, 367 33 * sizeof(vector128)); 368 else if (current->thread.used_vr) 369 memset(¤t->thread.vr_state, 0, 33 * sizeof(vector128)); 370 /* Always get VRSAVE back */ 371 if (v_regs != NULL) 372 err |= __get_user(current->thread.vrsave, (u32 __user *)&v_regs[33]); 373 else 374 current->thread.vrsave = 0; 375 if (cpu_has_feature(CPU_FTR_ALTIVEC)) 376 mtspr(SPRN_VRSAVE, current->thread.vrsave); 377 #endif /* CONFIG_ALTIVEC */ 378 /* restore floating point */ 379 err |= copy_fpr_from_user(current, &sc->fp_regs); 380 #ifdef CONFIG_VSX 381 /* 382 * Get additional VSX data. Update v_regs to point after the 383 * VMX data. Copy VSX low doubleword from userspace to local 384 * buffer for formatting, then into the taskstruct. 385 */ 386 v_regs += ELF_NVRREG; 387 if ((msr & MSR_VSX) != 0) 388 err |= copy_vsx_from_user(current, v_regs); 389 else 390 for (i = 0; i < 32 ; i++) 391 current->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0; 392 #endif 393 return err; 394 } 395 396 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 397 /* 398 * Restore the two sigcontexts from the frame of a transactional processes. 399 */ 400 401 static long restore_tm_sigcontexts(struct pt_regs *regs, 402 struct sigcontext __user *sc, 403 struct sigcontext __user *tm_sc) 404 { 405 #ifdef CONFIG_ALTIVEC 406 elf_vrreg_t __user *v_regs, *tm_v_regs; 407 #endif 408 unsigned long err = 0; 409 unsigned long msr; 410 #ifdef CONFIG_VSX 411 int i; 412 #endif 413 /* copy the GPRs */ 414 err |= __copy_from_user(regs->gpr, tm_sc->gp_regs, sizeof(regs->gpr)); 415 err |= __copy_from_user(¤t->thread.ckpt_regs, sc->gp_regs, 416 sizeof(regs->gpr)); 417 418 /* 419 * TFHAR is restored from the checkpointed 'wound-back' ucontext's NIP. 420 * TEXASR was set by the signal delivery reclaim, as was TFIAR. 421 * Users doing anything abhorrent like thread-switching w/ signals for 422 * TM-Suspended code will have to back TEXASR/TFIAR up themselves. 423 * For the case of getting a signal and simply returning from it, 424 * we don't need to re-copy them here. 425 */ 426 err |= __get_user(regs->nip, &tm_sc->gp_regs[PT_NIP]); 427 err |= __get_user(current->thread.tm_tfhar, &sc->gp_regs[PT_NIP]); 428 429 /* get MSR separately, transfer the LE bit if doing signal return */ 430 err |= __get_user(msr, &sc->gp_regs[PT_MSR]); 431 /* pull in MSR TM from user context */ 432 regs->msr = (regs->msr & ~MSR_TS_MASK) | (msr & MSR_TS_MASK); 433 434 /* pull in MSR LE from user context */ 435 regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE); 436 437 /* The following non-GPR non-FPR non-VR state is also checkpointed: */ 438 err |= __get_user(regs->ctr, &tm_sc->gp_regs[PT_CTR]); 439 err |= __get_user(regs->link, &tm_sc->gp_regs[PT_LNK]); 440 err |= __get_user(regs->xer, &tm_sc->gp_regs[PT_XER]); 441 err |= __get_user(regs->ccr, &tm_sc->gp_regs[PT_CCR]); 442 err |= __get_user(current->thread.ckpt_regs.ctr, 443 &sc->gp_regs[PT_CTR]); 444 err |= __get_user(current->thread.ckpt_regs.link, 445 &sc->gp_regs[PT_LNK]); 446 err |= __get_user(current->thread.ckpt_regs.xer, 447 &sc->gp_regs[PT_XER]); 448 err |= __get_user(current->thread.ckpt_regs.ccr, 449 &sc->gp_regs[PT_CCR]); 450 451 /* These regs are not checkpointed; they can go in 'regs'. */ 452 err |= __get_user(regs->trap, &sc->gp_regs[PT_TRAP]); 453 err |= __get_user(regs->dar, &sc->gp_regs[PT_DAR]); 454 err |= __get_user(regs->dsisr, &sc->gp_regs[PT_DSISR]); 455 err |= __get_user(regs->result, &sc->gp_regs[PT_RESULT]); 456 457 /* 458 * Do this before updating the thread state in 459 * current->thread.fpr/vr. That way, if we get preempted 460 * and another task grabs the FPU/Altivec, it won't be 461 * tempted to save the current CPU state into the thread_struct 462 * and corrupt what we are writing there. 463 */ 464 discard_lazy_cpu_state(); 465 466 /* 467 * Force reload of FP/VEC. 468 * This has to be done before copying stuff into current->thread.fpr/vr 469 * for the reasons explained in the previous comment. 470 */ 471 regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC | MSR_VSX); 472 473 #ifdef CONFIG_ALTIVEC 474 err |= __get_user(v_regs, &sc->v_regs); 475 err |= __get_user(tm_v_regs, &tm_sc->v_regs); 476 if (err) 477 return err; 478 if (v_regs && !access_ok(VERIFY_READ, v_regs, 34 * sizeof(vector128))) 479 return -EFAULT; 480 if (tm_v_regs && !access_ok(VERIFY_READ, 481 tm_v_regs, 34 * sizeof(vector128))) 482 return -EFAULT; 483 /* Copy 33 vec registers (vr0..31 and vscr) from the stack */ 484 if (v_regs != NULL && tm_v_regs != NULL && (msr & MSR_VEC) != 0) { 485 err |= __copy_from_user(¤t->thread.vr_state, v_regs, 486 33 * sizeof(vector128)); 487 err |= __copy_from_user(¤t->thread.transact_vr, tm_v_regs, 488 33 * sizeof(vector128)); 489 } 490 else if (current->thread.used_vr) { 491 memset(¤t->thread.vr_state, 0, 33 * sizeof(vector128)); 492 memset(¤t->thread.transact_vr, 0, 33 * sizeof(vector128)); 493 } 494 /* Always get VRSAVE back */ 495 if (v_regs != NULL && tm_v_regs != NULL) { 496 err |= __get_user(current->thread.vrsave, 497 (u32 __user *)&v_regs[33]); 498 err |= __get_user(current->thread.transact_vrsave, 499 (u32 __user *)&tm_v_regs[33]); 500 } 501 else { 502 current->thread.vrsave = 0; 503 current->thread.transact_vrsave = 0; 504 } 505 if (cpu_has_feature(CPU_FTR_ALTIVEC)) 506 mtspr(SPRN_VRSAVE, current->thread.vrsave); 507 #endif /* CONFIG_ALTIVEC */ 508 /* restore floating point */ 509 err |= copy_fpr_from_user(current, &sc->fp_regs); 510 err |= copy_transact_fpr_from_user(current, &tm_sc->fp_regs); 511 #ifdef CONFIG_VSX 512 /* 513 * Get additional VSX data. Update v_regs to point after the 514 * VMX data. Copy VSX low doubleword from userspace to local 515 * buffer for formatting, then into the taskstruct. 516 */ 517 if (v_regs && ((msr & MSR_VSX) != 0)) { 518 v_regs += ELF_NVRREG; 519 tm_v_regs += ELF_NVRREG; 520 err |= copy_vsx_from_user(current, v_regs); 521 err |= copy_transact_vsx_from_user(current, tm_v_regs); 522 } else { 523 for (i = 0; i < 32 ; i++) { 524 current->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0; 525 current->thread.transact_fp.fpr[i][TS_VSRLOWOFFSET] = 0; 526 } 527 } 528 #endif 529 tm_enable(); 530 /* This loads the checkpointed FP/VEC state, if used */ 531 tm_recheckpoint(¤t->thread, msr); 532 533 /* This loads the speculative FP/VEC state, if used */ 534 if (msr & MSR_FP) { 535 do_load_up_transact_fpu(¤t->thread); 536 regs->msr |= (MSR_FP | current->thread.fpexc_mode); 537 } 538 #ifdef CONFIG_ALTIVEC 539 if (msr & MSR_VEC) { 540 do_load_up_transact_altivec(¤t->thread); 541 regs->msr |= MSR_VEC; 542 } 543 #endif 544 545 return err; 546 } 547 #endif 548 549 /* 550 * Setup the trampoline code on the stack 551 */ 552 static long setup_trampoline(unsigned int syscall, unsigned int __user *tramp) 553 { 554 int i; 555 long err = 0; 556 557 /* addi r1, r1, __SIGNAL_FRAMESIZE # Pop the dummy stackframe */ 558 err |= __put_user(0x38210000UL | (__SIGNAL_FRAMESIZE & 0xffff), &tramp[0]); 559 /* li r0, __NR_[rt_]sigreturn| */ 560 err |= __put_user(0x38000000UL | (syscall & 0xffff), &tramp[1]); 561 /* sc */ 562 err |= __put_user(0x44000002UL, &tramp[2]); 563 564 /* Minimal traceback info */ 565 for (i=TRAMP_TRACEBACK; i < TRAMP_SIZE ;i++) 566 err |= __put_user(0, &tramp[i]); 567 568 if (!err) 569 flush_icache_range((unsigned long) &tramp[0], 570 (unsigned long) &tramp[TRAMP_SIZE]); 571 572 return err; 573 } 574 575 /* 576 * Userspace code may pass a ucontext which doesn't include VSX added 577 * at the end. We need to check for this case. 578 */ 579 #define UCONTEXTSIZEWITHOUTVSX \ 580 (sizeof(struct ucontext) - 32*sizeof(long)) 581 582 /* 583 * Handle {get,set,swap}_context operations 584 */ 585 int sys_swapcontext(struct ucontext __user *old_ctx, 586 struct ucontext __user *new_ctx, 587 long ctx_size, long r6, long r7, long r8, struct pt_regs *regs) 588 { 589 unsigned char tmp; 590 sigset_t set; 591 unsigned long new_msr = 0; 592 int ctx_has_vsx_region = 0; 593 594 if (new_ctx && 595 get_user(new_msr, &new_ctx->uc_mcontext.gp_regs[PT_MSR])) 596 return -EFAULT; 597 /* 598 * Check that the context is not smaller than the original 599 * size (with VMX but without VSX) 600 */ 601 if (ctx_size < UCONTEXTSIZEWITHOUTVSX) 602 return -EINVAL; 603 /* 604 * If the new context state sets the MSR VSX bits but 605 * it doesn't provide VSX state. 606 */ 607 if ((ctx_size < sizeof(struct ucontext)) && 608 (new_msr & MSR_VSX)) 609 return -EINVAL; 610 /* Does the context have enough room to store VSX data? */ 611 if (ctx_size >= sizeof(struct ucontext)) 612 ctx_has_vsx_region = 1; 613 614 if (old_ctx != NULL) { 615 if (!access_ok(VERIFY_WRITE, old_ctx, ctx_size) 616 || setup_sigcontext(&old_ctx->uc_mcontext, regs, 0, NULL, 0, 617 ctx_has_vsx_region) 618 || __copy_to_user(&old_ctx->uc_sigmask, 619 ¤t->blocked, sizeof(sigset_t))) 620 return -EFAULT; 621 } 622 if (new_ctx == NULL) 623 return 0; 624 if (!access_ok(VERIFY_READ, new_ctx, ctx_size) 625 || __get_user(tmp, (u8 __user *) new_ctx) 626 || __get_user(tmp, (u8 __user *) new_ctx + ctx_size - 1)) 627 return -EFAULT; 628 629 /* 630 * If we get a fault copying the context into the kernel's 631 * image of the user's registers, we can't just return -EFAULT 632 * because the user's registers will be corrupted. For instance 633 * the NIP value may have been updated but not some of the 634 * other registers. Given that we have done the access_ok 635 * and successfully read the first and last bytes of the region 636 * above, this should only happen in an out-of-memory situation 637 * or if another thread unmaps the region containing the context. 638 * We kill the task with a SIGSEGV in this situation. 639 */ 640 641 if (__copy_from_user(&set, &new_ctx->uc_sigmask, sizeof(set))) 642 do_exit(SIGSEGV); 643 set_current_blocked(&set); 644 if (restore_sigcontext(regs, NULL, 0, &new_ctx->uc_mcontext)) 645 do_exit(SIGSEGV); 646 647 /* This returns like rt_sigreturn */ 648 set_thread_flag(TIF_RESTOREALL); 649 return 0; 650 } 651 652 653 /* 654 * Do a signal return; undo the signal stack. 655 */ 656 657 int sys_rt_sigreturn(unsigned long r3, unsigned long r4, unsigned long r5, 658 unsigned long r6, unsigned long r7, unsigned long r8, 659 struct pt_regs *regs) 660 { 661 struct ucontext __user *uc = (struct ucontext __user *)regs->gpr[1]; 662 sigset_t set; 663 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 664 unsigned long msr; 665 #endif 666 667 /* Always make any pending restarted system calls return -EINTR */ 668 current_thread_info()->restart_block.fn = do_no_restart_syscall; 669 670 if (!access_ok(VERIFY_READ, uc, sizeof(*uc))) 671 goto badframe; 672 673 if (__copy_from_user(&set, &uc->uc_sigmask, sizeof(set))) 674 goto badframe; 675 set_current_blocked(&set); 676 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 677 if (__get_user(msr, &uc->uc_mcontext.gp_regs[PT_MSR])) 678 goto badframe; 679 if (MSR_TM_ACTIVE(msr)) { 680 /* We recheckpoint on return. */ 681 struct ucontext __user *uc_transact; 682 if (__get_user(uc_transact, &uc->uc_link)) 683 goto badframe; 684 if (restore_tm_sigcontexts(regs, &uc->uc_mcontext, 685 &uc_transact->uc_mcontext)) 686 goto badframe; 687 } 688 else 689 /* Fall through, for non-TM restore */ 690 #endif 691 if (restore_sigcontext(regs, NULL, 1, &uc->uc_mcontext)) 692 goto badframe; 693 694 if (restore_altstack(&uc->uc_stack)) 695 goto badframe; 696 697 set_thread_flag(TIF_RESTOREALL); 698 return 0; 699 700 badframe: 701 #if DEBUG_SIG 702 printk("badframe in sys_rt_sigreturn, regs=%p uc=%p &uc->uc_mcontext=%p\n", 703 regs, uc, &uc->uc_mcontext); 704 #endif 705 if (show_unhandled_signals) 706 printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32, 707 current->comm, current->pid, "rt_sigreturn", 708 (long)uc, regs->nip, regs->link); 709 710 force_sig(SIGSEGV, current); 711 return 0; 712 } 713 714 int handle_rt_signal64(int signr, struct k_sigaction *ka, siginfo_t *info, 715 sigset_t *set, struct pt_regs *regs) 716 { 717 struct rt_sigframe __user *frame; 718 unsigned long newsp = 0; 719 long err = 0; 720 721 frame = get_sigframe(ka, get_tm_stackpointer(regs), sizeof(*frame), 0); 722 if (unlikely(frame == NULL)) 723 goto badframe; 724 725 err |= __put_user(&frame->info, &frame->pinfo); 726 err |= __put_user(&frame->uc, &frame->puc); 727 err |= copy_siginfo_to_user(&frame->info, info); 728 if (err) 729 goto badframe; 730 731 /* Create the ucontext. */ 732 err |= __put_user(0, &frame->uc.uc_flags); 733 err |= __save_altstack(&frame->uc.uc_stack, regs->gpr[1]); 734 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 735 if (MSR_TM_ACTIVE(regs->msr)) { 736 /* The ucontext_t passed to userland points to the second 737 * ucontext_t (for transactional state) with its uc_link ptr. 738 */ 739 err |= __put_user(&frame->uc_transact, &frame->uc.uc_link); 740 err |= setup_tm_sigcontexts(&frame->uc.uc_mcontext, 741 &frame->uc_transact.uc_mcontext, 742 regs, signr, 743 NULL, 744 (unsigned long)ka->sa.sa_handler); 745 } else 746 #endif 747 { 748 err |= __put_user(0, &frame->uc.uc_link); 749 err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, signr, 750 NULL, (unsigned long)ka->sa.sa_handler, 751 1); 752 } 753 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); 754 if (err) 755 goto badframe; 756 757 /* Make sure signal handler doesn't get spurious FP exceptions */ 758 current->thread.fp_state.fpscr = 0; 759 760 /* Set up to return from userspace. */ 761 if (vdso64_rt_sigtramp && current->mm->context.vdso_base) { 762 regs->link = current->mm->context.vdso_base + vdso64_rt_sigtramp; 763 } else { 764 err |= setup_trampoline(__NR_rt_sigreturn, &frame->tramp[0]); 765 if (err) 766 goto badframe; 767 regs->link = (unsigned long) &frame->tramp[0]; 768 } 769 770 /* Allocate a dummy caller frame for the signal handler. */ 771 newsp = ((unsigned long)frame) - __SIGNAL_FRAMESIZE; 772 err |= put_user(regs->gpr[1], (unsigned long __user *)newsp); 773 774 /* Set up "regs" so we "return" to the signal handler. */ 775 if (is_elf2_task()) { 776 regs->nip = (unsigned long) ka->sa.sa_handler; 777 regs->gpr[12] = regs->nip; 778 } else { 779 /* Handler is *really* a pointer to the function descriptor for 780 * the signal routine. The first entry in the function 781 * descriptor is the entry address of signal and the second 782 * entry is the TOC value we need to use. 783 */ 784 func_descr_t __user *funct_desc_ptr = 785 (func_descr_t __user *) ka->sa.sa_handler; 786 787 err |= get_user(regs->nip, &funct_desc_ptr->entry); 788 err |= get_user(regs->gpr[2], &funct_desc_ptr->toc); 789 } 790 791 /* enter the signal handler in native-endian mode */ 792 regs->msr &= ~MSR_LE; 793 regs->msr |= (MSR_KERNEL & MSR_LE); 794 regs->gpr[1] = newsp; 795 regs->gpr[3] = signr; 796 regs->result = 0; 797 if (ka->sa.sa_flags & SA_SIGINFO) { 798 err |= get_user(regs->gpr[4], (unsigned long __user *)&frame->pinfo); 799 err |= get_user(regs->gpr[5], (unsigned long __user *)&frame->puc); 800 regs->gpr[6] = (unsigned long) frame; 801 } else { 802 regs->gpr[4] = (unsigned long)&frame->uc.uc_mcontext; 803 } 804 if (err) 805 goto badframe; 806 807 return 1; 808 809 badframe: 810 #if DEBUG_SIG 811 printk("badframe in setup_rt_frame, regs=%p frame=%p newsp=%lx\n", 812 regs, frame, newsp); 813 #endif 814 if (show_unhandled_signals) 815 printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32, 816 current->comm, current->pid, "setup_rt_frame", 817 (long)frame, regs->nip, regs->link); 818 819 force_sigsegv(signr, current); 820 return 0; 821 } 822