Check in gVisor.

PiperOrigin-RevId: 194583126
Change-Id: Ica1d8821a90f74e7e745962d71801c598c652463

1 files changed, 177 insertions, 0 deletions

diff --git a/pkg/abi/linux/signal.go b/pkg/abi/linux/signal.go
new file mode 100644
index 000000000..cd09008b5
--- /dev/null
+++ b/pkg/abi/linux/signal.go
@@ -0,0 +1,177 @@
+// Copyright 2018 Google Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package linux
+
+import (
+	"gvisor.googlesource.com/gvisor/pkg/bits"
+)
+
+const (
+	// SignalMaximum is the highest valid signal number.
+	SignalMaximum = 64
+
+	// FirstStdSignal is the lowest standard signal number.
+	FirstStdSignal = 1
+
+	// LastStdSignal is the highest standard signal number.
+	LastStdSignal = 31
+
+	// FirstRTSignal is the lowest real-time signal number.
+	//
+	// 32 (SIGCANCEL) and 33 (SIGSETXID) are used internally by glibc.
+	FirstRTSignal = 32
+
+	// LastRTSignal is the highest real-time signal number.
+	LastRTSignal = 64
+
+	// NumStdSignals is the number of standard signals.
+	NumStdSignals = LastStdSignal - FirstStdSignal + 1
+
+	// NumRTSignals is the number of realtime signals.
+	NumRTSignals = LastRTSignal - FirstRTSignal + 1
+)
+
+// Signal is a signal number.
+type Signal int
+
+// IsValid returns true if s is a valid standard or realtime signal. (0 is not
+// considered valid; interfaces special-casing signal number 0 should check for
+// 0 first before asserting validity.)
+func (s Signal) IsValid() bool {
+	return s > 0 && s <= SignalMaximum
+}
+
+// IsStandard returns true if s is a standard signal.
+//
+// Preconditions: s.IsValid().
+func (s Signal) IsStandard() bool {
+	return s <= LastStdSignal
+}
+
+// IsRealtime returns true if s is a realtime signal.
+//
+// Preconditions: s.IsValid().
+func (s Signal) IsRealtime() bool {
+	return s >= FirstRTSignal
+}
+
+// Index returns the index for signal s into arrays of both standard and
+// realtime signals (e.g. signal masks).
+//
+// Preconditions: s.IsValid().
+func (s Signal) Index() int {
+	return int(s - 1)
+}
+
+// Signals.
+const (
+	SIGABRT   = Signal(6)
+	SIGALRM   = Signal(14)
+	SIGBUS    = Signal(7)
+	SIGCHLD   = Signal(17)
+	SIGCLD    = Signal(17)
+	SIGCONT   = Signal(18)
+	SIGFPE    = Signal(8)
+	SIGHUP    = Signal(1)
+	SIGILL    = Signal(4)
+	SIGINT    = Signal(2)
+	SIGIO     = Signal(29)
+	SIGIOT    = Signal(6)
+	SIGKILL   = Signal(9)
+	SIGPIPE   = Signal(13)
+	SIGPOLL   = Signal(29)
+	SIGPROF   = Signal(27)
+	SIGPWR    = Signal(30)
+	SIGQUIT   = Signal(3)
+	SIGSEGV   = Signal(11)
+	SIGSTKFLT = Signal(16)
+	SIGSTOP   = Signal(19)
+	SIGSYS    = Signal(31)
+	SIGTERM   = Signal(15)
+	SIGTRAP   = Signal(5)
+	SIGTSTP   = Signal(20)
+	SIGTTIN   = Signal(21)
+	SIGTTOU   = Signal(22)
+	SIGUNUSED = Signal(31)
+	SIGURG    = Signal(23)
+	SIGUSR1   = Signal(10)
+	SIGUSR2   = Signal(12)
+	SIGVTALRM = Signal(26)
+	SIGWINCH  = Signal(28)
+	SIGXCPU   = Signal(24)
+	SIGXFSZ   = Signal(25)
+)
+
+// SignalSet is a signal mask with a bit corresponding to each signal.
+type SignalSet uint64
+
+// SignalSetSize is the size in bytes of a SignalSet.
+const SignalSetSize = 8
+
+// MakeSignalSet returns SignalSet with the bit corresponding to each of the
+// given signals set.
+func MakeSignalSet(sigs ...Signal) SignalSet {
+	indices := make([]int, len(sigs))
+	for i, sig := range sigs {
+		indices[i] = sig.Index()
+	}
+	return SignalSet(bits.Mask64(indices...))
+}
+
+// SignalSetOf returns a SignalSet with a single signal set.
+func SignalSetOf(sig Signal) SignalSet {
+	return SignalSet(bits.MaskOf64(sig.Index()))
+}
+
+// ForEachSignal invokes f for each signal set in the given mask.
+func ForEachSignal(mask SignalSet, f func(sig Signal)) {
+	bits.ForEachSetBit64(uint64(mask), func(i int) {
+		f(Signal(i + 1))
+	})
+}
+
+// 'how' values for rt_sigprocmask(2).
+const (
+	// SIG_BLOCK blocks the signals in the set.
+	SIG_BLOCK = 0
+
+	// SIG_UNBLOCK blocks the signals in the set.
+	SIG_UNBLOCK = 1
+
+	// SIG_SETMASK sets the signal mask to set.
+	SIG_SETMASK = 2
+)
+
+// Signal actions for rt_sigaction(2), from uapi/asm-generic/signal-defs.h.
+const (
+	// SIG_DFL performs the default action.
+	SIG_DFL = 0
+
+	// SIG_IGN ignores the signal.
+	SIG_IGN = 1
+)
+
+// Signal action flags for rt_sigaction(2), from uapi/asm-generic/signal.h
+const (
+	SA_NOCLDSTOP   = 0x00000001
+	SA_NOCLDWAIT   = 0x00000002
+	SA_SIGINFO     = 0x00000004
+	SA_ONSTACK     = 0x08000000
+	SA_RESTART     = 0x10000000
+	SA_NODEFER     = 0x40000000
+	SA_RESTARTHAND = 0x80000000
+	SA_NOMASK      = SA_NODEFER
+	SA_ONESHOT     = SA_RESTARTHAND
+)