cachepc-qemu

Fork of AMDESE/qemu with changes for cachepc side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-qemu
Log | Files | Refs | Submodules | LICENSE | sfeed.txt

signal.c (21351B)


      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.  */
     35struct 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.  */
     77struct 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.  */
     93enum {
     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
    144struct 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.  */
    165struct 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
    175struct 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
    189struct 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
    199struct target_func_ptr {
    200    target_ulong entry;
    201    target_ulong toc;
    202};
    203
    204#endif
    205
    206/* See arch/powerpc/kernel/signal.c.  */
    207static 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
    228static 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(env->xer, &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
    306static 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
    313static 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 ccr;
    319
    320    int i;
    321
    322    if (!sig) {
    323        save_r2 = env->gpr[2];
    324    }
    325
    326    /* Restore general registers.  */
    327    for (i = 0; i < ARRAY_SIZE(env->gpr); i++) {
    328        __get_user(env->gpr[i], &frame->mc_gregs[i]);
    329    }
    330    __get_user(env->nip, &frame->mc_gregs[TARGET_PT_NIP]);
    331    __get_user(env->ctr, &frame->mc_gregs[TARGET_PT_CTR]);
    332    __get_user(env->lr, &frame->mc_gregs[TARGET_PT_LNK]);
    333    __get_user(env->xer, &frame->mc_gregs[TARGET_PT_XER]);
    334    __get_user(ccr, &frame->mc_gregs[TARGET_PT_CCR]);
    335
    336    for (i = 0; i < ARRAY_SIZE(env->crf); i++) {
    337        env->crf[i] = (ccr >> (32 - ((i + 1) * 4))) & 0xf;
    338    }
    339
    340    if (!sig) {
    341        env->gpr[2] = save_r2;
    342    }
    343    /* Restore MSR.  */
    344    __get_user(msr, &frame->mc_gregs[TARGET_PT_MSR]);
    345
    346    /* If doing signal return, restore the previous little-endian mode.  */
    347    if (sig) {
    348        ppc_store_msr(env, ((env->msr & ~(1ull << MSR_LE)) |
    349                            (msr & (1ull << MSR_LE))));
    350    }
    351
    352    /* Restore Altivec registers if necessary.  */
    353    if (env->insns_flags & PPC_ALTIVEC) {
    354        ppc_avr_t *v_regs;
    355        uint32_t *vrsave;
    356#if defined(TARGET_PPC64)
    357        uint64_t v_addr;
    358        /* 64-bit needs to recover the pointer to the vectors from the frame */
    359        __get_user(v_addr, &frame->v_regs);
    360        v_regs = g2h(env_cpu(env), v_addr);
    361#else
    362        v_regs = (ppc_avr_t *)frame->mc_vregs.altivec;
    363#endif
    364        for (i = 0; i < 32; i++) {
    365            ppc_avr_t *avr = cpu_avr_ptr(env, i);
    366            ppc_avr_t *vreg = &v_regs[i];
    367
    368            __get_user(avr->u64[PPC_VEC_HI], &vreg->u64[0]);
    369            __get_user(avr->u64[PPC_VEC_LO], &vreg->u64[1]);
    370        }
    371#if defined(TARGET_PPC64)
    372        vrsave = (uint32_t *)&v_regs[33];
    373#else
    374        vrsave = (uint32_t *)&v_regs[32];
    375#endif
    376        __get_user(env->spr[SPR_VRSAVE], vrsave);
    377    }
    378
    379#if defined(TARGET_PPC64)
    380    /* Restore VSX second halves */
    381    if (env->insns_flags2 & PPC2_VSX) {
    382        uint64_t *vsregs = (uint64_t *)&frame->mc_vregs.altivec[34];
    383        for (i = 0; i < 32; i++) {
    384            uint64_t *vsrl = cpu_vsrl_ptr(env, i);
    385            __get_user(*vsrl, &vsregs[i]);
    386        }
    387    }
    388#endif
    389
    390    /* Restore floating point registers.  */
    391    if (env->insns_flags & PPC_FLOAT) {
    392        uint64_t fpscr;
    393        for (i = 0; i < 32; i++) {
    394            uint64_t *fpr = cpu_fpr_ptr(env, i);
    395            __get_user(*fpr, &frame->mc_fregs[i]);
    396        }
    397        __get_user(fpscr, &frame->mc_fregs[32]);
    398        env->fpscr = (uint32_t) fpscr;
    399    }
    400
    401#if !defined(TARGET_PPC64)
    402    /* Save SPE registers.  The kernel only saves the high half.  */
    403    if (env->insns_flags & PPC_SPE) {
    404        for (i = 0; i < ARRAY_SIZE(env->gprh); i++) {
    405            __get_user(env->gprh[i], &frame->mc_vregs.spe[i]);
    406        }
    407        __get_user(env->spe_fscr, &frame->mc_vregs.spe[32]);
    408    }
    409#endif
    410}
    411
    412#if !defined(TARGET_PPC64)
    413void setup_frame(int sig, struct target_sigaction *ka,
    414                 target_sigset_t *set, CPUPPCState *env)
    415{
    416    struct target_sigframe *frame;
    417    struct target_sigcontext *sc;
    418    target_ulong frame_addr, newsp;
    419    int err = 0;
    420
    421    frame_addr = get_sigframe(ka, env, sizeof(*frame));
    422    trace_user_setup_frame(env, frame_addr);
    423    if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 1))
    424        goto sigsegv;
    425    sc = &frame->sctx;
    426
    427    __put_user(ka->_sa_handler, &sc->handler);
    428    __put_user(set->sig[0], &sc->oldmask);
    429    __put_user(set->sig[1], &sc->_unused[3]);
    430    __put_user(h2g(&frame->mctx), &sc->regs);
    431    __put_user(sig, &sc->signal);
    432
    433    /* Save user regs.  */
    434    save_user_regs(env, &frame->mctx);
    435
    436    env->lr = default_sigreturn;
    437
    438    /* Turn off all fp exceptions.  */
    439    env->fpscr = 0;
    440
    441    /* Create a stack frame for the caller of the handler.  */
    442    newsp = frame_addr - SIGNAL_FRAMESIZE;
    443    err |= put_user(env->gpr[1], newsp, target_ulong);
    444
    445    if (err)
    446        goto sigsegv;
    447
    448    /* Set up registers for signal handler.  */
    449    env->gpr[1] = newsp;
    450    env->gpr[3] = sig;
    451    env->gpr[4] = frame_addr + offsetof(struct target_sigframe, sctx);
    452
    453    env->nip = (target_ulong) ka->_sa_handler;
    454
    455    /* Signal handlers are entered in big-endian mode.  */
    456    ppc_store_msr(env, env->msr & ~(1ull << MSR_LE));
    457
    458    unlock_user_struct(frame, frame_addr, 1);
    459    return;
    460
    461sigsegv:
    462    unlock_user_struct(frame, frame_addr, 1);
    463    force_sigsegv(sig);
    464}
    465#endif /* !defined(TARGET_PPC64) */
    466
    467void setup_rt_frame(int sig, struct target_sigaction *ka,
    468                    target_siginfo_t *info,
    469                    target_sigset_t *set, CPUPPCState *env)
    470{
    471    struct target_rt_sigframe *rt_sf;
    472    struct target_mcontext *mctx = 0;
    473    target_ulong rt_sf_addr, newsp = 0;
    474    int i, err = 0;
    475#if defined(TARGET_PPC64)
    476    struct target_sigcontext *sc = 0;
    477#if !defined(TARGET_ABI32)
    478    struct image_info *image = ((TaskState *)thread_cpu->opaque)->info;
    479#endif
    480#endif
    481
    482    rt_sf_addr = get_sigframe(ka, env, sizeof(*rt_sf));
    483    if (!lock_user_struct(VERIFY_WRITE, rt_sf, rt_sf_addr, 1))
    484        goto sigsegv;
    485
    486    tswap_siginfo(&rt_sf->info, info);
    487
    488    __put_user(0, &rt_sf->uc.tuc_flags);
    489    __put_user(0, &rt_sf->uc.tuc_link);
    490    target_save_altstack(&rt_sf->uc.tuc_stack, env);
    491#if !defined(TARGET_PPC64)
    492    __put_user(h2g (&rt_sf->uc.tuc_mcontext),
    493               &rt_sf->uc.tuc_regs);
    494#endif
    495    for(i = 0; i < TARGET_NSIG_WORDS; i++) {
    496        __put_user(set->sig[i], &rt_sf->uc.tuc_sigmask.sig[i]);
    497    }
    498
    499#if defined(TARGET_PPC64)
    500    mctx = &rt_sf->uc.tuc_sigcontext.mcontext;
    501
    502    sc = &rt_sf->uc.tuc_sigcontext;
    503    __put_user(h2g(mctx), &sc->regs);
    504    __put_user(sig, &sc->signal);
    505#else
    506    mctx = &rt_sf->uc.tuc_mcontext;
    507#endif
    508
    509    save_user_regs(env, mctx);
    510
    511    env->lr = default_rt_sigreturn;
    512
    513    /* Turn off all fp exceptions.  */
    514    env->fpscr = 0;
    515
    516    /* Create a stack frame for the caller of the handler.  */
    517    newsp = rt_sf_addr - (SIGNAL_FRAMESIZE + 16);
    518    err |= put_user(env->gpr[1], newsp, target_ulong);
    519
    520    if (err)
    521        goto sigsegv;
    522
    523    /* Set up registers for signal handler.  */
    524    env->gpr[1] = newsp;
    525    env->gpr[3] = (target_ulong) sig;
    526    env->gpr[4] = (target_ulong) h2g(&rt_sf->info);
    527    env->gpr[5] = (target_ulong) h2g(&rt_sf->uc);
    528    env->gpr[6] = (target_ulong) h2g(rt_sf);
    529
    530#if defined(TARGET_PPC64) && !defined(TARGET_ABI32)
    531    if (get_ppc64_abi(image) < 2) {
    532        /* ELFv1 PPC64 function pointers are pointers to OPD entries. */
    533        struct target_func_ptr *handler =
    534            (struct target_func_ptr *)g2h(env_cpu(env), ka->_sa_handler);
    535        env->nip = tswapl(handler->entry);
    536        env->gpr[2] = tswapl(handler->toc);
    537    } else {
    538        /* ELFv2 PPC64 function pointers are entry points. R12 must also be set. */
    539        env->gpr[12] = env->nip = ka->_sa_handler;
    540    }
    541#else
    542    env->nip = (target_ulong) ka->_sa_handler;
    543#endif
    544
    545#ifdef TARGET_WORDS_BIGENDIAN
    546    /* Signal handlers are entered in big-endian mode.  */
    547    ppc_store_msr(env, env->msr & ~(1ull << MSR_LE));
    548#else
    549    /* Signal handlers are entered in little-endian mode.  */
    550    ppc_store_msr(env, env->msr | (1ull << MSR_LE));
    551#endif
    552
    553    unlock_user_struct(rt_sf, rt_sf_addr, 1);
    554    return;
    555
    556sigsegv:
    557    unlock_user_struct(rt_sf, rt_sf_addr, 1);
    558    force_sigsegv(sig);
    559
    560}
    561
    562#if !defined(TARGET_PPC64) || defined(TARGET_ABI32)
    563long do_sigreturn(CPUPPCState *env)
    564{
    565    struct target_sigcontext *sc = NULL;
    566    struct target_mcontext *sr = NULL;
    567    target_ulong sr_addr = 0, sc_addr;
    568    sigset_t blocked;
    569    target_sigset_t set;
    570
    571    sc_addr = env->gpr[1] + SIGNAL_FRAMESIZE;
    572    if (!lock_user_struct(VERIFY_READ, sc, sc_addr, 1))
    573        goto sigsegv;
    574
    575#if defined(TARGET_PPC64)
    576    set.sig[0] = sc->oldmask + ((uint64_t)(sc->_unused[3]) << 32);
    577#else
    578    __get_user(set.sig[0], &sc->oldmask);
    579    __get_user(set.sig[1], &sc->_unused[3]);
    580#endif
    581    target_to_host_sigset_internal(&blocked, &set);
    582    set_sigmask(&blocked);
    583
    584    __get_user(sr_addr, &sc->regs);
    585    if (!lock_user_struct(VERIFY_READ, sr, sr_addr, 1))
    586        goto sigsegv;
    587    restore_user_regs(env, sr, 1);
    588
    589    unlock_user_struct(sr, sr_addr, 1);
    590    unlock_user_struct(sc, sc_addr, 1);
    591    return -TARGET_QEMU_ESIGRETURN;
    592
    593sigsegv:
    594    unlock_user_struct(sr, sr_addr, 1);
    595    unlock_user_struct(sc, sc_addr, 1);
    596    force_sig(TARGET_SIGSEGV);
    597    return -TARGET_QEMU_ESIGRETURN;
    598}
    599#endif /* !defined(TARGET_PPC64) */
    600
    601/* See arch/powerpc/kernel/signal_32.c.  */
    602static int do_setcontext(struct target_ucontext *ucp, CPUPPCState *env, int sig)
    603{
    604    struct target_mcontext *mcp;
    605    target_ulong mcp_addr;
    606    sigset_t blocked;
    607    target_sigset_t set;
    608
    609    if (copy_from_user(&set, h2g(ucp) + offsetof(struct target_ucontext, tuc_sigmask),
    610                       sizeof (set)))
    611        return 1;
    612
    613#if defined(TARGET_PPC64)
    614    mcp_addr = h2g(ucp) +
    615        offsetof(struct target_ucontext, tuc_sigcontext.mcontext);
    616#else
    617    __get_user(mcp_addr, &ucp->tuc_regs);
    618#endif
    619
    620    if (!lock_user_struct(VERIFY_READ, mcp, mcp_addr, 1))
    621        return 1;
    622
    623    target_to_host_sigset_internal(&blocked, &set);
    624    set_sigmask(&blocked);
    625    restore_user_regs(env, mcp, sig);
    626
    627    unlock_user_struct(mcp, mcp_addr, 1);
    628    return 0;
    629}
    630
    631long do_rt_sigreturn(CPUPPCState *env)
    632{
    633    struct target_rt_sigframe *rt_sf = NULL;
    634    target_ulong rt_sf_addr;
    635
    636    rt_sf_addr = env->gpr[1] + SIGNAL_FRAMESIZE + 16;
    637    if (!lock_user_struct(VERIFY_READ, rt_sf, rt_sf_addr, 1))
    638        goto sigsegv;
    639
    640    if (do_setcontext(&rt_sf->uc, env, 1))
    641        goto sigsegv;
    642
    643    target_restore_altstack(&rt_sf->uc.tuc_stack, env);
    644
    645    unlock_user_struct(rt_sf, rt_sf_addr, 1);
    646    return -TARGET_QEMU_ESIGRETURN;
    647
    648sigsegv:
    649    unlock_user_struct(rt_sf, rt_sf_addr, 1);
    650    force_sig(TARGET_SIGSEGV);
    651    return -TARGET_QEMU_ESIGRETURN;
    652}
    653
    654/* This syscall implements {get,set,swap}context for userland.  */
    655abi_long do_swapcontext(CPUArchState *env, abi_ulong uold_ctx,
    656                        abi_ulong unew_ctx, abi_long ctx_size)
    657{
    658    struct target_ucontext *uctx;
    659    struct target_mcontext *mctx;
    660
    661    /* For ppc32, ctx_size is "reserved for future use".
    662     * For ppc64, we do not yet support the VSX extension.
    663     */
    664    if (ctx_size < sizeof(struct target_ucontext)) {
    665        return -TARGET_EINVAL;
    666    }
    667
    668    if (uold_ctx) {
    669        TaskState *ts = (TaskState *)thread_cpu->opaque;
    670
    671        if (!lock_user_struct(VERIFY_WRITE, uctx, uold_ctx, 1)) {
    672            return -TARGET_EFAULT;
    673        }
    674
    675#ifdef TARGET_PPC64
    676        mctx = &uctx->tuc_sigcontext.mcontext;
    677#else
    678        /* ??? The kernel aligns the pointer down here into padding, but
    679         * in setup_rt_frame we don't.  Be self-compatible for now.
    680         */
    681        mctx = &uctx->tuc_mcontext;
    682        __put_user(h2g(mctx), &uctx->tuc_regs);
    683#endif
    684
    685        save_user_regs(env, mctx);
    686        host_to_target_sigset(&uctx->tuc_sigmask, &ts->signal_mask);
    687
    688        unlock_user_struct(uctx, uold_ctx, 1);
    689    }
    690
    691    if (unew_ctx) {
    692        int err;
    693
    694        if (!lock_user_struct(VERIFY_READ, uctx, unew_ctx, 1)) {
    695            return -TARGET_EFAULT;
    696        }
    697        err = do_setcontext(uctx, env, 0);
    698        unlock_user_struct(uctx, unew_ctx, 1);
    699
    700        if (err) {
    701            /* We cannot return to a partially updated context.  */
    702            force_sig(TARGET_SIGSEGV);
    703        }
    704        return -TARGET_QEMU_ESIGRETURN;
    705    }
    706
    707    return 0;
    708}
    709
    710void setup_sigtramp(abi_ulong sigtramp_page)
    711{
    712    uint32_t *tramp = lock_user(VERIFY_WRITE, sigtramp_page, 2 * 8, 0);
    713    assert(tramp != NULL);
    714
    715#ifdef TARGET_ARCH_HAS_SETUP_FRAME
    716    default_sigreturn = sigtramp_page;
    717    encode_trampoline(TARGET_NR_sigreturn, tramp + 0);
    718#endif
    719
    720    default_rt_sigreturn = sigtramp_page + 8;
    721    encode_trampoline(TARGET_NR_rt_sigreturn, tramp + 2);
    722
    723    unlock_user(tramp, sigtramp_page, 2 * 8);
    724}