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