linux-user/ppc/signal.c

   1 /*
   2  *  Emulation of Linux signals
   3  *
   4  *  Copyright (c) 2003 Fabrice Bellard
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation; either version 2 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19 #include "qemu/osdep.h"
  20 #include "qemu.h"
  21 #include "user-internals.h"
  22 #include "signal-common.h"
  23 #include "linux-user/trace.h"
  24
  25 /* Size of dummy stack frame allocated when calling signal handler.
  26    See arch/powerpc/include/asm/ptrace.h.  */
  27 #if defined(TARGET_PPC64)
  28 #define SIGNAL_FRAMESIZE 128
  29 #else
  30 #define SIGNAL_FRAMESIZE 64
  31 #endif
  32
  33 /* See arch/powerpc/include/asm/ucontext.h.  Only used for 32-bit PPC;
  34    on 64-bit PPC, sigcontext and mcontext are one and the same.  */
  35 struct target_mcontext {
  36     target_ulong mc_gregs[48];
  37     /* Includes fpscr.  */
  38     uint64_t mc_fregs[33];
  39
  40 #if defined(TARGET_PPC64)
  41     /* Pointer to the vector regs */
  42     target_ulong v_regs;
  43     /*
  44      * On ppc64, this mcontext structure is naturally *unaligned*,
  45      * or rather it is aligned on a 8 bytes boundary but not on
  46      * a 16 byte boundary.  This pad fixes it up.  This is why we
  47      * cannot use ppc_avr_t, which would force alignment.  This is
  48      * also why the vector regs are referenced in the ABI by the
  49      * v_regs pointer above so any amount of padding can be added here.
  50      */
  51     target_ulong pad;
  52     /* VSCR and VRSAVE are saved separately.  Also reserve space for VSX. */
  53     struct {
  54         uint64_t altivec[34 + 16][2];
  55     } mc_vregs;
  56 #else
  57     target_ulong mc_pad[2];
  58
  59     /* We need to handle Altivec and SPE at the same time, which no
  60        kernel needs to do.  Fortunately, the kernel defines this bit to
  61        be Altivec-register-large all the time, rather than trying to
  62        twiddle it based on the specific platform.  */
  63     union {
  64         /* SPE vector registers.  One extra for SPEFSCR.  */
  65         uint32_t spe[33];
  66         /*
  67          * Altivec vector registers.  One extra for VRSAVE.
  68          * On ppc32, we are already aligned to 16 bytes.  We could
  69          * use ppc_avr_t, but choose to share the same type as ppc64.
  70          */
  71         uint64_t altivec[33][2];
  72     } mc_vregs;
  73 #endif
  74 };
  75
  76 /* See arch/powerpc/include/asm/sigcontext.h.  */
  77 struct target_sigcontext {
  78     target_ulong _unused[4];
  79     int32_t signal;
  80 #if defined(TARGET_PPC64)
  81     int32_t pad0;
  82 #endif
  83     target_ulong handler;
  84     target_ulong oldmask;
  85     target_ulong regs;      /* struct pt_regs __user * */
  86 #if defined(TARGET_PPC64)
  87     struct target_mcontext mcontext;
  88 #endif
  89 };
  90
  91 /* Indices for target_mcontext.mc_gregs, below.
  92    See arch/powerpc/include/asm/ptrace.h for details.  */
  93 enum {
  94     TARGET_PT_R0 = 0,
  95     TARGET_PT_R1 = 1,
  96     TARGET_PT_R2 = 2,
  97     TARGET_PT_R3 = 3,
  98     TARGET_PT_R4 = 4,
  99     TARGET_PT_R5 = 5,
 100     TARGET_PT_R6 = 6,
 101     TARGET_PT_R7 = 7,
 102     TARGET_PT_R8 = 8,
 103     TARGET_PT_R9 = 9,
 104     TARGET_PT_R10 = 10,
 105     TARGET_PT_R11 = 11,
 106     TARGET_PT_R12 = 12,
 107     TARGET_PT_R13 = 13,
 108     TARGET_PT_R14 = 14,
 109     TARGET_PT_R15 = 15,
 110     TARGET_PT_R16 = 16,
 111     TARGET_PT_R17 = 17,
 112     TARGET_PT_R18 = 18,
 113     TARGET_PT_R19 = 19,
 114     TARGET_PT_R20 = 20,
 115     TARGET_PT_R21 = 21,
 116     TARGET_PT_R22 = 22,
 117     TARGET_PT_R23 = 23,
 118     TARGET_PT_R24 = 24,
 119     TARGET_PT_R25 = 25,
 120     TARGET_PT_R26 = 26,
 121     TARGET_PT_R27 = 27,
 122     TARGET_PT_R28 = 28,
 123     TARGET_PT_R29 = 29,
 124     TARGET_PT_R30 = 30,
 125     TARGET_PT_R31 = 31,
 126     TARGET_PT_NIP = 32,
 127     TARGET_PT_MSR = 33,
 128     TARGET_PT_ORIG_R3 = 34,
 129     TARGET_PT_CTR = 35,
 130     TARGET_PT_LNK = 36,
 131     TARGET_PT_XER = 37,
 132     TARGET_PT_CCR = 38,
 133     /* Yes, there are two registers with #39.  One is 64-bit only.  */
 134     TARGET_PT_MQ = 39,
 135     TARGET_PT_SOFTE = 39,
 136     TARGET_PT_TRAP = 40,
 137     TARGET_PT_DAR = 41,
 138     TARGET_PT_DSISR = 42,
 139     TARGET_PT_RESULT = 43,
 140     TARGET_PT_REGS_COUNT = 44
 141 };
 142
 143
 144 struct target_ucontext {
 145     target_ulong tuc_flags;
 146     target_ulong tuc_link;    /* ucontext_t __user * */
 147     struct target_sigaltstack tuc_stack;
 148 #if !defined(TARGET_PPC64)
 149     int32_t tuc_pad[7];
 150     target_ulong tuc_regs;    /* struct mcontext __user *
 151                                 points to uc_mcontext field */
 152 #endif
 153     target_sigset_t tuc_sigmask;
 154 #if defined(TARGET_PPC64)
 155     target_sigset_t unused[15]; /* Allow for uc_sigmask growth */
 156     struct target_sigcontext tuc_sigcontext;
 157 #else
 158     int32_t tuc_maskext[30];
 159     int32_t tuc_pad2[3];
 160     struct target_mcontext tuc_mcontext;
 161 #endif
 162 };
 163
 164 /* See arch/powerpc/kernel/signal_32.c.  */
 165 struct target_sigframe {
 166     struct target_sigcontext sctx;
 167     struct target_mcontext mctx;
 168     int32_t abigap[56];
 169 };
 170
 171 #if defined(TARGET_PPC64)
 172
 173 #define TARGET_TRAMP_SIZE 6
 174
 175 struct target_rt_sigframe {
 176     /* sys_rt_sigreturn requires the ucontext be the first field */
 177     struct target_ucontext uc;
 178     target_ulong  _unused[2];
 179     uint32_t trampoline[TARGET_TRAMP_SIZE];
 180     target_ulong pinfo; /* struct siginfo __user * */
 181     target_ulong puc; /* void __user * */
 182     struct target_siginfo info;
 183     /* 64 bit ABI allows for 288 bytes below sp before decrementing it. */
 184     char abigap[288];
 185 } __attribute__((aligned(16)));
 186
 187 #else
 188
 189 struct target_rt_sigframe {
 190     struct target_siginfo info;
 191     struct target_ucontext uc;
 192     int32_t abigap[56];
 193 };
 194
 195 #endif
 196
 197 #if defined(TARGET_PPC64)
 198
 199 struct target_func_ptr {
 200     target_ulong entry;
 201     target_ulong toc;
 202 };
 203
 204 #endif
 205
 206 /* See arch/powerpc/kernel/signal.c.  */
 207 static target_ulong get_sigframe(struct target_sigaction *ka,
 208                                  CPUPPCState *env,
 209                                  int frame_size)
 210 {
 211     target_ulong oldsp;
 212
 213     oldsp = target_sigsp(get_sp_from_cpustate(env), ka);
 214
 215     return (oldsp - frame_size) & ~0xFUL;
 216 }
 217
 218 #if ((defined(TARGET_WORDS_BIGENDIAN) && defined(HOST_WORDS_BIGENDIAN)) || \
 219      (!defined(HOST_WORDS_BIGENDIAN) && !defined(TARGET_WORDS_BIGENDIAN)))
 220 #define PPC_VEC_HI      0
 221 #define PPC_VEC_LO      1
 222 #else
 223 #define PPC_VEC_HI      1
 224 #define PPC_VEC_LO      0
 225 #endif
 226
 227
 228 static void save_user_regs(CPUPPCState *env, struct target_mcontext *frame)
 229 {
 230     target_ulong msr = env->msr;
 231     int i;
 232     target_ulong ccr = 0;
 233
 234     /* In general, the kernel attempts to be intelligent about what it
 235        needs to save for Altivec/FP/SPE registers.  We don't care that
 236        much, so we just go ahead and save everything.  */
 237
 238     /* Save general registers.  */
 239     for (i = 0; i < ARRAY_SIZE(env->gpr); i++) {
 240         __put_user(env->gpr[i], &frame->mc_gregs[i]);
 241     }
 242     __put_user(env->nip, &frame->mc_gregs[TARGET_PT_NIP]);
 243     __put_user(env->ctr, &frame->mc_gregs[TARGET_PT_CTR]);
 244     __put_user(env->lr, &frame->mc_gregs[TARGET_PT_LNK]);
 245     __put_user(cpu_read_xer(env), &frame->mc_gregs[TARGET_PT_XER]);
 246
 247     for (i = 0; i < ARRAY_SIZE(env->crf); i++) {
 248         ccr |= env->crf[i] << (32 - ((i + 1) * 4));
 249     }
 250     __put_user(ccr, &frame->mc_gregs[TARGET_PT_CCR]);
 251
 252     /* Save Altivec registers if necessary.  */
 253     if (env->insns_flags & PPC_ALTIVEC) {
 254         uint32_t *vrsave;
 255         for (i = 0; i < 32; i++) {
 256             ppc_avr_t *avr = cpu_avr_ptr(env, i);
 257             ppc_avr_t *vreg = (ppc_avr_t *)&frame->mc_vregs.altivec[i];
 258
 259             __put_user(avr->u64[PPC_VEC_HI], &vreg->u64[0]);
 260             __put_user(avr->u64[PPC_VEC_LO], &vreg->u64[1]);
 261         }
 262 #if defined(TARGET_PPC64)
 263         vrsave = (uint32_t *)&frame->mc_vregs.altivec[33];
 264         /* 64-bit needs to put a pointer to the vectors in the frame */
 265         __put_user(h2g(frame->mc_vregs.altivec), &frame->v_regs);
 266 #else
 267         vrsave = (uint32_t *)&frame->mc_vregs.altivec[32];
 268 #endif
 269         __put_user((uint32_t)env->spr[SPR_VRSAVE], vrsave);
 270     }
 271
 272 #if defined(TARGET_PPC64)
 273     /* Save VSX second halves */
 274     if (env->insns_flags2 & PPC2_VSX) {
 275         uint64_t *vsregs = (uint64_t *)&frame->mc_vregs.altivec[34];
 276         for (i = 0; i < 32; i++) {
 277             uint64_t *vsrl = cpu_vsrl_ptr(env, i);
 278             __put_user(*vsrl, &vsregs[i]);
 279         }
 280     }
 281 #endif
 282
 283     /* Save floating point registers.  */
 284     if (env->insns_flags & PPC_FLOAT) {
 285         for (i = 0; i < 32; i++) {
 286             uint64_t *fpr = cpu_fpr_ptr(env, i);
 287             __put_user(*fpr, &frame->mc_fregs[i]);
 288         }
 289         __put_user((uint64_t) env->fpscr, &frame->mc_fregs[32]);
 290     }
 291
 292 #if !defined(TARGET_PPC64)
 293     /* Save SPE registers.  The kernel only saves the high half.  */
 294     if (env->insns_flags & PPC_SPE) {
 295         for (i = 0; i < ARRAY_SIZE(env->gprh); i++) {
 296             __put_user(env->gprh[i], &frame->mc_vregs.spe[i]);
 297         }
 298         __put_user(env->spe_fscr, &frame->mc_vregs.spe[32]);
 299     }
 300 #endif
 301
 302     /* Store MSR.  */
 303     __put_user(msr, &frame->mc_gregs[TARGET_PT_MSR]);
 304 }
 305
 306 static void encode_trampoline(int sigret, uint32_t *tramp)
 307 {
 308     /* Set up the sigreturn trampoline: li r0,sigret; sc.  */
 309     __put_user(0x38000000 | sigret, &tramp[0]);
 310     __put_user(0x44000002, &tramp[1]);
 311 }
 312
 313 static void restore_user_regs(CPUPPCState *env,
 314                               struct target_mcontext *frame, int sig)
 315 {
 316     target_ulong save_r2 = 0;
 317     target_ulong msr;
 318     target_ulong xer;
 319     target_ulong ccr;
 320
 321     int i;
 322
 323     if (!sig) {
 324         save_r2 = env->gpr[2];
 325     }
 326
 327     /* Restore general registers.  */
 328     for (i = 0; i < ARRAY_SIZE(env->gpr); i++) {
 329         __get_user(env->gpr[i], &frame->mc_gregs[i]);
 330     }
 331     __get_user(env->nip, &frame->mc_gregs[TARGET_PT_NIP]);
 332     __get_user(env->ctr, &frame->mc_gregs[TARGET_PT_CTR]);
 333     __get_user(env->lr, &frame->mc_gregs[TARGET_PT_LNK]);
 334
 335     __get_user(xer, &frame->mc_gregs[TARGET_PT_XER]);
 336     cpu_write_xer(env, xer);
 337
 338     __get_user(ccr, &frame->mc_gregs[TARGET_PT_CCR]);
 339     for (i = 0; i < ARRAY_SIZE(env->crf); i++) {
 340         env->crf[i] = (ccr >> (32 - ((i + 1) * 4))) & 0xf;
 341     }
 342
 343     if (!sig) {
 344         env->gpr[2] = save_r2;
 345     }
 346     /* Restore MSR.  */
 347     __get_user(msr, &frame->mc_gregs[TARGET_PT_MSR]);
 348
 349     /* If doing signal return, restore the previous little-endian mode.  */
 350     if (sig) {
 351         ppc_store_msr(env, ((env->msr & ~(1ull << MSR_LE)) |
 352                             (msr & (1ull << MSR_LE))));
 353     }
 354
 355     /* Restore Altivec registers if necessary.  */
 356     if (env->insns_flags & PPC_ALTIVEC) {
 357         ppc_avr_t *v_regs;
 358         uint32_t *vrsave;
 359 #if defined(TARGET_PPC64)
 360         uint64_t v_addr;
 361         /* 64-bit needs to recover the pointer to the vectors from the frame */
 362         __get_user(v_addr, &frame->v_regs);
 363         v_regs = g2h(env_cpu(env), v_addr);
 364 #else
 365         v_regs = (ppc_avr_t *)frame->mc_vregs.altivec;
 366 #endif
 367         for (i = 0; i < 32; i++) {
 368             ppc_avr_t *avr = cpu_avr_ptr(env, i);
 369             ppc_avr_t *vreg = &v_regs[i];
 370
 371             __get_user(avr->u64[PPC_VEC_HI], &vreg->u64[0]);
 372             __get_user(avr->u64[PPC_VEC_LO], &vreg->u64[1]);
 373         }
 374 #if defined(TARGET_PPC64)
 375         vrsave = (uint32_t *)&v_regs[33];
 376 #else
 377         vrsave = (uint32_t *)&v_regs[32];
 378 #endif
 379         __get_user(env->spr[SPR_VRSAVE], vrsave);
 380     }
 381
 382 #if defined(TARGET_PPC64)
 383     /* Restore VSX second halves */
 384     if (env->insns_flags2 & PPC2_VSX) {
 385         uint64_t *vsregs = (uint64_t *)&frame->mc_vregs.altivec[34];
 386         for (i = 0; i < 32; i++) {
 387             uint64_t *vsrl = cpu_vsrl_ptr(env, i);
 388             __get_user(*vsrl, &vsregs[i]);
 389         }
 390     }
 391 #endif
 392
 393     /* Restore floating point registers.  */
 394     if (env->insns_flags & PPC_FLOAT) {
 395         uint64_t fpscr;
 396         for (i = 0; i < 32; i++) {
 397             uint64_t *fpr = cpu_fpr_ptr(env, i);
 398             __get_user(*fpr, &frame->mc_fregs[i]);
 399         }
 400         __get_user(fpscr, &frame->mc_fregs[32]);
 401         env->fpscr = (uint32_t) fpscr;
 402     }
 403
 404 #if !defined(TARGET_PPC64)
 405     /* Save SPE registers.  The kernel only saves the high half.  */
 406     if (env->insns_flags & PPC_SPE) {
 407         for (i = 0; i < ARRAY_SIZE(env->gprh); i++) {
 408             __get_user(env->gprh[i], &frame->mc_vregs.spe[i]);
 409         }
 410         __get_user(env->spe_fscr, &frame->mc_vregs.spe[32]);
 411     }
 412 #endif
 413 }
 414
 415 #if !defined(TARGET_PPC64)
 416 void setup_frame(int sig, struct target_sigaction *ka,
 417                  target_sigset_t *set, CPUPPCState *env)
 418 {
 419     struct target_sigframe *frame;
 420     struct target_sigcontext *sc;
 421     target_ulong frame_addr, newsp;
 422     int err = 0;
 423
 424     frame_addr = get_sigframe(ka, env, sizeof(*frame));
 425     trace_user_setup_frame(env, frame_addr);
 426     if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 1))
 427         goto sigsegv;
 428     sc = &frame->sctx;
 429
 430     __put_user(ka->_sa_handler, &sc->handler);
 431     __put_user(set->sig[0], &sc->oldmask);
 432     __put_user(set->sig[1], &sc->_unused[3]);
 433     __put_user(h2g(&frame->mctx), &sc->regs);
 434     __put_user(sig, &sc->signal);
 435
 436     /* Save user regs.  */
 437     save_user_regs(env, &frame->mctx);
 438
 439     env->lr = default_sigreturn;
 440
 441     /* Turn off all fp exceptions.  */
 442     env->fpscr = 0;
 443
 444     /* Create a stack frame for the caller of the handler.  */
 445     newsp = frame_addr - SIGNAL_FRAMESIZE;
 446     err |= put_user(env->gpr[1], newsp, target_ulong);
 447
 448     if (err)
 449         goto sigsegv;
 450
 451     /* Set up registers for signal handler.  */
 452     env->gpr[1] = newsp;
 453     env->gpr[3] = sig;
 454     env->gpr[4] = frame_addr + offsetof(struct target_sigframe, sctx);
 455
 456     env->nip = (target_ulong) ka->_sa_handler;
 457
 458     /* Signal handlers are entered in big-endian mode.  */
 459     ppc_store_msr(env, env->msr & ~(1ull << MSR_LE));
 460
 461     unlock_user_struct(frame, frame_addr, 1);
 462     return;
 463
 464 sigsegv:
 465     unlock_user_struct(frame, frame_addr, 1);
 466     force_sigsegv(sig);
 467 }
 468 #endif /* !defined(TARGET_PPC64) */
 469
 470 void setup_rt_frame(int sig, struct target_sigaction *ka,
 471                     target_siginfo_t *info,
 472                     target_sigset_t *set, CPUPPCState *env)
 473 {
 474     struct target_rt_sigframe *rt_sf;
 475     struct target_mcontext *mctx = 0;
 476     target_ulong rt_sf_addr, newsp = 0;
 477     int i, err = 0;
 478 #if defined(TARGET_PPC64)
 479     struct target_sigcontext *sc = 0;
 480     struct image_info *image = ((TaskState *)thread_cpu->opaque)->info;
 481 #endif
 482
 483     rt_sf_addr = get_sigframe(ka, env, sizeof(*rt_sf));
 484     if (!lock_user_struct(VERIFY_WRITE, rt_sf, rt_sf_addr, 1))
 485         goto sigsegv;
 486
 487     tswap_siginfo(&rt_sf->info, info);
 488
 489     __put_user(0, &rt_sf->uc.tuc_flags);
 490     __put_user(0, &rt_sf->uc.tuc_link);
 491     target_save_altstack(&rt_sf->uc.tuc_stack, env);
 492 #if !defined(TARGET_PPC64)
 493     __put_user(h2g (&rt_sf->uc.tuc_mcontext),
 494                &rt_sf->uc.tuc_regs);
 495 #endif
 496     for(i = 0; i < TARGET_NSIG_WORDS; i++) {
 497         __put_user(set->sig[i], &rt_sf->uc.tuc_sigmask.sig[i]);
 498     }
 499
 500 #if defined(TARGET_PPC64)
 501     mctx = &rt_sf->uc.tuc_sigcontext.mcontext;
 502
 503     sc = &rt_sf->uc.tuc_sigcontext;
 504     __put_user(h2g(mctx), &sc->regs);
 505     __put_user(sig, &sc->signal);
 506 #else
 507     mctx = &rt_sf->uc.tuc_mcontext;
 508 #endif
 509
 510     save_user_regs(env, mctx);
 511
 512     env->lr = default_rt_sigreturn;
 513
 514     /* Turn off all fp exceptions.  */
 515     env->fpscr = 0;
 516
 517     /* Create a stack frame for the caller of the handler.  */
 518     newsp = rt_sf_addr - (SIGNAL_FRAMESIZE + 16);
 519     err |= put_user(env->gpr[1], newsp, target_ulong);
 520
 521     if (err)
 522         goto sigsegv;
 523
 524     /* Set up registers for signal handler.  */
 525     env->gpr[1] = newsp;
 526     env->gpr[3] = (target_ulong) sig;
 527     env->gpr[4] = (target_ulong) h2g(&rt_sf->info);
 528     env->gpr[5] = (target_ulong) h2g(&rt_sf->uc);
 529     env->gpr[6] = (target_ulong) h2g(rt_sf);
 530
 531 #if defined(TARGET_PPC64)
 532     if (get_ppc64_abi(image) < 2) {
 533         /* ELFv1 PPC64 function pointers are pointers to OPD entries. */
 534         struct target_func_ptr *handler =
 535             (struct target_func_ptr *)g2h(env_cpu(env), ka->_sa_handler);
 536         env->nip = tswapl(handler->entry);
 537         env->gpr[2] = tswapl(handler->toc);
 538     } else {
 539         /* ELFv2 PPC64 function pointers are entry points. R12 must also be set. */
 540         env->gpr[12] = env->nip = ka->_sa_handler;
 541     }
 542 #else
 543     env->nip = (target_ulong) ka->_sa_handler;
 544 #endif
 545
 546 #ifdef TARGET_WORDS_BIGENDIAN
 547     /* Signal handlers are entered in big-endian mode.  */
 548     ppc_store_msr(env, env->msr & ~(1ull << MSR_LE));
 549 #else
 550     /* Signal handlers are entered in little-endian mode.  */
 551     ppc_store_msr(env, env->msr | (1ull << MSR_LE));
 552 #endif
 553
 554     unlock_user_struct(rt_sf, rt_sf_addr, 1);
 555     return;
 556
 557 sigsegv:
 558     unlock_user_struct(rt_sf, rt_sf_addr, 1);
 559     force_sigsegv(sig);
 560
 561 }
 562
 563 #if !defined(TARGET_PPC64)
 564 long do_sigreturn(CPUPPCState *env)
 565 {
 566     struct target_sigcontext *sc = NULL;
 567     struct target_mcontext *sr = NULL;
 568     target_ulong sr_addr = 0, sc_addr;
 569     sigset_t blocked;
 570     target_sigset_t set;
 571
 572     sc_addr = env->gpr[1] + SIGNAL_FRAMESIZE;
 573     if (!lock_user_struct(VERIFY_READ, sc, sc_addr, 1))
 574         goto sigsegv;
 575
 576     __get_user(set.sig[0], &sc->oldmask);
 577     __get_user(set.sig[1], &sc->_unused[3]);
 578
 579     target_to_host_sigset_internal(&blocked, &set);
 580     set_sigmask(&blocked);
 581
 582     __get_user(sr_addr, &sc->regs);
 583     if (!lock_user_struct(VERIFY_READ, sr, sr_addr, 1))
 584         goto sigsegv;
 585     restore_user_regs(env, sr, 1);
 586
 587     unlock_user_struct(sr, sr_addr, 1);
 588     unlock_user_struct(sc, sc_addr, 1);
 589     return -QEMU_ESIGRETURN;
 590
 591 sigsegv:
 592     unlock_user_struct(sr, sr_addr, 1);
 593     unlock_user_struct(sc, sc_addr, 1);
 594     force_sig(TARGET_SIGSEGV);
 595     return -QEMU_ESIGRETURN;
 596 }
 597 #endif /* !defined(TARGET_PPC64) */
 598
 599 /* See arch/powerpc/kernel/signal_32.c.  */
 600 static int do_setcontext(struct target_ucontext *ucp, CPUPPCState *env, int sig)
 601 {
 602     struct target_mcontext *mcp;
 603     target_ulong mcp_addr;
 604     sigset_t blocked;
 605     target_sigset_t set;
 606
 607     if (copy_from_user(&set, h2g(ucp) + offsetof(struct target_ucontext, tuc_sigmask),
 608                        sizeof (set)))
 609         return 1;
 610
 611 #if defined(TARGET_PPC64)
 612     mcp_addr = h2g(ucp) +
 613         offsetof(struct target_ucontext, tuc_sigcontext.mcontext);
 614 #else
 615     __get_user(mcp_addr, &ucp->tuc_regs);
 616 #endif
 617
 618     if (!lock_user_struct(VERIFY_READ, mcp, mcp_addr, 1))
 619         return 1;
 620
 621     target_to_host_sigset_internal(&blocked, &set);
 622     set_sigmask(&blocked);
 623     restore_user_regs(env, mcp, sig);
 624
 625     unlock_user_struct(mcp, mcp_addr, 1);
 626     return 0;
 627 }
 628
 629 long do_rt_sigreturn(CPUPPCState *env)
 630 {
 631     struct target_rt_sigframe *rt_sf = NULL;
 632     target_ulong rt_sf_addr;
 633
 634     rt_sf_addr = env->gpr[1] + SIGNAL_FRAMESIZE + 16;
 635     if (!lock_user_struct(VERIFY_READ, rt_sf, rt_sf_addr, 1))
 636         goto sigsegv;
 637
 638     if (do_setcontext(&rt_sf->uc, env, 1))
 639         goto sigsegv;
 640
 641     target_restore_altstack(&rt_sf->uc.tuc_stack, env);
 642
 643     unlock_user_struct(rt_sf, rt_sf_addr, 1);
 644     return -QEMU_ESIGRETURN;
 645
 646 sigsegv:
 647     unlock_user_struct(rt_sf, rt_sf_addr, 1);
 648     force_sig(TARGET_SIGSEGV);
 649     return -QEMU_ESIGRETURN;
 650 }
 651
 652 /* This syscall implements {get,set,swap}context for userland.  */
 653 abi_long do_swapcontext(CPUArchState *env, abi_ulong uold_ctx,
 654                         abi_ulong unew_ctx, abi_long ctx_size)
 655 {
 656     struct target_ucontext *uctx;
 657     struct target_mcontext *mctx;
 658
 659     /* For ppc32, ctx_size is "reserved for future use".
 660      * For ppc64, we do not yet support the VSX extension.
 661      */
 662     if (ctx_size < sizeof(struct target_ucontext)) {
 663         return -TARGET_EINVAL;
 664     }
 665
 666     if (uold_ctx) {
 667         TaskState *ts = (TaskState *)thread_cpu->opaque;
 668
 669         if (!lock_user_struct(VERIFY_WRITE, uctx, uold_ctx, 1)) {
 670             return -TARGET_EFAULT;
 671         }
 672
 673 #ifdef TARGET_PPC64
 674         mctx = &uctx->tuc_sigcontext.mcontext;
 675 #else
 676         /* ??? The kernel aligns the pointer down here into padding, but
 677          * in setup_rt_frame we don't.  Be self-compatible for now.
 678          */
 679         mctx = &uctx->tuc_mcontext;
 680         __put_user(h2g(mctx), &uctx->tuc_regs);
 681 #endif
 682
 683         save_user_regs(env, mctx);
 684         host_to_target_sigset(&uctx->tuc_sigmask, &ts->signal_mask);
 685
 686         unlock_user_struct(uctx, uold_ctx, 1);
 687     }
 688
 689     if (unew_ctx) {
 690         int err;
 691
 692         if (!lock_user_struct(VERIFY_READ, uctx, unew_ctx, 1)) {
 693             return -TARGET_EFAULT;
 694         }
 695         err = do_setcontext(uctx, env, 0);
 696         unlock_user_struct(uctx, unew_ctx, 1);
 697
 698         if (err) {
 699             /* We cannot return to a partially updated context.  */
 700             force_sig(TARGET_SIGSEGV);
 701         }
 702         return -QEMU_ESIGRETURN;
 703     }
 704
 705     return 0;
 706 }
 707
 708 void setup_sigtramp(abi_ulong sigtramp_page)
 709 {
 710     uint32_t *tramp = lock_user(VERIFY_WRITE, sigtramp_page, 2 * 8, 0);
 711     assert(tramp != NULL);
 712
 713 #ifdef TARGET_ARCH_HAS_SETUP_FRAME
 714     default_sigreturn = sigtramp_page;
 715     encode_trampoline(TARGET_NR_sigreturn, tramp + 0);
 716 #endif
 717
 718     default_rt_sigreturn = sigtramp_page + 8;
 719     encode_trampoline(TARGET_NR_rt_sigreturn, tramp + 2);
 720
 721     unlock_user(tramp, sigtramp_page, 2 * 8);
 722 }