LXR qemu/linux-user/s390x/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 "signal-common.h"
  22#include "linux-user/trace.h"
  23
  24#define __NUM_GPRS 16
  25#define __NUM_FPRS 16
  26#define __NUM_ACRS 16
  27
  28#define S390_SYSCALL_SIZE   2
  29#define __SIGNAL_FRAMESIZE      160 /* FIXME: 31-bit mode -> 96 */
  30
  31#define _SIGCONTEXT_NSIG        64
  32#define _SIGCONTEXT_NSIG_BPW    64 /* FIXME: 31-bit mode -> 32 */
  33#define _SIGCONTEXT_NSIG_WORDS  (_SIGCONTEXT_NSIG / _SIGCONTEXT_NSIG_BPW)
  34#define _SIGMASK_COPY_SIZE    (sizeof(unsigned long)*_SIGCONTEXT_NSIG_WORDS)
  35#define PSW_ADDR_AMODE            0x0000000000000000UL /* 0x80000000UL for 31-bit */
  36#define S390_SYSCALL_OPCODE ((uint16_t)0x0a00)
  37
  38typedef struct {
  39    target_psw_t psw;
  40    target_ulong gprs[__NUM_GPRS];
  41    unsigned int acrs[__NUM_ACRS];
  42} target_s390_regs_common;
  43
  44typedef struct {
  45    unsigned int fpc;
  46    double   fprs[__NUM_FPRS];
  47} target_s390_fp_regs;
  48
  49typedef struct {
  50    target_s390_regs_common regs;
  51    target_s390_fp_regs     fpregs;
  52} target_sigregs;
  53
  54struct target_sigcontext {
  55    target_ulong   oldmask[_SIGCONTEXT_NSIG_WORDS];
  56    target_sigregs *sregs;
  57};
  58
  59typedef struct {
  60    uint8_t callee_used_stack[__SIGNAL_FRAMESIZE];
  61    struct target_sigcontext sc;
  62    target_sigregs sregs;
  63    int signo;
  64    uint8_t retcode[S390_SYSCALL_SIZE];
  65} sigframe;
  66
  67struct target_ucontext {
  68    target_ulong tuc_flags;
  69    struct target_ucontext *tuc_link;
  70    target_stack_t tuc_stack;
  71    target_sigregs tuc_mcontext;
  72    target_sigset_t tuc_sigmask;   /* mask last for extensibility */
  73};
  74
  75typedef struct {
  76    uint8_t callee_used_stack[__SIGNAL_FRAMESIZE];
  77    uint8_t retcode[S390_SYSCALL_SIZE];
  78    struct target_siginfo info;
  79    struct target_ucontext uc;
  80} rt_sigframe;
  81
  82static inline abi_ulong
  83get_sigframe(struct target_sigaction *ka, CPUS390XState *env, size_t frame_size)
  84{
  85    abi_ulong sp;
  86
  87    /* Default to using normal stack */
  88    sp = get_sp_from_cpustate(env);
  89
  90    /* This is the X/Open sanctioned signal stack switching.  */
  91    if (ka->sa_flags & TARGET_SA_ONSTACK) {
  92        sp = target_sigsp(sp, ka);
  93    }
  94
  95    /* This is the legacy signal stack switching. */
  96    else if (/* FIXME !user_mode(regs) */ 0 &&
  97             !(ka->sa_flags & TARGET_SA_RESTORER) &&
  98             ka->sa_restorer) {
  99        sp = (abi_ulong) ka->sa_restorer;
 100    }
 101
 102    return (sp - frame_size) & -8ul;
 103}
 104
 105static void save_sigregs(CPUS390XState *env, target_sigregs *sregs)
 106{
 107    int i;
 108    //save_access_regs(current->thread.acrs); FIXME
 109
 110    /* Copy a 'clean' PSW mask to the user to avoid leaking
 111       information about whether PER is currently on.  */
 112    __put_user(env->psw.mask, &sregs->regs.psw.mask);
 113    __put_user(env->psw.addr, &sregs->regs.psw.addr);
 114    for (i = 0; i < 16; i++) {
 115        __put_user(env->regs[i], &sregs->regs.gprs[i]);
 116    }
 117    for (i = 0; i < 16; i++) {
 118        __put_user(env->aregs[i], &sregs->regs.acrs[i]);
 119    }
 120    /*
 121     * We have to store the fp registers to current->thread.fp_regs
 122     * to merge them with the emulated registers.
 123     */
 124    //save_fp_regs(&current->thread.fp_regs); FIXME
 125    for (i = 0; i < 16; i++) {
 126        __put_user(get_freg(env, i)->ll, &sregs->fpregs.fprs[i]);
 127    }
 128}
 129
 130void setup_frame(int sig, struct target_sigaction *ka,
 131                 target_sigset_t *set, CPUS390XState *env)
 132{
 133    sigframe *frame;
 134    abi_ulong frame_addr;
 135
 136    frame_addr = get_sigframe(ka, env, sizeof(*frame));
 137    trace_user_setup_frame(env, frame_addr);
 138    if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) {
 139        goto give_sigsegv;
 140    }
 141
 142    __put_user(set->sig[0], &frame->sc.oldmask[0]);
 143
 144    save_sigregs(env, &frame->sregs);
 145
 146    __put_user((abi_ulong)(unsigned long)&frame->sregs,
 147               (abi_ulong *)&frame->sc.sregs);
 148
 149    /* Set up to return from userspace.  If provided, use a stub
 150       already in userspace.  */
 151    if (ka->sa_flags & TARGET_SA_RESTORER) {
 152        env->regs[14] = (unsigned long)
 153                ka->sa_restorer | PSW_ADDR_AMODE;
 154    } else {
 155        env->regs[14] = (frame_addr + offsetof(sigframe, retcode))
 156                        | PSW_ADDR_AMODE;
 157        __put_user(S390_SYSCALL_OPCODE | TARGET_NR_sigreturn,
 158                   (uint16_t *)(frame->retcode));
 159    }
 160
 161    /* Set up backchain. */
 162    __put_user(env->regs[15], (abi_ulong *) frame);
 163
 164    /* Set up registers for signal handler */
 165    env->regs[15] = frame_addr;
 166    env->psw.addr = (target_ulong) ka->_sa_handler | PSW_ADDR_AMODE;
 167
 168    env->regs[2] = sig; //map_signal(sig);
 169    env->regs[3] = frame_addr += offsetof(typeof(*frame), sc);
 170
 171    /* We forgot to include these in the sigcontext.
 172       To avoid breaking binary compatibility, they are passed as args. */
 173    env->regs[4] = 0; // FIXME: no clue... current->thread.trap_no;
 174    env->regs[5] = 0; // FIXME: no clue... current->thread.prot_addr;
 175
 176    /* Place signal number on stack to allow backtrace from handler.  */
 177    __put_user(env->regs[2], &frame->signo);
 178    unlock_user_struct(frame, frame_addr, 1);
 179    return;
 180
 181give_sigsegv:
 182    force_sigsegv(sig);
 183}
 184
 185void setup_rt_frame(int sig, struct target_sigaction *ka,
 186                    target_siginfo_t *info,
 187                    target_sigset_t *set, CPUS390XState *env)
 188{
 189    int i;
 190    rt_sigframe *frame;
 191    abi_ulong frame_addr;
 192
 193    frame_addr = get_sigframe(ka, env, sizeof *frame);
 194    trace_user_setup_rt_frame(env, frame_addr);
 195    if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) {
 196        goto give_sigsegv;
 197    }
 198
 199    tswap_siginfo(&frame->info, info);
 200
 201    /* Create the ucontext.  */
 202    __put_user(0, &frame->uc.tuc_flags);
 203    __put_user((abi_ulong)0, (abi_ulong *)&frame->uc.tuc_link);
 204    target_save_altstack(&frame->uc.tuc_stack, env);
 205    save_sigregs(env, &frame->uc.tuc_mcontext);
 206    for (i = 0; i < TARGET_NSIG_WORDS; i++) {
 207        __put_user((abi_ulong)set->sig[i],
 208                   (abi_ulong *)&frame->uc.tuc_sigmask.sig[i]);
 209    }
 210
 211    /* Set up to return from userspace.  If provided, use a stub
 212       already in userspace.  */
 213    if (ka->sa_flags & TARGET_SA_RESTORER) {
 214        env->regs[14] = (unsigned long) ka->sa_restorer | PSW_ADDR_AMODE;
 215    } else {
 216        env->regs[14] = (unsigned long) frame->retcode | PSW_ADDR_AMODE;
 217        __put_user(S390_SYSCALL_OPCODE | TARGET_NR_rt_sigreturn,
 218                   (uint16_t *)(frame->retcode));
 219    }
 220
 221    /* Set up backchain. */
 222    __put_user(env->regs[15], (abi_ulong *) frame);
 223
 224    /* Set up registers for signal handler */
 225    env->regs[15] = frame_addr;
 226    env->psw.addr = (target_ulong) ka->_sa_handler | PSW_ADDR_AMODE;
 227
 228    env->regs[2] = sig; //map_signal(sig);
 229    env->regs[3] = frame_addr + offsetof(typeof(*frame), info);
 230    env->regs[4] = frame_addr + offsetof(typeof(*frame), uc);
 231    return;
 232
 233give_sigsegv:
 234    force_sigsegv(sig);
 235}
 236
 237static int
 238restore_sigregs(CPUS390XState *env, target_sigregs *sc)
 239{
 240    int err = 0;
 241    int i;
 242
 243    for (i = 0; i < 16; i++) {
 244        __get_user(env->regs[i], &sc->regs.gprs[i]);
 245    }
 246
 247    __get_user(env->psw.mask, &sc->regs.psw.mask);
 248    trace_user_s390x_restore_sigregs(env, (unsigned long long)sc->regs.psw.addr,
 249                                     (unsigned long long)env->psw.addr);
 250    __get_user(env->psw.addr, &sc->regs.psw.addr);
 251    /* FIXME: 31-bit -> | PSW_ADDR_AMODE */
 252
 253    for (i = 0; i < 16; i++) {
 254        __get_user(env->aregs[i], &sc->regs.acrs[i]);
 255    }
 256    for (i = 0; i < 16; i++) {
 257        __get_user(get_freg(env, i)->ll, &sc->fpregs.fprs[i]);
 258    }
 259
 260    return err;
 261}
 262
 263long do_sigreturn(CPUS390XState *env)
 264{
 265    sigframe *frame;
 266    abi_ulong frame_addr = env->regs[15];
 267    target_sigset_t target_set;
 268    sigset_t set;
 269
 270    trace_user_do_sigreturn(env, frame_addr);
 271    if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) {
 272        goto badframe;
 273    }
 274    __get_user(target_set.sig[0], &frame->sc.oldmask[0]);
 275
 276    target_to_host_sigset_internal(&set, &target_set);
 277    set_sigmask(&set); /* ~_BLOCKABLE? */
 278
 279    if (restore_sigregs(env, &frame->sregs)) {
 280        goto badframe;
 281    }
 282
 283    unlock_user_struct(frame, frame_addr, 0);
 284    return -TARGET_QEMU_ESIGRETURN;
 285
 286badframe:
 287    force_sig(TARGET_SIGSEGV);
 288    return -TARGET_QEMU_ESIGRETURN;
 289}
 290
 291long do_rt_sigreturn(CPUS390XState *env)
 292{
 293    rt_sigframe *frame;
 294    abi_ulong frame_addr = env->regs[15];
 295    sigset_t set;
 296
 297    trace_user_do_rt_sigreturn(env, frame_addr);
 298    if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) {
 299        goto badframe;
 300    }
 301    target_to_host_sigset(&set, &frame->uc.tuc_sigmask);
 302
 303    set_sigmask(&set); /* ~_BLOCKABLE? */
 304
 305    if (restore_sigregs(env, &frame->uc.tuc_mcontext)) {
 306        goto badframe;
 307    }
 308
 309    if (do_sigaltstack(frame_addr + offsetof(rt_sigframe, uc.tuc_stack), 0,
 310                       get_sp_from_cpustate(env)) == -EFAULT) {
 311        goto badframe;
 312    }
 313    unlock_user_struct(frame, frame_addr, 0);
 314    return -TARGET_QEMU_ESIGRETURN;
 315
 316badframe:
 317    unlock_user_struct(frame, frame_addr, 0);
 318    force_sig(TARGET_SIGSEGV);
 319    return -TARGET_QEMU_ESIGRETURN;
 320}
 321