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
  38 typedef struct {
  39     target_psw_t psw;
  40     target_ulong gprs[__NUM_GPRS];
  41     unsigned int acrs[__NUM_ACRS];
  42 } target_s390_regs_common;
  43
  44 typedef struct {
  45     unsigned int fpc;
  46     double   fprs[__NUM_FPRS];
  47 } target_s390_fp_regs;
  48
  49 typedef struct {
  50     target_s390_regs_common regs;
  51     target_s390_fp_regs     fpregs;
  52 } target_sigregs;
  53
  54 struct target_sigcontext {
  55     target_ulong   oldmask[_SIGCONTEXT_NSIG_WORDS];
  56     target_sigregs *sregs;
  57 };
  58
  59 typedef 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
  67 struct 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
  75 typedef 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
  82 static inline abi_ulong
  83 get_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
 105 static 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), &sregs->fpregs.fprs[i]);
 127     }
 128 }
 129
 130 void 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
 181 give_sigsegv:
 182     force_sigsegv(sig);
 183 }
 184
 185 void 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] = ka->sa_restorer | PSW_ADDR_AMODE;
 215     } else {
 216         env->regs[14] = (frame_addr + offsetof(typeof(*frame), retcode))
 217                         | PSW_ADDR_AMODE;
 218         __put_user(S390_SYSCALL_OPCODE | TARGET_NR_rt_sigreturn,
 219                    (uint16_t *)(frame->retcode));
 220     }
 221
 222     /* Set up backchain. */
 223     __put_user(env->regs[15], (abi_ulong *) frame);
 224
 225     /* Set up registers for signal handler */
 226     env->regs[15] = frame_addr;
 227     env->psw.addr = (target_ulong) ka->_sa_handler | PSW_ADDR_AMODE;
 228
 229     env->regs[2] = sig; //map_signal(sig);
 230     env->regs[3] = frame_addr + offsetof(typeof(*frame), info);
 231     env->regs[4] = frame_addr + offsetof(typeof(*frame), uc);
 232     return;
 233
 234 give_sigsegv:
 235     force_sigsegv(sig);
 236 }
 237
 238 static int
 239 restore_sigregs(CPUS390XState *env, target_sigregs *sc)
 240 {
 241     int err = 0;
 242     int i;
 243
 244     for (i = 0; i < 16; i++) {
 245         __get_user(env->regs[i], &sc->regs.gprs[i]);
 246     }
 247
 248     __get_user(env->psw.mask, &sc->regs.psw.mask);
 249     trace_user_s390x_restore_sigregs(env, (unsigned long long)sc->regs.psw.addr,
 250                                      (unsigned long long)env->psw.addr);
 251     __get_user(env->psw.addr, &sc->regs.psw.addr);
 252     /* FIXME: 31-bit -> | PSW_ADDR_AMODE */
 253
 254     for (i = 0; i < 16; i++) {
 255         __get_user(env->aregs[i], &sc->regs.acrs[i]);
 256     }
 257     for (i = 0; i < 16; i++) {
 258         __get_user(*get_freg(env, i), &sc->fpregs.fprs[i]);
 259     }
 260
 261     return err;
 262 }
 263
 264 long do_sigreturn(CPUS390XState *env)
 265 {
 266     sigframe *frame;
 267     abi_ulong frame_addr = env->regs[15];
 268     target_sigset_t target_set;
 269     sigset_t set;
 270
 271     trace_user_do_sigreturn(env, frame_addr);
 272     if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) {
 273         goto badframe;
 274     }
 275     __get_user(target_set.sig[0], &frame->sc.oldmask[0]);
 276
 277     target_to_host_sigset_internal(&set, &target_set);
 278     set_sigmask(&set); /* ~_BLOCKABLE? */
 279
 280     if (restore_sigregs(env, &frame->sregs)) {
 281         goto badframe;
 282     }
 283
 284     unlock_user_struct(frame, frame_addr, 0);
 285     return -TARGET_QEMU_ESIGRETURN;
 286
 287 badframe:
 288     force_sig(TARGET_SIGSEGV);
 289     return -TARGET_QEMU_ESIGRETURN;
 290 }
 291
 292 long do_rt_sigreturn(CPUS390XState *env)
 293 {
 294     rt_sigframe *frame;
 295     abi_ulong frame_addr = env->regs[15];
 296     sigset_t set;
 297
 298     trace_user_do_rt_sigreturn(env, frame_addr);
 299     if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) {
 300         goto badframe;
 301     }
 302     target_to_host_sigset(&set, &frame->uc.tuc_sigmask);
 303
 304     set_sigmask(&set); /* ~_BLOCKABLE? */
 305
 306     if (restore_sigregs(env, &frame->uc.tuc_mcontext)) {
 307         goto badframe;
 308     }
 309
 310     if (do_sigaltstack(frame_addr + offsetof(rt_sigframe, uc.tuc_stack), 0,
 311                        get_sp_from_cpustate(env)) == -EFAULT) {
 312         goto badframe;
 313     }
 314     unlock_user_struct(frame, frame_addr, 0);
 315     return -TARGET_QEMU_ESIGRETURN;
 316
 317 badframe:
 318     unlock_user_struct(frame, frame_addr, 0);
 319     force_sig(TARGET_SIGSEGV);
 320     return -TARGET_QEMU_ESIGRETURN;
 321 }