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