bsd-user/signal-common.h

   1 /*
   2  * Emulation of BSD signals
   3  *
   4  * Copyright (c) 2013 Stacey Son
   5  *
   6  * SPDX-License-Identifier: GPL-2.0-or-later
   7  */
   8
   9 #ifndef SIGNAL_COMMON_H
  10 #define SIGNAL_COMMON_H
  11
  12 /**
  13  * block_signals: block all signals while handling this guest syscall
  14  *
  15  * Block all signals, and arrange that the signal mask is returned to
  16  * its correct value for the guest before we resume execution of guest code.
  17  * If this function returns non-zero, then the caller should immediately
  18  * return -TARGET_ERESTARTSYS to the main loop, which will take the pending
  19  * signal and restart execution of the syscall.
  20  * If block_signals() returns zero, then the caller can continue with
  21  * emulation of the system call knowing that no signals can be taken
  22  * (and therefore that no race conditions will result).
  23  * This should only be called once, because if it is called a second time
  24  * it will always return non-zero. (Think of it like a mutex that can't
  25  * be recursively locked.)
  26  * Signals will be unblocked again by process_pending_signals().
  27  *
  28  * Return value: non-zero if there was a pending signal, zero if not.
  29  */
  30 int block_signals(void); /* Returns non zero if signal pending */
  31
  32 long do_rt_sigreturn(CPUArchState *env);
  33 int do_sigaction(int sig, const struct target_sigaction *act,
  34                 struct target_sigaction *oact);
  35 abi_long do_sigaltstack(abi_ulong uss_addr, abi_ulong uoss_addr, abi_ulong sp);
  36 long do_sigreturn(CPUArchState *env, abi_ulong addr);
  37 void force_sig_fault(int sig, int code, abi_ulong addr);
  38 int host_to_target_signal(int sig);
  39 void host_to_target_sigset(target_sigset_t *d, const sigset_t *s);
  40 void process_pending_signals(CPUArchState *env);
  41 void queue_signal(CPUArchState *env, int sig, int si_type,
  42                   target_siginfo_t *info);
  43 void signal_init(void);
  44 int target_to_host_signal(int sig);
  45 void target_to_host_sigset(sigset_t *d, const target_sigset_t *s);
  46
  47 /*
  48  * Within QEMU the top 8 bits of si_code indicate which of the parts of the
  49  * union in target_siginfo is valid. This only applies between
  50  * host_to_target_siginfo_noswap() and tswap_siginfo(); it does not appear
  51  * either within host siginfo_t or in target_siginfo structures which we get
  52  * from the guest userspace program. Linux kenrels use this internally, but BSD
  53  * kernels don't do this, but its a useful abstraction.
  54  *
  55  * The linux-user version of this uses the top 16 bits, but FreeBSD's SI_USER
  56  * and other signal indepenent SI_ codes have bit 16 set, so we only use the top
  57  * byte instead.
  58  *
  59  * For FreeBSD, we have si_pid, si_uid, si_status, and si_addr always. Linux and
  60  * {Open,Net}BSD have a different approach (where their reason field is larger,
  61  * but whose siginfo has fewer fields always).
  62  *
  63  * QEMU_SI_CAPSICUM is currently only FreeBSD 14 current only, so only define
  64  * it where _capsicum is available.
  65  */
  66 #define QEMU_SI_NOINFO   0      /* nothing other than si_signo valid */
  67 #define QEMU_SI_FAULT    1      /* _fault is valid in _reason */
  68 #define QEMU_SI_TIMER    2      /* _timer is valid in _reason */
  69 #define QEMU_SI_MESGQ    3      /* _mesgq is valid in _reason */
  70 #define QEMU_SI_POLL     4      /* _poll is valid in _reason */
  71 #if defined(__FreeBSD_version) && __FreeBSD_version >= 1400026
  72 #define QEMU_SI_CAPSICUM 5      /* _capsicum is valid in _reason */
  73 #endif
  74
  75 #endif