bsd-user/signal.c: implement do_sigaction

[mirror_qemu.git] / bsd-user / signal-common.h

diff --git a/bsd-user/signal-common.h b/bsd-user/signal-common.h
index 786ec592d189cd5345643025ca9df810404eadfd..7ff8e8f2e40c370fe3eecc263c14f49964145074 100644 (file)
--- a/bsd-user/signal-common.h
+++ b/bsd-user/signal-common.h
@@ -9,7 +9,29 @@
 #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);