linux-user/openrisc/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     struct target_pt_regs regs;
  27     abi_ulong oldmask;
  28     abi_ulong usp;
  29 };
  30
  31 struct target_ucontext {
  32     abi_ulong tuc_flags;
  33     abi_ulong tuc_link;
  34     target_stack_t tuc_stack;
  35     struct target_sigcontext tuc_mcontext;
  36     target_sigset_t tuc_sigmask;   /* mask last for extensibility */
  37 };
  38
  39 struct target_rt_sigframe {
  40     abi_ulong pinfo;
  41     uint64_t puc;
  42     struct target_siginfo info;
  43     struct target_sigcontext sc;
  44     struct target_ucontext uc;
  45     unsigned char retcode[16];  /* trampoline code */
  46 };
  47
  48 /* This is the asm-generic/ucontext.h version */
  49 #if 0
  50 static int restore_sigcontext(CPUOpenRISCState *regs,
  51                               struct target_sigcontext *sc)
  52 {
  53     unsigned int err = 0;
  54     unsigned long old_usp;
  55
  56     /* Alwys make any pending restarted system call return -EINTR */
  57     current_thread_info()->restart_block.fn = do_no_restart_syscall;
  58
  59     /* restore the regs from &sc->regs (same as sc, since regs is first)
  60      * (sc is already checked for VERIFY_READ since the sigframe was
  61      *  checked in sys_sigreturn previously)
  62      */
  63
  64     if (copy_from_user(regs, &sc, sizeof(struct target_pt_regs))) {
  65         goto badframe;
  66     }
  67
  68     /* make sure the U-flag is set so user-mode cannot fool us */
  69
  70     regs->sr &= ~SR_SM;
  71
  72     /* restore the old USP as it was before we stacked the sc etc.
  73      * (we cannot just pop the sigcontext since we aligned the sp and
  74      *  stuff after pushing it)
  75      */
  76
  77     __get_user(old_usp, &sc->usp);
  78     phx_signal("old_usp 0x%lx", old_usp);
  79
  80     __PHX__ REALLY           /* ??? */
  81     wrusp(old_usp);
  82     regs->gpr[1] = old_usp;
  83
  84     /* TODO: the other ports use regs->orig_XX to disable syscall checks
  85      * after this completes, but we don't use that mechanism. maybe we can
  86      * use it now ?
  87      */
  88
  89     return err;
  90
  91 badframe:
  92     return 1;
  93 }
  94 #endif
  95
  96 /* Set up a signal frame.  */
  97
  98 static void setup_sigcontext(struct target_sigcontext *sc,
  99                              CPUOpenRISCState *regs,
 100                              unsigned long mask)
 101 {
 102     unsigned long usp = cpu_get_gpr(regs, 1);
 103
 104     /* copy the regs. they are first in sc so we can use sc directly */
 105
 106     /*copy_to_user(&sc, regs, sizeof(struct target_pt_regs));*/
 107
 108     /* Set the frametype to CRIS_FRAME_NORMAL for the execution of
 109        the signal handler. The frametype will be restored to its previous
 110        value in restore_sigcontext. */
 111     /*regs->frametype = CRIS_FRAME_NORMAL;*/
 112
 113     /* then some other stuff */
 114     __put_user(mask, &sc->oldmask);
 115     __put_user(usp, &sc->usp);
 116 }
 117
 118 static inline unsigned long align_sigframe(unsigned long sp)
 119 {
 120     return sp & ~3UL;
 121 }
 122
 123 static inline abi_ulong get_sigframe(struct target_sigaction *ka,
 124                                      CPUOpenRISCState *regs,
 125                                      size_t frame_size)
 126 {
 127     unsigned long sp = get_sp_from_cpustate(regs);
 128     int onsigstack = on_sig_stack(sp);
 129
 130     /* redzone */
 131     sp = target_sigsp(sp, ka);
 132
 133     sp = align_sigframe(sp - frame_size);
 134
 135     /*
 136      * If we are on the alternate signal stack and would overflow it, don't.
 137      * Return an always-bogus address instead so we will die with SIGSEGV.
 138      */
 139
 140     if (onsigstack && !likely(on_sig_stack(sp))) {
 141         return -1L;
 142     }
 143
 144     return sp;
 145 }
 146
 147 void setup_rt_frame(int sig, struct target_sigaction *ka,
 148                     target_siginfo_t *info,
 149                     target_sigset_t *set, CPUOpenRISCState *env)
 150 {
 151     int err = 0;
 152     abi_ulong frame_addr;
 153     unsigned long return_ip;
 154     struct target_rt_sigframe *frame;
 155     abi_ulong info_addr, uc_addr;
 156
 157     frame_addr = get_sigframe(ka, env, sizeof(*frame));
 158     trace_user_setup_rt_frame(env, frame_addr);
 159     if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) {
 160         goto give_sigsegv;
 161     }
 162
 163     info_addr = frame_addr + offsetof(struct target_rt_sigframe, info);
 164     __put_user(info_addr, &frame->pinfo);
 165     uc_addr = frame_addr + offsetof(struct target_rt_sigframe, uc);
 166     __put_user(uc_addr, &frame->puc);
 167
 168     if (ka->sa_flags & SA_SIGINFO) {
 169         tswap_siginfo(&frame->info, info);
 170     }
 171
 172     /*err |= __clear_user(&frame->uc, offsetof(ucontext_t, uc_mcontext));*/
 173     __put_user(0, &frame->uc.tuc_flags);
 174     __put_user(0, &frame->uc.tuc_link);
 175     target_save_altstack(&frame->uc.tuc_stack, env);
 176     setup_sigcontext(&frame->sc, env, set->sig[0]);
 177
 178     /*err |= copy_to_user(frame->uc.tuc_sigmask, set, sizeof(*set));*/
 179
 180     /* trampoline - the desired return ip is the retcode itself */
 181     return_ip = (unsigned long)&frame->retcode;
 182     /* This is l.ori r11,r0,__NR_sigreturn, l.sys 1 */
 183     __put_user(0xa960, (short *)(frame->retcode + 0));
 184     __put_user(TARGET_NR_rt_sigreturn, (short *)(frame->retcode + 2));
 185     __put_user(0x20000001, (unsigned long *)(frame->retcode + 4));
 186     __put_user(0x15000000, (unsigned long *)(frame->retcode + 8));
 187
 188     if (err) {
 189         goto give_sigsegv;
 190     }
 191
 192     /* TODO what is the current->exec_domain stuff and invmap ? */
 193
 194     /* Set up registers for signal handler */
 195     env->pc = (unsigned long)ka->_sa_handler; /* what we enter NOW */
 196     cpu_set_gpr(env, 9, (unsigned long)return_ip);     /* what we enter LATER */
 197     cpu_set_gpr(env, 3, (unsigned long)sig);           /* arg 1: signo */
 198     cpu_set_gpr(env, 4, (unsigned long)&frame->info);  /* arg 2: (siginfo_t*) */
 199     cpu_set_gpr(env, 5, (unsigned long)&frame->uc);    /* arg 3: ucontext */
 200
 201     /* actually move the usp to reflect the stacked frame */
 202     cpu_set_gpr(env, 1, (unsigned long)frame);
 203
 204     return;
 205
 206 give_sigsegv:
 207     unlock_user_struct(frame, frame_addr, 1);
 208     force_sigsegv(sig);
 209 }
 210
 211 long do_sigreturn(CPUOpenRISCState *env)
 212 {
 213     trace_user_do_sigreturn(env, 0);
 214     fprintf(stderr, "do_sigreturn: not implemented\n");
 215     return -TARGET_ENOSYS;
 216 }
 217
 218 long do_rt_sigreturn(CPUOpenRISCState *env)
 219 {
 220     trace_user_do_rt_sigreturn(env, 0);
 221     fprintf(stderr, "do_rt_sigreturn: not implemented\n");
 222     return -TARGET_ENOSYS;
 223 }