arch/powerpc/kernel/signal_64.c

   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         /* New 64 bit little-endian ABI allows redzone of 512 bytes below sp */
  69         char abigap[USER_REDZONE_SIZE];
  70 } __attribute__ ((aligned (16)));
  71
  72 static const char fmt32[] = KERN_INFO \
  73         "%s[%d]: bad frame in %s: %08lx nip %08lx lr %08lx\n";
  74 static const char fmt64[] = KERN_INFO \
  75         "%s[%d]: bad frame in %s: %016lx nip %016lx lr %016lx\n";
  76
  77 /*
  78  * 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, &current->thread.vr_state,
 107                                       33 * sizeof(vector128));
 108                 /* set MSR_VEC in the MSR value in the frame to indicate that sc->v_reg)
 109                  * contains valid data.
 110                  */
 111                 msr |= MSR_VEC;
 112         }
 113         /* We always copy to/from vrsave, it's 0 if we don't have or don't
 114          * use altivec.
 115          */
 116         if (cpu_has_feature(CPU_FTR_ALTIVEC))
 117                 current->thread.vrsave = mfspr(SPRN_VRSAVE);
 118         err |= __put_user(current->thread.vrsave, (u32 __user *)&v_regs[33]);
 119 #else /* CONFIG_ALTIVEC */
 120         err |= __put_user(0, &sc->v_regs);
 121 #endif /* CONFIG_ALTIVEC */
 122         flush_fp_to_thread(current);
 123         /* copy fpr regs and fpscr */
 124         err |= copy_fpr_to_user(&sc->fp_regs, current);
 125
 126         /*
 127          * Clear the MSR VSX bit to indicate there is no valid state attached
 128          * to this context, except in the specific case below where we set it.
 129          */
 130         msr &= ~MSR_VSX;
 131 #ifdef CONFIG_VSX
 132         /*
 133          * Copy VSX low doubleword to local buffer for formatting,
 134          * then out to userspace.  Update v_regs to point after the
 135          * VMX data.
 136          */
 137         if (current->thread.used_vsr && ctx_has_vsx_region) {
 138                 __giveup_vsx(current);
 139                 v_regs += ELF_NVRREG;
 140                 err |= copy_vsx_to_user(v_regs, current);
 141                 /* set MSR_VSX in the MSR value in the frame to
 142                  * indicate that sc->vs_reg) contains valid data.
 143                  */
 144                 msr |= MSR_VSX;
 145         }
 146 #endif /* CONFIG_VSX */
 147         err |= __put_user(&sc->gp_regs, &sc->regs);
 148         WARN_ON(!FULL_REGS(regs));
 149         err |= __copy_to_user(&sc->gp_regs, regs, GP_REGS_SIZE);
 150         err |= __put_user(msr, &sc->gp_regs[PT_MSR]);
 151         err |= __put_user(signr, &sc->signal);
 152         err |= __put_user(handler, &sc->handler);
 153         if (set != NULL)
 154                 err |=  __put_user(set->sig[0], &sc->oldmask);
 155
 156         return err;
 157 }
 158
 159 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 160 /*
 161  * As above, but Transactional Memory is in use, so deliver sigcontexts
 162  * containing checkpointed and transactional register states.
 163  *
 164  * To do this, we treclaim (done before entering here) to gather both sets of
 165  * registers and set up the 'normal' sigcontext registers with rolled-back
 166  * register values such that a simple signal handler sees a correct
 167  * checkpointed register state.  If interested, a TM-aware sighandler can
 168  * examine the transactional registers in the 2nd sigcontext to determine the
 169  * real origin of the signal.
 170  */
 171 static long setup_tm_sigcontexts(struct sigcontext __user *sc,
 172                                  struct sigcontext __user *tm_sc,
 173                                  struct pt_regs *regs,
 174                                  int signr, sigset_t *set, unsigned long handler)
 175 {
 176         /* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the
 177          * process never used altivec yet (MSR_VEC is zero in pt_regs of
 178          * the context). This is very important because we must ensure we
 179          * don't lose the VRSAVE content that may have been set prior to
 180          * the process doing its first vector operation
 181          * Userland shall check AT_HWCAP to know wether it can rely on the
 182          * v_regs pointer or not.
 183          */
 184 #ifdef CONFIG_ALTIVEC
 185         elf_vrreg_t __user *v_regs = (elf_vrreg_t __user *)
 186                 (((unsigned long)sc->vmx_reserve + 15) & ~0xful);
 187         elf_vrreg_t __user *tm_v_regs = (elf_vrreg_t __user *)
 188                 (((unsigned long)tm_sc->vmx_reserve + 15) & ~0xful);
 189 #endif
 190         unsigned long msr = regs->msr;
 191         long err = 0;
 192
 193         BUG_ON(!MSR_TM_ACTIVE(regs->msr));
 194
 195         /* Remove TM bits from thread's MSR.  The MSR in the sigcontext
 196          * just indicates to userland that we were doing a transaction, but we
 197          * don't want to return in transactional state.  This also ensures
 198          * that flush_fp_to_thread won't set TIF_RESTORE_TM again.
 199          */
 200         regs->msr &= ~MSR_TS_MASK;
 201
 202         flush_fp_to_thread(current);
 203
 204 #ifdef CONFIG_ALTIVEC
 205         err |= __put_user(v_regs, &sc->v_regs);
 206         err |= __put_user(tm_v_regs, &tm_sc->v_regs);
 207
 208         /* save altivec registers */
 209         if (current->thread.used_vr) {
 210                 flush_altivec_to_thread(current);
 211                 /* Copy 33 vec registers (vr0..31 and vscr) to the stack */
 212                 err |= __copy_to_user(v_regs, &current->thread.vr_state,
 213                                       33 * sizeof(vector128));
 214                 /* If VEC was enabled there are transactional VRs valid too,
 215                  * else they're a copy of the checkpointed VRs.
 216                  */
 217                 if (msr & MSR_VEC)
 218                         err |= __copy_to_user(tm_v_regs,
 219                                               &current->thread.transact_vr,
 220                                               33 * sizeof(vector128));
 221                 else
 222                         err |= __copy_to_user(tm_v_regs,
 223                                               &current->thread.vr_state,
 224                                               33 * sizeof(vector128));
 225
 226                 /* set MSR_VEC in the MSR value in the frame to indicate
 227                  * that sc->v_reg contains valid data.
 228                  */
 229                 msr |= MSR_VEC;
 230         }
 231         /* We always copy to/from vrsave, it's 0 if we don't have or don't
 232          * use altivec.
 233          */
 234         if (cpu_has_feature(CPU_FTR_ALTIVEC))
 235                 current->thread.vrsave = mfspr(SPRN_VRSAVE);
 236         err |= __put_user(current->thread.vrsave, (u32 __user *)&v_regs[33]);
 237         if (msr & MSR_VEC)
 238                 err |= __put_user(current->thread.transact_vrsave,
 239                                   (u32 __user *)&tm_v_regs[33]);
 240         else
 241                 err |= __put_user(current->thread.vrsave,
 242                                   (u32 __user *)&tm_v_regs[33]);
 243
 244 #else /* CONFIG_ALTIVEC */
 245         err |= __put_user(0, &sc->v_regs);
 246         err |= __put_user(0, &tm_sc->v_regs);
 247 #endif /* CONFIG_ALTIVEC */
 248
 249         /* copy fpr regs and fpscr */
 250         err |= copy_fpr_to_user(&sc->fp_regs, current);
 251         if (msr & MSR_FP)
 252                 err |= copy_transact_fpr_to_user(&tm_sc->fp_regs, current);
 253         else
 254                 err |= copy_fpr_to_user(&tm_sc->fp_regs, current);
 255
 256 #ifdef CONFIG_VSX
 257         /*
 258          * Copy VSX low doubleword to local buffer for formatting,
 259          * then out to userspace.  Update v_regs to point after the
 260          * VMX data.
 261          */
 262         if (current->thread.used_vsr) {
 263                 __giveup_vsx(current);
 264                 v_regs += ELF_NVRREG;
 265                 tm_v_regs += ELF_NVRREG;
 266
 267                 err |= copy_vsx_to_user(v_regs, current);
 268
 269                 if (msr & MSR_VSX)
 270                         err |= copy_transact_vsx_to_user(tm_v_regs, current);
 271                 else
 272                         err |= copy_vsx_to_user(tm_v_regs, current);
 273
 274                 /* set MSR_VSX in the MSR value in the frame to
 275                  * indicate that sc->vs_reg) contains valid data.
 276                  */
 277                 msr |= MSR_VSX;
 278         }
 279 #endif /* CONFIG_VSX */
 280
 281         err |= __put_user(&sc->gp_regs, &sc->regs);
 282         err |= __put_user(&tm_sc->gp_regs, &tm_sc->regs);
 283         WARN_ON(!FULL_REGS(regs));
 284         err |= __copy_to_user(&tm_sc->gp_regs, regs, GP_REGS_SIZE);
 285         err |= __copy_to_user(&sc->gp_regs,
 286                               &current->thread.ckpt_regs, GP_REGS_SIZE);
 287         err |= __put_user(msr, &tm_sc->gp_regs[PT_MSR]);
 288         err |= __put_user(msr, &sc->gp_regs[PT_MSR]);
 289         err |= __put_user(signr, &sc->signal);
 290         err |= __put_user(handler, &sc->handler);
 291         if (set != NULL)
 292                 err |=  __put_user(set->sig[0], &sc->oldmask);
 293
 294         return err;
 295 }
 296 #endif
 297
 298 /*
 299  * Restore the sigcontext from the signal frame.
 300  */
 301
 302 static long restore_sigcontext(struct pt_regs *regs, sigset_t *set, int sig,
 303                               struct sigcontext __user *sc)
 304 {
 305 #ifdef CONFIG_ALTIVEC
 306         elf_vrreg_t __user *v_regs;
 307 #endif
 308         unsigned long err = 0;
 309         unsigned long save_r13 = 0;
 310         unsigned long msr;
 311 #ifdef CONFIG_VSX
 312         int i;
 313 #endif
 314
 315         /* If this is not a signal return, we preserve the TLS in r13 */
 316         if (!sig)
 317                 save_r13 = regs->gpr[13];
 318
 319         /* copy the GPRs */
 320         err |= __copy_from_user(regs->gpr, sc->gp_regs, sizeof(regs->gpr));
 321         err |= __get_user(regs->nip, &sc->gp_regs[PT_NIP]);
 322         /* get MSR separately, transfer the LE bit if doing signal return */
 323         err |= __get_user(msr, &sc->gp_regs[PT_MSR]);
 324         if (sig)
 325                 regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE);
 326         err |= __get_user(regs->orig_gpr3, &sc->gp_regs[PT_ORIG_R3]);
 327         err |= __get_user(regs->ctr, &sc->gp_regs[PT_CTR]);
 328         err |= __get_user(regs->link, &sc->gp_regs[PT_LNK]);
 329         err |= __get_user(regs->xer, &sc->gp_regs[PT_XER]);
 330         err |= __get_user(regs->ccr, &sc->gp_regs[PT_CCR]);
 331         /* skip SOFTE */
 332         regs->trap = 0;
 333         err |= __get_user(regs->dar, &sc->gp_regs[PT_DAR]);
 334         err |= __get_user(regs->dsisr, &sc->gp_regs[PT_DSISR]);
 335         err |= __get_user(regs->result, &sc->gp_regs[PT_RESULT]);
 336
 337         if (!sig)
 338                 regs->gpr[13] = save_r13;
 339         if (set != NULL)
 340                 err |=  __get_user(set->sig[0], &sc->oldmask);
 341
 342         /*
 343          * Do this before updating the thread state in
 344          * current->thread.fpr/vr.  That way, if we get preempted
 345          * and another task grabs the FPU/Altivec, it won't be
 346          * tempted to save the current CPU state into the thread_struct
 347          * and corrupt what we are writing there.
 348          */
 349         discard_lazy_cpu_state();
 350
 351         /*
 352          * Force reload of FP/VEC.
 353          * This has to be done before copying stuff into current->thread.fpr/vr
 354          * for the reasons explained in the previous comment.
 355          */
 356         regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC | MSR_VSX);
 357
 358 #ifdef CONFIG_ALTIVEC
 359         err |= __get_user(v_regs, &sc->v_regs);
 360         if (err)
 361                 return err;
 362         if (v_regs && !access_ok(VERIFY_READ, v_regs, 34 * sizeof(vector128)))
 363                 return -EFAULT;
 364         /* Copy 33 vec registers (vr0..31 and vscr) from the stack */
 365         if (v_regs != NULL && (msr & MSR_VEC) != 0)
 366                 err |= __copy_from_user(&current->thread.vr_state, v_regs,
 367                                         33 * sizeof(vector128));
 368         else if (current->thread.used_vr)
 369                 memset(&current->thread.vr_state, 0, 33 * sizeof(vector128));
 370         /* Always get VRSAVE back */
 371         if (v_regs != NULL)
 372                 err |= __get_user(current->thread.vrsave, (u32 __user *)&v_regs[33]);
 373         else
 374                 current->thread.vrsave = 0;
 375         if (cpu_has_feature(CPU_FTR_ALTIVEC))
 376                 mtspr(SPRN_VRSAVE, current->thread.vrsave);
 377 #endif /* CONFIG_ALTIVEC */
 378         /* restore floating point */
 379         err |= copy_fpr_from_user(current, &sc->fp_regs);
 380 #ifdef CONFIG_VSX
 381         /*
 382          * Get additional VSX data. Update v_regs to point after the
 383          * VMX data.  Copy VSX low doubleword from userspace to local
 384          * buffer for formatting, then into the taskstruct.
 385          */
 386         v_regs += ELF_NVRREG;
 387         if ((msr & MSR_VSX) != 0)
 388                 err |= copy_vsx_from_user(current, v_regs);
 389         else
 390                 for (i = 0; i < 32 ; i++)
 391                         current->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
 392 #endif
 393         return err;
 394 }
 395
 396 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 397 /*
 398  * Restore the two sigcontexts from the frame of a transactional processes.
 399  */
 400
 401 static long restore_tm_sigcontexts(struct pt_regs *regs,
 402                                    struct sigcontext __user *sc,
 403                                    struct sigcontext __user *tm_sc)
 404 {
 405 #ifdef CONFIG_ALTIVEC
 406         elf_vrreg_t __user *v_regs, *tm_v_regs;
 407 #endif
 408         unsigned long err = 0;
 409         unsigned long msr;
 410 #ifdef CONFIG_VSX
 411         int i;
 412 #endif
 413         /* copy the GPRs */
 414         err |= __copy_from_user(regs->gpr, tm_sc->gp_regs, sizeof(regs->gpr));
 415         err |= __copy_from_user(&current->thread.ckpt_regs, sc->gp_regs,
 416                                 sizeof(regs->gpr));
 417
 418         /*
 419          * TFHAR is restored from the checkpointed 'wound-back' ucontext's NIP.
 420          * TEXASR was set by the signal delivery reclaim, as was TFIAR.
 421          * Users doing anything abhorrent like thread-switching w/ signals for
 422          * TM-Suspended code will have to back TEXASR/TFIAR up themselves.
 423          * For the case of getting a signal and simply returning from it,
 424          * we don't need to re-copy them here.
 425          */
 426         err |= __get_user(regs->nip, &tm_sc->gp_regs[PT_NIP]);
 427         err |= __get_user(current->thread.tm_tfhar, &sc->gp_regs[PT_NIP]);
 428
 429         /* get MSR separately, transfer the LE bit if doing signal return */
 430         err |= __get_user(msr, &sc->gp_regs[PT_MSR]);
 431         /* pull in MSR TM from user context */
 432         regs->msr = (regs->msr & ~MSR_TS_MASK) | (msr & MSR_TS_MASK);
 433
 434         /* pull in MSR LE from user context */
 435         regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE);
 436
 437         /* The following non-GPR non-FPR non-VR state is also checkpointed: */
 438         err |= __get_user(regs->ctr, &tm_sc->gp_regs[PT_CTR]);
 439         err |= __get_user(regs->link, &tm_sc->gp_regs[PT_LNK]);
 440         err |= __get_user(regs->xer, &tm_sc->gp_regs[PT_XER]);
 441         err |= __get_user(regs->ccr, &tm_sc->gp_regs[PT_CCR]);
 442         err |= __get_user(current->thread.ckpt_regs.ctr,
 443                           &sc->gp_regs[PT_CTR]);
 444         err |= __get_user(current->thread.ckpt_regs.link,
 445                           &sc->gp_regs[PT_LNK]);
 446         err |= __get_user(current->thread.ckpt_regs.xer,
 447                           &sc->gp_regs[PT_XER]);
 448         err |= __get_user(current->thread.ckpt_regs.ccr,
 449                           &sc->gp_regs[PT_CCR]);
 450
 451         /* These regs are not checkpointed; they can go in 'regs'. */
 452         err |= __get_user(regs->trap, &sc->gp_regs[PT_TRAP]);
 453         err |= __get_user(regs->dar, &sc->gp_regs[PT_DAR]);
 454         err |= __get_user(regs->dsisr, &sc->gp_regs[PT_DSISR]);
 455         err |= __get_user(regs->result, &sc->gp_regs[PT_RESULT]);
 456
 457         /*
 458          * Do this before updating the thread state in
 459          * current->thread.fpr/vr.  That way, if we get preempted
 460          * and another task grabs the FPU/Altivec, it won't be
 461          * tempted to save the current CPU state into the thread_struct
 462          * and corrupt what we are writing there.
 463          */
 464         discard_lazy_cpu_state();
 465
 466         /*
 467          * Force reload of FP/VEC.
 468          * This has to be done before copying stuff into current->thread.fpr/vr
 469          * for the reasons explained in the previous comment.
 470          */
 471         regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC | MSR_VSX);
 472
 473 #ifdef CONFIG_ALTIVEC
 474         err |= __get_user(v_regs, &sc->v_regs);
 475         err |= __get_user(tm_v_regs, &tm_sc->v_regs);
 476         if (err)
 477                 return err;
 478         if (v_regs && !access_ok(VERIFY_READ, v_regs, 34 * sizeof(vector128)))
 479                 return -EFAULT;
 480         if (tm_v_regs && !access_ok(VERIFY_READ,
 481                                     tm_v_regs, 34 * sizeof(vector128)))
 482                 return -EFAULT;
 483         /* Copy 33 vec registers (vr0..31 and vscr) from the stack */
 484         if (v_regs != NULL && tm_v_regs != NULL && (msr & MSR_VEC) != 0) {
 485                 err |= __copy_from_user(&current->thread.vr_state, v_regs,
 486                                         33 * sizeof(vector128));
 487                 err |= __copy_from_user(&current->thread.transact_vr, tm_v_regs,
 488                                         33 * sizeof(vector128));
 489         }
 490         else if (current->thread.used_vr) {
 491                 memset(&current->thread.vr_state, 0, 33 * sizeof(vector128));
 492                 memset(&current->thread.transact_vr, 0, 33 * sizeof(vector128));
 493         }
 494         /* Always get VRSAVE back */
 495         if (v_regs != NULL && tm_v_regs != NULL) {
 496                 err |= __get_user(current->thread.vrsave,
 497                                   (u32 __user *)&v_regs[33]);
 498                 err |= __get_user(current->thread.transact_vrsave,
 499                                   (u32 __user *)&tm_v_regs[33]);
 500         }
 501         else {
 502                 current->thread.vrsave = 0;
 503                 current->thread.transact_vrsave = 0;
 504         }
 505         if (cpu_has_feature(CPU_FTR_ALTIVEC))
 506                 mtspr(SPRN_VRSAVE, current->thread.vrsave);
 507 #endif /* CONFIG_ALTIVEC */
 508         /* restore floating point */
 509         err |= copy_fpr_from_user(current, &sc->fp_regs);
 510         err |= copy_transact_fpr_from_user(current, &tm_sc->fp_regs);
 511 #ifdef CONFIG_VSX
 512         /*
 513          * Get additional VSX data. Update v_regs to point after the
 514          * VMX data.  Copy VSX low doubleword from userspace to local
 515          * buffer for formatting, then into the taskstruct.
 516          */
 517         if (v_regs && ((msr & MSR_VSX) != 0)) {
 518                 v_regs += ELF_NVRREG;
 519                 tm_v_regs += ELF_NVRREG;
 520                 err |= copy_vsx_from_user(current, v_regs);
 521                 err |= copy_transact_vsx_from_user(current, tm_v_regs);
 522         } else {
 523                 for (i = 0; i < 32 ; i++) {
 524                         current->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
 525                         current->thread.transact_fp.fpr[i][TS_VSRLOWOFFSET] = 0;
 526                 }
 527         }
 528 #endif
 529         tm_enable();
 530         /* Make sure the transaction is marked as failed */
 531         current->thread.tm_texasr |= TEXASR_FS;
 532         /* This loads the checkpointed FP/VEC state, if used */
 533         tm_recheckpoint(&current->thread, msr);
 534
 535         /* This loads the speculative FP/VEC state, if used */
 536         if (msr & MSR_FP) {
 537                 do_load_up_transact_fpu(&current->thread);
 538                 regs->msr |= (MSR_FP | current->thread.fpexc_mode);
 539         }
 540 #ifdef CONFIG_ALTIVEC
 541         if (msr & MSR_VEC) {
 542                 do_load_up_transact_altivec(&current->thread);
 543                 regs->msr |= MSR_VEC;
 544         }
 545 #endif
 546
 547         return err;
 548 }
 549 #endif
 550
 551 /*
 552  * Setup the trampoline code on the stack
 553  */
 554 static long setup_trampoline(unsigned int syscall, unsigned int __user *tramp)
 555 {
 556         int i;
 557         long err = 0;
 558
 559         /* addi r1, r1, __SIGNAL_FRAMESIZE  # Pop the dummy stackframe */
 560         err |= __put_user(0x38210000UL | (__SIGNAL_FRAMESIZE & 0xffff), &tramp[0]);
 561         /* li r0, __NR_[rt_]sigreturn| */
 562         err |= __put_user(0x38000000UL | (syscall & 0xffff), &tramp[1]);
 563         /* sc */
 564         err |= __put_user(0x44000002UL, &tramp[2]);
 565
 566         /* Minimal traceback info */
 567         for (i=TRAMP_TRACEBACK; i < TRAMP_SIZE ;i++)
 568                 err |= __put_user(0, &tramp[i]);
 569
 570         if (!err)
 571                 flush_icache_range((unsigned long) &tramp[0],
 572                            (unsigned long) &tramp[TRAMP_SIZE]);
 573
 574         return err;
 575 }
 576
 577 /*
 578  * Userspace code may pass a ucontext which doesn't include VSX added
 579  * at the end.  We need to check for this case.
 580  */
 581 #define UCONTEXTSIZEWITHOUTVSX \
 582                 (sizeof(struct ucontext) - 32*sizeof(long))
 583
 584 /*
 585  * Handle {get,set,swap}_context operations
 586  */
 587 int sys_swapcontext(struct ucontext __user *old_ctx,
 588                     struct ucontext __user *new_ctx,
 589                     long ctx_size, long r6, long r7, long r8, struct pt_regs *regs)
 590 {
 591         unsigned char tmp;
 592         sigset_t set;
 593         unsigned long new_msr = 0;
 594         int ctx_has_vsx_region = 0;
 595
 596         if (new_ctx &&
 597             get_user(new_msr, &new_ctx->uc_mcontext.gp_regs[PT_MSR]))
 598                 return -EFAULT;
 599         /*
 600          * Check that the context is not smaller than the original
 601          * size (with VMX but without VSX)
 602          */
 603         if (ctx_size < UCONTEXTSIZEWITHOUTVSX)
 604                 return -EINVAL;
 605         /*
 606          * If the new context state sets the MSR VSX bits but
 607          * it doesn't provide VSX state.
 608          */
 609         if ((ctx_size < sizeof(struct ucontext)) &&
 610             (new_msr & MSR_VSX))
 611                 return -EINVAL;
 612         /* Does the context have enough room to store VSX data? */
 613         if (ctx_size >= sizeof(struct ucontext))
 614                 ctx_has_vsx_region = 1;
 615
 616         if (old_ctx != NULL) {
 617                 if (!access_ok(VERIFY_WRITE, old_ctx, ctx_size)
 618                     || setup_sigcontext(&old_ctx->uc_mcontext, regs, 0, NULL, 0,
 619                                         ctx_has_vsx_region)
 620                     || __copy_to_user(&old_ctx->uc_sigmask,
 621                                       &current->blocked, sizeof(sigset_t)))
 622                         return -EFAULT;
 623         }
 624         if (new_ctx == NULL)
 625                 return 0;
 626         if (!access_ok(VERIFY_READ, new_ctx, ctx_size)
 627             || __get_user(tmp, (u8 __user *) new_ctx)
 628             || __get_user(tmp, (u8 __user *) new_ctx + ctx_size - 1))
 629                 return -EFAULT;
 630
 631         /*
 632          * If we get a fault copying the context into the kernel's
 633          * image of the user's registers, we can't just return -EFAULT
 634          * because the user's registers will be corrupted.  For instance
 635          * the NIP value may have been updated but not some of the
 636          * other registers.  Given that we have done the access_ok
 637          * and successfully read the first and last bytes of the region
 638          * above, this should only happen in an out-of-memory situation
 639          * or if another thread unmaps the region containing the context.
 640          * We kill the task with a SIGSEGV in this situation.
 641          */
 642
 643         if (__copy_from_user(&set, &new_ctx->uc_sigmask, sizeof(set)))
 644                 do_exit(SIGSEGV);
 645         set_current_blocked(&set);
 646         if (restore_sigcontext(regs, NULL, 0, &new_ctx->uc_mcontext))
 647                 do_exit(SIGSEGV);
 648
 649         /* This returns like rt_sigreturn */
 650         set_thread_flag(TIF_RESTOREALL);
 651         return 0;
 652 }
 653
 654
 655 /*
 656  * Do a signal return; undo the signal stack.
 657  */
 658
 659 int sys_rt_sigreturn(unsigned long r3, unsigned long r4, unsigned long r5,
 660                      unsigned long r6, unsigned long r7, unsigned long r8,
 661                      struct pt_regs *regs)
 662 {
 663         struct ucontext __user *uc = (struct ucontext __user *)regs->gpr[1];
 664         sigset_t set;
 665 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 666         unsigned long msr;
 667 #endif
 668
 669         /* Always make any pending restarted system calls return -EINTR */
 670         current_thread_info()->restart_block.fn = do_no_restart_syscall;
 671
 672         if (!access_ok(VERIFY_READ, uc, sizeof(*uc)))
 673                 goto badframe;
 674
 675         if (__copy_from_user(&set, &uc->uc_sigmask, sizeof(set)))
 676                 goto badframe;
 677         set_current_blocked(&set);
 678 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 679         if (__get_user(msr, &uc->uc_mcontext.gp_regs[PT_MSR]))
 680                 goto badframe;
 681         if (MSR_TM_ACTIVE(msr)) {
 682                 /* We recheckpoint on return. */
 683                 struct ucontext __user *uc_transact;
 684                 if (__get_user(uc_transact, &uc->uc_link))
 685                         goto badframe;
 686                 if (restore_tm_sigcontexts(regs, &uc->uc_mcontext,
 687                                            &uc_transact->uc_mcontext))
 688                         goto badframe;
 689         }
 690         else
 691         /* Fall through, for non-TM restore */
 692 #endif
 693         if (restore_sigcontext(regs, NULL, 1, &uc->uc_mcontext))
 694                 goto badframe;
 695
 696         if (restore_altstack(&uc->uc_stack))
 697                 goto badframe;
 698
 699         set_thread_flag(TIF_RESTOREALL);
 700         return 0;
 701
 702 badframe:
 703 #if DEBUG_SIG
 704         printk("badframe in sys_rt_sigreturn, regs=%p uc=%p &uc->uc_mcontext=%p\n",
 705                regs, uc, &uc->uc_mcontext);
 706 #endif
 707         if (show_unhandled_signals)
 708                 printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32,
 709                                    current->comm, current->pid, "rt_sigreturn",
 710                                    (long)uc, regs->nip, regs->link);
 711
 712         force_sig(SIGSEGV, current);
 713         return 0;
 714 }
 715
 716 int handle_rt_signal64(int signr, struct k_sigaction *ka, siginfo_t *info,
 717                 sigset_t *set, struct pt_regs *regs)
 718 {
 719         struct rt_sigframe __user *frame;
 720         unsigned long newsp = 0;
 721         long err = 0;
 722
 723         frame = get_sigframe(ka, get_tm_stackpointer(regs), sizeof(*frame), 0);
 724         if (unlikely(frame == NULL))
 725                 goto badframe;
 726
 727         err |= __put_user(&frame->info, &frame->pinfo);
 728         err |= __put_user(&frame->uc, &frame->puc);
 729         err |= copy_siginfo_to_user(&frame->info, info);
 730         if (err)
 731                 goto badframe;
 732
 733         /* Create the ucontext.  */
 734         err |= __put_user(0, &frame->uc.uc_flags);
 735         err |= __save_altstack(&frame->uc.uc_stack, regs->gpr[1]);
 736 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 737         if (MSR_TM_ACTIVE(regs->msr)) {
 738                 /* The ucontext_t passed to userland points to the second
 739                  * ucontext_t (for transactional state) with its uc_link ptr.
 740                  */
 741                 err |= __put_user(&frame->uc_transact, &frame->uc.uc_link);
 742                 err |= setup_tm_sigcontexts(&frame->uc.uc_mcontext,
 743                                             &frame->uc_transact.uc_mcontext,
 744                                             regs, signr,
 745                                             NULL,
 746                                             (unsigned long)ka->sa.sa_handler);
 747         } else
 748 #endif
 749         {
 750                 err |= __put_user(0, &frame->uc.uc_link);
 751                 err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, signr,
 752                                         NULL, (unsigned long)ka->sa.sa_handler,
 753                                         1);
 754         }
 755         err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
 756         if (err)
 757                 goto badframe;
 758
 759         /* Make sure signal handler doesn't get spurious FP exceptions */
 760         current->thread.fp_state.fpscr = 0;
 761
 762         /* Set up to return from userspace. */
 763         if (vdso64_rt_sigtramp && current->mm->context.vdso_base) {
 764                 regs->link = current->mm->context.vdso_base + vdso64_rt_sigtramp;
 765         } else {
 766                 err |= setup_trampoline(__NR_rt_sigreturn, &frame->tramp[0]);
 767                 if (err)
 768                         goto badframe;
 769                 regs->link = (unsigned long) &frame->tramp[0];
 770         }
 771
 772         /* Allocate a dummy caller frame for the signal handler. */
 773         newsp = ((unsigned long)frame) - __SIGNAL_FRAMESIZE;
 774         err |= put_user(regs->gpr[1], (unsigned long __user *)newsp);
 775
 776         /* Set up "regs" so we "return" to the signal handler. */
 777         if (is_elf2_task()) {
 778                 regs->nip = (unsigned long) ka->sa.sa_handler;
 779                 regs->gpr[12] = regs->nip;
 780         } else {
 781                 /* Handler is *really* a pointer to the function descriptor for
 782                  * the signal routine.  The first entry in the function
 783                  * descriptor is the entry address of signal and the second
 784                  * entry is the TOC value we need to use.
 785                  */
 786                 func_descr_t __user *funct_desc_ptr =
 787                         (func_descr_t __user *) ka->sa.sa_handler;
 788
 789                 err |= get_user(regs->nip, &funct_desc_ptr->entry);
 790                 err |= get_user(regs->gpr[2], &funct_desc_ptr->toc);
 791         }
 792
 793         /* enter the signal handler in native-endian mode */
 794         regs->msr &= ~MSR_LE;
 795         regs->msr |= (MSR_KERNEL & MSR_LE);
 796         regs->gpr[1] = newsp;
 797         regs->gpr[3] = signr;
 798         regs->result = 0;
 799         if (ka->sa.sa_flags & SA_SIGINFO) {
 800                 err |= get_user(regs->gpr[4], (unsigned long __user *)&frame->pinfo);
 801                 err |= get_user(regs->gpr[5], (unsigned long __user *)&frame->puc);
 802                 regs->gpr[6] = (unsigned long) frame;
 803         } else {
 804                 regs->gpr[4] = (unsigned long)&frame->uc.uc_mcontext;
 805         }
 806         if (err)
 807                 goto badframe;
 808
 809         return 1;
 810
 811 badframe:
 812 #if DEBUG_SIG
 813         printk("badframe in setup_rt_frame, regs=%p frame=%p newsp=%lx\n",
 814                regs, frame, newsp);
 815 #endif
 816         if (show_unhandled_signals)
 817                 printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32,
 818                                    current->comm, current->pid, "setup_rt_frame",
 819                                    (long)frame, regs->nip, regs->link);
 820
 821         force_sigsegv(signr, current);
 822         return 0;
 823 }