1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Signal handling for 32bit PPC and 32bit tasks on 64bit PPC 4 * 5 * PowerPC version 6 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) 7 * Copyright (C) 2001 IBM 8 * Copyright (C) 1997,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz) 9 * Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu) 10 * 11 * Derived from "arch/i386/kernel/signal.c" 12 * Copyright (C) 1991, 1992 Linus Torvalds 13 * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson 14 */ 15 16 #include <linux/sched.h> 17 #include <linux/mm.h> 18 #include <linux/smp.h> 19 #include <linux/kernel.h> 20 #include <linux/signal.h> 21 #include <linux/errno.h> 22 #include <linux/elf.h> 23 #include <linux/ptrace.h> 24 #include <linux/pagemap.h> 25 #include <linux/ratelimit.h> 26 #include <linux/syscalls.h> 27 #ifdef CONFIG_PPC64 28 #include <linux/compat.h> 29 #else 30 #include <linux/wait.h> 31 #include <linux/unistd.h> 32 #include <linux/stddef.h> 33 #include <linux/tty.h> 34 #include <linux/binfmts.h> 35 #endif 36 37 #include <linux/uaccess.h> 38 #include <asm/cacheflush.h> 39 #include <asm/syscalls.h> 40 #include <asm/sigcontext.h> 41 #include <asm/vdso.h> 42 #include <asm/switch_to.h> 43 #include <asm/tm.h> 44 #include <asm/asm-prototypes.h> 45 #ifdef CONFIG_PPC64 46 #include "ppc32.h" 47 #include <asm/unistd.h> 48 #else 49 #include <asm/ucontext.h> 50 #endif 51 52 #include "signal.h" 53 54 55 #ifdef CONFIG_PPC64 56 #define old_sigaction old_sigaction32 57 #define sigcontext sigcontext32 58 #define mcontext mcontext32 59 #define ucontext ucontext32 60 61 /* 62 * Userspace code may pass a ucontext which doesn't include VSX added 63 * at the end. We need to check for this case. 64 */ 65 #define UCONTEXTSIZEWITHOUTVSX \ 66 (sizeof(struct ucontext) - sizeof(elf_vsrreghalf_t32)) 67 68 /* 69 * Returning 0 means we return to userspace via 70 * ret_from_except and thus restore all user 71 * registers from *regs. This is what we need 72 * to do when a signal has been delivered. 73 */ 74 75 #define GP_REGS_SIZE min(sizeof(elf_gregset_t32), sizeof(struct pt_regs32)) 76 #undef __SIGNAL_FRAMESIZE 77 #define __SIGNAL_FRAMESIZE __SIGNAL_FRAMESIZE32 78 #undef ELF_NVRREG 79 #define ELF_NVRREG ELF_NVRREG32 80 81 /* 82 * Functions for flipping sigsets (thanks to brain dead generic 83 * implementation that makes things simple for little endian only) 84 */ 85 #define unsafe_put_sigset_t unsafe_put_compat_sigset 86 87 static inline int get_sigset_t(sigset_t *set, 88 const compat_sigset_t __user *uset) 89 { 90 return get_compat_sigset(set, uset); 91 } 92 93 #define to_user_ptr(p) ptr_to_compat(p) 94 #define from_user_ptr(p) compat_ptr(p) 95 96 static __always_inline int 97 save_general_regs_unsafe(struct pt_regs *regs, struct mcontext __user *frame) 98 { 99 elf_greg_t64 *gregs = (elf_greg_t64 *)regs; 100 int val, i; 101 102 WARN_ON(!FULL_REGS(regs)); 103 104 for (i = 0; i <= PT_RESULT; i ++) { 105 /* Force usr to alway see softe as 1 (interrupts enabled) */ 106 if (i == PT_SOFTE) 107 val = 1; 108 else 109 val = gregs[i]; 110 111 unsafe_put_user(val, &frame->mc_gregs[i], failed); 112 } 113 return 0; 114 115 failed: 116 return 1; 117 } 118 119 static inline int restore_general_regs(struct pt_regs *regs, 120 struct mcontext __user *sr) 121 { 122 elf_greg_t64 *gregs = (elf_greg_t64 *)regs; 123 int i; 124 125 for (i = 0; i <= PT_RESULT; i++) { 126 if ((i == PT_MSR) || (i == PT_SOFTE)) 127 continue; 128 if (__get_user(gregs[i], &sr->mc_gregs[i])) 129 return -EFAULT; 130 } 131 return 0; 132 } 133 134 #else /* CONFIG_PPC64 */ 135 136 #define GP_REGS_SIZE min(sizeof(elf_gregset_t), sizeof(struct pt_regs)) 137 138 #define unsafe_put_sigset_t(uset, set, label) do { \ 139 sigset_t __user *__us = uset ; \ 140 const sigset_t *__s = set; \ 141 \ 142 unsafe_copy_to_user(__us, __s, sizeof(*__us), label); \ 143 } while (0) 144 145 static inline int get_sigset_t(sigset_t *set, const sigset_t __user *uset) 146 { 147 return copy_from_user(set, uset, sizeof(*uset)); 148 } 149 150 #define to_user_ptr(p) ((unsigned long)(p)) 151 #define from_user_ptr(p) ((void __user *)(p)) 152 153 static __always_inline int 154 save_general_regs_unsafe(struct pt_regs *regs, struct mcontext __user *frame) 155 { 156 WARN_ON(!FULL_REGS(regs)); 157 unsafe_copy_to_user(&frame->mc_gregs, regs, GP_REGS_SIZE, failed); 158 return 0; 159 160 failed: 161 return 1; 162 } 163 164 static inline int restore_general_regs(struct pt_regs *regs, 165 struct mcontext __user *sr) 166 { 167 /* copy up to but not including MSR */ 168 if (__copy_from_user(regs, &sr->mc_gregs, 169 PT_MSR * sizeof(elf_greg_t))) 170 return -EFAULT; 171 /* copy from orig_r3 (the word after the MSR) up to the end */ 172 if (__copy_from_user(®s->orig_gpr3, &sr->mc_gregs[PT_ORIG_R3], 173 GP_REGS_SIZE - PT_ORIG_R3 * sizeof(elf_greg_t))) 174 return -EFAULT; 175 return 0; 176 } 177 #endif 178 179 #define unsafe_save_general_regs(regs, frame, label) do { \ 180 if (save_general_regs_unsafe(regs, frame)) \ 181 goto label; \ 182 } while (0) 183 184 /* 185 * When we have signals to deliver, we set up on the 186 * user stack, going down from the original stack pointer: 187 * an ABI gap of 56 words 188 * an mcontext struct 189 * a sigcontext struct 190 * a gap of __SIGNAL_FRAMESIZE bytes 191 * 192 * Each of these things must be a multiple of 16 bytes in size. The following 193 * structure represent all of this except the __SIGNAL_FRAMESIZE gap 194 * 195 */ 196 struct sigframe { 197 struct sigcontext sctx; /* the sigcontext */ 198 struct mcontext mctx; /* all the register values */ 199 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 200 struct sigcontext sctx_transact; 201 struct mcontext mctx_transact; 202 #endif 203 /* 204 * Programs using the rs6000/xcoff abi can save up to 19 gp 205 * regs and 18 fp regs below sp before decrementing it. 206 */ 207 int abigap[56]; 208 }; 209 210 /* 211 * When we have rt signals to deliver, we set up on the 212 * user stack, going down from the original stack pointer: 213 * one rt_sigframe struct (siginfo + ucontext + ABI gap) 214 * a gap of __SIGNAL_FRAMESIZE+16 bytes 215 * (the +16 is to get the siginfo and ucontext in the same 216 * positions as in older kernels). 217 * 218 * Each of these things must be a multiple of 16 bytes in size. 219 * 220 */ 221 struct rt_sigframe { 222 #ifdef CONFIG_PPC64 223 compat_siginfo_t info; 224 #else 225 struct siginfo info; 226 #endif 227 struct ucontext uc; 228 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 229 struct ucontext uc_transact; 230 #endif 231 /* 232 * Programs using the rs6000/xcoff abi can save up to 19 gp 233 * regs and 18 fp regs below sp before decrementing it. 234 */ 235 int abigap[56]; 236 }; 237 238 /* 239 * Save the current user registers on the user stack. 240 * We only save the altivec/spe registers if the process has used 241 * altivec/spe instructions at some point. 242 */ 243 static void prepare_save_user_regs(int ctx_has_vsx_region) 244 { 245 /* Make sure floating point registers are stored in regs */ 246 flush_fp_to_thread(current); 247 #ifdef CONFIG_ALTIVEC 248 if (current->thread.used_vr) 249 flush_altivec_to_thread(current); 250 if (cpu_has_feature(CPU_FTR_ALTIVEC)) 251 current->thread.vrsave = mfspr(SPRN_VRSAVE); 252 #endif 253 #ifdef CONFIG_VSX 254 if (current->thread.used_vsr && ctx_has_vsx_region) 255 flush_vsx_to_thread(current); 256 #endif 257 #ifdef CONFIG_SPE 258 if (current->thread.used_spe) 259 flush_spe_to_thread(current); 260 #endif 261 } 262 263 static int save_user_regs_unsafe(struct pt_regs *regs, struct mcontext __user *frame, 264 struct mcontext __user *tm_frame, int ctx_has_vsx_region) 265 { 266 unsigned long msr = regs->msr; 267 268 /* save general registers */ 269 unsafe_save_general_regs(regs, frame, failed); 270 271 #ifdef CONFIG_ALTIVEC 272 /* save altivec registers */ 273 if (current->thread.used_vr) { 274 unsafe_copy_to_user(&frame->mc_vregs, ¤t->thread.vr_state, 275 ELF_NVRREG * sizeof(vector128), failed); 276 /* set MSR_VEC in the saved MSR value to indicate that 277 frame->mc_vregs contains valid data */ 278 msr |= MSR_VEC; 279 } 280 /* else assert((regs->msr & MSR_VEC) == 0) */ 281 282 /* We always copy to/from vrsave, it's 0 if we don't have or don't 283 * use altivec. Since VSCR only contains 32 bits saved in the least 284 * significant bits of a vector, we "cheat" and stuff VRSAVE in the 285 * most significant bits of that same vector. --BenH 286 * Note that the current VRSAVE value is in the SPR at this point. 287 */ 288 unsafe_put_user(current->thread.vrsave, (u32 __user *)&frame->mc_vregs[32], 289 failed); 290 #endif /* CONFIG_ALTIVEC */ 291 unsafe_copy_fpr_to_user(&frame->mc_fregs, current, failed); 292 293 /* 294 * Clear the MSR VSX bit to indicate there is no valid state attached 295 * to this context, except in the specific case below where we set it. 296 */ 297 msr &= ~MSR_VSX; 298 #ifdef CONFIG_VSX 299 /* 300 * Copy VSR 0-31 upper half from thread_struct to local 301 * buffer, then write that to userspace. Also set MSR_VSX in 302 * the saved MSR value to indicate that frame->mc_vregs 303 * contains valid data 304 */ 305 if (current->thread.used_vsr && ctx_has_vsx_region) { 306 unsafe_copy_vsx_to_user(&frame->mc_vsregs, current, failed); 307 msr |= MSR_VSX; 308 } 309 #endif /* CONFIG_VSX */ 310 #ifdef CONFIG_SPE 311 /* save spe registers */ 312 if (current->thread.used_spe) { 313 unsafe_copy_to_user(&frame->mc_vregs, current->thread.evr, 314 ELF_NEVRREG * sizeof(u32), failed); 315 /* set MSR_SPE in the saved MSR value to indicate that 316 frame->mc_vregs contains valid data */ 317 msr |= MSR_SPE; 318 } 319 /* else assert((regs->msr & MSR_SPE) == 0) */ 320 321 /* We always copy to/from spefscr */ 322 unsafe_put_user(current->thread.spefscr, 323 (u32 __user *)&frame->mc_vregs + ELF_NEVRREG, failed); 324 #endif /* CONFIG_SPE */ 325 326 unsafe_put_user(msr, &frame->mc_gregs[PT_MSR], failed); 327 328 /* We need to write 0 the MSR top 32 bits in the tm frame so that we 329 * can check it on the restore to see if TM is active 330 */ 331 if (tm_frame) 332 unsafe_put_user(0, &tm_frame->mc_gregs[PT_MSR], failed); 333 334 return 0; 335 336 failed: 337 return 1; 338 } 339 340 #define unsafe_save_user_regs(regs, frame, tm_frame, has_vsx, label) do { \ 341 if (save_user_regs_unsafe(regs, frame, tm_frame, has_vsx)) \ 342 goto label; \ 343 } while (0) 344 345 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 346 /* 347 * Save the current user registers on the user stack. 348 * We only save the altivec/spe registers if the process has used 349 * altivec/spe instructions at some point. 350 * We also save the transactional registers to a second ucontext in the 351 * frame. 352 * 353 * See save_user_regs_unsafe() and signal_64.c:setup_tm_sigcontexts(). 354 */ 355 static void prepare_save_tm_user_regs(void) 356 { 357 WARN_ON(tm_suspend_disabled); 358 359 #ifdef CONFIG_ALTIVEC 360 if (cpu_has_feature(CPU_FTR_ALTIVEC)) 361 current->thread.ckvrsave = mfspr(SPRN_VRSAVE); 362 #endif 363 #ifdef CONFIG_SPE 364 if (current->thread.used_spe) 365 flush_spe_to_thread(current); 366 #endif 367 } 368 369 static int save_tm_user_regs_unsafe(struct pt_regs *regs, struct mcontext __user *frame, 370 struct mcontext __user *tm_frame, unsigned long msr) 371 { 372 /* Save both sets of general registers */ 373 unsafe_save_general_regs(¤t->thread.ckpt_regs, frame, failed); 374 unsafe_save_general_regs(regs, tm_frame, failed); 375 376 /* Stash the top half of the 64bit MSR into the 32bit MSR word 377 * of the transactional mcontext. This way we have a backward-compatible 378 * MSR in the 'normal' (checkpointed) mcontext and additionally one can 379 * also look at what type of transaction (T or S) was active at the 380 * time of the signal. 381 */ 382 unsafe_put_user((msr >> 32), &tm_frame->mc_gregs[PT_MSR], failed); 383 384 #ifdef CONFIG_ALTIVEC 385 /* save altivec registers */ 386 if (current->thread.used_vr) { 387 unsafe_copy_to_user(&frame->mc_vregs, ¤t->thread.ckvr_state, 388 ELF_NVRREG * sizeof(vector128), failed); 389 if (msr & MSR_VEC) 390 unsafe_copy_to_user(&tm_frame->mc_vregs, 391 ¤t->thread.vr_state, 392 ELF_NVRREG * sizeof(vector128), failed); 393 else 394 unsafe_copy_to_user(&tm_frame->mc_vregs, 395 ¤t->thread.ckvr_state, 396 ELF_NVRREG * sizeof(vector128), failed); 397 398 /* set MSR_VEC in the saved MSR value to indicate that 399 * frame->mc_vregs contains valid data 400 */ 401 msr |= MSR_VEC; 402 } 403 404 /* We always copy to/from vrsave, it's 0 if we don't have or don't 405 * use altivec. Since VSCR only contains 32 bits saved in the least 406 * significant bits of a vector, we "cheat" and stuff VRSAVE in the 407 * most significant bits of that same vector. --BenH 408 */ 409 unsafe_put_user(current->thread.ckvrsave, 410 (u32 __user *)&frame->mc_vregs[32], failed); 411 if (msr & MSR_VEC) 412 unsafe_put_user(current->thread.vrsave, 413 (u32 __user *)&tm_frame->mc_vregs[32], failed); 414 else 415 unsafe_put_user(current->thread.ckvrsave, 416 (u32 __user *)&tm_frame->mc_vregs[32], failed); 417 #endif /* CONFIG_ALTIVEC */ 418 419 unsafe_copy_ckfpr_to_user(&frame->mc_fregs, current, failed); 420 if (msr & MSR_FP) 421 unsafe_copy_fpr_to_user(&tm_frame->mc_fregs, current, failed); 422 else 423 unsafe_copy_ckfpr_to_user(&tm_frame->mc_fregs, current, failed); 424 425 #ifdef CONFIG_VSX 426 /* 427 * Copy VSR 0-31 upper half from thread_struct to local 428 * buffer, then write that to userspace. Also set MSR_VSX in 429 * the saved MSR value to indicate that frame->mc_vregs 430 * contains valid data 431 */ 432 if (current->thread.used_vsr) { 433 unsafe_copy_ckvsx_to_user(&frame->mc_vsregs, current, failed); 434 if (msr & MSR_VSX) 435 unsafe_copy_vsx_to_user(&tm_frame->mc_vsregs, current, failed); 436 else 437 unsafe_copy_ckvsx_to_user(&tm_frame->mc_vsregs, current, failed); 438 439 msr |= MSR_VSX; 440 } 441 #endif /* CONFIG_VSX */ 442 #ifdef CONFIG_SPE 443 /* SPE regs are not checkpointed with TM, so this section is 444 * simply the same as in save_user_regs_unsafe(). 445 */ 446 if (current->thread.used_spe) { 447 unsafe_copy_to_user(&frame->mc_vregs, current->thread.evr, 448 ELF_NEVRREG * sizeof(u32), failed); 449 /* set MSR_SPE in the saved MSR value to indicate that 450 * frame->mc_vregs contains valid data */ 451 msr |= MSR_SPE; 452 } 453 454 /* We always copy to/from spefscr */ 455 unsafe_put_user(current->thread.spefscr, 456 (u32 __user *)&frame->mc_vregs + ELF_NEVRREG, failed); 457 #endif /* CONFIG_SPE */ 458 459 unsafe_put_user(msr, &frame->mc_gregs[PT_MSR], failed); 460 461 return 0; 462 463 failed: 464 return 1; 465 } 466 #else 467 static void prepare_save_tm_user_regs(void) { } 468 469 static int save_tm_user_regs_unsafe(struct pt_regs *regs, struct mcontext __user *frame, 470 struct mcontext __user *tm_frame, unsigned long msr) 471 { 472 return 0; 473 } 474 #endif 475 476 #define unsafe_save_tm_user_regs(regs, frame, tm_frame, msr, label) do { \ 477 if (save_tm_user_regs_unsafe(regs, frame, tm_frame, msr)) \ 478 goto label; \ 479 } while (0) 480 481 /* 482 * Restore the current user register values from the user stack, 483 * (except for MSR). 484 */ 485 static long restore_user_regs(struct pt_regs *regs, 486 struct mcontext __user *sr, int sig) 487 { 488 long err; 489 unsigned int save_r2 = 0; 490 unsigned long msr; 491 #ifdef CONFIG_VSX 492 int i; 493 #endif 494 495 /* 496 * restore general registers but not including MSR or SOFTE. Also 497 * take care of keeping r2 (TLS) intact if not a signal 498 */ 499 if (!sig) 500 save_r2 = (unsigned int)regs->gpr[2]; 501 err = restore_general_regs(regs, sr); 502 set_trap_norestart(regs); 503 err |= __get_user(msr, &sr->mc_gregs[PT_MSR]); 504 if (!sig) 505 regs->gpr[2] = (unsigned long) save_r2; 506 if (err) 507 return 1; 508 509 /* if doing signal return, restore the previous little-endian mode */ 510 if (sig) 511 regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE); 512 513 #ifdef CONFIG_ALTIVEC 514 /* 515 * Force the process to reload the altivec registers from 516 * current->thread when it next does altivec instructions 517 */ 518 regs->msr &= ~MSR_VEC; 519 if (msr & MSR_VEC) { 520 /* restore altivec registers from the stack */ 521 if (__copy_from_user(¤t->thread.vr_state, &sr->mc_vregs, 522 sizeof(sr->mc_vregs))) 523 return 1; 524 current->thread.used_vr = true; 525 } else if (current->thread.used_vr) 526 memset(¤t->thread.vr_state, 0, 527 ELF_NVRREG * sizeof(vector128)); 528 529 /* Always get VRSAVE back */ 530 if (__get_user(current->thread.vrsave, (u32 __user *)&sr->mc_vregs[32])) 531 return 1; 532 if (cpu_has_feature(CPU_FTR_ALTIVEC)) 533 mtspr(SPRN_VRSAVE, current->thread.vrsave); 534 #endif /* CONFIG_ALTIVEC */ 535 if (copy_fpr_from_user(current, &sr->mc_fregs)) 536 return 1; 537 538 #ifdef CONFIG_VSX 539 /* 540 * Force the process to reload the VSX registers from 541 * current->thread when it next does VSX instruction. 542 */ 543 regs->msr &= ~MSR_VSX; 544 if (msr & MSR_VSX) { 545 /* 546 * Restore altivec registers from the stack to a local 547 * buffer, then write this out to the thread_struct 548 */ 549 if (copy_vsx_from_user(current, &sr->mc_vsregs)) 550 return 1; 551 current->thread.used_vsr = true; 552 } else if (current->thread.used_vsr) 553 for (i = 0; i < 32 ; i++) 554 current->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0; 555 #endif /* CONFIG_VSX */ 556 /* 557 * force the process to reload the FP registers from 558 * current->thread when it next does FP instructions 559 */ 560 regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1); 561 562 #ifdef CONFIG_SPE 563 /* force the process to reload the spe registers from 564 current->thread when it next does spe instructions */ 565 regs->msr &= ~MSR_SPE; 566 if (msr & MSR_SPE) { 567 /* restore spe registers from the stack */ 568 if (__copy_from_user(current->thread.evr, &sr->mc_vregs, 569 ELF_NEVRREG * sizeof(u32))) 570 return 1; 571 current->thread.used_spe = true; 572 } else if (current->thread.used_spe) 573 memset(current->thread.evr, 0, ELF_NEVRREG * sizeof(u32)); 574 575 /* Always get SPEFSCR back */ 576 if (__get_user(current->thread.spefscr, (u32 __user *)&sr->mc_vregs + ELF_NEVRREG)) 577 return 1; 578 #endif /* CONFIG_SPE */ 579 580 return 0; 581 } 582 583 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 584 /* 585 * Restore the current user register values from the user stack, except for 586 * MSR, and recheckpoint the original checkpointed register state for processes 587 * in transactions. 588 */ 589 static long restore_tm_user_regs(struct pt_regs *regs, 590 struct mcontext __user *sr, 591 struct mcontext __user *tm_sr) 592 { 593 long err; 594 unsigned long msr, msr_hi; 595 #ifdef CONFIG_VSX 596 int i; 597 #endif 598 599 if (tm_suspend_disabled) 600 return 1; 601 /* 602 * restore general registers but not including MSR or SOFTE. Also 603 * take care of keeping r2 (TLS) intact if not a signal. 604 * See comment in signal_64.c:restore_tm_sigcontexts(); 605 * TFHAR is restored from the checkpointed NIP; TEXASR and TFIAR 606 * were set by the signal delivery. 607 */ 608 err = restore_general_regs(regs, tm_sr); 609 err |= restore_general_regs(¤t->thread.ckpt_regs, sr); 610 611 err |= __get_user(current->thread.tm_tfhar, &sr->mc_gregs[PT_NIP]); 612 613 err |= __get_user(msr, &sr->mc_gregs[PT_MSR]); 614 if (err) 615 return 1; 616 617 /* Restore the previous little-endian mode */ 618 regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE); 619 620 #ifdef CONFIG_ALTIVEC 621 regs->msr &= ~MSR_VEC; 622 if (msr & MSR_VEC) { 623 /* restore altivec registers from the stack */ 624 if (__copy_from_user(¤t->thread.ckvr_state, &sr->mc_vregs, 625 sizeof(sr->mc_vregs)) || 626 __copy_from_user(¤t->thread.vr_state, 627 &tm_sr->mc_vregs, 628 sizeof(sr->mc_vregs))) 629 return 1; 630 current->thread.used_vr = true; 631 } else if (current->thread.used_vr) { 632 memset(¤t->thread.vr_state, 0, 633 ELF_NVRREG * sizeof(vector128)); 634 memset(¤t->thread.ckvr_state, 0, 635 ELF_NVRREG * sizeof(vector128)); 636 } 637 638 /* Always get VRSAVE back */ 639 if (__get_user(current->thread.ckvrsave, 640 (u32 __user *)&sr->mc_vregs[32]) || 641 __get_user(current->thread.vrsave, 642 (u32 __user *)&tm_sr->mc_vregs[32])) 643 return 1; 644 if (cpu_has_feature(CPU_FTR_ALTIVEC)) 645 mtspr(SPRN_VRSAVE, current->thread.ckvrsave); 646 #endif /* CONFIG_ALTIVEC */ 647 648 regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1); 649 650 if (copy_fpr_from_user(current, &sr->mc_fregs) || 651 copy_ckfpr_from_user(current, &tm_sr->mc_fregs)) 652 return 1; 653 654 #ifdef CONFIG_VSX 655 regs->msr &= ~MSR_VSX; 656 if (msr & MSR_VSX) { 657 /* 658 * Restore altivec registers from the stack to a local 659 * buffer, then write this out to the thread_struct 660 */ 661 if (copy_vsx_from_user(current, &tm_sr->mc_vsregs) || 662 copy_ckvsx_from_user(current, &sr->mc_vsregs)) 663 return 1; 664 current->thread.used_vsr = true; 665 } else if (current->thread.used_vsr) 666 for (i = 0; i < 32 ; i++) { 667 current->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0; 668 current->thread.ckfp_state.fpr[i][TS_VSRLOWOFFSET] = 0; 669 } 670 #endif /* CONFIG_VSX */ 671 672 #ifdef CONFIG_SPE 673 /* SPE regs are not checkpointed with TM, so this section is 674 * simply the same as in restore_user_regs(). 675 */ 676 regs->msr &= ~MSR_SPE; 677 if (msr & MSR_SPE) { 678 if (__copy_from_user(current->thread.evr, &sr->mc_vregs, 679 ELF_NEVRREG * sizeof(u32))) 680 return 1; 681 current->thread.used_spe = true; 682 } else if (current->thread.used_spe) 683 memset(current->thread.evr, 0, ELF_NEVRREG * sizeof(u32)); 684 685 /* Always get SPEFSCR back */ 686 if (__get_user(current->thread.spefscr, (u32 __user *)&sr->mc_vregs 687 + ELF_NEVRREG)) 688 return 1; 689 #endif /* CONFIG_SPE */ 690 691 /* Get the top half of the MSR from the user context */ 692 if (__get_user(msr_hi, &tm_sr->mc_gregs[PT_MSR])) 693 return 1; 694 msr_hi <<= 32; 695 /* If TM bits are set to the reserved value, it's an invalid context */ 696 if (MSR_TM_RESV(msr_hi)) 697 return 1; 698 699 /* 700 * Disabling preemption, since it is unsafe to be preempted 701 * with MSR[TS] set without recheckpointing. 702 */ 703 preempt_disable(); 704 705 /* 706 * CAUTION: 707 * After regs->MSR[TS] being updated, make sure that get_user(), 708 * put_user() or similar functions are *not* called. These 709 * functions can generate page faults which will cause the process 710 * to be de-scheduled with MSR[TS] set but without calling 711 * tm_recheckpoint(). This can cause a bug. 712 * 713 * Pull in the MSR TM bits from the user context 714 */ 715 regs->msr = (regs->msr & ~MSR_TS_MASK) | (msr_hi & MSR_TS_MASK); 716 /* Now, recheckpoint. This loads up all of the checkpointed (older) 717 * registers, including FP and V[S]Rs. After recheckpointing, the 718 * transactional versions should be loaded. 719 */ 720 tm_enable(); 721 /* Make sure the transaction is marked as failed */ 722 current->thread.tm_texasr |= TEXASR_FS; 723 /* This loads the checkpointed FP/VEC state, if used */ 724 tm_recheckpoint(¤t->thread); 725 726 /* This loads the speculative FP/VEC state, if used */ 727 msr_check_and_set(msr & (MSR_FP | MSR_VEC)); 728 if (msr & MSR_FP) { 729 load_fp_state(¤t->thread.fp_state); 730 regs->msr |= (MSR_FP | current->thread.fpexc_mode); 731 } 732 #ifdef CONFIG_ALTIVEC 733 if (msr & MSR_VEC) { 734 load_vr_state(¤t->thread.vr_state); 735 regs->msr |= MSR_VEC; 736 } 737 #endif 738 739 preempt_enable(); 740 741 return 0; 742 } 743 #endif 744 745 #ifdef CONFIG_PPC64 746 747 #define copy_siginfo_to_user copy_siginfo_to_user32 748 749 #endif /* CONFIG_PPC64 */ 750 751 /* 752 * Set up a signal frame for a "real-time" signal handler 753 * (one which gets siginfo). 754 */ 755 int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset, 756 struct task_struct *tsk) 757 { 758 struct rt_sigframe __user *frame; 759 struct mcontext __user *mctx; 760 struct mcontext __user *tm_mctx = NULL; 761 unsigned long newsp = 0; 762 unsigned long tramp; 763 struct pt_regs *regs = tsk->thread.regs; 764 /* Save the thread's msr before get_tm_stackpointer() changes it */ 765 unsigned long msr = regs->msr; 766 767 /* Set up Signal Frame */ 768 frame = get_sigframe(ksig, tsk, sizeof(*frame), 1); 769 mctx = &frame->uc.uc_mcontext; 770 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 771 tm_mctx = &frame->uc_transact.uc_mcontext; 772 #endif 773 if (MSR_TM_ACTIVE(msr)) 774 prepare_save_tm_user_regs(); 775 else 776 prepare_save_user_regs(1); 777 778 if (!user_access_begin(frame, sizeof(*frame))) 779 goto badframe; 780 781 /* Put the siginfo & fill in most of the ucontext */ 782 unsafe_put_user(0, &frame->uc.uc_flags, failed); 783 #ifdef CONFIG_PPC64 784 unsafe_compat_save_altstack(&frame->uc.uc_stack, regs->gpr[1], failed); 785 #else 786 unsafe_save_altstack(&frame->uc.uc_stack, regs->gpr[1], failed); 787 #endif 788 unsafe_put_user(to_user_ptr(&frame->uc.uc_mcontext), &frame->uc.uc_regs, failed); 789 790 if (MSR_TM_ACTIVE(msr)) { 791 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 792 unsafe_put_user((unsigned long)&frame->uc_transact, 793 &frame->uc.uc_link, failed); 794 unsafe_put_user((unsigned long)tm_mctx, 795 &frame->uc_transact.uc_regs, failed); 796 #endif 797 unsafe_save_tm_user_regs(regs, mctx, tm_mctx, msr, failed); 798 } else { 799 unsafe_put_user(0, &frame->uc.uc_link, failed); 800 unsafe_save_user_regs(regs, mctx, tm_mctx, 1, failed); 801 } 802 803 /* Save user registers on the stack */ 804 if (tsk->mm->context.vdso) { 805 tramp = VDSO32_SYMBOL(tsk->mm->context.vdso, sigtramp_rt32); 806 } else { 807 tramp = (unsigned long)mctx->mc_pad; 808 /* Set up the sigreturn trampoline: li r0,sigret; sc */ 809 unsafe_put_user(PPC_INST_ADDI + __NR_rt_sigreturn, &mctx->mc_pad[0], 810 failed); 811 unsafe_put_user(PPC_INST_SC, &mctx->mc_pad[1], failed); 812 asm("dcbst %y0; sync; icbi %y0; sync" :: "Z" (mctx->mc_pad[0])); 813 } 814 unsafe_put_sigset_t(&frame->uc.uc_sigmask, oldset, failed); 815 816 user_access_end(); 817 818 if (copy_siginfo_to_user(&frame->info, &ksig->info)) 819 goto badframe; 820 821 regs->link = tramp; 822 823 #ifdef CONFIG_PPC_FPU_REGS 824 tsk->thread.fp_state.fpscr = 0; /* turn off all fp exceptions */ 825 #endif 826 827 /* create a stack frame for the caller of the handler */ 828 newsp = ((unsigned long)frame) - (__SIGNAL_FRAMESIZE + 16); 829 if (put_user(regs->gpr[1], (u32 __user *)newsp)) 830 goto badframe; 831 832 /* Fill registers for signal handler */ 833 regs->gpr[1] = newsp; 834 regs->gpr[3] = ksig->sig; 835 regs->gpr[4] = (unsigned long)&frame->info; 836 regs->gpr[5] = (unsigned long)&frame->uc; 837 regs->gpr[6] = (unsigned long)frame; 838 regs->nip = (unsigned long) ksig->ka.sa.sa_handler; 839 /* enter the signal handler in native-endian mode */ 840 regs->msr &= ~MSR_LE; 841 regs->msr |= (MSR_KERNEL & MSR_LE); 842 return 0; 843 844 failed: 845 user_access_end(); 846 847 badframe: 848 signal_fault(tsk, regs, "handle_rt_signal32", frame); 849 850 return 1; 851 } 852 853 /* 854 * OK, we're invoking a handler 855 */ 856 int handle_signal32(struct ksignal *ksig, sigset_t *oldset, 857 struct task_struct *tsk) 858 { 859 struct sigcontext __user *sc; 860 struct sigframe __user *frame; 861 struct mcontext __user *mctx; 862 struct mcontext __user *tm_mctx = NULL; 863 unsigned long newsp = 0; 864 unsigned long tramp; 865 struct pt_regs *regs = tsk->thread.regs; 866 /* Save the thread's msr before get_tm_stackpointer() changes it */ 867 unsigned long msr = regs->msr; 868 869 /* Set up Signal Frame */ 870 frame = get_sigframe(ksig, tsk, sizeof(*frame), 1); 871 mctx = &frame->mctx; 872 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 873 tm_mctx = &frame->mctx_transact; 874 #endif 875 if (MSR_TM_ACTIVE(msr)) 876 prepare_save_tm_user_regs(); 877 else 878 prepare_save_user_regs(1); 879 880 if (!user_access_begin(frame, sizeof(*frame))) 881 goto badframe; 882 sc = (struct sigcontext __user *) &frame->sctx; 883 884 #if _NSIG != 64 885 #error "Please adjust handle_signal()" 886 #endif 887 unsafe_put_user(to_user_ptr(ksig->ka.sa.sa_handler), &sc->handler, failed); 888 unsafe_put_user(oldset->sig[0], &sc->oldmask, failed); 889 #ifdef CONFIG_PPC64 890 unsafe_put_user((oldset->sig[0] >> 32), &sc->_unused[3], failed); 891 #else 892 unsafe_put_user(oldset->sig[1], &sc->_unused[3], failed); 893 #endif 894 unsafe_put_user(to_user_ptr(mctx), &sc->regs, failed); 895 unsafe_put_user(ksig->sig, &sc->signal, failed); 896 897 if (MSR_TM_ACTIVE(msr)) 898 unsafe_save_tm_user_regs(regs, mctx, tm_mctx, msr, failed); 899 else 900 unsafe_save_user_regs(regs, mctx, tm_mctx, 1, failed); 901 902 if (tsk->mm->context.vdso) { 903 tramp = VDSO32_SYMBOL(tsk->mm->context.vdso, sigtramp32); 904 } else { 905 tramp = (unsigned long)mctx->mc_pad; 906 /* Set up the sigreturn trampoline: li r0,sigret; sc */ 907 unsafe_put_user(PPC_INST_ADDI + __NR_sigreturn, &mctx->mc_pad[0], failed); 908 unsafe_put_user(PPC_INST_SC, &mctx->mc_pad[1], failed); 909 asm("dcbst %y0; sync; icbi %y0; sync" :: "Z" (mctx->mc_pad[0])); 910 } 911 user_access_end(); 912 913 regs->link = tramp; 914 915 #ifdef CONFIG_PPC_FPU_REGS 916 tsk->thread.fp_state.fpscr = 0; /* turn off all fp exceptions */ 917 #endif 918 919 /* create a stack frame for the caller of the handler */ 920 newsp = ((unsigned long)frame) - __SIGNAL_FRAMESIZE; 921 if (put_user(regs->gpr[1], (u32 __user *)newsp)) 922 goto badframe; 923 924 regs->gpr[1] = newsp; 925 regs->gpr[3] = ksig->sig; 926 regs->gpr[4] = (unsigned long) sc; 927 regs->nip = (unsigned long)ksig->ka.sa.sa_handler; 928 /* enter the signal handler in native-endian mode */ 929 regs->msr &= ~MSR_LE; 930 regs->msr |= (MSR_KERNEL & MSR_LE); 931 return 0; 932 933 failed: 934 user_access_end(); 935 936 badframe: 937 signal_fault(tsk, regs, "handle_signal32", frame); 938 939 return 1; 940 } 941 942 static int do_setcontext(struct ucontext __user *ucp, struct pt_regs *regs, int sig) 943 { 944 sigset_t set; 945 struct mcontext __user *mcp; 946 947 if (get_sigset_t(&set, &ucp->uc_sigmask)) 948 return -EFAULT; 949 #ifdef CONFIG_PPC64 950 { 951 u32 cmcp; 952 953 if (__get_user(cmcp, &ucp->uc_regs)) 954 return -EFAULT; 955 mcp = (struct mcontext __user *)(u64)cmcp; 956 /* no need to check access_ok(mcp), since mcp < 4GB */ 957 } 958 #else 959 if (__get_user(mcp, &ucp->uc_regs)) 960 return -EFAULT; 961 if (!access_ok(mcp, sizeof(*mcp))) 962 return -EFAULT; 963 #endif 964 set_current_blocked(&set); 965 if (restore_user_regs(regs, mcp, sig)) 966 return -EFAULT; 967 968 return 0; 969 } 970 971 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 972 static int do_setcontext_tm(struct ucontext __user *ucp, 973 struct ucontext __user *tm_ucp, 974 struct pt_regs *regs) 975 { 976 sigset_t set; 977 struct mcontext __user *mcp; 978 struct mcontext __user *tm_mcp; 979 u32 cmcp; 980 u32 tm_cmcp; 981 982 if (get_sigset_t(&set, &ucp->uc_sigmask)) 983 return -EFAULT; 984 985 if (__get_user(cmcp, &ucp->uc_regs) || 986 __get_user(tm_cmcp, &tm_ucp->uc_regs)) 987 return -EFAULT; 988 mcp = (struct mcontext __user *)(u64)cmcp; 989 tm_mcp = (struct mcontext __user *)(u64)tm_cmcp; 990 /* no need to check access_ok(mcp), since mcp < 4GB */ 991 992 set_current_blocked(&set); 993 if (restore_tm_user_regs(regs, mcp, tm_mcp)) 994 return -EFAULT; 995 996 return 0; 997 } 998 #endif 999 1000 #ifdef CONFIG_PPC64 1001 COMPAT_SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx, 1002 struct ucontext __user *, new_ctx, int, ctx_size) 1003 #else 1004 SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx, 1005 struct ucontext __user *, new_ctx, long, ctx_size) 1006 #endif 1007 { 1008 struct pt_regs *regs = current_pt_regs(); 1009 int ctx_has_vsx_region = 0; 1010 1011 #ifdef CONFIG_PPC64 1012 unsigned long new_msr = 0; 1013 1014 if (new_ctx) { 1015 struct mcontext __user *mcp; 1016 u32 cmcp; 1017 1018 /* 1019 * Get pointer to the real mcontext. No need for 1020 * access_ok since we are dealing with compat 1021 * pointers. 1022 */ 1023 if (__get_user(cmcp, &new_ctx->uc_regs)) 1024 return -EFAULT; 1025 mcp = (struct mcontext __user *)(u64)cmcp; 1026 if (__get_user(new_msr, &mcp->mc_gregs[PT_MSR])) 1027 return -EFAULT; 1028 } 1029 /* 1030 * Check that the context is not smaller than the original 1031 * size (with VMX but without VSX) 1032 */ 1033 if (ctx_size < UCONTEXTSIZEWITHOUTVSX) 1034 return -EINVAL; 1035 /* 1036 * If the new context state sets the MSR VSX bits but 1037 * it doesn't provide VSX state. 1038 */ 1039 if ((ctx_size < sizeof(struct ucontext)) && 1040 (new_msr & MSR_VSX)) 1041 return -EINVAL; 1042 /* Does the context have enough room to store VSX data? */ 1043 if (ctx_size >= sizeof(struct ucontext)) 1044 ctx_has_vsx_region = 1; 1045 #else 1046 /* Context size is for future use. Right now, we only make sure 1047 * we are passed something we understand 1048 */ 1049 if (ctx_size < sizeof(struct ucontext)) 1050 return -EINVAL; 1051 #endif 1052 if (old_ctx != NULL) { 1053 struct mcontext __user *mctx; 1054 1055 /* 1056 * old_ctx might not be 16-byte aligned, in which 1057 * case old_ctx->uc_mcontext won't be either. 1058 * Because we have the old_ctx->uc_pad2 field 1059 * before old_ctx->uc_mcontext, we need to round down 1060 * from &old_ctx->uc_mcontext to a 16-byte boundary. 1061 */ 1062 mctx = (struct mcontext __user *) 1063 ((unsigned long) &old_ctx->uc_mcontext & ~0xfUL); 1064 prepare_save_user_regs(ctx_has_vsx_region); 1065 if (!user_write_access_begin(old_ctx, ctx_size)) 1066 return -EFAULT; 1067 unsafe_save_user_regs(regs, mctx, NULL, ctx_has_vsx_region, failed); 1068 unsafe_put_sigset_t(&old_ctx->uc_sigmask, ¤t->blocked, failed); 1069 unsafe_put_user(to_user_ptr(mctx), &old_ctx->uc_regs, failed); 1070 user_write_access_end(); 1071 } 1072 if (new_ctx == NULL) 1073 return 0; 1074 if (!access_ok(new_ctx, ctx_size) || 1075 fault_in_pages_readable((u8 __user *)new_ctx, ctx_size)) 1076 return -EFAULT; 1077 1078 /* 1079 * If we get a fault copying the context into the kernel's 1080 * image of the user's registers, we can't just return -EFAULT 1081 * because the user's registers will be corrupted. For instance 1082 * the NIP value may have been updated but not some of the 1083 * other registers. Given that we have done the access_ok 1084 * and successfully read the first and last bytes of the region 1085 * above, this should only happen in an out-of-memory situation 1086 * or if another thread unmaps the region containing the context. 1087 * We kill the task with a SIGSEGV in this situation. 1088 */ 1089 if (do_setcontext(new_ctx, regs, 0)) 1090 do_exit(SIGSEGV); 1091 1092 set_thread_flag(TIF_RESTOREALL); 1093 return 0; 1094 1095 failed: 1096 user_write_access_end(); 1097 return -EFAULT; 1098 } 1099 1100 #ifdef CONFIG_PPC64 1101 COMPAT_SYSCALL_DEFINE0(rt_sigreturn) 1102 #else 1103 SYSCALL_DEFINE0(rt_sigreturn) 1104 #endif 1105 { 1106 struct rt_sigframe __user *rt_sf; 1107 struct pt_regs *regs = current_pt_regs(); 1108 int tm_restore = 0; 1109 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 1110 struct ucontext __user *uc_transact; 1111 unsigned long msr_hi; 1112 unsigned long tmp; 1113 #endif 1114 /* Always make any pending restarted system calls return -EINTR */ 1115 current->restart_block.fn = do_no_restart_syscall; 1116 1117 rt_sf = (struct rt_sigframe __user *) 1118 (regs->gpr[1] + __SIGNAL_FRAMESIZE + 16); 1119 if (!access_ok(rt_sf, sizeof(*rt_sf))) 1120 goto bad; 1121 1122 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 1123 /* 1124 * If there is a transactional state then throw it away. 1125 * The purpose of a sigreturn is to destroy all traces of the 1126 * signal frame, this includes any transactional state created 1127 * within in. We only check for suspended as we can never be 1128 * active in the kernel, we are active, there is nothing better to 1129 * do than go ahead and Bad Thing later. 1130 * The cause is not important as there will never be a 1131 * recheckpoint so it's not user visible. 1132 */ 1133 if (MSR_TM_SUSPENDED(mfmsr())) 1134 tm_reclaim_current(0); 1135 1136 if (__get_user(tmp, &rt_sf->uc.uc_link)) 1137 goto bad; 1138 uc_transact = (struct ucontext __user *)(uintptr_t)tmp; 1139 if (uc_transact) { 1140 u32 cmcp; 1141 struct mcontext __user *mcp; 1142 1143 if (__get_user(cmcp, &uc_transact->uc_regs)) 1144 return -EFAULT; 1145 mcp = (struct mcontext __user *)(u64)cmcp; 1146 /* The top 32 bits of the MSR are stashed in the transactional 1147 * ucontext. */ 1148 if (__get_user(msr_hi, &mcp->mc_gregs[PT_MSR])) 1149 goto bad; 1150 1151 if (MSR_TM_ACTIVE(msr_hi<<32)) { 1152 /* Trying to start TM on non TM system */ 1153 if (!cpu_has_feature(CPU_FTR_TM)) 1154 goto bad; 1155 /* We only recheckpoint on return if we're 1156 * transaction. 1157 */ 1158 tm_restore = 1; 1159 if (do_setcontext_tm(&rt_sf->uc, uc_transact, regs)) 1160 goto bad; 1161 } 1162 } 1163 if (!tm_restore) { 1164 /* 1165 * Unset regs->msr because ucontext MSR TS is not 1166 * set, and recheckpoint was not called. This avoid 1167 * hitting a TM Bad thing at RFID 1168 */ 1169 regs->msr &= ~MSR_TS_MASK; 1170 } 1171 /* Fall through, for non-TM restore */ 1172 #endif 1173 if (!tm_restore) 1174 if (do_setcontext(&rt_sf->uc, regs, 1)) 1175 goto bad; 1176 1177 /* 1178 * It's not clear whether or why it is desirable to save the 1179 * sigaltstack setting on signal delivery and restore it on 1180 * signal return. But other architectures do this and we have 1181 * always done it up until now so it is probably better not to 1182 * change it. -- paulus 1183 */ 1184 #ifdef CONFIG_PPC64 1185 if (compat_restore_altstack(&rt_sf->uc.uc_stack)) 1186 goto bad; 1187 #else 1188 if (restore_altstack(&rt_sf->uc.uc_stack)) 1189 goto bad; 1190 #endif 1191 set_thread_flag(TIF_RESTOREALL); 1192 return 0; 1193 1194 bad: 1195 signal_fault(current, regs, "sys_rt_sigreturn", rt_sf); 1196 1197 force_sig(SIGSEGV); 1198 return 0; 1199 } 1200 1201 #ifdef CONFIG_PPC32 1202 SYSCALL_DEFINE3(debug_setcontext, struct ucontext __user *, ctx, 1203 int, ndbg, struct sig_dbg_op __user *, dbg) 1204 { 1205 struct pt_regs *regs = current_pt_regs(); 1206 struct sig_dbg_op op; 1207 int i; 1208 unsigned long new_msr = regs->msr; 1209 #ifdef CONFIG_PPC_ADV_DEBUG_REGS 1210 unsigned long new_dbcr0 = current->thread.debug.dbcr0; 1211 #endif 1212 1213 for (i=0; i<ndbg; i++) { 1214 if (copy_from_user(&op, dbg + i, sizeof(op))) 1215 return -EFAULT; 1216 switch (op.dbg_type) { 1217 case SIG_DBG_SINGLE_STEPPING: 1218 #ifdef CONFIG_PPC_ADV_DEBUG_REGS 1219 if (op.dbg_value) { 1220 new_msr |= MSR_DE; 1221 new_dbcr0 |= (DBCR0_IDM | DBCR0_IC); 1222 } else { 1223 new_dbcr0 &= ~DBCR0_IC; 1224 if (!DBCR_ACTIVE_EVENTS(new_dbcr0, 1225 current->thread.debug.dbcr1)) { 1226 new_msr &= ~MSR_DE; 1227 new_dbcr0 &= ~DBCR0_IDM; 1228 } 1229 } 1230 #else 1231 if (op.dbg_value) 1232 new_msr |= MSR_SE; 1233 else 1234 new_msr &= ~MSR_SE; 1235 #endif 1236 break; 1237 case SIG_DBG_BRANCH_TRACING: 1238 #ifdef CONFIG_PPC_ADV_DEBUG_REGS 1239 return -EINVAL; 1240 #else 1241 if (op.dbg_value) 1242 new_msr |= MSR_BE; 1243 else 1244 new_msr &= ~MSR_BE; 1245 #endif 1246 break; 1247 1248 default: 1249 return -EINVAL; 1250 } 1251 } 1252 1253 /* We wait until here to actually install the values in the 1254 registers so if we fail in the above loop, it will not 1255 affect the contents of these registers. After this point, 1256 failure is a problem, anyway, and it's very unlikely unless 1257 the user is really doing something wrong. */ 1258 regs->msr = new_msr; 1259 #ifdef CONFIG_PPC_ADV_DEBUG_REGS 1260 current->thread.debug.dbcr0 = new_dbcr0; 1261 #endif 1262 1263 if (!access_ok(ctx, sizeof(*ctx)) || 1264 fault_in_pages_readable((u8 __user *)ctx, sizeof(*ctx))) 1265 return -EFAULT; 1266 1267 /* 1268 * If we get a fault copying the context into the kernel's 1269 * image of the user's registers, we can't just return -EFAULT 1270 * because the user's registers will be corrupted. For instance 1271 * the NIP value may have been updated but not some of the 1272 * other registers. Given that we have done the access_ok 1273 * and successfully read the first and last bytes of the region 1274 * above, this should only happen in an out-of-memory situation 1275 * or if another thread unmaps the region containing the context. 1276 * We kill the task with a SIGSEGV in this situation. 1277 */ 1278 if (do_setcontext(ctx, regs, 1)) { 1279 signal_fault(current, regs, "sys_debug_setcontext", ctx); 1280 1281 force_sig(SIGSEGV); 1282 goto out; 1283 } 1284 1285 /* 1286 * It's not clear whether or why it is desirable to save the 1287 * sigaltstack setting on signal delivery and restore it on 1288 * signal return. But other architectures do this and we have 1289 * always done it up until now so it is probably better not to 1290 * change it. -- paulus 1291 */ 1292 restore_altstack(&ctx->uc_stack); 1293 1294 set_thread_flag(TIF_RESTOREALL); 1295 out: 1296 return 0; 1297 } 1298 #endif 1299 1300 /* 1301 * Do a signal return; undo the signal stack. 1302 */ 1303 #ifdef CONFIG_PPC64 1304 COMPAT_SYSCALL_DEFINE0(sigreturn) 1305 #else 1306 SYSCALL_DEFINE0(sigreturn) 1307 #endif 1308 { 1309 struct pt_regs *regs = current_pt_regs(); 1310 struct sigframe __user *sf; 1311 struct sigcontext __user *sc; 1312 struct sigcontext sigctx; 1313 struct mcontext __user *sr; 1314 void __user *addr; 1315 sigset_t set; 1316 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 1317 struct mcontext __user *mcp, *tm_mcp; 1318 unsigned long msr_hi; 1319 #endif 1320 1321 /* Always make any pending restarted system calls return -EINTR */ 1322 current->restart_block.fn = do_no_restart_syscall; 1323 1324 sf = (struct sigframe __user *)(regs->gpr[1] + __SIGNAL_FRAMESIZE); 1325 sc = &sf->sctx; 1326 addr = sc; 1327 if (copy_from_user(&sigctx, sc, sizeof(sigctx))) 1328 goto badframe; 1329 1330 #ifdef CONFIG_PPC64 1331 /* 1332 * Note that PPC32 puts the upper 32 bits of the sigmask in the 1333 * unused part of the signal stackframe 1334 */ 1335 set.sig[0] = sigctx.oldmask + ((long)(sigctx._unused[3]) << 32); 1336 #else 1337 set.sig[0] = sigctx.oldmask; 1338 set.sig[1] = sigctx._unused[3]; 1339 #endif 1340 set_current_blocked(&set); 1341 1342 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 1343 mcp = (struct mcontext __user *)&sf->mctx; 1344 tm_mcp = (struct mcontext __user *)&sf->mctx_transact; 1345 if (__get_user(msr_hi, &tm_mcp->mc_gregs[PT_MSR])) 1346 goto badframe; 1347 if (MSR_TM_ACTIVE(msr_hi<<32)) { 1348 if (!cpu_has_feature(CPU_FTR_TM)) 1349 goto badframe; 1350 if (restore_tm_user_regs(regs, mcp, tm_mcp)) 1351 goto badframe; 1352 } else 1353 #endif 1354 { 1355 sr = (struct mcontext __user *)from_user_ptr(sigctx.regs); 1356 addr = sr; 1357 if (!access_ok(sr, sizeof(*sr)) 1358 || restore_user_regs(regs, sr, 1)) 1359 goto badframe; 1360 } 1361 1362 set_thread_flag(TIF_RESTOREALL); 1363 return 0; 1364 1365 badframe: 1366 signal_fault(current, regs, "sys_sigreturn", addr); 1367 1368 force_sig(SIGSEGV); 1369 return 0; 1370 } 1371