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-rw-r--r--bsd-user/signal-common.h70
1 files changed, 70 insertions, 0 deletions
diff --git a/bsd-user/signal-common.h b/bsd-user/signal-common.h
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+/*
+ * Emulation of BSD signals
+ *
+ * Copyright (c) 2013 Stacey Son
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#ifndef SIGNAL_COMMON_H
+#define SIGNAL_COMMON_H
+
+/**
+ * block_signals: block all signals while handling this guest syscall
+ *
+ * Block all signals, and arrange that the signal mask is returned to
+ * its correct value for the guest before we resume execution of guest code.
+ * If this function returns non-zero, then the caller should immediately
+ * return -TARGET_ERESTARTSYS to the main loop, which will take the pending
+ * signal and restart execution of the syscall.
+ * If block_signals() returns zero, then the caller can continue with
+ * emulation of the system call knowing that no signals can be taken
+ * (and therefore that no race conditions will result).
+ * This should only be called once, because if it is called a second time
+ * it will always return non-zero. (Think of it like a mutex that can't
+ * be recursively locked.)
+ * Signals will be unblocked again by process_pending_signals().
+ *
+ * Return value: non-zero if there was a pending signal, zero if not.
+ */
+int block_signals(void); /* Returns non zero if signal pending */
+
+long do_rt_sigreturn(CPUArchState *env);
+int do_sigaction(int sig, const struct target_sigaction *act,
+ struct target_sigaction *oact);
+abi_long do_sigaltstack(abi_ulong uss_addr, abi_ulong uoss_addr, abi_ulong sp);
+long do_sigreturn(CPUArchState *env, abi_ulong addr);
+void force_sig_fault(int sig, int code, abi_ulong addr);
+int host_to_target_signal(int sig);
+void host_to_target_sigset(target_sigset_t *d, const sigset_t *s);
+void process_pending_signals(CPUArchState *env);
+void queue_signal(CPUArchState *env, int sig, int si_type,
+ target_siginfo_t *info);
+void signal_init(void);
+int target_to_host_signal(int sig);
+void target_to_host_sigset(sigset_t *d, const target_sigset_t *s);
+
+/*
+ * Within QEMU the top 8 bits of si_code indicate which of the parts of the
+ * union in target_siginfo is valid. This only applies between
+ * host_to_target_siginfo_noswap() and tswap_siginfo(); it does not appear
+ * either within host siginfo_t or in target_siginfo structures which we get
+ * from the guest userspace program. Linux kenrels use this internally, but BSD
+ * kernels don't do this, but its a useful abstraction.
+ *
+ * The linux-user version of this uses the top 16 bits, but FreeBSD's SI_USER
+ * and other signal indepenent SI_ codes have bit 16 set, so we only use the top
+ * byte instead.
+ *
+ * For FreeBSD, we have si_pid, si_uid, si_status, and si_addr always. Linux and
+ * {Open,Net}BSD have a different approach (where their reason field is larger,
+ * but whose siginfo has fewer fields always).
+ */
+#define QEMU_SI_NOINFO 0 /* nothing other than si_signo valid */
+#define QEMU_SI_FAULT 1 /* _fault is valid in _reason */
+#define QEMU_SI_TIMER 2 /* _timer is valid in _reason */
+#define QEMU_SI_MESGQ 3 /* _mesgq is valid in _reason */
+#define QEMU_SI_POLL 4 /* _poll is valid in _reason */
+#define QEMU_SI_CAPSICUM 5 /* _capsicum is valid in _reason */
+
+#endif