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 "user-internals.h"
  22 #include "signal-common.h"
  23 #include "linux-user/trace.h"
  24
  25 typedef struct target_sigcontext {
  26     struct target_pt_regs regs;
  27     abi_ulong oldmask;
  28 } target_sigcontext;
  29
  30 typedef struct target_ucontext {
  31     abi_ulong tuc_flags;
  32     abi_ulong tuc_link;
  33     target_stack_t tuc_stack;
  34     target_sigcontext tuc_mcontext;
  35     target_sigset_t tuc_sigmask;   /* mask last for extensibility */
  36 } target_ucontext;
  37
  38 typedef struct target_rt_sigframe {
  39     struct target_siginfo info;
  40     target_ucontext uc;
  41 } target_rt_sigframe;
  42
  43 static void restore_sigcontext(CPUOpenRISCState *env, target_sigcontext *sc)
  44 {
  45     int i;
  46     abi_ulong v;
  47
  48     for (i = 0; i < 32; ++i) {
  49         __get_user(v, &sc->regs.gpr[i]);
  50         cpu_set_gpr(env, i, v);
  51     }
  52     __get_user(env->pc, &sc->regs.pc);
  53
  54     /* Make sure the supervisor flag is clear.  */
  55     __get_user(v, &sc->regs.sr);
  56     cpu_set_sr(env, v & ~SR_SM);
  57 }
  58
  59 /* Set up a signal frame.  */
  60
  61 static void setup_sigcontext(target_sigcontext *sc, CPUOpenRISCState *env)
  62 {
  63     int i;
  64
  65     for (i = 0; i < 32; ++i) {
  66         __put_user(cpu_get_gpr(env, i), &sc->regs.gpr[i]);
  67     }
  68
  69     __put_user(env->pc, &sc->regs.pc);
  70     __put_user(cpu_get_sr(env), &sc->regs.sr);
  71 }
  72
  73 static inline abi_ulong get_sigframe(struct target_sigaction *ka,
  74                                      CPUOpenRISCState *env,
  75                                      size_t frame_size)
  76 {
  77     target_ulong sp = get_sp_from_cpustate(env);
  78
  79     /* Honor redzone now.  If we swap to signal stack, no need to waste
  80      * the 128 bytes by subtracting afterward.
  81      */
  82     sp -= 128;
  83
  84     sp = target_sigsp(sp, ka);
  85     sp -= frame_size;
  86     sp = QEMU_ALIGN_DOWN(sp, 4);
  87
  88     return sp;
  89 }
  90
  91 void setup_rt_frame(int sig, struct target_sigaction *ka,
  92                     target_siginfo_t *info,
  93                     target_sigset_t *set, CPUOpenRISCState *env)
  94 {
  95     abi_ulong frame_addr;
  96     target_rt_sigframe *frame;
  97     int i;
  98
  99     frame_addr = get_sigframe(ka, env, sizeof(*frame));
 100     trace_user_setup_rt_frame(env, frame_addr);
 101     if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) {
 102         goto give_sigsegv;
 103     }
 104
 105     if (ka->sa_flags & SA_SIGINFO) {
 106         frame->info = *info;
 107     }
 108
 109     __put_user(0, &frame->uc.tuc_flags);
 110     __put_user(0, &frame->uc.tuc_link);
 111
 112     target_save_altstack(&frame->uc.tuc_stack, env);
 113     setup_sigcontext(&frame->uc.tuc_mcontext, env);
 114     for (i = 0; i < TARGET_NSIG_WORDS; ++i) {
 115         __put_user(set->sig[i], &frame->uc.tuc_sigmask.sig[i]);
 116     }
 117
 118     /* Set up registers for signal handler */
 119     cpu_set_gpr(env, 9, default_rt_sigreturn);
 120     cpu_set_gpr(env, 3, sig);
 121     cpu_set_gpr(env, 4, frame_addr + offsetof(target_rt_sigframe, info));
 122     cpu_set_gpr(env, 5, frame_addr + offsetof(target_rt_sigframe, uc));
 123     cpu_set_gpr(env, 1, frame_addr);
 124
 125     /* For debugging convenience, set ppc to the insn that faulted.  */
 126     env->ppc = env->pc;
 127     /* When setting the PC for the signal handler, exit delay slot.  */
 128     env->pc = ka->_sa_handler;
 129     env->dflag = 0;
 130     return;
 131
 132 give_sigsegv:
 133     unlock_user_struct(frame, frame_addr, 1);
 134     force_sigsegv(sig);
 135 }
 136
 137 long do_rt_sigreturn(CPUOpenRISCState *env)
 138 {
 139     abi_ulong frame_addr = get_sp_from_cpustate(env);
 140     target_rt_sigframe *frame;
 141     sigset_t set;
 142
 143     trace_user_do_rt_sigreturn(env, 0);
 144     if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) {
 145         goto badframe;
 146     }
 147     if (frame_addr & 3) {
 148         goto badframe;
 149     }
 150
 151     target_to_host_sigset(&set, &frame->uc.tuc_sigmask);
 152     set_sigmask(&set);
 153
 154     restore_sigcontext(env, &frame->uc.tuc_mcontext);
 155     target_restore_altstack(&frame->uc.tuc_stack, env);
 156
 157     unlock_user_struct(frame, frame_addr, 0);
 158     return cpu_get_gpr(env, 11);
 159
 160  badframe:
 161     unlock_user_struct(frame, frame_addr, 0);
 162     force_sig(TARGET_SIGSEGV);
 163     return 0;
 164 }
 165
 166 void setup_sigtramp(abi_ulong sigtramp_page)
 167 {
 168     uint32_t *tramp = lock_user(VERIFY_WRITE, sigtramp_page, 8, 0);
 169     assert(tramp != NULL);
 170
 171     /* This is l.ori r11,r0,__NR_sigreturn; l.sys 1 */
 172     __put_user(0xa9600000 | TARGET_NR_rt_sigreturn, tramp + 0);
 173     __put_user(0x20000001, tramp + 1);
 174
 175     default_rt_sigreturn = sigtramp_page;
 176     unlock_user(tramp, sigtramp_page, 8);
 177 }