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