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 "target_signal.h"
  22 #include "signal-common.h"
  23 #include "linux-user/trace.h"
  24
  25 #define __NUM_GPRS 16
  26 #define __NUM_FPRS 16
  27 #define __NUM_ACRS 16
  28
  29 #define S390_SYSCALL_SIZE   2
  30 #define __SIGNAL_FRAMESIZE      160 /* FIXME: 31-bit mode -> 96 */
  31
  32 #define _SIGCONTEXT_NSIG        64
  33 #define _SIGCONTEXT_NSIG_BPW    64 /* FIXME: 31-bit mode -> 32 */
  34 #define _SIGCONTEXT_NSIG_WORDS  (_SIGCONTEXT_NSIG / _SIGCONTEXT_NSIG_BPW)
  35 #define _SIGMASK_COPY_SIZE    (sizeof(unsigned long)*_SIGCONTEXT_NSIG_WORDS)
  36 #define PSW_ADDR_AMODE            0x0000000000000000UL /* 0x80000000UL for 31-bit */
  37 #define S390_SYSCALL_OPCODE ((uint16_t)0x0a00)
  38
  39 typedef struct {
  40     target_psw_t psw;
  41     target_ulong gprs[__NUM_GPRS];
  42     unsigned int acrs[__NUM_ACRS];
  43 } target_s390_regs_common;
  44
  45 typedef struct {
  46     unsigned int fpc;
  47     double   fprs[__NUM_FPRS];
  48 } target_s390_fp_regs;
  49
  50 typedef struct {
  51     target_s390_regs_common regs;
  52     target_s390_fp_regs     fpregs;
  53 } target_sigregs;
  54
  55 struct target_sigcontext {
  56     target_ulong   oldmask[_SIGCONTEXT_NSIG_WORDS];
  57     target_sigregs *sregs;
  58 };
  59
  60 typedef struct {
  61     uint8_t callee_used_stack[__SIGNAL_FRAMESIZE];
  62     struct target_sigcontext sc;
  63     target_sigregs sregs;
  64     int signo;
  65     uint8_t retcode[S390_SYSCALL_SIZE];
  66 } sigframe;
  67
  68 struct target_ucontext {
  69     target_ulong tuc_flags;
  70     struct target_ucontext *tuc_link;
  71     target_stack_t tuc_stack;
  72     target_sigregs tuc_mcontext;
  73     target_sigset_t tuc_sigmask;   /* mask last for extensibility */
  74 };
  75
  76 typedef struct {
  77     uint8_t callee_used_stack[__SIGNAL_FRAMESIZE];
  78     uint8_t retcode[S390_SYSCALL_SIZE];
  79     struct target_siginfo info;
  80     struct target_ucontext uc;
  81 } rt_sigframe;
  82
  83 static inline abi_ulong
  84 get_sigframe(struct target_sigaction *ka, CPUS390XState *env, size_t frame_size)
  85 {
  86     abi_ulong sp;
  87
  88     /* Default to using normal stack */
  89     sp = env->regs[15];
  90
  91     /* This is the X/Open sanctioned signal stack switching.  */
  92     if (ka->sa_flags & TARGET_SA_ONSTACK) {
  93         if (!sas_ss_flags(sp)) {
  94             sp = target_sigaltstack_used.ss_sp +
  95                  target_sigaltstack_used.ss_size;
  96         }
  97     }
  98
  99     /* This is the legacy signal stack switching. */
 100     else if (/* FIXME !user_mode(regs) */ 0 &&
 101              !(ka->sa_flags & TARGET_SA_RESTORER) &&
 102              ka->sa_restorer) {
 103         sp = (abi_ulong) ka->sa_restorer;
 104     }
 105
 106     return (sp - frame_size) & -8ul;
 107 }
 108
 109 static void save_sigregs(CPUS390XState *env, target_sigregs *sregs)
 110 {
 111     int i;
 112     //save_access_regs(current->thread.acrs); FIXME
 113
 114     /* Copy a 'clean' PSW mask to the user to avoid leaking
 115        information about whether PER is currently on.  */
 116     __put_user(env->psw.mask, &sregs->regs.psw.mask);
 117     __put_user(env->psw.addr, &sregs->regs.psw.addr);
 118     for (i = 0; i < 16; i++) {
 119         __put_user(env->regs[i], &sregs->regs.gprs[i]);
 120     }
 121     for (i = 0; i < 16; i++) {
 122         __put_user(env->aregs[i], &sregs->regs.acrs[i]);
 123     }
 124     /*
 125      * We have to store the fp registers to current->thread.fp_regs
 126      * to merge them with the emulated registers.
 127      */
 128     //save_fp_regs(&current->thread.fp_regs); FIXME
 129     for (i = 0; i < 16; i++) {
 130         __put_user(get_freg(env, i)->ll, &sregs->fpregs.fprs[i]);
 131     }
 132 }
 133
 134 void setup_frame(int sig, struct target_sigaction *ka,
 135                  target_sigset_t *set, CPUS390XState *env)
 136 {
 137     sigframe *frame;
 138     abi_ulong frame_addr;
 139
 140     frame_addr = get_sigframe(ka, env, sizeof(*frame));
 141     trace_user_setup_frame(env, frame_addr);
 142     if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) {
 143         goto give_sigsegv;
 144     }
 145
 146     __put_user(set->sig[0], &frame->sc.oldmask[0]);
 147
 148     save_sigregs(env, &frame->sregs);
 149
 150     __put_user((abi_ulong)(unsigned long)&frame->sregs,
 151                (abi_ulong *)&frame->sc.sregs);
 152
 153     /* Set up to return from userspace.  If provided, use a stub
 154        already in userspace.  */
 155     if (ka->sa_flags & TARGET_SA_RESTORER) {
 156         env->regs[14] = (unsigned long)
 157                 ka->sa_restorer | PSW_ADDR_AMODE;
 158     } else {
 159         env->regs[14] = (frame_addr + offsetof(sigframe, retcode))
 160                         | PSW_ADDR_AMODE;
 161         __put_user(S390_SYSCALL_OPCODE | TARGET_NR_sigreturn,
 162                    (uint16_t *)(frame->retcode));
 163     }
 164
 165     /* Set up backchain. */
 166     __put_user(env->regs[15], (abi_ulong *) frame);
 167
 168     /* Set up registers for signal handler */
 169     env->regs[15] = frame_addr;
 170     env->psw.addr = (target_ulong) ka->_sa_handler | PSW_ADDR_AMODE;
 171
 172     env->regs[2] = sig; //map_signal(sig);
 173     env->regs[3] = frame_addr += offsetof(typeof(*frame), sc);
 174
 175     /* We forgot to include these in the sigcontext.
 176        To avoid breaking binary compatibility, they are passed as args. */
 177     env->regs[4] = 0; // FIXME: no clue... current->thread.trap_no;
 178     env->regs[5] = 0; // FIXME: no clue... current->thread.prot_addr;
 179
 180     /* Place signal number on stack to allow backtrace from handler.  */
 181     __put_user(env->regs[2], &frame->signo);
 182     unlock_user_struct(frame, frame_addr, 1);
 183     return;
 184
 185 give_sigsegv:
 186     force_sigsegv(sig);
 187 }
 188
 189 void setup_rt_frame(int sig, struct target_sigaction *ka,
 190                     target_siginfo_t *info,
 191                     target_sigset_t *set, CPUS390XState *env)
 192 {
 193     int i;
 194     rt_sigframe *frame;
 195     abi_ulong frame_addr;
 196
 197     frame_addr = get_sigframe(ka, env, sizeof *frame);
 198     trace_user_setup_rt_frame(env, frame_addr);
 199     if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) {
 200         goto give_sigsegv;
 201     }
 202
 203     tswap_siginfo(&frame->info, info);
 204
 205     /* Create the ucontext.  */
 206     __put_user(0, &frame->uc.tuc_flags);
 207     __put_user((abi_ulong)0, (abi_ulong *)&frame->uc.tuc_link);
 208     __put_user(target_sigaltstack_used.ss_sp, &frame->uc.tuc_stack.ss_sp);
 209     __put_user(sas_ss_flags(get_sp_from_cpustate(env)),
 210                &frame->uc.tuc_stack.ss_flags);
 211     __put_user(target_sigaltstack_used.ss_size, &frame->uc.tuc_stack.ss_size);
 212     save_sigregs(env, &frame->uc.tuc_mcontext);
 213     for (i = 0; i < TARGET_NSIG_WORDS; i++) {
 214         __put_user((abi_ulong)set->sig[i],
 215                    (abi_ulong *)&frame->uc.tuc_sigmask.sig[i]);
 216     }
 217
 218     /* Set up to return from userspace.  If provided, use a stub
 219        already in userspace.  */
 220     if (ka->sa_flags & TARGET_SA_RESTORER) {
 221         env->regs[14] = (unsigned long) ka->sa_restorer | PSW_ADDR_AMODE;
 222     } else {
 223         env->regs[14] = (unsigned long) frame->retcode | PSW_ADDR_AMODE;
 224         __put_user(S390_SYSCALL_OPCODE | TARGET_NR_rt_sigreturn,
 225                    (uint16_t *)(frame->retcode));
 226     }
 227
 228     /* Set up backchain. */
 229     __put_user(env->regs[15], (abi_ulong *) frame);
 230
 231     /* Set up registers for signal handler */
 232     env->regs[15] = frame_addr;
 233     env->psw.addr = (target_ulong) ka->_sa_handler | PSW_ADDR_AMODE;
 234
 235     env->regs[2] = sig; //map_signal(sig);
 236     env->regs[3] = frame_addr + offsetof(typeof(*frame), info);
 237     env->regs[4] = frame_addr + offsetof(typeof(*frame), uc);
 238     return;
 239
 240 give_sigsegv:
 241     force_sigsegv(sig);
 242 }
 243
 244 static int
 245 restore_sigregs(CPUS390XState *env, target_sigregs *sc)
 246 {
 247     int err = 0;
 248     int i;
 249
 250     for (i = 0; i < 16; i++) {
 251         __get_user(env->regs[i], &sc->regs.gprs[i]);
 252     }
 253
 254     __get_user(env->psw.mask, &sc->regs.psw.mask);
 255     trace_user_s390x_restore_sigregs(env, (unsigned long long)sc->regs.psw.addr,
 256                                      (unsigned long long)env->psw.addr);
 257     __get_user(env->psw.addr, &sc->regs.psw.addr);
 258     /* FIXME: 31-bit -> | PSW_ADDR_AMODE */
 259
 260     for (i = 0; i < 16; i++) {
 261         __get_user(env->aregs[i], &sc->regs.acrs[i]);
 262     }
 263     for (i = 0; i < 16; i++) {
 264         __get_user(get_freg(env, i)->ll, &sc->fpregs.fprs[i]);
 265     }
 266
 267     return err;
 268 }
 269
 270 long do_sigreturn(CPUS390XState *env)
 271 {
 272     sigframe *frame;
 273     abi_ulong frame_addr = env->regs[15];
 274     target_sigset_t target_set;
 275     sigset_t set;
 276
 277     trace_user_do_sigreturn(env, frame_addr);
 278     if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) {
 279         goto badframe;
 280     }
 281     __get_user(target_set.sig[0], &frame->sc.oldmask[0]);
 282
 283     target_to_host_sigset_internal(&set, &target_set);
 284     set_sigmask(&set); /* ~_BLOCKABLE? */
 285
 286     if (restore_sigregs(env, &frame->sregs)) {
 287         goto badframe;
 288     }
 289
 290     unlock_user_struct(frame, frame_addr, 0);
 291     return -TARGET_QEMU_ESIGRETURN;
 292
 293 badframe:
 294     force_sig(TARGET_SIGSEGV);
 295     return -TARGET_QEMU_ESIGRETURN;
 296 }
 297
 298 long do_rt_sigreturn(CPUS390XState *env)
 299 {
 300     rt_sigframe *frame;
 301     abi_ulong frame_addr = env->regs[15];
 302     sigset_t set;
 303
 304     trace_user_do_rt_sigreturn(env, frame_addr);
 305     if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) {
 306         goto badframe;
 307     }
 308     target_to_host_sigset(&set, &frame->uc.tuc_sigmask);
 309
 310     set_sigmask(&set); /* ~_BLOCKABLE? */
 311
 312     if (restore_sigregs(env, &frame->uc.tuc_mcontext)) {
 313         goto badframe;
 314     }
 315
 316     if (do_sigaltstack(frame_addr + offsetof(rt_sigframe, uc.tuc_stack), 0,
 317                        get_sp_from_cpustate(env)) == -EFAULT) {
 318         goto badframe;
 319     }
 320     unlock_user_struct(frame, frame_addr, 0);
 321     return -TARGET_QEMU_ESIGRETURN;
 322
 323 badframe:
 324     unlock_user_struct(frame, frame_addr, 0);
 325     force_sig(TARGET_SIGSEGV);
 326     return -TARGET_QEMU_ESIGRETURN;
 327 }