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