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 __SIGNAL_FRAMESIZE      160 /* FIXME: 31-bit mode -> 96 */
  29
  30 #define _SIGCONTEXT_NSIG        64
  31 #define _SIGCONTEXT_NSIG_BPW    64 /* FIXME: 31-bit mode -> 32 */
  32 #define _SIGCONTEXT_NSIG_WORDS  (_SIGCONTEXT_NSIG / _SIGCONTEXT_NSIG_BPW)
  33 #define _SIGMASK_COPY_SIZE    (sizeof(unsigned long)*_SIGCONTEXT_NSIG_WORDS)
  34 #define S390_SYSCALL_OPCODE ((uint16_t)0x0a00)
  35
  36 typedef struct {
  37     target_psw_t psw;
  38     abi_ulong gprs[__NUM_GPRS];
  39     abi_uint acrs[__NUM_ACRS];
  40 } target_s390_regs_common;
  41
  42 typedef struct {
  43     uint32_t fpc;
  44     uint32_t pad;
  45     uint64_t fprs[__NUM_FPRS];
  46 } target_s390_fp_regs;
  47
  48 typedef struct {
  49     target_s390_regs_common regs;
  50     target_s390_fp_regs     fpregs;
  51 } target_sigregs;
  52
  53 typedef struct {
  54     uint64_t vxrs_low[16];
  55     uint64_t vxrs_high[16][2];
  56     uint8_t reserved[128];
  57 } target_sigregs_ext;
  58
  59 typedef struct {
  60     abi_ulong oldmask[_SIGCONTEXT_NSIG_WORDS];
  61     abi_ulong sregs;
  62 } target_sigcontext;
  63
  64 typedef struct {
  65     uint8_t callee_used_stack[__SIGNAL_FRAMESIZE];
  66     target_sigcontext sc;
  67     target_sigregs sregs;
  68     int signo;
  69     target_sigregs_ext sregs_ext;
  70     uint16_t retcode;
  71 } sigframe;
  72
  73 #define TARGET_UC_VXRS 2
  74
  75 struct target_ucontext {
  76     abi_ulong tuc_flags;
  77     abi_ulong tuc_link;
  78     target_stack_t tuc_stack;
  79     target_sigregs tuc_mcontext;
  80     target_sigset_t tuc_sigmask;
  81     uint8_t reserved[128 - sizeof(target_sigset_t)];
  82     target_sigregs_ext tuc_mcontext_ext;
  83 };
  84
  85 typedef struct {
  86     uint8_t callee_used_stack[__SIGNAL_FRAMESIZE];
  87     uint16_t retcode;
  88     struct target_siginfo info;
  89     struct target_ucontext uc;
  90 } rt_sigframe;
  91
  92 static inline abi_ulong
  93 get_sigframe(struct target_sigaction *ka, CPUS390XState *env, size_t frame_size)
  94 {
  95     abi_ulong sp;
  96
  97     /* Default to using normal stack */
  98     sp = get_sp_from_cpustate(env);
  99
 100     /* This is the X/Open sanctioned signal stack switching.  */
 101     if (ka->sa_flags & TARGET_SA_ONSTACK) {
 102         sp = target_sigsp(sp, ka);
 103     }
 104
 105     /* This is the legacy signal stack switching. */
 106     else if (/* FIXME !user_mode(regs) */ 0 &&
 107              !(ka->sa_flags & TARGET_SA_RESTORER) &&
 108              ka->sa_restorer) {
 109         sp = (abi_ulong) ka->sa_restorer;
 110     }
 111
 112     return (sp - frame_size) & -8ul;
 113 }
 114
 115 static void save_sigregs(CPUS390XState *env, target_sigregs *sregs)
 116 {
 117     int i;
 118
 119     /*
 120      * Copy a 'clean' PSW mask to the user to avoid leaking
 121      * information about whether PER is currently on.
 122      */
 123     __put_user(env->psw.mask, &sregs->regs.psw.mask);
 124     __put_user(env->psw.addr, &sregs->regs.psw.addr);
 125
 126     for (i = 0; i < 16; i++) {
 127         __put_user(env->regs[i], &sregs->regs.gprs[i]);
 128     }
 129     for (i = 0; i < 16; i++) {
 130         __put_user(env->aregs[i], &sregs->regs.acrs[i]);
 131     }
 132
 133     /*
 134      * We have to store the fp registers to current->thread.fp_regs
 135      * to merge them with the emulated registers.
 136      */
 137     for (i = 0; i < 16; i++) {
 138         __put_user(*get_freg(env, i), &sregs->fpregs.fprs[i]);
 139     }
 140 }
 141
 142 static void save_sigregs_ext(CPUS390XState *env, target_sigregs_ext *ext)
 143 {
 144     int i;
 145
 146     /*
 147      * if (MACHINE_HAS_VX) ...
 148      * That said, we always allocate the stack storage and the
 149      * space is always available in env.
 150      */
 151     for (i = 0; i < 16; ++i) {
 152         __put_user(env->vregs[i][1], &ext->vxrs_low[i]);
 153     }
 154     for (i = 0; i < 16; ++i) {
 155         __put_user(env->vregs[i + 16][0], &ext->vxrs_high[i][0]);
 156         __put_user(env->vregs[i + 16][1], &ext->vxrs_high[i][1]);
 157     }
 158 }
 159
 160 void setup_frame(int sig, struct target_sigaction *ka,
 161                  target_sigset_t *set, CPUS390XState *env)
 162 {
 163     sigframe *frame;
 164     abi_ulong frame_addr;
 165     abi_ulong restorer;
 166
 167     frame_addr = get_sigframe(ka, env, sizeof(*frame));
 168     trace_user_setup_frame(env, frame_addr);
 169     if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) {
 170         force_sigsegv(sig);
 171         return;
 172     }
 173
 174     /* Set up backchain. */
 175     __put_user(env->regs[15], (abi_ulong *) frame);
 176
 177     /* Create struct sigcontext on the signal stack. */
 178     /* Make sure that we're initializing all of oldmask. */
 179     QEMU_BUILD_BUG_ON(ARRAY_SIZE(frame->sc.oldmask) != 1);
 180     __put_user(set->sig[0], &frame->sc.oldmask[0]);
 181     __put_user(frame_addr + offsetof(sigframe, sregs), &frame->sc.sregs);
 182
 183     /* Create _sigregs on the signal stack */
 184     save_sigregs(env, &frame->sregs);
 185
 186     /*
 187      * ??? The kernel uses regs->gprs[2] here, which is not yet the signo.
 188      * Moreover the comment talks about allowing backtrace, which is really
 189      * done by the r15 copy above.
 190      */
 191     __put_user(sig, &frame->signo);
 192
 193     /* Create sigregs_ext on the signal stack. */
 194     save_sigregs_ext(env, &frame->sregs_ext);
 195
 196     /*
 197      * Set up to return from userspace.
 198      * If provided, use a stub already in userspace.
 199      */
 200     if (ka->sa_flags & TARGET_SA_RESTORER) {
 201         restorer = ka->sa_restorer;
 202     } else {
 203         restorer = frame_addr + offsetof(sigframe, retcode);
 204         __put_user(S390_SYSCALL_OPCODE | TARGET_NR_sigreturn,
 205                    &frame->retcode);
 206     }
 207
 208     /* Set up registers for signal handler */
 209     env->regs[14] = restorer;
 210     env->regs[15] = frame_addr;
 211     /* Force default amode and default user address space control. */
 212     env->psw.mask = PSW_MASK_64 | PSW_MASK_32 | PSW_ASC_PRIMARY
 213                   | (env->psw.mask & ~PSW_MASK_ASC);
 214     env->psw.addr = ka->_sa_handler;
 215
 216     env->regs[2] = sig;
 217     env->regs[3] = frame_addr + offsetof(typeof(*frame), sc);
 218
 219     /*
 220      * We forgot to include these in the sigcontext.
 221      * To avoid breaking binary compatibility, they are passed as args.
 222      */
 223     env->regs[4] = 0; /* FIXME: regs->int_code & 127 */
 224     env->regs[5] = 0; /* FIXME: regs->int_parm_long */
 225     env->regs[6] = 0; /* FIXME: current->thread.last_break */
 226
 227     unlock_user_struct(frame, frame_addr, 1);
 228 }
 229
 230 void setup_rt_frame(int sig, struct target_sigaction *ka,
 231                     target_siginfo_t *info,
 232                     target_sigset_t *set, CPUS390XState *env)
 233 {
 234     rt_sigframe *frame;
 235     abi_ulong frame_addr;
 236     abi_ulong restorer;
 237     abi_ulong uc_flags;
 238
 239     frame_addr = get_sigframe(ka, env, sizeof *frame);
 240     trace_user_setup_rt_frame(env, frame_addr);
 241     if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) {
 242         force_sigsegv(sig);
 243         return;
 244     }
 245
 246     /* Set up backchain. */
 247     __put_user(env->regs[15], (abi_ulong *) frame);
 248
 249     /*
 250      * Set up to return from userspace.
 251      * If provided, use a stub already in userspace.
 252      */
 253     if (ka->sa_flags & TARGET_SA_RESTORER) {
 254         restorer = ka->sa_restorer;
 255     } else {
 256         restorer = frame_addr + offsetof(typeof(*frame), retcode);
 257         __put_user(S390_SYSCALL_OPCODE | TARGET_NR_rt_sigreturn,
 258                    &frame->retcode);
 259     }
 260
 261     /* Create siginfo on the signal stack. */
 262     tswap_siginfo(&frame->info, info);
 263
 264     /* Create ucontext on the signal stack. */
 265     uc_flags = 0;
 266     if (s390_has_feat(S390_FEAT_VECTOR)) {
 267         uc_flags |= TARGET_UC_VXRS;
 268     }
 269     __put_user(uc_flags, &frame->uc.tuc_flags);
 270     __put_user(0, &frame->uc.tuc_link);
 271     target_save_altstack(&frame->uc.tuc_stack, env);
 272     save_sigregs(env, &frame->uc.tuc_mcontext);
 273     save_sigregs_ext(env, &frame->uc.tuc_mcontext_ext);
 274     tswap_sigset(&frame->uc.tuc_sigmask, set);
 275
 276     /* Set up registers for signal handler */
 277     env->regs[14] = restorer;
 278     env->regs[15] = frame_addr;
 279     /* Force default amode and default user address space control. */
 280     env->psw.mask = PSW_MASK_64 | PSW_MASK_32 | PSW_ASC_PRIMARY
 281                   | (env->psw.mask & ~PSW_MASK_ASC);
 282     env->psw.addr = ka->_sa_handler;
 283
 284     env->regs[2] = sig;
 285     env->regs[3] = frame_addr + offsetof(typeof(*frame), info);
 286     env->regs[4] = frame_addr + offsetof(typeof(*frame), uc);
 287     env->regs[5] = 0; /* FIXME: current->thread.last_break */
 288 }
 289
 290 static void restore_sigregs(CPUS390XState *env, target_sigregs *sc)
 291 {
 292     target_ulong prev_addr;
 293     int i;
 294
 295     for (i = 0; i < 16; i++) {
 296         __get_user(env->regs[i], &sc->regs.gprs[i]);
 297     }
 298
 299     prev_addr = env->psw.addr;
 300     __get_user(env->psw.mask, &sc->regs.psw.mask);
 301     __get_user(env->psw.addr, &sc->regs.psw.addr);
 302     trace_user_s390x_restore_sigregs(env, env->psw.addr, prev_addr);
 303
 304     for (i = 0; i < 16; i++) {
 305         __get_user(env->aregs[i], &sc->regs.acrs[i]);
 306     }
 307     for (i = 0; i < 16; i++) {
 308         __get_user(*get_freg(env, i), &sc->fpregs.fprs[i]);
 309     }
 310 }
 311
 312 static void restore_sigregs_ext(CPUS390XState *env, target_sigregs_ext *ext)
 313 {
 314     int i;
 315
 316     /*
 317      * if (MACHINE_HAS_VX) ...
 318      * That said, we always allocate the stack storage and the
 319      * space is always available in env.
 320      */
 321     for (i = 0; i < 16; ++i) {
 322         __get_user(env->vregs[i][1], &ext->vxrs_low[i]);
 323     }
 324     for (i = 0; i < 16; ++i) {
 325         __get_user(env->vregs[i + 16][0], &ext->vxrs_high[i][0]);
 326         __get_user(env->vregs[i + 16][1], &ext->vxrs_high[i][1]);
 327     }
 328 }
 329
 330 long do_sigreturn(CPUS390XState *env)
 331 {
 332     sigframe *frame;
 333     abi_ulong frame_addr = env->regs[15];
 334     target_sigset_t target_set;
 335     sigset_t set;
 336
 337     trace_user_do_sigreturn(env, frame_addr);
 338     if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) {
 339         force_sig(TARGET_SIGSEGV);
 340         return -TARGET_QEMU_ESIGRETURN;
 341     }
 342
 343     /* Make sure that we're initializing all of target_set. */
 344     QEMU_BUILD_BUG_ON(ARRAY_SIZE(target_set.sig) != 1);
 345     __get_user(target_set.sig[0], &frame->sc.oldmask[0]);
 346
 347     target_to_host_sigset_internal(&set, &target_set);
 348     set_sigmask(&set); /* ~_BLOCKABLE? */
 349
 350     restore_sigregs(env, &frame->sregs);
 351     restore_sigregs_ext(env, &frame->sregs_ext);
 352
 353     unlock_user_struct(frame, frame_addr, 0);
 354     return -TARGET_QEMU_ESIGRETURN;
 355 }
 356
 357 long do_rt_sigreturn(CPUS390XState *env)
 358 {
 359     rt_sigframe *frame;
 360     abi_ulong frame_addr = env->regs[15];
 361     sigset_t set;
 362
 363     trace_user_do_rt_sigreturn(env, frame_addr);
 364     if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) {
 365         force_sig(TARGET_SIGSEGV);
 366         return -TARGET_QEMU_ESIGRETURN;
 367     }
 368     target_to_host_sigset(&set, &frame->uc.tuc_sigmask);
 369
 370     set_sigmask(&set); /* ~_BLOCKABLE? */
 371
 372     restore_sigregs(env, &frame->uc.tuc_mcontext);
 373     restore_sigregs_ext(env, &frame->uc.tuc_mcontext_ext);
 374
 375     target_restore_altstack(&frame->uc.tuc_stack, env);
 376
 377     unlock_user_struct(frame, frame_addr, 0);
 378     return -TARGET_QEMU_ESIGRETURN;
 379 }