linux-user/signal-common.h

   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
  20 #ifndef SIGNAL_COMMON_H
  21 #define SIGNAL_COMMON_H
  22
  23 #include "special-errno.h"
  24
  25 /* Fallback addresses into sigtramp page. */
  26 extern abi_ulong default_sigreturn;
  27 extern abi_ulong default_rt_sigreturn;
  28
  29 void setup_sigtramp(abi_ulong tramp_page);
  30
  31 int on_sig_stack(unsigned long sp);
  32 int sas_ss_flags(unsigned long sp);
  33 abi_ulong target_sigsp(abi_ulong sp, struct target_sigaction *ka);
  34 void target_save_altstack(target_stack_t *uss, CPUArchState *env);
  35 abi_long target_restore_altstack(target_stack_t *uss, CPUArchState *env);
  36
  37 static inline void target_sigemptyset(target_sigset_t *set)
  38 {
  39     memset(set, 0, sizeof(*set));
  40 }
  41
  42 void host_to_target_sigset_internal(target_sigset_t *d,
  43                                     const sigset_t *s);
  44 void target_to_host_sigset_internal(sigset_t *d,
  45                                     const target_sigset_t *s);
  46 void tswap_siginfo(target_siginfo_t *tinfo,
  47                    const target_siginfo_t *info);
  48 void set_sigmask(const sigset_t *set);
  49 void force_sig(int sig);
  50 void force_sigsegv(int oldsig);
  51 void force_sig_fault(int sig, int code, abi_ulong addr);
  52 #if defined(TARGET_ARCH_HAS_SETUP_FRAME)
  53 void setup_frame(int sig, struct target_sigaction *ka,
  54                  target_sigset_t *set, CPUArchState *env);
  55 #endif
  56 void setup_rt_frame(int sig, struct target_sigaction *ka,
  57                     target_siginfo_t *info,
  58                     target_sigset_t *set, CPUArchState *env);
  59
  60 void process_pending_signals(CPUArchState *cpu_env);
  61 void signal_init(void);
  62 void queue_signal(CPUArchState *env, int sig, int si_type,
  63                   target_siginfo_t *info);
  64 void host_to_target_siginfo(target_siginfo_t *tinfo, const siginfo_t *info);
  65 void target_to_host_siginfo(siginfo_t *info, const target_siginfo_t *tinfo);
  66 int target_to_host_signal(int sig);
  67 int host_to_target_signal(int sig);
  68 long do_sigreturn(CPUArchState *env);
  69 long do_rt_sigreturn(CPUArchState *env);
  70 abi_long do_sigaltstack(abi_ulong uss_addr, abi_ulong uoss_addr,
  71                         CPUArchState *env);
  72 int do_sigprocmask(int how, const sigset_t *set, sigset_t *oldset);
  73 abi_long do_swapcontext(CPUArchState *env, abi_ulong uold_ctx,
  74                         abi_ulong unew_ctx, abi_long ctx_size);
  75 /**
  76  * block_signals: block all signals while handling this guest syscall
  77  *
  78  * Block all signals, and arrange that the signal mask is returned to
  79  * its correct value for the guest before we resume execution of guest code.
  80  * If this function returns non-zero, then the caller should immediately
  81  * return -QEMU_ERESTARTSYS to the main loop, which will take the pending
  82  * signal and restart execution of the syscall.
  83  * If block_signals() returns zero, then the caller can continue with
  84  * emulation of the system call knowing that no signals can be taken
  85  * (and therefore that no race conditions will result).
  86  * This should only be called once, because if it is called a second time
  87  * it will always return non-zero. (Think of it like a mutex that can't
  88  * be recursively locked.)
  89  * Signals will be unblocked again by process_pending_signals().
  90  *
  91  * Return value: non-zero if there was a pending signal, zero if not.
  92  */
  93 int block_signals(void); /* Returns non zero if signal pending */
  94
  95 /**
  96  * process_sigsuspend_mask: read and apply syscall-local signal mask
  97  *
  98  * Read the guest signal mask from @sigset, length @sigsize.
  99  * Convert that to a host signal mask and save it to sigpending_mask.
 100  *
 101  * Return value: negative target errno, or zero;
 102  *               store &sigpending_mask into *pset on success.
 103  */
 104 int process_sigsuspend_mask(sigset_t **pset, target_ulong sigset,
 105                             target_ulong sigsize);
 106
 107 /**
 108  * finish_sigsuspend_mask: finish a sigsuspend-like syscall
 109  *
 110  * Set in_sigsuspend if we need to use the modified sigset
 111  * during process_pending_signals.
 112  */
 113 static inline void finish_sigsuspend_mask(int ret)
 114 {
 115     if (ret != -QEMU_ERESTARTSYS) {
 116         TaskState *ts = (TaskState *)thread_cpu->opaque;
 117         ts->in_sigsuspend = 1;
 118     }
 119 }
 120
 121 #endif