linux-user/nios2/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 "user-internals.h"
  22 #include "signal-common.h"
  23 #include "linux-user/trace.h"
  24
  25 #define MCONTEXT_VERSION 2
  26
  27 struct target_sigcontext {
  28     int version;
  29     unsigned long gregs[32];
  30 };
  31
  32 struct target_ucontext {
  33     abi_ulong tuc_flags;
  34     abi_ulong tuc_link;
  35     target_stack_t tuc_stack;
  36     struct target_sigcontext tuc_mcontext;
  37     target_sigset_t tuc_sigmask;   /* mask last for extensibility */
  38 };
  39
  40 struct target_rt_sigframe {
  41     struct target_siginfo info;
  42     struct target_ucontext uc;
  43 };
  44
  45 static void rt_setup_ucontext(struct target_ucontext *uc, CPUNios2State *env)
  46 {
  47     unsigned long *gregs = uc->tuc_mcontext.gregs;
  48
  49     __put_user(MCONTEXT_VERSION, &uc->tuc_mcontext.version);
  50     __put_user(env->regs[1], &gregs[0]);
  51     __put_user(env->regs[2], &gregs[1]);
  52     __put_user(env->regs[3], &gregs[2]);
  53     __put_user(env->regs[4], &gregs[3]);
  54     __put_user(env->regs[5], &gregs[4]);
  55     __put_user(env->regs[6], &gregs[5]);
  56     __put_user(env->regs[7], &gregs[6]);
  57     __put_user(env->regs[8], &gregs[7]);
  58     __put_user(env->regs[9], &gregs[8]);
  59     __put_user(env->regs[10], &gregs[9]);
  60     __put_user(env->regs[11], &gregs[10]);
  61     __put_user(env->regs[12], &gregs[11]);
  62     __put_user(env->regs[13], &gregs[12]);
  63     __put_user(env->regs[14], &gregs[13]);
  64     __put_user(env->regs[15], &gregs[14]);
  65     __put_user(env->regs[16], &gregs[15]);
  66     __put_user(env->regs[17], &gregs[16]);
  67     __put_user(env->regs[18], &gregs[17]);
  68     __put_user(env->regs[19], &gregs[18]);
  69     __put_user(env->regs[20], &gregs[19]);
  70     __put_user(env->regs[21], &gregs[20]);
  71     __put_user(env->regs[22], &gregs[21]);
  72     __put_user(env->regs[23], &gregs[22]);
  73     __put_user(env->regs[R_RA], &gregs[23]);
  74     __put_user(env->regs[R_FP], &gregs[24]);
  75     __put_user(env->regs[R_GP], &gregs[25]);
  76     __put_user(env->pc, &gregs[27]);
  77     __put_user(env->regs[R_SP], &gregs[28]);
  78 }
  79
  80 static int rt_restore_ucontext(CPUNios2State *env, struct target_ucontext *uc)
  81 {
  82     int temp;
  83     unsigned long *gregs = uc->tuc_mcontext.gregs;
  84
  85     /* Always make any pending restarted system calls return -EINTR */
  86     /* current->restart_block.fn = do_no_restart_syscall; */
  87
  88     __get_user(temp, &uc->tuc_mcontext.version);
  89     if (temp != MCONTEXT_VERSION) {
  90         return 1;
  91     }
  92
  93     /* restore passed registers */
  94     __get_user(env->regs[1], &gregs[0]);
  95     __get_user(env->regs[2], &gregs[1]);
  96     __get_user(env->regs[3], &gregs[2]);
  97     __get_user(env->regs[4], &gregs[3]);
  98     __get_user(env->regs[5], &gregs[4]);
  99     __get_user(env->regs[6], &gregs[5]);
 100     __get_user(env->regs[7], &gregs[6]);
 101     __get_user(env->regs[8], &gregs[7]);
 102     __get_user(env->regs[9], &gregs[8]);
 103     __get_user(env->regs[10], &gregs[9]);
 104     __get_user(env->regs[11], &gregs[10]);
 105     __get_user(env->regs[12], &gregs[11]);
 106     __get_user(env->regs[13], &gregs[12]);
 107     __get_user(env->regs[14], &gregs[13]);
 108     __get_user(env->regs[15], &gregs[14]);
 109     __get_user(env->regs[16], &gregs[15]);
 110     __get_user(env->regs[17], &gregs[16]);
 111     __get_user(env->regs[18], &gregs[17]);
 112     __get_user(env->regs[19], &gregs[18]);
 113     __get_user(env->regs[20], &gregs[19]);
 114     __get_user(env->regs[21], &gregs[20]);
 115     __get_user(env->regs[22], &gregs[21]);
 116     __get_user(env->regs[23], &gregs[22]);
 117     /* gregs[23] is handled below */
 118     /* Verify, should this be settable */
 119     __get_user(env->regs[R_FP], &gregs[24]);
 120     /* Verify, should this be settable */
 121     __get_user(env->regs[R_GP], &gregs[25]);
 122     /* Not really necessary no user settable bits */
 123     __get_user(temp, &gregs[26]);
 124     __get_user(env->pc, &gregs[27]);
 125
 126     __get_user(env->regs[R_RA], &gregs[23]);
 127     __get_user(env->regs[R_SP], &gregs[28]);
 128
 129     target_restore_altstack(&uc->tuc_stack, env);
 130     return 0;
 131 }
 132
 133 static abi_ptr get_sigframe(struct target_sigaction *ka, CPUNios2State *env,
 134                             size_t frame_size)
 135 {
 136     unsigned long usp;
 137
 138     /* This is the X/Open sanctioned signal stack switching.  */
 139     usp = target_sigsp(get_sp_from_cpustate(env), ka);
 140
 141     /* Verify, is it 32 or 64 bit aligned */
 142     return (usp - frame_size) & -8;
 143 }
 144
 145 void setup_rt_frame(int sig, struct target_sigaction *ka,
 146                     target_siginfo_t *info,
 147                     target_sigset_t *set,
 148                     CPUNios2State *env)
 149 {
 150     struct target_rt_sigframe *frame;
 151     abi_ptr frame_addr;
 152     int i;
 153
 154     frame_addr = get_sigframe(ka, env, sizeof(*frame));
 155     if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) {
 156         force_sigsegv(sig);
 157         return;
 158     }
 159
 160     tswap_siginfo(&frame->info, info);
 161
 162     /* Create the ucontext.  */
 163     __put_user(0, &frame->uc.tuc_flags);
 164     __put_user(0, &frame->uc.tuc_link);
 165     target_save_altstack(&frame->uc.tuc_stack, env);
 166     rt_setup_ucontext(&frame->uc, env);
 167     for (i = 0; i < TARGET_NSIG_WORDS; i++) {
 168         __put_user(set->sig[i], &frame->uc.tuc_sigmask.sig[i]);
 169     }
 170
 171     /* Set up to return from userspace; jump to fixed address sigreturn
 172        trampoline on kuser page.  */
 173     env->regs[R_RA] = (unsigned long) (0x1044);
 174
 175     /* Set up registers for signal handler */
 176     env->regs[R_SP] = frame_addr;
 177     env->regs[4] = sig;
 178     env->regs[5] = frame_addr + offsetof(struct target_rt_sigframe, info);
 179     env->regs[6] = frame_addr + offsetof(struct target_rt_sigframe, uc);
 180     env->pc = ka->_sa_handler;
 181
 182     unlock_user_struct(frame, frame_addr, 1);
 183 }
 184
 185 long do_rt_sigreturn(CPUNios2State *env)
 186 {
 187     /* Verify, can we follow the stack back */
 188     abi_ulong frame_addr = env->regs[R_SP];
 189     struct target_rt_sigframe *frame;
 190     sigset_t set;
 191
 192     if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) {
 193         goto badframe;
 194     }
 195
 196     target_to_host_sigset(&set, &frame->uc.tuc_sigmask);
 197     set_sigmask(&set);
 198
 199     if (rt_restore_ucontext(env, &frame->uc)) {
 200         goto badframe;
 201     }
 202
 203     unlock_user_struct(frame, frame_addr, 0);
 204     return -QEMU_ESIGRETURN;
 205
 206 badframe:
 207     unlock_user_struct(frame, frame_addr, 0);
 208     force_sig(TARGET_SIGSEGV);
 209     return -QEMU_ESIGRETURN;
 210 }