linux-user/hexagon/signal.c

   1 /*
   2  *  Emulation of Linux signals
   3  *
   4  *  Copyright (c) 2003 Fabrice Bellard
   5  *  Copyright(c) 2019-2021 Qualcomm Innovation Center, Inc. All Rights Reserved.
   6  *
   7  *  This program is free software; you can redistribute it and/or modify
   8  *  it under the terms of the GNU General Public License as published by
   9  *  the Free Software Foundation; either version 2 of the License, or
  10  *  (at your option) any later version.
  11  *
  12  *  This program is distributed in the hope that it will be useful,
  13  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *  GNU General Public License for more details.
  16  *
  17  *  You should have received a copy of the GNU General Public License
  18  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
  19  */
  20 #include "qemu/osdep.h"
  21 #include "qemu.h"
  22 #include "user-internals.h"
  23 #include "signal-common.h"
  24 #include "linux-user/trace.h"
  25
  26 struct target_sigcontext {
  27     target_ulong r0,  r1,  r2,  r3;
  28     target_ulong r4,  r5,  r6,  r7;
  29     target_ulong r8,  r9, r10, r11;
  30     target_ulong r12, r13, r14, r15;
  31     target_ulong r16, r17, r18, r19;
  32     target_ulong r20, r21, r22, r23;
  33     target_ulong r24, r25, r26, r27;
  34     target_ulong r28, r29, r30, r31;
  35     target_ulong sa0;
  36     target_ulong lc0;
  37     target_ulong sa1;
  38     target_ulong lc1;
  39     target_ulong m0;
  40     target_ulong m1;
  41     target_ulong usr;
  42     target_ulong gp;
  43     target_ulong ugp;
  44     target_ulong pc;
  45     target_ulong cause;
  46     target_ulong badva;
  47     target_ulong pred[NUM_PREGS];
  48 };
  49
  50 struct target_ucontext {
  51     unsigned long uc_flags;
  52     target_ulong uc_link; /* target pointer */
  53     target_stack_t uc_stack;
  54     struct target_sigcontext uc_mcontext;
  55     target_sigset_t uc_sigmask;
  56 };
  57
  58 struct target_rt_sigframe {
  59     uint32_t tramp[2];
  60     struct target_siginfo info;
  61     struct target_ucontext uc;
  62 };
  63
  64 static abi_ulong get_sigframe(struct target_sigaction *ka,
  65                               CPUHexagonState *regs, size_t framesize)
  66 {
  67     abi_ulong sp = get_sp_from_cpustate(regs);
  68
  69     /* This is the X/Open sanctioned signal stack switching.  */
  70     sp = target_sigsp(sp, ka) - framesize;
  71
  72     sp = QEMU_ALIGN_DOWN(sp, 8);
  73
  74     return sp;
  75 }
  76
  77 static void setup_sigcontext(struct target_sigcontext *sc, CPUHexagonState *env)
  78 {
  79     __put_user(env->gpr[HEX_REG_R00], &sc->r0);
  80     __put_user(env->gpr[HEX_REG_R01], &sc->r1);
  81     __put_user(env->gpr[HEX_REG_R02], &sc->r2);
  82     __put_user(env->gpr[HEX_REG_R03], &sc->r3);
  83     __put_user(env->gpr[HEX_REG_R04], &sc->r4);
  84     __put_user(env->gpr[HEX_REG_R05], &sc->r5);
  85     __put_user(env->gpr[HEX_REG_R06], &sc->r6);
  86     __put_user(env->gpr[HEX_REG_R07], &sc->r7);
  87     __put_user(env->gpr[HEX_REG_R08], &sc->r8);
  88     __put_user(env->gpr[HEX_REG_R09], &sc->r9);
  89     __put_user(env->gpr[HEX_REG_R10], &sc->r10);
  90     __put_user(env->gpr[HEX_REG_R11], &sc->r11);
  91     __put_user(env->gpr[HEX_REG_R12], &sc->r12);
  92     __put_user(env->gpr[HEX_REG_R13], &sc->r13);
  93     __put_user(env->gpr[HEX_REG_R14], &sc->r14);
  94     __put_user(env->gpr[HEX_REG_R15], &sc->r15);
  95     __put_user(env->gpr[HEX_REG_R16], &sc->r16);
  96     __put_user(env->gpr[HEX_REG_R17], &sc->r17);
  97     __put_user(env->gpr[HEX_REG_R18], &sc->r18);
  98     __put_user(env->gpr[HEX_REG_R19], &sc->r19);
  99     __put_user(env->gpr[HEX_REG_R20], &sc->r20);
 100     __put_user(env->gpr[HEX_REG_R21], &sc->r21);
 101     __put_user(env->gpr[HEX_REG_R22], &sc->r22);
 102     __put_user(env->gpr[HEX_REG_R23], &sc->r23);
 103     __put_user(env->gpr[HEX_REG_R24], &sc->r24);
 104     __put_user(env->gpr[HEX_REG_R25], &sc->r25);
 105     __put_user(env->gpr[HEX_REG_R26], &sc->r26);
 106     __put_user(env->gpr[HEX_REG_R27], &sc->r27);
 107     __put_user(env->gpr[HEX_REG_R28], &sc->r28);
 108     __put_user(env->gpr[HEX_REG_R29], &sc->r29);
 109     __put_user(env->gpr[HEX_REG_R30], &sc->r30);
 110     __put_user(env->gpr[HEX_REG_R31], &sc->r31);
 111     __put_user(env->gpr[HEX_REG_SA0], &sc->sa0);
 112     __put_user(env->gpr[HEX_REG_LC0], &sc->lc0);
 113     __put_user(env->gpr[HEX_REG_SA1], &sc->sa1);
 114     __put_user(env->gpr[HEX_REG_LC1], &sc->lc1);
 115     __put_user(env->gpr[HEX_REG_M0], &sc->m0);
 116     __put_user(env->gpr[HEX_REG_M1], &sc->m1);
 117     __put_user(env->gpr[HEX_REG_USR], &sc->usr);
 118     __put_user(env->gpr[HEX_REG_GP], &sc->gp);
 119     __put_user(env->gpr[HEX_REG_UGP], &sc->ugp);
 120     __put_user(env->gpr[HEX_REG_PC], &sc->pc);
 121
 122     int i;
 123     for (i = 0; i < NUM_PREGS; i++) {
 124         __put_user(env->pred[i], &(sc->pred[i]));
 125     }
 126 }
 127
 128 static void setup_ucontext(struct target_ucontext *uc,
 129                            CPUHexagonState *env, target_sigset_t *set)
 130 {
 131     __put_user(0,    &(uc->uc_flags));
 132     __put_user(0,    &(uc->uc_link));
 133
 134     target_save_altstack(&uc->uc_stack, env);
 135
 136     int i;
 137     for (i = 0; i < TARGET_NSIG_WORDS; i++) {
 138         __put_user(set->sig[i], &(uc->uc_sigmask.sig[i]));
 139     }
 140
 141     setup_sigcontext(&uc->uc_mcontext, env);
 142 }
 143
 144 static inline void install_sigtramp(uint32_t *tramp)
 145 {
 146     __put_user(0x7800d166, tramp + 0); /*  { r6=#__NR_rt_sigreturn } */
 147     __put_user(0x5400c004, tramp + 1); /*  { trap0(#1) } */
 148 }
 149
 150 void setup_rt_frame(int sig, struct target_sigaction *ka,
 151                     target_siginfo_t *info,
 152                     target_sigset_t *set, CPUHexagonState *env)
 153 {
 154     abi_ulong frame_addr;
 155     struct target_rt_sigframe *frame;
 156
 157     frame_addr = get_sigframe(ka, env, sizeof(*frame));
 158     trace_user_setup_rt_frame(env, frame_addr);
 159
 160     if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) {
 161         goto badframe;
 162     }
 163
 164     setup_ucontext(&frame->uc, env, set);
 165     frame->info = *info;
 166     /*
 167      * The on-stack signal trampoline is no longer executed;
 168      * however, the libgcc signal frame unwinding code checks
 169      * for the presence of these two numeric magic values.
 170      */
 171     install_sigtramp(frame->tramp);
 172
 173     env->gpr[HEX_REG_PC] = ka->_sa_handler;
 174     env->gpr[HEX_REG_SP] = frame_addr;
 175     env->gpr[HEX_REG_R00] = sig;
 176     env->gpr[HEX_REG_R01] =
 177         frame_addr + offsetof(struct target_rt_sigframe, info);
 178     env->gpr[HEX_REG_R02] =
 179         frame_addr + offsetof(struct target_rt_sigframe, uc);
 180     env->gpr[HEX_REG_LR] = default_rt_sigreturn;
 181
 182     return;
 183
 184 badframe:
 185     unlock_user_struct(frame, frame_addr, 1);
 186     if (sig == TARGET_SIGSEGV) {
 187         ka->_sa_handler = TARGET_SIG_DFL;
 188     }
 189     force_sig(TARGET_SIGSEGV);
 190 }
 191
 192 static void restore_sigcontext(CPUHexagonState *env,
 193                                struct target_sigcontext *sc)
 194 {
 195     __get_user(env->gpr[HEX_REG_R00], &sc->r0);
 196     __get_user(env->gpr[HEX_REG_R01], &sc->r1);
 197     __get_user(env->gpr[HEX_REG_R02], &sc->r2);
 198     __get_user(env->gpr[HEX_REG_R03], &sc->r3);
 199     __get_user(env->gpr[HEX_REG_R04], &sc->r4);
 200     __get_user(env->gpr[HEX_REG_R05], &sc->r5);
 201     __get_user(env->gpr[HEX_REG_R06], &sc->r6);
 202     __get_user(env->gpr[HEX_REG_R07], &sc->r7);
 203     __get_user(env->gpr[HEX_REG_R08], &sc->r8);
 204     __get_user(env->gpr[HEX_REG_R09], &sc->r9);
 205     __get_user(env->gpr[HEX_REG_R10], &sc->r10);
 206     __get_user(env->gpr[HEX_REG_R11], &sc->r11);
 207     __get_user(env->gpr[HEX_REG_R12], &sc->r12);
 208     __get_user(env->gpr[HEX_REG_R13], &sc->r13);
 209     __get_user(env->gpr[HEX_REG_R14], &sc->r14);
 210     __get_user(env->gpr[HEX_REG_R15], &sc->r15);
 211     __get_user(env->gpr[HEX_REG_R16], &sc->r16);
 212     __get_user(env->gpr[HEX_REG_R17], &sc->r17);
 213     __get_user(env->gpr[HEX_REG_R18], &sc->r18);
 214     __get_user(env->gpr[HEX_REG_R19], &sc->r19);
 215     __get_user(env->gpr[HEX_REG_R20], &sc->r20);
 216     __get_user(env->gpr[HEX_REG_R21], &sc->r21);
 217     __get_user(env->gpr[HEX_REG_R22], &sc->r22);
 218     __get_user(env->gpr[HEX_REG_R23], &sc->r23);
 219     __get_user(env->gpr[HEX_REG_R24], &sc->r24);
 220     __get_user(env->gpr[HEX_REG_R25], &sc->r25);
 221     __get_user(env->gpr[HEX_REG_R26], &sc->r26);
 222     __get_user(env->gpr[HEX_REG_R27], &sc->r27);
 223     __get_user(env->gpr[HEX_REG_R28], &sc->r28);
 224     __get_user(env->gpr[HEX_REG_R29], &sc->r29);
 225     __get_user(env->gpr[HEX_REG_R30], &sc->r30);
 226     __get_user(env->gpr[HEX_REG_R31], &sc->r31);
 227     __get_user(env->gpr[HEX_REG_SA0], &sc->sa0);
 228     __get_user(env->gpr[HEX_REG_LC0], &sc->lc0);
 229     __get_user(env->gpr[HEX_REG_SA1], &sc->sa1);
 230     __get_user(env->gpr[HEX_REG_LC1], &sc->lc1);
 231     __get_user(env->gpr[HEX_REG_M0], &sc->m0);
 232     __get_user(env->gpr[HEX_REG_M1], &sc->m1);
 233     __get_user(env->gpr[HEX_REG_USR], &sc->usr);
 234     __get_user(env->gpr[HEX_REG_GP], &sc->gp);
 235     __get_user(env->gpr[HEX_REG_UGP], &sc->ugp);
 236     __get_user(env->gpr[HEX_REG_PC], &sc->pc);
 237
 238     int i;
 239     for (i = 0; i < NUM_PREGS; i++) {
 240         __get_user(env->pred[i], &(sc->pred[i]));
 241     }
 242 }
 243
 244 static void restore_ucontext(CPUHexagonState *env, struct target_ucontext *uc)
 245 {
 246     sigset_t blocked;
 247     target_sigset_t target_set;
 248     int i;
 249
 250     target_sigemptyset(&target_set);
 251     for (i = 0; i < TARGET_NSIG_WORDS; i++) {
 252         __get_user(target_set.sig[i], &(uc->uc_sigmask.sig[i]));
 253     }
 254
 255     target_to_host_sigset_internal(&blocked, &target_set);
 256     set_sigmask(&blocked);
 257
 258     restore_sigcontext(env, &uc->uc_mcontext);
 259 }
 260
 261 long do_rt_sigreturn(CPUHexagonState *env)
 262 {
 263     struct target_rt_sigframe *frame;
 264     abi_ulong frame_addr;
 265
 266     frame_addr = env->gpr[HEX_REG_SP];
 267     trace_user_do_sigreturn(env, frame_addr);
 268     if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) {
 269         goto badframe;
 270     }
 271
 272     restore_ucontext(env, &frame->uc);
 273     target_restore_altstack(&frame->uc.uc_stack, env);
 274
 275     unlock_user_struct(frame, frame_addr, 0);
 276     return -QEMU_ESIGRETURN;
 277
 278 badframe:
 279     unlock_user_struct(frame, frame_addr, 0);
 280     force_sig(TARGET_SIGSEGV);
 281     return 0;
 282 }
 283
 284 void setup_sigtramp(abi_ulong sigtramp_page)
 285 {
 286     uint32_t *tramp = lock_user(VERIFY_WRITE, sigtramp_page, 4 * 2, 0);
 287     assert(tramp != NULL);
 288
 289     default_rt_sigreturn = sigtramp_page;
 290     install_sigtramp(tramp);
 291
 292     unlock_user(tramp, sigtramp_page, 4 * 2);
 293 }