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 "target_signal.h"
  22 #include "signal-common.h"
  23 #include "linux-user/trace.h"
  24
  25 struct target_sigcontext {
  26     union {
  27         /* General-purpose registers.  */
  28         abi_ulong gregs[56];
  29         struct {
  30             abi_ulong __gregs[53];
  31             abi_ulong tp;        /* Aliases gregs[TREG_TP].  */
  32             abi_ulong sp;        /* Aliases gregs[TREG_SP].  */
  33             abi_ulong lr;        /* Aliases gregs[TREG_LR].  */
  34         };
  35     };
  36     abi_ulong pc;        /* Program counter.  */
  37     abi_ulong ics;       /* In Interrupt Critical Section?  */
  38     abi_ulong faultnum;  /* Fault number.  */
  39     abi_ulong pad[5];
  40 };
  41
  42 struct target_ucontext {
  43     abi_ulong tuc_flags;
  44     abi_ulong tuc_link;
  45     target_stack_t tuc_stack;
  46     struct target_sigcontext tuc_mcontext;
  47     target_sigset_t tuc_sigmask;   /* mask last for extensibility */
  48 };
  49
  50 struct target_rt_sigframe {
  51     unsigned char save_area[16]; /* caller save area */
  52     struct target_siginfo info;
  53     struct target_ucontext uc;
  54     abi_ulong retcode[2];
  55 };
  56
  57 #define INSN_MOVELI_R10_139  0x00045fe551483000ULL /* { moveli r10, 139 } */
  58 #define INSN_SWINT1          0x286b180051485000ULL /* { swint1 } */
  59
  60
  61 static void setup_sigcontext(struct target_sigcontext *sc,
  62                              CPUArchState *env, int signo)
  63 {
  64     int i;
  65
  66     for (i = 0; i < TILEGX_R_COUNT; ++i) {
  67         __put_user(env->regs[i], &sc->gregs[i]);
  68     }
  69
  70     __put_user(env->pc, &sc->pc);
  71     __put_user(0, &sc->ics);
  72     __put_user(signo, &sc->faultnum);
  73 }
  74
  75 static void restore_sigcontext(CPUTLGState *env, struct target_sigcontext *sc)
  76 {
  77     int i;
  78
  79     for (i = 0; i < TILEGX_R_COUNT; ++i) {
  80         __get_user(env->regs[i], &sc->gregs[i]);
  81     }
  82
  83     __get_user(env->pc, &sc->pc);
  84 }
  85
  86 static abi_ulong get_sigframe(struct target_sigaction *ka, CPUArchState *env,
  87                               size_t frame_size)
  88 {
  89     unsigned long sp = get_sp_from_cpustate(env);
  90
  91     if (on_sig_stack(sp) && !likely(on_sig_stack(sp - frame_size))) {
  92         return -1UL;
  93     }
  94
  95     sp = target_sigsp(sp, ka) - frame_size;
  96     sp &= -16UL;
  97     return sp;
  98 }
  99
 100 void setup_rt_frame(int sig, struct target_sigaction *ka,
 101                     target_siginfo_t *info,
 102                     target_sigset_t *set, CPUArchState *env)
 103 {
 104     abi_ulong frame_addr;
 105     struct target_rt_sigframe *frame;
 106     unsigned long restorer;
 107
 108     frame_addr = get_sigframe(ka, env, sizeof(*frame));
 109     trace_user_setup_rt_frame(env, frame_addr);
 110     if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) {
 111         goto give_sigsegv;
 112     }
 113
 114     /* Always write at least the signal number for the stack backtracer. */
 115     if (ka->sa_flags & TARGET_SA_SIGINFO) {
 116         /* At sigreturn time, restore the callee-save registers too. */
 117         tswap_siginfo(&frame->info, info);
 118         /* regs->flags |= PT_FLAGS_RESTORE_REGS; FIXME: we can skip it? */
 119     } else {
 120         __put_user(info->si_signo, &frame->info.si_signo);
 121     }
 122
 123     /* Create the ucontext.  */
 124     __put_user(0, &frame->uc.tuc_flags);
 125     __put_user(0, &frame->uc.tuc_link);
 126     target_save_altstack(&frame->uc.tuc_stack, env);
 127     setup_sigcontext(&frame->uc.tuc_mcontext, env, info->si_signo);
 128
 129     if (ka->sa_flags & TARGET_SA_RESTORER) {
 130         restorer = (unsigned long) ka->sa_restorer;
 131     } else {
 132         __put_user(INSN_MOVELI_R10_139, &frame->retcode[0]);
 133         __put_user(INSN_SWINT1, &frame->retcode[1]);
 134         restorer = frame_addr + offsetof(struct target_rt_sigframe, retcode);
 135     }
 136     env->pc = (unsigned long) ka->_sa_handler;
 137     env->regs[TILEGX_R_SP] = (unsigned long) frame;
 138     env->regs[TILEGX_R_LR] = restorer;
 139     env->regs[0] = (unsigned long) sig;
 140     env->regs[1] = (unsigned long) &frame->info;
 141     env->regs[2] = (unsigned long) &frame->uc;
 142     /* regs->flags |= PT_FLAGS_CALLER_SAVES; FIXME: we can skip it? */
 143
 144     unlock_user_struct(frame, frame_addr, 1);
 145     return;
 146
 147 give_sigsegv:
 148     force_sigsegv(sig);
 149 }
 150
 151 long do_rt_sigreturn(CPUTLGState *env)
 152 {
 153     abi_ulong frame_addr = env->regs[TILEGX_R_SP];
 154     struct target_rt_sigframe *frame;
 155     sigset_t set;
 156
 157     trace_user_do_rt_sigreturn(env, frame_addr);
 158     if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) {
 159         goto badframe;
 160     }
 161     target_to_host_sigset(&set, &frame->uc.tuc_sigmask);
 162     set_sigmask(&set);
 163
 164     restore_sigcontext(env, &frame->uc.tuc_mcontext);
 165     if (do_sigaltstack(frame_addr + offsetof(struct target_rt_sigframe,
 166                                              uc.tuc_stack),
 167                        0, env->regs[TILEGX_R_SP]) == -EFAULT) {
 168         goto badframe;
 169     }
 170
 171     unlock_user_struct(frame, frame_addr, 0);
 172     return -TARGET_QEMU_ESIGRETURN;
 173
 174
 175  badframe:
 176     unlock_user_struct(frame, frame_addr, 0);
 177     force_sig(TARGET_SIGSEGV);
 178     return -TARGET_QEMU_ESIGRETURN;
 179 }