| /* | 
 |  *  Emulation of Linux signals | 
 |  * | 
 |  *  Copyright (c) 2003 Fabrice Bellard | 
 |  * | 
 |  *  This program is free software; you can redistribute it and/or modify | 
 |  *  it under the terms of the GNU General Public License as published by | 
 |  *  the Free Software Foundation; either version 2 of the License, or | 
 |  *  (at your option) any later version. | 
 |  * | 
 |  *  This program is distributed in the hope that it will be useful, | 
 |  *  but WITHOUT ANY WARRANTY; without even the implied warranty of | 
 |  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the | 
 |  *  GNU General Public License for more details. | 
 |  * | 
 |  *  You should have received a copy of the GNU General Public License | 
 |  *  along with this program; if not, see <http://www.gnu.org/licenses/>. | 
 |  */ | 
 | #include "qemu/osdep.h" | 
 | #include "qemu.h" | 
 | #include "user-internals.h" | 
 | #include "signal-common.h" | 
 | #include "linux-user/trace.h" | 
 |  | 
 | struct target_sigcontext { | 
 |     abi_ulong sc_pc; | 
 |     abi_ulong sc_ps; | 
 |     abi_ulong sc_lbeg; | 
 |     abi_ulong sc_lend; | 
 |     abi_ulong sc_lcount; | 
 |     abi_ulong sc_sar; | 
 |     abi_ulong sc_acclo; | 
 |     abi_ulong sc_acchi; | 
 |     abi_ulong sc_a[16]; | 
 |     abi_ulong sc_xtregs; | 
 | }; | 
 |  | 
 | struct target_ucontext { | 
 |     abi_ulong tuc_flags; | 
 |     abi_ulong tuc_link; | 
 |     target_stack_t tuc_stack; | 
 |     struct target_sigcontext tuc_mcontext; | 
 |     target_sigset_t tuc_sigmask; | 
 | }; | 
 |  | 
 | struct target_rt_sigframe { | 
 |     target_siginfo_t info; | 
 |     struct target_ucontext uc; | 
 |     /* TODO: xtregs */ | 
 |     uint8_t retcode[6]; | 
 |     abi_ulong window[4]; | 
 | }; | 
 |  | 
 | static abi_ulong get_sigframe(struct target_sigaction *sa, | 
 |                               CPUXtensaState *env, | 
 |                               unsigned long framesize) | 
 | { | 
 |     abi_ulong sp; | 
 |  | 
 |     sp = target_sigsp(get_sp_from_cpustate(env), sa); | 
 |  | 
 |     return (sp - framesize) & -16; | 
 | } | 
 |  | 
 | static int flush_window_regs(CPUXtensaState *env) | 
 | { | 
 |     uint32_t wb = env->sregs[WINDOW_BASE]; | 
 |     uint32_t ws = xtensa_replicate_windowstart(env) >> (wb + 1); | 
 |     unsigned d = ctz32(ws) + 1; | 
 |     unsigned i; | 
 |     int ret = 0; | 
 |  | 
 |     for (i = d; i < env->config->nareg / 4; i += d) { | 
 |         uint32_t ssp, osp; | 
 |         unsigned j; | 
 |  | 
 |         ws >>= d; | 
 |         xtensa_rotate_window(env, d); | 
 |  | 
 |         if (ws & 0x1) { | 
 |             ssp = env->regs[5]; | 
 |             d = 1; | 
 |         } else if (ws & 0x2) { | 
 |             ssp = env->regs[9]; | 
 |             ret |= get_user_ual(osp, env->regs[1] - 12); | 
 |             osp -= 32; | 
 |             d = 2; | 
 |         } else if (ws & 0x4) { | 
 |             ssp = env->regs[13]; | 
 |             ret |= get_user_ual(osp, env->regs[1] - 12); | 
 |             osp -= 48; | 
 |             d = 3; | 
 |         } else { | 
 |             g_assert_not_reached(); | 
 |         } | 
 |  | 
 |         for (j = 0; j < 4; ++j) { | 
 |             ret |= put_user_ual(env->regs[j], ssp - 16 + j * 4); | 
 |         } | 
 |         for (j = 4; j < d * 4; ++j) { | 
 |             ret |= put_user_ual(env->regs[j], osp - 16 + j * 4); | 
 |         } | 
 |     } | 
 |     xtensa_rotate_window(env, d); | 
 |     g_assert(env->sregs[WINDOW_BASE] == wb); | 
 |     return ret == 0; | 
 | } | 
 |  | 
 | static int setup_sigcontext(struct target_rt_sigframe *frame, | 
 |                             CPUXtensaState *env) | 
 | { | 
 |     struct target_sigcontext *sc = &frame->uc.tuc_mcontext; | 
 |     int i; | 
 |  | 
 |     __put_user(env->pc, &sc->sc_pc); | 
 |     __put_user(env->sregs[PS], &sc->sc_ps); | 
 |     __put_user(env->sregs[LBEG], &sc->sc_lbeg); | 
 |     __put_user(env->sregs[LEND], &sc->sc_lend); | 
 |     __put_user(env->sregs[LCOUNT], &sc->sc_lcount); | 
 |     if (!flush_window_regs(env)) { | 
 |         return 0; | 
 |     } | 
 |     for (i = 0; i < 16; ++i) { | 
 |         __put_user(env->regs[i], sc->sc_a + i); | 
 |     } | 
 |     __put_user(0, &sc->sc_xtregs); | 
 |     /* TODO: xtregs */ | 
 |     return 1; | 
 | } | 
 |  | 
 | static void install_sigtramp(uint8_t *tramp) | 
 | { | 
 | #if TARGET_BIG_ENDIAN | 
 |     /* Generate instruction:  MOVI a2, __NR_rt_sigreturn */ | 
 |     __put_user(0x22, &tramp[0]); | 
 |     __put_user(0x0a, &tramp[1]); | 
 |     __put_user(TARGET_NR_rt_sigreturn, &tramp[2]); | 
 |     /* Generate instruction:  SYSCALL */ | 
 |     __put_user(0x00, &tramp[3]); | 
 |     __put_user(0x05, &tramp[4]); | 
 |     __put_user(0x00, &tramp[5]); | 
 | #else | 
 |     /* Generate instruction:  MOVI a2, __NR_rt_sigreturn */ | 
 |     __put_user(0x22, &tramp[0]); | 
 |     __put_user(0xa0, &tramp[1]); | 
 |     __put_user(TARGET_NR_rt_sigreturn, &tramp[2]); | 
 |     /* Generate instruction:  SYSCALL */ | 
 |     __put_user(0x00, &tramp[3]); | 
 |     __put_user(0x50, &tramp[4]); | 
 |     __put_user(0x00, &tramp[5]); | 
 | #endif | 
 | } | 
 |  | 
 | void setup_rt_frame(int sig, struct target_sigaction *ka, | 
 |                     target_siginfo_t *info, | 
 |                     target_sigset_t *set, CPUXtensaState *env) | 
 | { | 
 |     abi_ulong frame_addr; | 
 |     struct target_rt_sigframe *frame; | 
 |     int is_fdpic = info_is_fdpic(((TaskState *)thread_cpu->opaque)->info); | 
 |     abi_ulong handler = 0; | 
 |     abi_ulong handler_fdpic_GOT = 0; | 
 |     uint32_t ra; | 
 |     bool abi_call0; | 
 |     unsigned base; | 
 |     int i; | 
 |  | 
 |     frame_addr = get_sigframe(ka, env, sizeof(*frame)); | 
 |     trace_user_setup_rt_frame(env, frame_addr); | 
 |  | 
 |     if (is_fdpic) { | 
 |         abi_ulong funcdesc_ptr = ka->_sa_handler; | 
 |  | 
 |         if (get_user_ual(handler, funcdesc_ptr) | 
 |             || get_user_ual(handler_fdpic_GOT, funcdesc_ptr + 4)) { | 
 |             goto give_sigsegv; | 
 |         } | 
 |     } else { | 
 |         handler = ka->_sa_handler; | 
 |     } | 
 |  | 
 |     if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) { | 
 |         goto give_sigsegv; | 
 |     } | 
 |  | 
 |     if (ka->sa_flags & SA_SIGINFO) { | 
 |         tswap_siginfo(&frame->info, info); | 
 |     } | 
 |  | 
 |     __put_user(0, &frame->uc.tuc_flags); | 
 |     __put_user(0, &frame->uc.tuc_link); | 
 |     target_save_altstack(&frame->uc.tuc_stack, env); | 
 |     if (!setup_sigcontext(frame, env)) { | 
 |         unlock_user_struct(frame, frame_addr, 0); | 
 |         goto give_sigsegv; | 
 |     } | 
 |     for (i = 0; i < TARGET_NSIG_WORDS; ++i) { | 
 |         __put_user(set->sig[i], &frame->uc.tuc_sigmask.sig[i]); | 
 |     } | 
 |  | 
 |     if (ka->sa_flags & TARGET_SA_RESTORER) { | 
 |         if (is_fdpic) { | 
 |             if (get_user_ual(ra, ka->sa_restorer)) { | 
 |                 unlock_user_struct(frame, frame_addr, 0); | 
 |                 goto give_sigsegv; | 
 |             } | 
 |         } else { | 
 |             ra = ka->sa_restorer; | 
 |         } | 
 |     } else { | 
 |         /* Not used, but retain for ABI compatibility. */ | 
 |         install_sigtramp(frame->retcode); | 
 |         ra = default_rt_sigreturn; | 
 |     } | 
 |     memset(env->regs, 0, sizeof(env->regs)); | 
 |     env->pc = handler; | 
 |     env->regs[1] = frame_addr; | 
 |     env->sregs[WINDOW_BASE] = 0; | 
 |     env->sregs[WINDOW_START] = 1; | 
 |  | 
 |     abi_call0 = (env->sregs[PS] & PS_WOE) == 0; | 
 |     env->sregs[PS] = PS_UM | (3 << PS_RING_SHIFT); | 
 |  | 
 |     if (abi_call0) { | 
 |         base = 0; | 
 |         env->regs[base] = ra; | 
 |     } else { | 
 |         env->sregs[PS] |= PS_WOE | (1 << PS_CALLINC_SHIFT); | 
 |         base = 4; | 
 |         env->regs[base] = (ra & 0x3fffffff) | 0x40000000; | 
 |     } | 
 |     env->regs[base + 2] = sig; | 
 |     env->regs[base + 3] = frame_addr + offsetof(struct target_rt_sigframe, | 
 |                                                 info); | 
 |     env->regs[base + 4] = frame_addr + offsetof(struct target_rt_sigframe, uc); | 
 |     if (is_fdpic) { | 
 |         env->regs[base + 11] = handler_fdpic_GOT; | 
 |     } | 
 |     unlock_user_struct(frame, frame_addr, 1); | 
 |     return; | 
 |  | 
 | give_sigsegv: | 
 |     force_sigsegv(sig); | 
 |     return; | 
 | } | 
 |  | 
 | static void restore_sigcontext(CPUXtensaState *env, | 
 |                                struct target_rt_sigframe *frame) | 
 | { | 
 |     struct target_sigcontext *sc = &frame->uc.tuc_mcontext; | 
 |     uint32_t ps; | 
 |     int i; | 
 |  | 
 |     __get_user(env->pc, &sc->sc_pc); | 
 |     __get_user(ps, &sc->sc_ps); | 
 |     __get_user(env->sregs[LBEG], &sc->sc_lbeg); | 
 |     __get_user(env->sregs[LEND], &sc->sc_lend); | 
 |     __get_user(env->sregs[LCOUNT], &sc->sc_lcount); | 
 |  | 
 |     env->sregs[WINDOW_BASE] = 0; | 
 |     env->sregs[WINDOW_START] = 1; | 
 |     env->sregs[PS] = deposit32(env->sregs[PS], | 
 |                                PS_CALLINC_SHIFT, | 
 |                                PS_CALLINC_LEN, | 
 |                                extract32(ps, PS_CALLINC_SHIFT, | 
 |                                          PS_CALLINC_LEN)); | 
 |     for (i = 0; i < 16; ++i) { | 
 |         __get_user(env->regs[i], sc->sc_a + i); | 
 |     } | 
 |     /* TODO: xtregs */ | 
 | } | 
 |  | 
 | long do_rt_sigreturn(CPUXtensaState *env) | 
 | { | 
 |     abi_ulong frame_addr = env->regs[1]; | 
 |     struct target_rt_sigframe *frame; | 
 |     sigset_t set; | 
 |  | 
 |     trace_user_do_rt_sigreturn(env, frame_addr); | 
 |     if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) { | 
 |         goto badframe; | 
 |     } | 
 |     target_to_host_sigset(&set, &frame->uc.tuc_sigmask); | 
 |     set_sigmask(&set); | 
 |  | 
 |     restore_sigcontext(env, frame); | 
 |     target_restore_altstack(&frame->uc.tuc_stack, env); | 
 |  | 
 |     unlock_user_struct(frame, frame_addr, 0); | 
 |     return -QEMU_ESIGRETURN; | 
 |  | 
 | badframe: | 
 |     unlock_user_struct(frame, frame_addr, 0); | 
 |     force_sig(TARGET_SIGSEGV); | 
 |     return -QEMU_ESIGRETURN; | 
 | } | 
 |  | 
 | void setup_sigtramp(abi_ulong sigtramp_page) | 
 | { | 
 |     uint8_t *tramp = lock_user(VERIFY_WRITE, sigtramp_page, 6, 0); | 
 |     assert(tramp != NULL); | 
 |  | 
 |     default_rt_sigreturn = sigtramp_page; | 
 |     install_sigtramp(tramp); | 
 |     unlock_user(tramp, sigtramp_page, 6); | 
 | } |