arch/powerpc/kernel/signal_64.c

   1 /*
   2  *  PowerPC version
   3  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
   4  *
   5  *  Derived from "arch/i386/kernel/signal.c"
   6  *    Copyright (C) 1991, 1992 Linus Torvalds
   7  *    1997-11-28  Modified for POSIX.1b signals by Richard Henderson
   8  *
   9  *  This program is free software; you can redistribute it and/or
  10  *  modify it under the terms of the GNU General Public License
  11  *  as published by the Free Software Foundation; either version
  12  *  2 of the License, or (at your option) any later version.
  13  */
  14
  15 #include <linux/sched.h>
  16 #include <linux/mm.h>
  17 #include <linux/smp.h>
  18 #include <linux/kernel.h>
  19 #include <linux/signal.h>
  20 #include <linux/errno.h>
  21 #include <linux/wait.h>
  22 #include <linux/unistd.h>
  23 #include <linux/stddef.h>
  24 #include <linux/elf.h>
  25 #include <linux/ptrace.h>
  26 #include <linux/ratelimit.h>
  27
  28 #include <asm/sigcontext.h>
  29 #include <asm/ucontext.h>
  30 #include <asm/uaccess.h>
  31 #include <asm/pgtable.h>
  32 #include <asm/unistd.h>
  33 #include <asm/cacheflush.h>
  34 #include <asm/syscalls.h>
  35 #include <asm/vdso.h>
  36 #include <asm/switch_to.h>
  37 #include <asm/tm.h>
  38
  39 #include "signal.h"
  40
  41 #define DEBUG_SIG 0
  42
  43 #define GP_REGS_SIZE    min(sizeof(elf_gregset_t), sizeof(struct pt_regs))
  44 #define FP_REGS_SIZE    sizeof(elf_fpregset_t)
  45
  46 #define TRAMP_TRACEBACK 3
  47 #define TRAMP_SIZE      6
  48
  49 /*
  50  * When we have signals to deliver, we set up on the user stack,
  51  * going down from the original stack pointer:
  52  *      1) a rt_sigframe struct which contains the ucontext
  53  *      2) a gap of __SIGNAL_FRAMESIZE bytes which acts as a dummy caller
  54  *         frame for the signal handler.
  55  */
  56
  57 struct rt_sigframe {
  58         /* sys_rt_sigreturn requires the ucontext be the first field */
  59         struct ucontext uc;
  60 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
  61         struct ucontext uc_transact;
  62 #endif
  63         unsigned long _unused[2];
  64         unsigned int tramp[TRAMP_SIZE];
  65         struct siginfo __user *pinfo;
  66         void __user *puc;
  67         struct siginfo info;
  68         /* 64 bit ABI allows for 288 bytes below sp before decrementing it. */
  69         char abigap[288];
  70 } __attribute__ ((aligned (16)));
  71
  72 static const char fmt32[] = KERN_INFO \
  73         "%s[%d]: bad frame in %s: %08lx nip %08lx lr %08lx\n";
  74 static const char fmt64[] = KERN_INFO \
  75         "%s[%d]: bad frame in %s: %016lx nip %016lx lr %016lx\n";
  76
  77 /*
  78  * Set up the sigcontext for the signal frame.
  79  */
  80
  81 static long setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
  82                  int signr, sigset_t *set, unsigned long handler,
  83                  int ctx_has_vsx_region)
  84 {
  85         /* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the
  86          * process never used altivec yet (MSR_VEC is zero in pt_regs of
  87          * the context). This is very important because we must ensure we
  88          * don't lose the VRSAVE content that may have been set prior to
  89          * the process doing its first vector operation
  90          * Userland shall check AT_HWCAP to know whether it can rely on the
  91          * v_regs pointer or not
  92          */
  93 #ifdef CONFIG_ALTIVEC
  94         elf_vrreg_t __user *v_regs = (elf_vrreg_t __user *)(((unsigned long)sc->vmx_reserve + 15) & ~0xful);
  95 #endif
  96         unsigned long msr = regs->msr;
  97         long err = 0;
  98
  99 #ifdef CONFIG_ALTIVEC
 100         err |= __put_user(v_regs, &sc->v_regs);
 101
 102         /* save altivec registers */
 103         if (current->thread.used_vr) {
 104                 flush_altivec_to_thread(current);
 105                 /* Copy 33 vec registers (vr0..31 and vscr) to the stack */
 106                 err |= __copy_to_user(v_regs, &current->thread.vr_state,
 107                                       33 * sizeof(vector128));
 108                 /* set MSR_VEC in the MSR value in the frame to indicate that sc->v_reg)
 109                  * contains valid data.
 110                  */
 111                 msr |= MSR_VEC;
 112         }
 113         /* We always copy to/from vrsave, it's 0 if we don't have or don't
 114          * use altivec.
 115          */
 116         if (cpu_has_feature(CPU_FTR_ALTIVEC))
 117                 current->thread.vrsave = mfspr(SPRN_VRSAVE);
 118         err |= __put_user(current->thread.vrsave, (u32 __user *)&v_regs[33]);
 119 #else /* CONFIG_ALTIVEC */
 120         err |= __put_user(0, &sc->v_regs);
 121 #endif /* CONFIG_ALTIVEC */
 122         flush_fp_to_thread(current);
 123         /* copy fpr regs and fpscr */
 124         err |= copy_fpr_to_user(&sc->fp_regs, current);
 125
 126         /*
 127          * Clear the MSR VSX bit to indicate there is no valid state attached
 128          * to this context, except in the specific case below where we set it.
 129          */
 130         msr &= ~MSR_VSX;
 131 #ifdef CONFIG_VSX
 132         /*
 133          * Copy VSX low doubleword to local buffer for formatting,
 134          * then out to userspace.  Update v_regs to point after the
 135          * VMX data.
 136          */
 137         if (current->thread.used_vsr && ctx_has_vsx_region) {
 138                 __giveup_vsx(current);
 139                 v_regs += ELF_NVRREG;
 140                 err |= copy_vsx_to_user(v_regs, current);
 141                 /* set MSR_VSX in the MSR value in the frame to
 142                  * indicate that sc->vs_reg) contains valid data.
 143                  */
 144                 msr |= MSR_VSX;
 145         }
 146 #endif /* CONFIG_VSX */
 147         err |= __put_user(&sc->gp_regs, &sc->regs);
 148         WARN_ON(!FULL_REGS(regs));
 149         err |= __copy_to_user(&sc->gp_regs, regs, GP_REGS_SIZE);
 150         err |= __put_user(msr, &sc->gp_regs[PT_MSR]);
 151         err |= __put_user(signr, &sc->signal);
 152         err |= __put_user(handler, &sc->handler);
 153         if (set != NULL)
 154                 err |=  __put_user(set->sig[0], &sc->oldmask);
 155
 156         return err;
 157 }
 158
 159 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 160 /*
 161  * As above, but Transactional Memory is in use, so deliver sigcontexts
 162  * containing checkpointed and transactional register states.
 163  *
 164  * To do this, we treclaim (done before entering here) to gather both sets of
 165  * registers and set up the 'normal' sigcontext registers with rolled-back
 166  * register values such that a simple signal handler sees a correct
 167  * checkpointed register state.  If interested, a TM-aware sighandler can
 168  * examine the transactional registers in the 2nd sigcontext to determine the
 169  * real origin of the signal.
 170  */
 171 static long setup_tm_sigcontexts(struct sigcontext __user *sc,
 172                                  struct sigcontext __user *tm_sc,
 173                                  struct pt_regs *regs,
 174                                  int signr, sigset_t *set, unsigned long handler)
 175 {
 176         /* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the
 177          * process never used altivec yet (MSR_VEC is zero in pt_regs of
 178          * the context). This is very important because we must ensure we
 179          * don't lose the VRSAVE content that may have been set prior to
 180          * the process doing its first vector operation
 181          * Userland shall check AT_HWCAP to know wether it can rely on the
 182          * v_regs pointer or not.
 183          */
 184 #ifdef CONFIG_ALTIVEC
 185         elf_vrreg_t __user *v_regs = (elf_vrreg_t __user *)
 186                 (((unsigned long)sc->vmx_reserve + 15) & ~0xful);
 187         elf_vrreg_t __user *tm_v_regs = (elf_vrreg_t __user *)
 188                 (((unsigned long)tm_sc->vmx_reserve + 15) & ~0xful);
 189 #endif
 190         unsigned long msr = regs->msr;
 191         long err = 0;
 192
 193         BUG_ON(!MSR_TM_ACTIVE(regs->msr));
 194
 195         flush_fp_to_thread(current);
 196
 197 #ifdef CONFIG_ALTIVEC
 198         err |= __put_user(v_regs, &sc->v_regs);
 199         err |= __put_user(tm_v_regs, &tm_sc->v_regs);
 200
 201         /* save altivec registers */
 202         if (current->thread.used_vr) {
 203                 flush_altivec_to_thread(current);
 204                 /* Copy 33 vec registers (vr0..31 and vscr) to the stack */
 205                 err |= __copy_to_user(v_regs, &current->thread.vr_state,
 206                                       33 * sizeof(vector128));
 207                 /* If VEC was enabled there are transactional VRs valid too,
 208                  * else they're a copy of the checkpointed VRs.
 209                  */
 210                 if (msr & MSR_VEC)
 211                         err |= __copy_to_user(tm_v_regs,
 212                                               &current->thread.transact_vr,
 213                                               33 * sizeof(vector128));
 214                 else
 215                         err |= __copy_to_user(tm_v_regs,
 216                                               &current->thread.vr_state,
 217                                               33 * sizeof(vector128));
 218
 219                 /* set MSR_VEC in the MSR value in the frame to indicate
 220                  * that sc->v_reg contains valid data.
 221                  */
 222                 msr |= MSR_VEC;
 223         }
 224         /* We always copy to/from vrsave, it's 0 if we don't have or don't
 225          * use altivec.
 226          */
 227         if (cpu_has_feature(CPU_FTR_ALTIVEC))
 228                 current->thread.vrsave = mfspr(SPRN_VRSAVE);
 229         err |= __put_user(current->thread.vrsave, (u32 __user *)&v_regs[33]);
 230         if (msr & MSR_VEC)
 231                 err |= __put_user(current->thread.transact_vrsave,
 232                                   (u32 __user *)&tm_v_regs[33]);
 233         else
 234                 err |= __put_user(current->thread.vrsave,
 235                                   (u32 __user *)&tm_v_regs[33]);
 236
 237 #else /* CONFIG_ALTIVEC */
 238         err |= __put_user(0, &sc->v_regs);
 239         err |= __put_user(0, &tm_sc->v_regs);
 240 #endif /* CONFIG_ALTIVEC */
 241
 242         /* copy fpr regs and fpscr */
 243         err |= copy_fpr_to_user(&sc->fp_regs, current);
 244         if (msr & MSR_FP)
 245                 err |= copy_transact_fpr_to_user(&tm_sc->fp_regs, current);
 246         else
 247                 err |= copy_fpr_to_user(&tm_sc->fp_regs, current);
 248
 249 #ifdef CONFIG_VSX
 250         /*
 251          * Copy VSX low doubleword to local buffer for formatting,
 252          * then out to userspace.  Update v_regs to point after the
 253          * VMX data.
 254          */
 255         if (current->thread.used_vsr) {
 256                 __giveup_vsx(current);
 257                 v_regs += ELF_NVRREG;
 258                 tm_v_regs += ELF_NVRREG;
 259
 260                 err |= copy_vsx_to_user(v_regs, current);
 261
 262                 if (msr & MSR_VSX)
 263                         err |= copy_transact_vsx_to_user(tm_v_regs, current);
 264                 else
 265                         err |= copy_vsx_to_user(tm_v_regs, current);
 266
 267                 /* set MSR_VSX in the MSR value in the frame to
 268                  * indicate that sc->vs_reg) contains valid data.
 269                  */
 270                 msr |= MSR_VSX;
 271         }
 272 #endif /* CONFIG_VSX */
 273
 274         err |= __put_user(&sc->gp_regs, &sc->regs);
 275         err |= __put_user(&tm_sc->gp_regs, &tm_sc->regs);
 276         WARN_ON(!FULL_REGS(regs));
 277         err |= __copy_to_user(&tm_sc->gp_regs, regs, GP_REGS_SIZE);
 278         err |= __copy_to_user(&sc->gp_regs,
 279                               &current->thread.ckpt_regs, GP_REGS_SIZE);
 280         err |= __put_user(msr, &tm_sc->gp_regs[PT_MSR]);
 281         err |= __put_user(msr, &sc->gp_regs[PT_MSR]);
 282         err |= __put_user(signr, &sc->signal);
 283         err |= __put_user(handler, &sc->handler);
 284         if (set != NULL)
 285                 err |=  __put_user(set->sig[0], &sc->oldmask);
 286
 287         return err;
 288 }
 289 #endif
 290
 291 /*
 292  * Restore the sigcontext from the signal frame.
 293  */
 294
 295 static long restore_sigcontext(struct pt_regs *regs, sigset_t *set, int sig,
 296                               struct sigcontext __user *sc)
 297 {
 298 #ifdef CONFIG_ALTIVEC
 299         elf_vrreg_t __user *v_regs;
 300 #endif
 301         unsigned long err = 0;
 302         unsigned long save_r13 = 0;
 303         unsigned long msr;
 304 #ifdef CONFIG_VSX
 305         int i;
 306 #endif
 307
 308         /* If this is not a signal return, we preserve the TLS in r13 */
 309         if (!sig)
 310                 save_r13 = regs->gpr[13];
 311
 312         /* copy the GPRs */
 313         err |= __copy_from_user(regs->gpr, sc->gp_regs, sizeof(regs->gpr));
 314         err |= __get_user(regs->nip, &sc->gp_regs[PT_NIP]);
 315         /* get MSR separately, transfer the LE bit if doing signal return */
 316         err |= __get_user(msr, &sc->gp_regs[PT_MSR]);
 317         if (sig)
 318                 regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE);
 319         err |= __get_user(regs->orig_gpr3, &sc->gp_regs[PT_ORIG_R3]);
 320         err |= __get_user(regs->ctr, &sc->gp_regs[PT_CTR]);
 321         err |= __get_user(regs->link, &sc->gp_regs[PT_LNK]);
 322         err |= __get_user(regs->xer, &sc->gp_regs[PT_XER]);
 323         err |= __get_user(regs->ccr, &sc->gp_regs[PT_CCR]);
 324         /* skip SOFTE */
 325         regs->trap = 0;
 326         err |= __get_user(regs->dar, &sc->gp_regs[PT_DAR]);
 327         err |= __get_user(regs->dsisr, &sc->gp_regs[PT_DSISR]);
 328         err |= __get_user(regs->result, &sc->gp_regs[PT_RESULT]);
 329
 330         if (!sig)
 331                 regs->gpr[13] = save_r13;
 332         if (set != NULL)
 333                 err |=  __get_user(set->sig[0], &sc->oldmask);
 334
 335         /*
 336          * Do this before updating the thread state in
 337          * current->thread.fpr/vr.  That way, if we get preempted
 338          * and another task grabs the FPU/Altivec, it won't be
 339          * tempted to save the current CPU state into the thread_struct
 340          * and corrupt what we are writing there.
 341          */
 342         discard_lazy_cpu_state();
 343
 344         /*
 345          * Force reload of FP/VEC.
 346          * This has to be done before copying stuff into current->thread.fpr/vr
 347          * for the reasons explained in the previous comment.
 348          */
 349         regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC | MSR_VSX);
 350
 351 #ifdef CONFIG_ALTIVEC
 352         err |= __get_user(v_regs, &sc->v_regs);
 353         if (err)
 354                 return err;
 355         if (v_regs && !access_ok(VERIFY_READ, v_regs, 34 * sizeof(vector128)))
 356                 return -EFAULT;
 357         /* Copy 33 vec registers (vr0..31 and vscr) from the stack */
 358         if (v_regs != NULL && (msr & MSR_VEC) != 0)
 359                 err |= __copy_from_user(&current->thread.vr_state, v_regs,
 360                                         33 * sizeof(vector128));
 361         else if (current->thread.used_vr)
 362                 memset(&current->thread.vr_state, 0, 33 * sizeof(vector128));
 363         /* Always get VRSAVE back */
 364         if (v_regs != NULL)
 365                 err |= __get_user(current->thread.vrsave, (u32 __user *)&v_regs[33]);
 366         else
 367                 current->thread.vrsave = 0;
 368         if (cpu_has_feature(CPU_FTR_ALTIVEC))
 369                 mtspr(SPRN_VRSAVE, current->thread.vrsave);
 370 #endif /* CONFIG_ALTIVEC */
 371         /* restore floating point */
 372         err |= copy_fpr_from_user(current, &sc->fp_regs);
 373 #ifdef CONFIG_VSX
 374         /*
 375          * Get additional VSX data. Update v_regs to point after the
 376          * VMX data.  Copy VSX low doubleword from userspace to local
 377          * buffer for formatting, then into the taskstruct.
 378          */
 379         v_regs += ELF_NVRREG;
 380         if ((msr & MSR_VSX) != 0)
 381                 err |= copy_vsx_from_user(current, v_regs);
 382         else
 383                 for (i = 0; i < 32 ; i++)
 384                         current->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
 385 #endif
 386         return err;
 387 }
 388
 389 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 390 /*
 391  * Restore the two sigcontexts from the frame of a transactional processes.
 392  */
 393
 394 static long restore_tm_sigcontexts(struct pt_regs *regs,
 395                                    struct sigcontext __user *sc,
 396                                    struct sigcontext __user *tm_sc)
 397 {
 398 #ifdef CONFIG_ALTIVEC
 399         elf_vrreg_t __user *v_regs, *tm_v_regs;
 400 #endif
 401         unsigned long err = 0;
 402         unsigned long msr;
 403 #ifdef CONFIG_VSX
 404         int i;
 405 #endif
 406         /* copy the GPRs */
 407         err |= __copy_from_user(regs->gpr, tm_sc->gp_regs, sizeof(regs->gpr));
 408         err |= __copy_from_user(&current->thread.ckpt_regs, sc->gp_regs,
 409                                 sizeof(regs->gpr));
 410
 411         /*
 412          * TFHAR is restored from the checkpointed 'wound-back' ucontext's NIP.
 413          * TEXASR was set by the signal delivery reclaim, as was TFIAR.
 414          * Users doing anything abhorrent like thread-switching w/ signals for
 415          * TM-Suspended code will have to back TEXASR/TFIAR up themselves.
 416          * For the case of getting a signal and simply returning from it,
 417          * we don't need to re-copy them here.
 418          */
 419         err |= __get_user(regs->nip, &tm_sc->gp_regs[PT_NIP]);
 420         err |= __get_user(current->thread.tm_tfhar, &sc->gp_regs[PT_NIP]);
 421
 422         /* get MSR separately, transfer the LE bit if doing signal return */
 423         err |= __get_user(msr, &sc->gp_regs[PT_MSR]);
 424         /* pull in MSR TM from user context */
 425         regs->msr = (regs->msr & ~MSR_TS_MASK) | (msr & MSR_TS_MASK);
 426
 427         /* pull in MSR LE from user context */
 428         regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE);
 429
 430         /* The following non-GPR non-FPR non-VR state is also checkpointed: */
 431         err |= __get_user(regs->ctr, &tm_sc->gp_regs[PT_CTR]);
 432         err |= __get_user(regs->link, &tm_sc->gp_regs[PT_LNK]);
 433         err |= __get_user(regs->xer, &tm_sc->gp_regs[PT_XER]);
 434         err |= __get_user(regs->ccr, &tm_sc->gp_regs[PT_CCR]);
 435         err |= __get_user(current->thread.ckpt_regs.ctr,
 436                           &sc->gp_regs[PT_CTR]);
 437         err |= __get_user(current->thread.ckpt_regs.link,
 438                           &sc->gp_regs[PT_LNK]);
 439         err |= __get_user(current->thread.ckpt_regs.xer,
 440                           &sc->gp_regs[PT_XER]);
 441         err |= __get_user(current->thread.ckpt_regs.ccr,
 442                           &sc->gp_regs[PT_CCR]);
 443
 444         /* These regs are not checkpointed; they can go in 'regs'. */
 445         err |= __get_user(regs->trap, &sc->gp_regs[PT_TRAP]);
 446         err |= __get_user(regs->dar, &sc->gp_regs[PT_DAR]);
 447         err |= __get_user(regs->dsisr, &sc->gp_regs[PT_DSISR]);
 448         err |= __get_user(regs->result, &sc->gp_regs[PT_RESULT]);
 449
 450         /*
 451          * Do this before updating the thread state in
 452          * current->thread.fpr/vr.  That way, if we get preempted
 453          * and another task grabs the FPU/Altivec, it won't be
 454          * tempted to save the current CPU state into the thread_struct
 455          * and corrupt what we are writing there.
 456          */
 457         discard_lazy_cpu_state();
 458
 459         /*
 460          * Force reload of FP/VEC.
 461          * This has to be done before copying stuff into current->thread.fpr/vr
 462          * for the reasons explained in the previous comment.
 463          */
 464         regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC | MSR_VSX);
 465
 466 #ifdef CONFIG_ALTIVEC
 467         err |= __get_user(v_regs, &sc->v_regs);
 468         err |= __get_user(tm_v_regs, &tm_sc->v_regs);
 469         if (err)
 470                 return err;
 471         if (v_regs && !access_ok(VERIFY_READ, v_regs, 34 * sizeof(vector128)))
 472                 return -EFAULT;
 473         if (tm_v_regs && !access_ok(VERIFY_READ,
 474                                     tm_v_regs, 34 * sizeof(vector128)))
 475                 return -EFAULT;
 476         /* Copy 33 vec registers (vr0..31 and vscr) from the stack */
 477         if (v_regs != NULL && tm_v_regs != NULL && (msr & MSR_VEC) != 0) {
 478                 err |= __copy_from_user(&current->thread.vr_state, v_regs,
 479                                         33 * sizeof(vector128));
 480                 err |= __copy_from_user(&current->thread.transact_vr, tm_v_regs,
 481                                         33 * sizeof(vector128));
 482         }
 483         else if (current->thread.used_vr) {
 484                 memset(&current->thread.vr_state, 0, 33 * sizeof(vector128));
 485                 memset(&current->thread.transact_vr, 0, 33 * sizeof(vector128));
 486         }
 487         /* Always get VRSAVE back */
 488         if (v_regs != NULL && tm_v_regs != NULL) {
 489                 err |= __get_user(current->thread.vrsave,
 490                                   (u32 __user *)&v_regs[33]);
 491                 err |= __get_user(current->thread.transact_vrsave,
 492                                   (u32 __user *)&tm_v_regs[33]);
 493         }
 494         else {
 495                 current->thread.vrsave = 0;
 496                 current->thread.transact_vrsave = 0;
 497         }
 498         if (cpu_has_feature(CPU_FTR_ALTIVEC))
 499                 mtspr(SPRN_VRSAVE, current->thread.vrsave);
 500 #endif /* CONFIG_ALTIVEC */
 501         /* restore floating point */
 502         err |= copy_fpr_from_user(current, &sc->fp_regs);
 503         err |= copy_transact_fpr_from_user(current, &tm_sc->fp_regs);
 504 #ifdef CONFIG_VSX
 505         /*
 506          * Get additional VSX data. Update v_regs to point after the
 507          * VMX data.  Copy VSX low doubleword from userspace to local
 508          * buffer for formatting, then into the taskstruct.
 509          */
 510         if (v_regs && ((msr & MSR_VSX) != 0)) {
 511                 v_regs += ELF_NVRREG;
 512                 tm_v_regs += ELF_NVRREG;
 513                 err |= copy_vsx_from_user(current, v_regs);
 514                 err |= copy_transact_vsx_from_user(current, tm_v_regs);
 515         } else {
 516                 for (i = 0; i < 32 ; i++) {
 517                         current->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
 518                         current->thread.transact_fp.fpr[i][TS_VSRLOWOFFSET] = 0;
 519                 }
 520         }
 521 #endif
 522         tm_enable();
 523         /* This loads the checkpointed FP/VEC state, if used */
 524         tm_recheckpoint(&current->thread, msr);
 525
 526         /* This loads the speculative FP/VEC state, if used */
 527         if (msr & MSR_FP) {
 528                 do_load_up_transact_fpu(&current->thread);
 529                 regs->msr |= (MSR_FP | current->thread.fpexc_mode);
 530         }
 531 #ifdef CONFIG_ALTIVEC
 532         if (msr & MSR_VEC) {
 533                 do_load_up_transact_altivec(&current->thread);
 534                 regs->msr |= MSR_VEC;
 535         }
 536 #endif
 537
 538         return err;
 539 }
 540 #endif
 541
 542 /*
 543  * Setup the trampoline code on the stack
 544  */
 545 static long setup_trampoline(unsigned int syscall, unsigned int __user *tramp)
 546 {
 547         int i;
 548         long err = 0;
 549
 550         /* addi r1, r1, __SIGNAL_FRAMESIZE  # Pop the dummy stackframe */
 551         err |= __put_user(0x38210000UL | (__SIGNAL_FRAMESIZE & 0xffff), &tramp[0]);
 552         /* li r0, __NR_[rt_]sigreturn| */
 553         err |= __put_user(0x38000000UL | (syscall & 0xffff), &tramp[1]);
 554         /* sc */
 555         err |= __put_user(0x44000002UL, &tramp[2]);
 556
 557         /* Minimal traceback info */
 558         for (i=TRAMP_TRACEBACK; i < TRAMP_SIZE ;i++)
 559                 err |= __put_user(0, &tramp[i]);
 560
 561         if (!err)
 562                 flush_icache_range((unsigned long) &tramp[0],
 563                            (unsigned long) &tramp[TRAMP_SIZE]);
 564
 565         return err;
 566 }
 567
 568 /*
 569  * Userspace code may pass a ucontext which doesn't include VSX added
 570  * at the end.  We need to check for this case.
 571  */
 572 #define UCONTEXTSIZEWITHOUTVSX \
 573                 (sizeof(struct ucontext) - 32*sizeof(long))
 574
 575 /*
 576  * Handle {get,set,swap}_context operations
 577  */
 578 int sys_swapcontext(struct ucontext __user *old_ctx,
 579                     struct ucontext __user *new_ctx,
 580                     long ctx_size, long r6, long r7, long r8, struct pt_regs *regs)
 581 {
 582         unsigned char tmp;
 583         sigset_t set;
 584         unsigned long new_msr = 0;
 585         int ctx_has_vsx_region = 0;
 586
 587         if (new_ctx &&
 588             get_user(new_msr, &new_ctx->uc_mcontext.gp_regs[PT_MSR]))
 589                 return -EFAULT;
 590         /*
 591          * Check that the context is not smaller than the original
 592          * size (with VMX but without VSX)
 593          */
 594         if (ctx_size < UCONTEXTSIZEWITHOUTVSX)
 595                 return -EINVAL;
 596         /*
 597          * If the new context state sets the MSR VSX bits but
 598          * it doesn't provide VSX state.
 599          */
 600         if ((ctx_size < sizeof(struct ucontext)) &&
 601             (new_msr & MSR_VSX))
 602                 return -EINVAL;
 603         /* Does the context have enough room to store VSX data? */
 604         if (ctx_size >= sizeof(struct ucontext))
 605                 ctx_has_vsx_region = 1;
 606
 607         if (old_ctx != NULL) {
 608                 if (!access_ok(VERIFY_WRITE, old_ctx, ctx_size)
 609                     || setup_sigcontext(&old_ctx->uc_mcontext, regs, 0, NULL, 0,
 610                                         ctx_has_vsx_region)
 611                     || __copy_to_user(&old_ctx->uc_sigmask,
 612                                       &current->blocked, sizeof(sigset_t)))
 613                         return -EFAULT;
 614         }
 615         if (new_ctx == NULL)
 616                 return 0;
 617         if (!access_ok(VERIFY_READ, new_ctx, ctx_size)
 618             || __get_user(tmp, (u8 __user *) new_ctx)
 619             || __get_user(tmp, (u8 __user *) new_ctx + ctx_size - 1))
 620                 return -EFAULT;
 621
 622         /*
 623          * If we get a fault copying the context into the kernel's
 624          * image of the user's registers, we can't just return -EFAULT
 625          * because the user's registers will be corrupted.  For instance
 626          * the NIP value may have been updated but not some of the
 627          * other registers.  Given that we have done the access_ok
 628          * and successfully read the first and last bytes of the region
 629          * above, this should only happen in an out-of-memory situation
 630          * or if another thread unmaps the region containing the context.
 631          * We kill the task with a SIGSEGV in this situation.
 632          */
 633
 634         if (__copy_from_user(&set, &new_ctx->uc_sigmask, sizeof(set)))
 635                 do_exit(SIGSEGV);
 636         set_current_blocked(&set);
 637         if (restore_sigcontext(regs, NULL, 0, &new_ctx->uc_mcontext))
 638                 do_exit(SIGSEGV);
 639
 640         /* This returns like rt_sigreturn */
 641         set_thread_flag(TIF_RESTOREALL);
 642         return 0;
 643 }
 644
 645
 646 /*
 647  * Do a signal return; undo the signal stack.
 648  */
 649
 650 int sys_rt_sigreturn(unsigned long r3, unsigned long r4, unsigned long r5,
 651                      unsigned long r6, unsigned long r7, unsigned long r8,
 652                      struct pt_regs *regs)
 653 {
 654         struct ucontext __user *uc = (struct ucontext __user *)regs->gpr[1];
 655         sigset_t set;
 656 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 657         unsigned long msr;
 658 #endif
 659
 660         /* Always make any pending restarted system calls return -EINTR */
 661         current_thread_info()->restart_block.fn = do_no_restart_syscall;
 662
 663         if (!access_ok(VERIFY_READ, uc, sizeof(*uc)))
 664                 goto badframe;
 665
 666         if (__copy_from_user(&set, &uc->uc_sigmask, sizeof(set)))
 667                 goto badframe;
 668         set_current_blocked(&set);
 669 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 670         if (__get_user(msr, &uc->uc_mcontext.gp_regs[PT_MSR]))
 671                 goto badframe;
 672         if (MSR_TM_ACTIVE(msr)) {
 673                 /* We recheckpoint on return. */
 674                 struct ucontext __user *uc_transact;
 675                 if (__get_user(uc_transact, &uc->uc_link))
 676                         goto badframe;
 677                 if (restore_tm_sigcontexts(regs, &uc->uc_mcontext,
 678                                            &uc_transact->uc_mcontext))
 679                         goto badframe;
 680         }
 681         else
 682         /* Fall through, for non-TM restore */
 683 #endif
 684         if (restore_sigcontext(regs, NULL, 1, &uc->uc_mcontext))
 685                 goto badframe;
 686
 687         if (restore_altstack(&uc->uc_stack))
 688                 goto badframe;
 689
 690         set_thread_flag(TIF_RESTOREALL);
 691         return 0;
 692
 693 badframe:
 694 #if DEBUG_SIG
 695         printk("badframe in sys_rt_sigreturn, regs=%p uc=%p &uc->uc_mcontext=%p\n",
 696                regs, uc, &uc->uc_mcontext);
 697 #endif
 698         if (show_unhandled_signals)
 699                 printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32,
 700                                    current->comm, current->pid, "rt_sigreturn",
 701                                    (long)uc, regs->nip, regs->link);
 702
 703         force_sig(SIGSEGV, current);
 704         return 0;
 705 }
 706
 707 int handle_rt_signal64(int signr, struct k_sigaction *ka, siginfo_t *info,
 708                 sigset_t *set, struct pt_regs *regs)
 709 {
 710         struct rt_sigframe __user *frame;
 711         unsigned long newsp = 0;
 712         long err = 0;
 713
 714         frame = get_sigframe(ka, get_tm_stackpointer(regs), sizeof(*frame), 0);
 715         if (unlikely(frame == NULL))
 716                 goto badframe;
 717
 718         err |= __put_user(&frame->info, &frame->pinfo);
 719         err |= __put_user(&frame->uc, &frame->puc);
 720         err |= copy_siginfo_to_user(&frame->info, info);
 721         if (err)
 722                 goto badframe;
 723
 724         /* Create the ucontext.  */
 725         err |= __put_user(0, &frame->uc.uc_flags);
 726         err |= __save_altstack(&frame->uc.uc_stack, regs->gpr[1]);
 727 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 728         if (MSR_TM_ACTIVE(regs->msr)) {
 729                 /* The ucontext_t passed to userland points to the second
 730                  * ucontext_t (for transactional state) with its uc_link ptr.
 731                  */
 732                 err |= __put_user(&frame->uc_transact, &frame->uc.uc_link);
 733                 err |= setup_tm_sigcontexts(&frame->uc.uc_mcontext,
 734                                             &frame->uc_transact.uc_mcontext,
 735                                             regs, signr,
 736                                             NULL,
 737                                             (unsigned long)ka->sa.sa_handler);
 738         } else
 739 #endif
 740         {
 741                 err |= __put_user(0, &frame->uc.uc_link);
 742                 err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, signr,
 743                                         NULL, (unsigned long)ka->sa.sa_handler,
 744                                         1);
 745         }
 746         err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
 747         if (err)
 748                 goto badframe;
 749
 750         /* Make sure signal handler doesn't get spurious FP exceptions */
 751         current->thread.fp_state.fpscr = 0;
 752 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 753         /* Remove TM bits from thread's MSR.  The MSR in the sigcontext
 754          * just indicates to userland that we were doing a transaction, but we
 755          * don't want to return in transactional state:
 756          */
 757         regs->msr &= ~MSR_TS_MASK;
 758 #endif
 759
 760         /* Set up to return from userspace. */
 761         if (vdso64_rt_sigtramp && current->mm->context.vdso_base) {
 762                 regs->link = current->mm->context.vdso_base + vdso64_rt_sigtramp;
 763         } else {
 764                 err |= setup_trampoline(__NR_rt_sigreturn, &frame->tramp[0]);
 765                 if (err)
 766                         goto badframe;
 767                 regs->link = (unsigned long) &frame->tramp[0];
 768         }
 769
 770         /* Allocate a dummy caller frame for the signal handler. */
 771         newsp = ((unsigned long)frame) - __SIGNAL_FRAMESIZE;
 772         err |= put_user(regs->gpr[1], (unsigned long __user *)newsp);
 773
 774         /* Set up "regs" so we "return" to the signal handler. */
 775         if (is_elf2_task()) {
 776                 regs->nip = (unsigned long) ka->sa.sa_handler;
 777                 regs->gpr[12] = regs->nip;
 778         } else {
 779                 /* Handler is *really* a pointer to the function descriptor for
 780                  * the signal routine.  The first entry in the function
 781                  * descriptor is the entry address of signal and the second
 782                  * entry is the TOC value we need to use.
 783                  */
 784                 func_descr_t __user *funct_desc_ptr =
 785                         (func_descr_t __user *) ka->sa.sa_handler;
 786
 787                 err |= get_user(regs->nip, &funct_desc_ptr->entry);
 788                 err |= get_user(regs->gpr[2], &funct_desc_ptr->toc);
 789         }
 790
 791         /* enter the signal handler in native-endian mode */
 792         regs->msr &= ~MSR_LE;
 793         regs->msr |= (MSR_KERNEL & MSR_LE);
 794         regs->gpr[1] = newsp;
 795         regs->gpr[3] = signr;
 796         regs->result = 0;
 797         if (ka->sa.sa_flags & SA_SIGINFO) {
 798                 err |= get_user(regs->gpr[4], (unsigned long __user *)&frame->pinfo);
 799                 err |= get_user(regs->gpr[5], (unsigned long __user *)&frame->puc);
 800                 regs->gpr[6] = (unsigned long) frame;
 801         } else {
 802                 regs->gpr[4] = (unsigned long)&frame->uc.uc_mcontext;
 803         }
 804         if (err)
 805                 goto badframe;
 806
 807         return 1;
 808
 809 badframe:
 810 #if DEBUG_SIG
 811         printk("badframe in setup_rt_frame, regs=%p frame=%p newsp=%lx\n",
 812                regs, frame, newsp);
 813 #endif
 814         if (show_unhandled_signals)
 815                 printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32,
 816                                    current->comm, current->pid, "setup_rt_frame",
 817                                    (long)frame, regs->nip, regs->link);
 818
 819         force_sigsegv(signr, current);
 820         return 0;
 821 }