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