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 <linux/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 #include <asm/asm-prototypes.h>
  39
  40 #include "signal.h"
  41
  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  * This computes a quad word aligned pointer inside the vmx_reserve array
  79  * element. For historical reasons sigcontext might not be quad word aligned,
  80  * but the location we write the VMX regs to must be. See the comment in
  81  * sigcontext for more detail.
  82  */
  83 #ifdef CONFIG_ALTIVEC
  84 static elf_vrreg_t __user *sigcontext_vmx_regs(struct sigcontext __user *sc)
  85 {
  86         return (elf_vrreg_t __user *) (((unsigned long)sc->vmx_reserve + 15) & ~0xful);
  87 }
  88 #endif
  89
  90 /*
  91  * Set up the sigcontext for the signal frame.
  92  */
  93
  94 static long setup_sigcontext(struct sigcontext __user *sc,
  95                 struct task_struct *tsk, int signr, sigset_t *set,
  96                 unsigned long handler, int ctx_has_vsx_region)
  97 {
  98         /* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the
  99          * process never used altivec yet (MSR_VEC is zero in pt_regs of
 100          * the context). This is very important because we must ensure we
 101          * don't lose the VRSAVE content that may have been set prior to
 102          * the process doing its first vector operation
 103          * Userland shall check AT_HWCAP to know whether it can rely on the
 104          * v_regs pointer or not
 105          */
 106 #ifdef CONFIG_ALTIVEC
 107         elf_vrreg_t __user *v_regs = sigcontext_vmx_regs(sc);
 108         unsigned long vrsave;
 109 #endif
 110         struct pt_regs *regs = tsk->thread.regs;
 111         unsigned long msr = regs->msr;
 112         long err = 0;
 113         /* Force usr to alway see softe as 1 (interrupts enabled) */
 114         unsigned long softe = 0x1;
 115
 116         BUG_ON(tsk != current);
 117
 118 #ifdef CONFIG_ALTIVEC
 119         err |= __put_user(v_regs, &sc->v_regs);
 120
 121         /* save altivec registers */
 122         if (tsk->thread.used_vr) {
 123                 flush_altivec_to_thread(tsk);
 124                 /* Copy 33 vec registers (vr0..31 and vscr) to the stack */
 125                 err |= __copy_to_user(v_regs, &tsk->thread.vr_state,
 126                                       33 * sizeof(vector128));
 127                 /* set MSR_VEC in the MSR value in the frame to indicate that sc->v_reg)
 128                  * contains valid data.
 129                  */
 130                 msr |= MSR_VEC;
 131         }
 132         /* We always copy to/from vrsave, it's 0 if we don't have or don't
 133          * use altivec.
 134          */
 135         vrsave = 0;
 136         if (cpu_has_feature(CPU_FTR_ALTIVEC)) {
 137                 vrsave = mfspr(SPRN_VRSAVE);
 138                 tsk->thread.vrsave = vrsave;
 139         }
 140
 141         err |= __put_user(vrsave, (u32 __user *)&v_regs[33]);
 142 #else /* CONFIG_ALTIVEC */
 143         err |= __put_user(0, &sc->v_regs);
 144 #endif /* CONFIG_ALTIVEC */
 145         flush_fp_to_thread(tsk);
 146         /* copy fpr regs and fpscr */
 147         err |= copy_fpr_to_user(&sc->fp_regs, tsk);
 148
 149         /*
 150          * Clear the MSR VSX bit to indicate there is no valid state attached
 151          * to this context, except in the specific case below where we set it.
 152          */
 153         msr &= ~MSR_VSX;
 154 #ifdef CONFIG_VSX
 155         /*
 156          * Copy VSX low doubleword to local buffer for formatting,
 157          * then out to userspace.  Update v_regs to point after the
 158          * VMX data.
 159          */
 160         if (tsk->thread.used_vsr && ctx_has_vsx_region) {
 161                 flush_vsx_to_thread(tsk);
 162                 v_regs += ELF_NVRREG;
 163                 err |= copy_vsx_to_user(v_regs, tsk);
 164                 /* set MSR_VSX in the MSR value in the frame to
 165                  * indicate that sc->vs_reg) contains valid data.
 166                  */
 167                 msr |= MSR_VSX;
 168         }
 169 #endif /* CONFIG_VSX */
 170         err |= __put_user(&sc->gp_regs, &sc->regs);
 171         WARN_ON(!FULL_REGS(regs));
 172         err |= __copy_to_user(&sc->gp_regs, regs, GP_REGS_SIZE);
 173         err |= __put_user(msr, &sc->gp_regs[PT_MSR]);
 174         err |= __put_user(softe, &sc->gp_regs[PT_SOFTE]);
 175         err |= __put_user(signr, &sc->signal);
 176         err |= __put_user(handler, &sc->handler);
 177         if (set != NULL)
 178                 err |=  __put_user(set->sig[0], &sc->oldmask);
 179
 180         return err;
 181 }
 182
 183 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 184 /*
 185  * As above, but Transactional Memory is in use, so deliver sigcontexts
 186  * containing checkpointed and transactional register states.
 187  *
 188  * To do this, we treclaim (done before entering here) to gather both sets of
 189  * registers and set up the 'normal' sigcontext registers with rolled-back
 190  * register values such that a simple signal handler sees a correct
 191  * checkpointed register state.  If interested, a TM-aware sighandler can
 192  * examine the transactional registers in the 2nd sigcontext to determine the
 193  * real origin of the signal.
 194  */
 195 static long setup_tm_sigcontexts(struct sigcontext __user *sc,
 196                                  struct sigcontext __user *tm_sc,
 197                                  struct task_struct *tsk,
 198                                  int signr, sigset_t *set, unsigned long handler)
 199 {
 200         /* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the
 201          * process never used altivec yet (MSR_VEC is zero in pt_regs of
 202          * the context). This is very important because we must ensure we
 203          * don't lose the VRSAVE content that may have been set prior to
 204          * the process doing its first vector operation
 205          * Userland shall check AT_HWCAP to know wether it can rely on the
 206          * v_regs pointer or not.
 207          */
 208 #ifdef CONFIG_ALTIVEC
 209         elf_vrreg_t __user *v_regs = sigcontext_vmx_regs(sc);
 210         elf_vrreg_t __user *tm_v_regs = sigcontext_vmx_regs(tm_sc);
 211 #endif
 212         struct pt_regs *regs = tsk->thread.regs;
 213         unsigned long msr = tsk->thread.regs->msr;
 214         long err = 0;
 215
 216         BUG_ON(tsk != current);
 217
 218         BUG_ON(!MSR_TM_ACTIVE(regs->msr));
 219
 220         WARN_ON(tm_suspend_disabled);
 221
 222         /* Restore checkpointed FP, VEC, and VSX bits from ckpt_regs as
 223          * it contains the correct FP, VEC, VSX state after we treclaimed
 224          * the transaction and giveup_all() was called on reclaiming.
 225          */
 226         msr |= tsk->thread.ckpt_regs.msr & (MSR_FP | MSR_VEC | MSR_VSX);
 227
 228         /* Remove TM bits from thread's MSR.  The MSR in the sigcontext
 229          * just indicates to userland that we were doing a transaction, but we
 230          * don't want to return in transactional state.  This also ensures
 231          * that flush_fp_to_thread won't set TIF_RESTORE_TM again.
 232          */
 233         regs->msr &= ~MSR_TS_MASK;
 234
 235 #ifdef CONFIG_ALTIVEC
 236         err |= __put_user(v_regs, &sc->v_regs);
 237         err |= __put_user(tm_v_regs, &tm_sc->v_regs);
 238
 239         /* save altivec registers */
 240         if (tsk->thread.used_vr) {
 241                 /* Copy 33 vec registers (vr0..31 and vscr) to the stack */
 242                 err |= __copy_to_user(v_regs, &tsk->thread.ckvr_state,
 243                                       33 * sizeof(vector128));
 244                 /* If VEC was enabled there are transactional VRs valid too,
 245                  * else they're a copy of the checkpointed VRs.
 246                  */
 247                 if (msr & MSR_VEC)
 248                         err |= __copy_to_user(tm_v_regs,
 249                                               &tsk->thread.vr_state,
 250                                               33 * sizeof(vector128));
 251                 else
 252                         err |= __copy_to_user(tm_v_regs,
 253                                               &tsk->thread.ckvr_state,
 254                                               33 * sizeof(vector128));
 255
 256                 /* set MSR_VEC in the MSR value in the frame to indicate
 257                  * that sc->v_reg contains valid data.
 258                  */
 259                 msr |= MSR_VEC;
 260         }
 261         /* We always copy to/from vrsave, it's 0 if we don't have or don't
 262          * use altivec.
 263          */
 264         if (cpu_has_feature(CPU_FTR_ALTIVEC))
 265                 tsk->thread.ckvrsave = mfspr(SPRN_VRSAVE);
 266         err |= __put_user(tsk->thread.ckvrsave, (u32 __user *)&v_regs[33]);
 267         if (msr & MSR_VEC)
 268                 err |= __put_user(tsk->thread.vrsave,
 269                                   (u32 __user *)&tm_v_regs[33]);
 270         else
 271                 err |= __put_user(tsk->thread.ckvrsave,
 272                                   (u32 __user *)&tm_v_regs[33]);
 273
 274 #else /* CONFIG_ALTIVEC */
 275         err |= __put_user(0, &sc->v_regs);
 276         err |= __put_user(0, &tm_sc->v_regs);
 277 #endif /* CONFIG_ALTIVEC */
 278
 279         /* copy fpr regs and fpscr */
 280         err |= copy_ckfpr_to_user(&sc->fp_regs, tsk);
 281         if (msr & MSR_FP)
 282                 err |= copy_fpr_to_user(&tm_sc->fp_regs, tsk);
 283         else
 284                 err |= copy_ckfpr_to_user(&tm_sc->fp_regs, tsk);
 285
 286 #ifdef CONFIG_VSX
 287         /*
 288          * Copy VSX low doubleword to local buffer for formatting,
 289          * then out to userspace.  Update v_regs to point after the
 290          * VMX data.
 291          */
 292         if (tsk->thread.used_vsr) {
 293                 v_regs += ELF_NVRREG;
 294                 tm_v_regs += ELF_NVRREG;
 295
 296                 err |= copy_ckvsx_to_user(v_regs, tsk);
 297
 298                 if (msr & MSR_VSX)
 299                         err |= copy_vsx_to_user(tm_v_regs, tsk);
 300                 else
 301                         err |= copy_ckvsx_to_user(tm_v_regs, tsk);
 302
 303                 /* set MSR_VSX in the MSR value in the frame to
 304                  * indicate that sc->vs_reg) contains valid data.
 305                  */
 306                 msr |= MSR_VSX;
 307         }
 308 #endif /* CONFIG_VSX */
 309
 310         err |= __put_user(&sc->gp_regs, &sc->regs);
 311         err |= __put_user(&tm_sc->gp_regs, &tm_sc->regs);
 312         WARN_ON(!FULL_REGS(regs));
 313         err |= __copy_to_user(&tm_sc->gp_regs, regs, GP_REGS_SIZE);
 314         err |= __copy_to_user(&sc->gp_regs,
 315                               &tsk->thread.ckpt_regs, GP_REGS_SIZE);
 316         err |= __put_user(msr, &tm_sc->gp_regs[PT_MSR]);
 317         err |= __put_user(msr, &sc->gp_regs[PT_MSR]);
 318         err |= __put_user(signr, &sc->signal);
 319         err |= __put_user(handler, &sc->handler);
 320         if (set != NULL)
 321                 err |=  __put_user(set->sig[0], &sc->oldmask);
 322
 323         return err;
 324 }
 325 #endif
 326
 327 /*
 328  * Restore the sigcontext from the signal frame.
 329  */
 330
 331 static long restore_sigcontext(struct task_struct *tsk, sigset_t *set, int sig,
 332                               struct sigcontext __user *sc)
 333 {
 334 #ifdef CONFIG_ALTIVEC
 335         elf_vrreg_t __user *v_regs;
 336 #endif
 337         unsigned long err = 0;
 338         unsigned long save_r13 = 0;
 339         unsigned long msr;
 340         struct pt_regs *regs = tsk->thread.regs;
 341 #ifdef CONFIG_VSX
 342         int i;
 343 #endif
 344
 345         BUG_ON(tsk != current);
 346
 347         /* If this is not a signal return, we preserve the TLS in r13 */
 348         if (!sig)
 349                 save_r13 = regs->gpr[13];
 350
 351         /* copy the GPRs */
 352         err |= __copy_from_user(regs->gpr, sc->gp_regs, sizeof(regs->gpr));
 353         err |= __get_user(regs->nip, &sc->gp_regs[PT_NIP]);
 354         /* get MSR separately, transfer the LE bit if doing signal return */
 355         err |= __get_user(msr, &sc->gp_regs[PT_MSR]);
 356         if (sig)
 357                 regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE);
 358         err |= __get_user(regs->orig_gpr3, &sc->gp_regs[PT_ORIG_R3]);
 359         err |= __get_user(regs->ctr, &sc->gp_regs[PT_CTR]);
 360         err |= __get_user(regs->link, &sc->gp_regs[PT_LNK]);
 361         err |= __get_user(regs->xer, &sc->gp_regs[PT_XER]);
 362         err |= __get_user(regs->ccr, &sc->gp_regs[PT_CCR]);
 363         /* skip SOFTE */
 364         regs->trap = 0;
 365         err |= __get_user(regs->dar, &sc->gp_regs[PT_DAR]);
 366         err |= __get_user(regs->dsisr, &sc->gp_regs[PT_DSISR]);
 367         err |= __get_user(regs->result, &sc->gp_regs[PT_RESULT]);
 368
 369         if (!sig)
 370                 regs->gpr[13] = save_r13;
 371         if (set != NULL)
 372                 err |=  __get_user(set->sig[0], &sc->oldmask);
 373
 374         /*
 375          * Force reload of FP/VEC.
 376          * This has to be done before copying stuff into tsk->thread.fpr/vr
 377          * for the reasons explained in the previous comment.
 378          */
 379         regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC | MSR_VSX);
 380
 381 #ifdef CONFIG_ALTIVEC
 382         err |= __get_user(v_regs, &sc->v_regs);
 383         if (err)
 384                 return err;
 385         if (v_regs && !access_ok(VERIFY_READ, v_regs, 34 * sizeof(vector128)))
 386                 return -EFAULT;
 387         /* Copy 33 vec registers (vr0..31 and vscr) from the stack */
 388         if (v_regs != NULL && (msr & MSR_VEC) != 0) {
 389                 err |= __copy_from_user(&tsk->thread.vr_state, v_regs,
 390                                         33 * sizeof(vector128));
 391                 tsk->thread.used_vr = true;
 392         } else if (tsk->thread.used_vr) {
 393                 memset(&tsk->thread.vr_state, 0, 33 * sizeof(vector128));
 394         }
 395         /* Always get VRSAVE back */
 396         if (v_regs != NULL)
 397                 err |= __get_user(tsk->thread.vrsave, (u32 __user *)&v_regs[33]);
 398         else
 399                 tsk->thread.vrsave = 0;
 400         if (cpu_has_feature(CPU_FTR_ALTIVEC))
 401                 mtspr(SPRN_VRSAVE, tsk->thread.vrsave);
 402 #endif /* CONFIG_ALTIVEC */
 403         /* restore floating point */
 404         err |= copy_fpr_from_user(tsk, &sc->fp_regs);
 405 #ifdef CONFIG_VSX
 406         /*
 407          * Get additional VSX data. Update v_regs to point after the
 408          * VMX data.  Copy VSX low doubleword from userspace to local
 409          * buffer for formatting, then into the taskstruct.
 410          */
 411         v_regs += ELF_NVRREG;
 412         if ((msr & MSR_VSX) != 0) {
 413                 err |= copy_vsx_from_user(tsk, v_regs);
 414                 tsk->thread.used_vsr = true;
 415         } else {
 416                 for (i = 0; i < 32 ; i++)
 417                         tsk->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
 418         }
 419 #endif
 420         return err;
 421 }
 422
 423 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 424 /*
 425  * Restore the two sigcontexts from the frame of a transactional processes.
 426  */
 427
 428 static long restore_tm_sigcontexts(struct task_struct *tsk,
 429                                    struct sigcontext __user *sc,
 430                                    struct sigcontext __user *tm_sc)
 431 {
 432 #ifdef CONFIG_ALTIVEC
 433         elf_vrreg_t __user *v_regs, *tm_v_regs;
 434 #endif
 435         unsigned long err = 0;
 436         unsigned long msr;
 437         struct pt_regs *regs = tsk->thread.regs;
 438 #ifdef CONFIG_VSX
 439         int i;
 440 #endif
 441
 442         BUG_ON(tsk != current);
 443
 444         if (tm_suspend_disabled)
 445                 return -EINVAL;
 446
 447         /* copy the GPRs */
 448         err |= __copy_from_user(regs->gpr, tm_sc->gp_regs, sizeof(regs->gpr));
 449         err |= __copy_from_user(&tsk->thread.ckpt_regs, sc->gp_regs,
 450                                 sizeof(regs->gpr));
 451
 452         /*
 453          * TFHAR is restored from the checkpointed 'wound-back' ucontext's NIP.
 454          * TEXASR was set by the signal delivery reclaim, as was TFIAR.
 455          * Users doing anything abhorrent like thread-switching w/ signals for
 456          * TM-Suspended code will have to back TEXASR/TFIAR up themselves.
 457          * For the case of getting a signal and simply returning from it,
 458          * we don't need to re-copy them here.
 459          */
 460         err |= __get_user(regs->nip, &tm_sc->gp_regs[PT_NIP]);
 461         err |= __get_user(tsk->thread.tm_tfhar, &sc->gp_regs[PT_NIP]);
 462
 463         /* get MSR separately, transfer the LE bit if doing signal return */
 464         err |= __get_user(msr, &sc->gp_regs[PT_MSR]);
 465         /* Don't allow reserved mode. */
 466         if (MSR_TM_RESV(msr))
 467                 return -EINVAL;
 468
 469         /* pull in MSR TS bits from user context */
 470         regs->msr = (regs->msr & ~MSR_TS_MASK) | (msr & MSR_TS_MASK);
 471
 472         /*
 473          * Ensure that TM is enabled in regs->msr before we leave the signal
 474          * handler. It could be the case that (a) user disabled the TM bit
 475          * through the manipulation of the MSR bits in uc_mcontext or (b) the
 476          * TM bit was disabled because a sufficient number of context switches
 477          * happened whilst in the signal handler and load_tm overflowed,
 478          * disabling the TM bit. In either case we can end up with an illegal
 479          * TM state leading to a TM Bad Thing when we return to userspace.
 480          */
 481         regs->msr |= MSR_TM;
 482
 483         /* pull in MSR LE from user context */
 484         regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE);
 485
 486         /* The following non-GPR non-FPR non-VR state is also checkpointed: */
 487         err |= __get_user(regs->ctr, &tm_sc->gp_regs[PT_CTR]);
 488         err |= __get_user(regs->link, &tm_sc->gp_regs[PT_LNK]);
 489         err |= __get_user(regs->xer, &tm_sc->gp_regs[PT_XER]);
 490         err |= __get_user(regs->ccr, &tm_sc->gp_regs[PT_CCR]);
 491         err |= __get_user(tsk->thread.ckpt_regs.ctr,
 492                           &sc->gp_regs[PT_CTR]);
 493         err |= __get_user(tsk->thread.ckpt_regs.link,
 494                           &sc->gp_regs[PT_LNK]);
 495         err |= __get_user(tsk->thread.ckpt_regs.xer,
 496                           &sc->gp_regs[PT_XER]);
 497         err |= __get_user(tsk->thread.ckpt_regs.ccr,
 498                           &sc->gp_regs[PT_CCR]);
 499
 500         /* These regs are not checkpointed; they can go in 'regs'. */
 501         err |= __get_user(regs->trap, &sc->gp_regs[PT_TRAP]);
 502         err |= __get_user(regs->dar, &sc->gp_regs[PT_DAR]);
 503         err |= __get_user(regs->dsisr, &sc->gp_regs[PT_DSISR]);
 504         err |= __get_user(regs->result, &sc->gp_regs[PT_RESULT]);
 505
 506         /*
 507          * Force reload of FP/VEC.
 508          * This has to be done before copying stuff into tsk->thread.fpr/vr
 509          * for the reasons explained in the previous comment.
 510          */
 511         regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC | MSR_VSX);
 512
 513 #ifdef CONFIG_ALTIVEC
 514         err |= __get_user(v_regs, &sc->v_regs);
 515         err |= __get_user(tm_v_regs, &tm_sc->v_regs);
 516         if (err)
 517                 return err;
 518         if (v_regs && !access_ok(VERIFY_READ, v_regs, 34 * sizeof(vector128)))
 519                 return -EFAULT;
 520         if (tm_v_regs && !access_ok(VERIFY_READ,
 521                                     tm_v_regs, 34 * sizeof(vector128)))
 522                 return -EFAULT;
 523         /* Copy 33 vec registers (vr0..31 and vscr) from the stack */
 524         if (v_regs != NULL && tm_v_regs != NULL && (msr & MSR_VEC) != 0) {
 525                 err |= __copy_from_user(&tsk->thread.ckvr_state, v_regs,
 526                                         33 * sizeof(vector128));
 527                 err |= __copy_from_user(&tsk->thread.vr_state, tm_v_regs,
 528                                         33 * sizeof(vector128));
 529                 current->thread.used_vr = true;
 530         }
 531         else if (tsk->thread.used_vr) {
 532                 memset(&tsk->thread.vr_state, 0, 33 * sizeof(vector128));
 533                 memset(&tsk->thread.ckvr_state, 0, 33 * sizeof(vector128));
 534         }
 535         /* Always get VRSAVE back */
 536         if (v_regs != NULL && tm_v_regs != NULL) {
 537                 err |= __get_user(tsk->thread.ckvrsave,
 538                                   (u32 __user *)&v_regs[33]);
 539                 err |= __get_user(tsk->thread.vrsave,
 540                                   (u32 __user *)&tm_v_regs[33]);
 541         }
 542         else {
 543                 tsk->thread.vrsave = 0;
 544                 tsk->thread.ckvrsave = 0;
 545         }
 546         if (cpu_has_feature(CPU_FTR_ALTIVEC))
 547                 mtspr(SPRN_VRSAVE, tsk->thread.vrsave);
 548 #endif /* CONFIG_ALTIVEC */
 549         /* restore floating point */
 550         err |= copy_fpr_from_user(tsk, &tm_sc->fp_regs);
 551         err |= copy_ckfpr_from_user(tsk, &sc->fp_regs);
 552 #ifdef CONFIG_VSX
 553         /*
 554          * Get additional VSX data. Update v_regs to point after the
 555          * VMX data.  Copy VSX low doubleword from userspace to local
 556          * buffer for formatting, then into the taskstruct.
 557          */
 558         if (v_regs && ((msr & MSR_VSX) != 0)) {
 559                 v_regs += ELF_NVRREG;
 560                 tm_v_regs += ELF_NVRREG;
 561                 err |= copy_vsx_from_user(tsk, tm_v_regs);
 562                 err |= copy_ckvsx_from_user(tsk, v_regs);
 563                 tsk->thread.used_vsr = true;
 564         } else {
 565                 for (i = 0; i < 32 ; i++) {
 566                         tsk->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
 567                         tsk->thread.ckfp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
 568                 }
 569         }
 570 #endif
 571         tm_enable();
 572         /* Make sure the transaction is marked as failed */
 573         tsk->thread.tm_texasr |= TEXASR_FS;
 574         /* This loads the checkpointed FP/VEC state, if used */
 575         tm_recheckpoint(&tsk->thread);
 576
 577         msr_check_and_set(msr & (MSR_FP | MSR_VEC));
 578         if (msr & MSR_FP) {
 579                 load_fp_state(&tsk->thread.fp_state);
 580                 regs->msr |= (MSR_FP | tsk->thread.fpexc_mode);
 581         }
 582         if (msr & MSR_VEC) {
 583                 load_vr_state(&tsk->thread.vr_state);
 584                 regs->msr |= MSR_VEC;
 585         }
 586
 587         return err;
 588 }
 589 #endif
 590
 591 /*
 592  * Setup the trampoline code on the stack
 593  */
 594 static long setup_trampoline(unsigned int syscall, unsigned int __user *tramp)
 595 {
 596         int i;
 597         long err = 0;
 598
 599         /* addi r1, r1, __SIGNAL_FRAMESIZE  # Pop the dummy stackframe */
 600         err |= __put_user(0x38210000UL | (__SIGNAL_FRAMESIZE & 0xffff), &tramp[0]);
 601         /* li r0, __NR_[rt_]sigreturn| */
 602         err |= __put_user(0x38000000UL | (syscall & 0xffff), &tramp[1]);
 603         /* sc */
 604         err |= __put_user(0x44000002UL, &tramp[2]);
 605
 606         /* Minimal traceback info */
 607         for (i=TRAMP_TRACEBACK; i < TRAMP_SIZE ;i++)
 608                 err |= __put_user(0, &tramp[i]);
 609
 610         if (!err)
 611                 flush_icache_range((unsigned long) &tramp[0],
 612                            (unsigned long) &tramp[TRAMP_SIZE]);
 613
 614         return err;
 615 }
 616
 617 /*
 618  * Userspace code may pass a ucontext which doesn't include VSX added
 619  * at the end.  We need to check for this case.
 620  */
 621 #define UCONTEXTSIZEWITHOUTVSX \
 622                 (sizeof(struct ucontext) - 32*sizeof(long))
 623
 624 /*
 625  * Handle {get,set,swap}_context operations
 626  */
 627 int sys_swapcontext(struct ucontext __user *old_ctx,
 628                     struct ucontext __user *new_ctx,
 629                     long ctx_size, long r6, long r7, long r8, struct pt_regs *regs)
 630 {
 631         unsigned char tmp;
 632         sigset_t set;
 633         unsigned long new_msr = 0;
 634         int ctx_has_vsx_region = 0;
 635
 636         BUG_ON(regs != current->thread.regs);
 637
 638         if (new_ctx &&
 639             get_user(new_msr, &new_ctx->uc_mcontext.gp_regs[PT_MSR]))
 640                 return -EFAULT;
 641         /*
 642          * Check that the context is not smaller than the original
 643          * size (with VMX but without VSX)
 644          */
 645         if (ctx_size < UCONTEXTSIZEWITHOUTVSX)
 646                 return -EINVAL;
 647         /*
 648          * If the new context state sets the MSR VSX bits but
 649          * it doesn't provide VSX state.
 650          */
 651         if ((ctx_size < sizeof(struct ucontext)) &&
 652             (new_msr & MSR_VSX))
 653                 return -EINVAL;
 654         /* Does the context have enough room to store VSX data? */
 655         if (ctx_size >= sizeof(struct ucontext))
 656                 ctx_has_vsx_region = 1;
 657
 658         if (old_ctx != NULL) {
 659                 if (!access_ok(VERIFY_WRITE, old_ctx, ctx_size)
 660                     || setup_sigcontext(&old_ctx->uc_mcontext, current, 0, NULL, 0,
 661                                         ctx_has_vsx_region)
 662                     || __copy_to_user(&old_ctx->uc_sigmask,
 663                                       &current->blocked, sizeof(sigset_t)))
 664                         return -EFAULT;
 665         }
 666         if (new_ctx == NULL)
 667                 return 0;
 668         if (!access_ok(VERIFY_READ, new_ctx, ctx_size)
 669             || __get_user(tmp, (u8 __user *) new_ctx)
 670             || __get_user(tmp, (u8 __user *) new_ctx + ctx_size - 1))
 671                 return -EFAULT;
 672
 673         /*
 674          * If we get a fault copying the context into the kernel's
 675          * image of the user's registers, we can't just return -EFAULT
 676          * because the user's registers will be corrupted.  For instance
 677          * the NIP value may have been updated but not some of the
 678          * other registers.  Given that we have done the access_ok
 679          * and successfully read the first and last bytes of the region
 680          * above, this should only happen in an out-of-memory situation
 681          * or if another thread unmaps the region containing the context.
 682          * We kill the task with a SIGSEGV in this situation.
 683          */
 684
 685         if (__copy_from_user(&set, &new_ctx->uc_sigmask, sizeof(set)))
 686                 do_exit(SIGSEGV);
 687         set_current_blocked(&set);
 688         if (restore_sigcontext(current, NULL, 0, &new_ctx->uc_mcontext))
 689                 do_exit(SIGSEGV);
 690
 691         /* This returns like rt_sigreturn */
 692         set_thread_flag(TIF_RESTOREALL);
 693         return 0;
 694 }
 695
 696
 697 /*
 698  * Do a signal return; undo the signal stack.
 699  */
 700
 701 int sys_rt_sigreturn(unsigned long r3, unsigned long r4, unsigned long r5,
 702                      unsigned long r6, unsigned long r7, unsigned long r8,
 703                      struct pt_regs *regs)
 704 {
 705         struct ucontext __user *uc = (struct ucontext __user *)regs->gpr[1];
 706         sigset_t set;
 707 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 708         unsigned long msr;
 709 #endif
 710
 711         BUG_ON(current->thread.regs != regs);
 712
 713         /* Always make any pending restarted system calls return -EINTR */
 714         current->restart_block.fn = do_no_restart_syscall;
 715
 716         if (!access_ok(VERIFY_READ, uc, sizeof(*uc)))
 717                 goto badframe;
 718
 719         if (__copy_from_user(&set, &uc->uc_sigmask, sizeof(set)))
 720                 goto badframe;
 721         set_current_blocked(&set);
 722
 723 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 724         /*
 725          * If there is a transactional state then throw it away.
 726          * The purpose of a sigreturn is to destroy all traces of the
 727          * signal frame, this includes any transactional state created
 728          * within in. We only check for suspended as we can never be
 729          * active in the kernel, we are active, there is nothing better to
 730          * do than go ahead and Bad Thing later.
 731          * The cause is not important as there will never be a
 732          * recheckpoint so it's not user visible.
 733          */
 734         if (MSR_TM_SUSPENDED(mfmsr()))
 735                 tm_reclaim_current(0);
 736
 737         if (__get_user(msr, &uc->uc_mcontext.gp_regs[PT_MSR]))
 738                 goto badframe;
 739         if (MSR_TM_ACTIVE(msr)) {
 740                 /* We recheckpoint on return. */
 741                 struct ucontext __user *uc_transact;
 742                 if (__get_user(uc_transact, &uc->uc_link))
 743                         goto badframe;
 744                 if (restore_tm_sigcontexts(current, &uc->uc_mcontext,
 745                                            &uc_transact->uc_mcontext))
 746                         goto badframe;
 747         }
 748         else
 749         /* Fall through, for non-TM restore */
 750 #endif
 751         if (restore_sigcontext(current, NULL, 1, &uc->uc_mcontext))
 752                 goto badframe;
 753
 754         if (restore_altstack(&uc->uc_stack))
 755                 goto badframe;
 756
 757         set_thread_flag(TIF_RESTOREALL);
 758         return 0;
 759
 760 badframe:
 761         if (show_unhandled_signals)
 762                 printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32,
 763                                    current->comm, current->pid, "rt_sigreturn",
 764                                    (long)uc, regs->nip, regs->link);
 765
 766         force_sig(SIGSEGV, current);
 767         return 0;
 768 }
 769
 770 int handle_rt_signal64(struct ksignal *ksig, sigset_t *set,
 771                 struct task_struct *tsk)
 772 {
 773         struct rt_sigframe __user *frame;
 774         unsigned long newsp = 0;
 775         long err = 0;
 776         struct pt_regs *regs = tsk->thread.regs;
 777
 778         BUG_ON(tsk != current);
 779
 780         frame = get_sigframe(ksig, get_tm_stackpointer(tsk), sizeof(*frame), 0);
 781         if (unlikely(frame == NULL))
 782                 goto badframe;
 783
 784         err |= __put_user(&frame->info, &frame->pinfo);
 785         err |= __put_user(&frame->uc, &frame->puc);
 786         err |= copy_siginfo_to_user(&frame->info, &ksig->info);
 787         if (err)
 788                 goto badframe;
 789
 790         /* Create the ucontext.  */
 791         err |= __put_user(0, &frame->uc.uc_flags);
 792         err |= __save_altstack(&frame->uc.uc_stack, regs->gpr[1]);
 793 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 794         if (MSR_TM_ACTIVE(regs->msr)) {
 795                 /* The ucontext_t passed to userland points to the second
 796                  * ucontext_t (for transactional state) with its uc_link ptr.
 797                  */
 798                 err |= __put_user(&frame->uc_transact, &frame->uc.uc_link);
 799                 err |= setup_tm_sigcontexts(&frame->uc.uc_mcontext,
 800                                             &frame->uc_transact.uc_mcontext,
 801                                             tsk, ksig->sig, NULL,
 802                                             (unsigned long)ksig->ka.sa.sa_handler);
 803         } else
 804 #endif
 805         {
 806                 err |= __put_user(0, &frame->uc.uc_link);
 807                 err |= setup_sigcontext(&frame->uc.uc_mcontext, tsk, ksig->sig,
 808                                         NULL, (unsigned long)ksig->ka.sa.sa_handler,
 809                                         1);
 810         }
 811         err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
 812         if (err)
 813                 goto badframe;
 814
 815         /* Make sure signal handler doesn't get spurious FP exceptions */
 816         tsk->thread.fp_state.fpscr = 0;
 817
 818         /* Set up to return from userspace. */
 819         if (vdso64_rt_sigtramp && tsk->mm->context.vdso_base) {
 820                 regs->link = tsk->mm->context.vdso_base + vdso64_rt_sigtramp;
 821         } else {
 822                 err |= setup_trampoline(__NR_rt_sigreturn, &frame->tramp[0]);
 823                 if (err)
 824                         goto badframe;
 825                 regs->link = (unsigned long) &frame->tramp[0];
 826         }
 827
 828         /* Allocate a dummy caller frame for the signal handler. */
 829         newsp = ((unsigned long)frame) - __SIGNAL_FRAMESIZE;
 830         err |= put_user(regs->gpr[1], (unsigned long __user *)newsp);
 831
 832         /* Set up "regs" so we "return" to the signal handler. */
 833         if (is_elf2_task()) {
 834                 regs->nip = (unsigned long) ksig->ka.sa.sa_handler;
 835                 regs->gpr[12] = regs->nip;
 836         } else {
 837                 /* Handler is *really* a pointer to the function descriptor for
 838                  * the signal routine.  The first entry in the function
 839                  * descriptor is the entry address of signal and the second
 840                  * entry is the TOC value we need to use.
 841                  */
 842                 func_descr_t __user *funct_desc_ptr =
 843                         (func_descr_t __user *) ksig->ka.sa.sa_handler;
 844
 845                 err |= get_user(regs->nip, &funct_desc_ptr->entry);
 846                 err |= get_user(regs->gpr[2], &funct_desc_ptr->toc);
 847         }
 848
 849         /* enter the signal handler in native-endian mode */
 850         regs->msr &= ~MSR_LE;
 851         regs->msr |= (MSR_KERNEL & MSR_LE);
 852         regs->gpr[1] = newsp;
 853         regs->gpr[3] = ksig->sig;
 854         regs->result = 0;
 855         if (ksig->ka.sa.sa_flags & SA_SIGINFO) {
 856                 err |= get_user(regs->gpr[4], (unsigned long __user *)&frame->pinfo);
 857                 err |= get_user(regs->gpr[5], (unsigned long __user *)&frame->puc);
 858                 regs->gpr[6] = (unsigned long) frame;
 859         } else {
 860                 regs->gpr[4] = (unsigned long)&frame->uc.uc_mcontext;
 861         }
 862         if (err)
 863                 goto badframe;
 864
 865         return 0;
 866
 867 badframe:
 868         if (show_unhandled_signals)
 869                 printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32,
 870                                    tsk->comm, tsk->pid, "setup_rt_frame",
 871                                    (long)frame, regs->nip, regs->link);
 872
 873         return 1;
 874 }