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