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