linux-user/tilegx/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 struct target_sigcontext {
  25     union {
  26         /* General-purpose registers.  */
  27         abi_ulong gregs[56];
  28         struct {
  29             abi_ulong __gregs[53];
  30             abi_ulong tp;        /* Aliases gregs[TREG_TP].  */
  31             abi_ulong sp;        /* Aliases gregs[TREG_SP].  */
  32             abi_ulong lr;        /* Aliases gregs[TREG_LR].  */
  33         };
  34     };
  35     abi_ulong pc;        /* Program counter.  */
  36     abi_ulong ics;       /* In Interrupt Critical Section?  */
  37     abi_ulong faultnum;  /* Fault number.  */
  38     abi_ulong pad[5];
  39 };
  40
  41 struct target_ucontext {
  42     abi_ulong tuc_flags;
  43     abi_ulong tuc_link;
  44     target_stack_t tuc_stack;
  45     struct target_sigcontext tuc_mcontext;
  46     target_sigset_t tuc_sigmask;   /* mask last for extensibility */
  47 };
  48
  49 struct target_rt_sigframe {
  50     unsigned char save_area[16]; /* caller save area */
  51     struct target_siginfo info;
  52     struct target_ucontext uc;
  53     abi_ulong retcode[2];
  54 };
  55
  56 #define INSN_MOVELI_R10_139  0x00045fe551483000ULL /* { moveli r10, 139 } */
  57 #define INSN_SWINT1          0x286b180051485000ULL /* { swint1 } */
  58
  59
  60 static void setup_sigcontext(struct target_sigcontext *sc,
  61                              CPUArchState *env, int signo)
  62 {
  63     int i;
  64
  65     for (i = 0; i < TILEGX_R_COUNT; ++i) {
  66         __put_user(env->regs[i], &sc->gregs[i]);
  67     }
  68
  69     __put_user(env->pc, &sc->pc);
  70     __put_user(0, &sc->ics);
  71     __put_user(signo, &sc->faultnum);
  72 }
  73
  74 static void restore_sigcontext(CPUTLGState *env, struct target_sigcontext *sc)
  75 {
  76     int i;
  77
  78     for (i = 0; i < TILEGX_R_COUNT; ++i) {
  79         __get_user(env->regs[i], &sc->gregs[i]);
  80     }
  81
  82     __get_user(env->pc, &sc->pc);
  83 }
  84
  85 static abi_ulong get_sigframe(struct target_sigaction *ka, CPUArchState *env,
  86                               size_t frame_size)
  87 {
  88     unsigned long sp = get_sp_from_cpustate(env);
  89
  90     if (on_sig_stack(sp) && !likely(on_sig_stack(sp - frame_size))) {
  91         return -1UL;
  92     }
  93
  94     sp = target_sigsp(sp, ka) - frame_size;
  95     sp &= -16UL;
  96     return sp;
  97 }
  98
  99 void setup_rt_frame(int sig, struct target_sigaction *ka,
 100                     target_siginfo_t *info,
 101                     target_sigset_t *set, CPUArchState *env)
 102 {
 103     abi_ulong frame_addr;
 104     struct target_rt_sigframe *frame;
 105     unsigned long restorer;
 106
 107     frame_addr = get_sigframe(ka, env, sizeof(*frame));
 108     trace_user_setup_rt_frame(env, frame_addr);
 109     if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) {
 110         goto give_sigsegv;
 111     }
 112
 113     /* Always write at least the signal number for the stack backtracer. */
 114     if (ka->sa_flags & TARGET_SA_SIGINFO) {
 115         /* At sigreturn time, restore the callee-save registers too. */
 116         tswap_siginfo(&frame->info, info);
 117         /* regs->flags |= PT_FLAGS_RESTORE_REGS; FIXME: we can skip it? */
 118     } else {
 119         __put_user(info->si_signo, &frame->info.si_signo);
 120     }
 121
 122     /* Create the ucontext.  */
 123     __put_user(0, &frame->uc.tuc_flags);
 124     __put_user(0, &frame->uc.tuc_link);
 125     target_save_altstack(&frame->uc.tuc_stack, env);
 126     setup_sigcontext(&frame->uc.tuc_mcontext, env, info->si_signo);
 127
 128     if (ka->sa_flags & TARGET_SA_RESTORER) {
 129         restorer = (unsigned long) ka->sa_restorer;
 130     } else {
 131         __put_user(INSN_MOVELI_R10_139, &frame->retcode[0]);
 132         __put_user(INSN_SWINT1, &frame->retcode[1]);
 133         restorer = frame_addr + offsetof(struct target_rt_sigframe, retcode);
 134     }
 135     env->pc = (unsigned long) ka->_sa_handler;
 136     env->regs[TILEGX_R_SP] = (unsigned long) frame;
 137     env->regs[TILEGX_R_LR] = restorer;
 138     env->regs[0] = (unsigned long) sig;
 139     env->regs[1] = (unsigned long) &frame->info;
 140     env->regs[2] = (unsigned long) &frame->uc;
 141     /* regs->flags |= PT_FLAGS_CALLER_SAVES; FIXME: we can skip it? */
 142
 143     unlock_user_struct(frame, frame_addr, 1);
 144     return;
 145
 146 give_sigsegv:
 147     force_sigsegv(sig);
 148 }
 149
 150 long do_rt_sigreturn(CPUTLGState *env)
 151 {
 152     abi_ulong frame_addr = env->regs[TILEGX_R_SP];
 153     struct target_rt_sigframe *frame;
 154     sigset_t set;
 155
 156     trace_user_do_rt_sigreturn(env, frame_addr);
 157     if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) {
 158         goto badframe;
 159     }
 160     target_to_host_sigset(&set, &frame->uc.tuc_sigmask);
 161     set_sigmask(&set);
 162
 163     restore_sigcontext(env, &frame->uc.tuc_mcontext);
 164     if (do_sigaltstack(frame_addr + offsetof(struct target_rt_sigframe,
 165                                              uc.tuc_stack),
 166                        0, env->regs[TILEGX_R_SP]) == -EFAULT) {
 167         goto badframe;
 168     }
 169
 170     unlock_user_struct(frame, frame_addr, 0);
 171     return -TARGET_QEMU_ESIGRETURN;
 172
 173
 174  badframe:
 175     unlock_user_struct(frame, frame_addr, 0);
 176     force_sig(TARGET_SIGSEGV);
 177     return -TARGET_QEMU_ESIGRETURN;
 178 }