Add profiling commands to runsc

Example:
  runsc debug --root=<dir> \
      --profile-heap=/tmp/heap.prof \
      --profile-cpu=/tmp/cpu.prod --profile-delay=30 \
      <container ID>
PiperOrigin-RevId: 237848456
Change-Id: Icff3f20c1b157a84d0922599eaea327320dad773

5 files changed, 37 insertions, 6 deletions

diff --git a/runsc/boot/config.go b/runsc/boot/config.go
index 400203c99..626fcabdd 100644
--- a/runsc/boot/config.go
+++ b/runsc/boot/config.go
@@ -202,6 +202,9 @@ type Config struct {
 	// SIGUSR2(12) to troubleshoot hangs. -1 disables it.
 	PanicSignal int
 
+	// ProfileEnable is set to prepare the sandbox to be profiled.
+	ProfileEnable bool
+
 	// TestOnlyAllowRunAsCurrentUserWithoutChroot should only be used in
 	// tests. It allows runsc to start the sandbox process as the current
 	// user, and without chrooting the sandbox process. This can be
@@ -228,6 +231,7 @@ func (c *Config) ToFlags() []string {
 		"--strace-log-size=" + strconv.Itoa(int(c.StraceLogSize)),
 		"--watchdog-action=" + c.WatchdogAction.String(),
 		"--panic-signal=" + strconv.Itoa(c.PanicSignal),
+		"--profile=" + strconv.FormatBool(c.ProfileEnable),
 	}
 	if c.TestOnlyAllowRunAsCurrentUserWithoutChroot {
 		// Only include if set since it is never to be used by users.
diff --git a/runsc/boot/controller.go b/runsc/boot/controller.go
index 23d476f7f..a864be720 100644
--- a/runsc/boot/controller.go
+++ b/runsc/boot/controller.go
@@ -95,6 +95,11 @@ const (
 
 	// SandboxStacks collects sandbox stacks for debugging.
 	SandboxStacks = "debug.Stacks"
+
+	// Profiling related commands (see pprof.go for more details).
+	StartCPUProfile = "Profile.StartCPUProfile"
+	StopCPUProfile  = "Profile.StopCPUProfile"
+	HeapProfile     = "Profile.HeapProfile"
 )
 
 // ControlSocketAddr generates an abstract unix socket name for the given ID.
@@ -135,6 +140,9 @@ func newController(fd int, l *Loader) (*controller, error) {
 	}
 
 	srv.Register(&debug{})
+	if l.conf.ProfileEnable {
+		srv.Register(&control.Profile{})
+	}
 
 	return &controller{
 		srv:     srv,
diff --git a/runsc/boot/filter/config.go b/runsc/boot/filter/config.go
index bde749861..1ba5b7257 100644
--- a/runsc/boot/filter/config.go
+++ b/runsc/boot/filter/config.go
@@ -470,3 +470,16 @@ func controlServerFilters(fd int) seccomp.SyscallRules {
 		},
 	}
 }
+
+// profileFilters returns extra syscalls made by runtime/pprof package.
+func profileFilters() seccomp.SyscallRules {
+	return seccomp.SyscallRules{
+		syscall.SYS_OPENAT: []seccomp.Rule{
+			{
+				seccomp.AllowAny{},
+				seccomp.AllowAny{},
+				seccomp.AllowValue(syscall.O_RDONLY | syscall.O_LARGEFILE | syscall.O_CLOEXEC),
+			},
+		},
+	}
+}
diff --git a/runsc/boot/filter/filter.go b/runsc/boot/filter/filter.go
index d69a6a2cc..fb197f9b1 100644
--- a/runsc/boot/filter/filter.go
+++ b/runsc/boot/filter/filter.go
@@ -29,9 +29,10 @@ import (
 
 // Options are seccomp filter related options.
 type Options struct {
-	Platform     platform.Platform
-	HostNetwork  bool
-	ControllerFD int
+	Platform      platform.Platform
+	HostNetwork   bool
+	ProfileEnable bool
+	ControllerFD  int
 }
 
 // Install installs seccomp filters for based on the given platform.
@@ -47,6 +48,10 @@ func Install(opt Options) error {
 		Report("host networking enabled: syscall filters less restrictive!")
 		s.Merge(hostInetFilters())
 	}
+	if opt.ProfileEnable {
+		Report("profile enabled: syscall filters less restrictive!")
+		s.Merge(profileFilters())
+	}
 
 	switch p := opt.Platform.(type) {
 	case *ptrace.PTrace:
diff --git a/runsc/boot/loader.go b/runsc/boot/loader.go
index 42fe6f312..4c7e6abfc 100644
--- a/runsc/boot/loader.go
+++ b/runsc/boot/loader.go
@@ -445,9 +445,10 @@ func (l *Loader) run() error {
 		filter.Report("syscall filter is DISABLED. Running in less secure mode.")
 	} else {
 		opts := filter.Options{
-			Platform:     l.k.Platform,
-			HostNetwork:  l.conf.Network == NetworkHost,
-			ControllerFD: l.ctrl.srv.FD(),
+			Platform:      l.k.Platform,
+			HostNetwork:   l.conf.Network == NetworkHost,
+			ProfileEnable: l.conf.ProfileEnable,
+			ControllerFD:  l.ctrl.srv.FD(),
 		}
 		if err := filter.Install(opts); err != nil {
 			return fmt.Errorf("installing seccomp filters: %v", err)