Format signals, signal masks in strace

Sample:

I1205 16:51:49.869701    2492 x:0] [   1] ioctl_test E rt_sigaction(SIGIO, 0x7e0e5b5e8500, 0x7e0e5b5e85a0)
I1205 16:51:49.869766    2492 x:0] [   1] ioctl_test X rt_sigaction(SIGIO, 0x7e0e5b5e8500, 0x7e0e5b5e85a0) = 0x0 (44.336?s)
I1205 16:51:49.869831    2492 x:0] [   1] ioctl_test E rt_sigprocmask(SIG_UNBLOCK, 0x7e0e5b5e8878 [SIGIO], 0x7e0e5b5e87c0, 0x8)
I1205 16:51:49.869866    2492 x:0] [   1] ioctl_test X rt_sigprocmask(SIG_UNBLOCK, 0x7e0e5b5e8878 [SIGIO], 0x7e0e5b5e87c0 [SIGIO 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64], 0x8) = 0x0 (2.575?s)

PiperOrigin-RevId: 224422404
Change-Id: I3ed3f2ec6b1a639baa9cacd37ce7ee325c3703e4

5 files changed, 117 insertions, 10 deletions

diff --git a/pkg/sentry/strace/BUILD b/pkg/sentry/strace/BUILD
index 52c7f325c..8517db1ac 100644
--- a/pkg/sentry/strace/BUILD
+++ b/pkg/sentry/strace/BUILD
@@ -11,6 +11,7 @@ go_library(
         "linux64.go",
         "open.go",
         "ptrace.go",
+        "signal.go",
         "socket.go",
         "strace.go",
         "syscalls.go",
diff --git a/pkg/sentry/strace/linux64.go b/pkg/sentry/strace/linux64.go
index 99714f12c..a2ca1a456 100644
--- a/pkg/sentry/strace/linux64.go
+++ b/pkg/sentry/strace/linux64.go
@@ -30,8 +30,8 @@ var linuxAMD64 = SyscallMap{
 	10:  makeSyscallInfo("mprotect", Hex, Hex, Hex),
 	11:  makeSyscallInfo("munmap", Hex, Hex),
 	12:  makeSyscallInfo("brk", Hex),
-	13:  makeSyscallInfo("rt_sigaction", Hex, Hex, Hex),
-	14:  makeSyscallInfo("rt_sigprocmask", Hex, Hex, Hex, Hex),
+	13:  makeSyscallInfo("rt_sigaction", Signal, Hex, Hex),
+	14:  makeSyscallInfo("rt_sigprocmask", SignalMaskAction, SigSet, PostSigSet, Hex),
 	15:  makeSyscallInfo("rt_sigreturn"),
 	16:  makeSyscallInfo("ioctl", Hex, Hex, Hex),
 	17:  makeSyscallInfo("pread64", Hex, ReadBuffer, Hex, Hex),
@@ -79,7 +79,7 @@ var linuxAMD64 = SyscallMap{
 	59:  makeSyscallInfo("execve", Path, ExecveStringVector, ExecveStringVector),
 	60:  makeSyscallInfo("exit", Hex),
 	61:  makeSyscallInfo("wait4", Hex, Hex, Hex, Rusage),
-	62:  makeSyscallInfo("kill", Hex, Hex),
+	62:  makeSyscallInfo("kill", Hex, Signal),
 	63:  makeSyscallInfo("uname", Uname),
 	64:  makeSyscallInfo("semget", Hex, Hex, Hex),
 	65:  makeSyscallInfo("semop", Hex, Hex, Hex),
@@ -145,8 +145,8 @@ var linuxAMD64 = SyscallMap{
 	125: makeSyscallInfo("capget", Hex, Hex),
 	126: makeSyscallInfo("capset", Hex, Hex),
 	127: makeSyscallInfo("rt_sigpending", Hex),
-	128: makeSyscallInfo("rt_sigtimedwait", Hex, Hex, Timespec, Hex),
-	129: makeSyscallInfo("rt_sigqueueinfo", Hex, Hex, Hex),
+	128: makeSyscallInfo("rt_sigtimedwait", SigSet, Hex, Timespec, Hex),
+	129: makeSyscallInfo("rt_sigqueueinfo", Hex, Signal, Hex),
 	130: makeSyscallInfo("rt_sigsuspend", Hex),
 	131: makeSyscallInfo("sigaltstack", Hex, Hex),
 	132: makeSyscallInfo("utime", Path, Utimbuf),
@@ -217,7 +217,7 @@ var linuxAMD64 = SyscallMap{
 	197: makeSyscallInfo("removexattr", Path, Path),
 	198: makeSyscallInfo("lremovexattr", Path, Path),
 	199: makeSyscallInfo("fremovexattr", Hex, Path),
-	200: makeSyscallInfo("tkill", Hex, Hex),
+	200: makeSyscallInfo("tkill", Hex, Signal),
 	201: makeSyscallInfo("time", Hex),
 	202: makeSyscallInfo("futex", Hex, FutexOp, Hex, Timespec, Hex, Hex),
 	203: makeSyscallInfo("sched_setaffinity", Hex, Hex, Hex),
@@ -251,7 +251,7 @@ var linuxAMD64 = SyscallMap{
 	231: makeSyscallInfo("exit_group", Hex),
 	232: makeSyscallInfo("epoll_wait", Hex, Hex, Hex, Hex),
 	233: makeSyscallInfo("epoll_ctl", Hex, Hex, Hex, Hex),
-	234: makeSyscallInfo("tgkill", Hex, Hex, Hex),
+	234: makeSyscallInfo("tgkill", Hex, Hex, Signal),
 	235: makeSyscallInfo("utimes", Path, Timeval),
 	// 236: vserver (not implemented in the Linux kernel)
 	237: makeSyscallInfo("mbind", Hex, Hex, Hex, Hex, Hex, Hex),
@@ -288,7 +288,7 @@ var linuxAMD64 = SyscallMap{
 	268: makeSyscallInfo("fchmodat", Hex, Path, Mode),
 	269: makeSyscallInfo("faccessat", Hex, Path, Oct, Hex),
 	270: makeSyscallInfo("pselect6", Hex, Hex, Hex, Hex, Hex, Hex),
-	271: makeSyscallInfo("ppoll", Hex, Hex, Timespec, Hex, Hex),
+	271: makeSyscallInfo("ppoll", Hex, Hex, Timespec, SigSet, Hex),
 	272: makeSyscallInfo("unshare", Hex),
 	273: makeSyscallInfo("set_robust_list", Hex, Hex),
 	274: makeSyscallInfo("get_robust_list", Hex, Hex, Hex),
@@ -298,7 +298,7 @@ var linuxAMD64 = SyscallMap{
 	278: makeSyscallInfo("vmsplice", Hex, Hex, Hex, Hex),
 	279: makeSyscallInfo("move_pages", Hex, Hex, Hex, Hex, Hex, Hex),
 	280: makeSyscallInfo("utimensat", Hex, Path, UTimeTimespec, Hex),
-	281: makeSyscallInfo("epoll_pwait", Hex, Hex, Hex, Hex, Hex, Hex),
+	281: makeSyscallInfo("epoll_pwait", Hex, Hex, Hex, Hex, SigSet, Hex),
 	282: makeSyscallInfo("signalfd", Hex, Hex, Hex),
 	283: makeSyscallInfo("timerfd_create", Hex, Hex),
 	284: makeSyscallInfo("eventfd", Hex),
@@ -314,7 +314,7 @@ var linuxAMD64 = SyscallMap{
 	294: makeSyscallInfo("inotify_init1", Hex),
 	295: makeSyscallInfo("preadv", Hex, ReadIOVec, Hex, Hex),
 	296: makeSyscallInfo("pwritev", Hex, WriteIOVec, Hex, Hex),
-	297: makeSyscallInfo("rt_tgsigqueueinfo", Hex, Hex, Hex, Hex),
+	297: makeSyscallInfo("rt_tgsigqueueinfo", Hex, Hex, Signal, Hex),
 	298: makeSyscallInfo("perf_event_open", Hex, Hex, Hex, Hex, Hex),
 	299: makeSyscallInfo("recvmmsg", Hex, Hex, Hex, Hex, Hex),
 	300: makeSyscallInfo("fanotify_init", Hex, Hex),
diff --git a/pkg/sentry/strace/signal.go b/pkg/sentry/strace/signal.go
new file mode 100644
index 000000000..00ed02a3c
--- /dev/null
+++ b/pkg/sentry/strace/signal.go
@@ -0,0 +1,86 @@
+// Copyright 2018 Google LLC
+//
+// 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 strace
+
+import (
+	"fmt"
+	"strings"
+
+	"gvisor.googlesource.com/gvisor/pkg/abi"
+	"gvisor.googlesource.com/gvisor/pkg/abi/linux"
+	"gvisor.googlesource.com/gvisor/pkg/sentry/kernel"
+	"gvisor.googlesource.com/gvisor/pkg/sentry/usermem"
+)
+
+// signalNames contains the names of all named signals.
+var signalNames = abi.ValueSet{
+	uint64(linux.SIGABRT):   "SIGABRT",
+	uint64(linux.SIGALRM):   "SIGALRM",
+	uint64(linux.SIGBUS):    "SIGBUS",
+	uint64(linux.SIGCHLD):   "SIGCHLD",
+	uint64(linux.SIGCONT):   "SIGCONT",
+	uint64(linux.SIGFPE):    "SIGFPE",
+	uint64(linux.SIGHUP):    "SIGHUP",
+	uint64(linux.SIGILL):    "SIGILL",
+	uint64(linux.SIGINT):    "SIGINT",
+	uint64(linux.SIGIO):     "SIGIO",
+	uint64(linux.SIGKILL):   "SIGKILL",
+	uint64(linux.SIGPIPE):   "SIGPIPE",
+	uint64(linux.SIGPROF):   "SIGPROF",
+	uint64(linux.SIGPWR):    "SIGPWR",
+	uint64(linux.SIGQUIT):   "SIGQUIT",
+	uint64(linux.SIGSEGV):   "SIGSEGV",
+	uint64(linux.SIGSTKFLT): "SIGSTKFLT",
+	uint64(linux.SIGSTOP):   "SIGSTOP",
+	uint64(linux.SIGSYS):    "SIGSYS",
+	uint64(linux.SIGTERM):   "SIGTERM",
+	uint64(linux.SIGTRAP):   "SIGTRAP",
+	uint64(linux.SIGTSTP):   "SIGTSTP",
+	uint64(linux.SIGTTIN):   "SIGTTIN",
+	uint64(linux.SIGTTOU):   "SIGTTOU",
+	uint64(linux.SIGURG):    "SIGURG",
+	uint64(linux.SIGUSR1):   "SIGUSR1",
+	uint64(linux.SIGUSR2):   "SIGUSR2",
+	uint64(linux.SIGVTALRM): "SIGVTALRM",
+	uint64(linux.SIGWINCH):  "SIGWINCH",
+	uint64(linux.SIGXCPU):   "SIGXCPU",
+	uint64(linux.SIGXFSZ):   "SIGXFSZ",
+}
+
+var signalMaskActions = abi.ValueSet{
+	linux.SIG_BLOCK:   "SIG_BLOCK",
+	linux.SIG_UNBLOCK: "SIG_UNBLOCK",
+	linux.SIG_SETMASK: "SIG_SETMASK",
+}
+
+func sigSet(t *kernel.Task, addr usermem.Addr) string {
+	if addr == 0 {
+		return "null"
+	}
+
+	var b [linux.SignalSetSize]byte
+	if _, err := t.CopyInBytes(addr, b[:]); err != nil {
+		return fmt.Sprintf("%#x (error copying sigset: %v)", addr, err)
+	}
+
+	set := linux.SignalSet(usermem.ByteOrder.Uint64(b[:]))
+
+	var signals []string
+	linux.ForEachSignal(set, func(sig linux.Signal) {
+		signals = append(signals, signalNames.ParseDecimal(uint64(sig)))
+	})
+
+	return fmt.Sprintf("%#x [%v]", addr, strings.Join(signals, " "))
+}
diff --git a/pkg/sentry/strace/strace.go b/pkg/sentry/strace/strace.go
index e40e0b57c..6df84e690 100644
--- a/pkg/sentry/strace/strace.go
+++ b/pkg/sentry/strace/strace.go
@@ -333,6 +333,12 @@ func (i *SyscallInfo) pre(t *kernel.Task, args arch.SyscallArguments, maximumBlo
 			output = append(output, PtraceRequestSet.Parse(args[arg].Uint64()))
 		case ItimerType:
 			output = append(output, ItimerTypes.Parse(uint64(args[arg].Int())))
+		case Signal:
+			output = append(output, signalNames.ParseDecimal(args[arg].Uint64()))
+		case SignalMaskAction:
+			output = append(output, signalMaskActions.Parse(uint64(args[arg].Int())))
+		case SigSet:
+			output = append(output, sigSet(t, args[arg].Pointer()))
 		case Oct:
 			output = append(output, "0o"+strconv.FormatUint(args[arg].Uint64(), 8))
 		case Hex:
@@ -391,6 +397,8 @@ func (i *SyscallInfo) post(t *kernel.Task, args arch.SyscallArguments, rval uint
 			output[arg] = timeval(t, args[arg].Pointer())
 		case Rusage:
 			output[arg] = rusage(t, args[arg].Pointer())
+		case PostSigSet:
+			output[arg] = sigSet(t, args[arg].Pointer())
 		}
 	}
 }
diff --git a/pkg/sentry/strace/syscalls.go b/pkg/sentry/strace/syscalls.go
index 9eeb18a03..22aecc009 100644
--- a/pkg/sentry/strace/syscalls.go
+++ b/pkg/sentry/strace/syscalls.go
@@ -170,6 +170,18 @@ const (
 
 	// ItimerType is an itimer type (ITIMER_REAL, etc).
 	ItimerType
+
+	// Signal is a signal number.
+	Signal
+
+	// SignalMaskAction is a signal mask action passed to rt_sigprocmask(2).
+	SignalMaskAction
+
+	// SigSet is a signal set.
+	SigSet
+
+	// PostSigSet is a signal set, formatted after syscall execution.
+	PostSigSet
 )
 
 // defaultFormat is the syscall argument format to use if the actual format is