syz-manager: print better message about disabled syscalls

Print better message and print it when verbosity >= 1.
This will allow to easier diff any changes in enabled
syscalls caused by future code changes.

5 files changed, 60 insertions, 50 deletions

diff --git a/pkg/host/syscalls.go b/pkg/host/syscalls.go
index cd49ded51..3068cec2b 100644
--- a/pkg/host/syscalls.go
+++ b/pkg/host/syscalls.go
@@ -15,29 +15,20 @@ func DetectSupportedSyscalls(target *prog.Target, sandbox string, enabled map[*p
 	log.Logf(1, "detecting supported syscalls")
 	supported := make(map[*prog.Syscall]bool)
 	unsupported := make(map[*prog.Syscall]string)
-	const disabledAttribute = "has disabled attribute in descriptions"
 	// These do not have own host and parasitize on some other OS.
 	if noHostChecks(target) {
 		for _, c := range target.Syscalls {
-			if c.Attrs.Disabled {
-				unsupported[c] = disabledAttribute
-			} else {
-				supported[c] = true
+			if c.Attrs.Disabled || !enabled[c] {
+				continue
 			}
+			supported[c] = true
 		}
 	} else {
 		for _, c := range target.Syscalls {
-			ok, reason := false, ""
-			switch {
-			case c.Attrs.Disabled:
-				ok = false
-				reason = disabledAttribute
-			case !enabled[c]:
-				ok = false
-				reason = "not in set of enabled calls"
-			default:
-				ok, reason = isSupported(c, target, sandbox)
+			if c.Attrs.Disabled || !enabled[c] {
+				continue
 			}
+			ok, reason := isSupported(c, target, sandbox)
 			if ok {
 				supported[c] = true
 			} else {
diff --git a/prog/resources.go b/prog/resources.go
index d739b528e..c200b2c5c 100644
--- a/prog/resources.go
+++ b/prog/resources.go
@@ -211,11 +211,12 @@ func (target *Target) TransitivelyEnabledCalls(enabled map[*Syscall]bool) (map[*
 				for _, ctor := range target.calcResourceCtors(res, true) {
 					names = append(names, ctor.Call.Name)
 				}
+				if len(names) > 5 {
+					names = append(names[:3], "...")
+				}
 				ctors[res.Name] = names
 			}
-			disabled[c] = fmt.Sprintf("no syscalls can create resource %v,"+
-				" enable some syscalls that can create it %v",
-				res.Name, ctors[res.Name])
+			disabled[c] = fmt.Sprintf("%v %v", res.Name, ctors[res.Name])
 			break
 		}
 	}
diff --git a/prog/resources_test.go b/prog/resources_test.go
index aa43580a1..180cfe1d6 100644
--- a/prog/resources_test.go
+++ b/prog/resources_test.go
@@ -92,8 +92,7 @@ func TestTransitivelyEnabledCallsLinux(t *testing.T) {
 		t.Fatalf("disabled %v syscalls, want 8", len(disabled))
 	}
 	for c, reason := range disabled {
-		if !strings.Contains(reason, "no syscalls can create resource fd_epoll,"+
-			" enable some syscalls that can create it [epoll_create epoll_create1]") {
+		if !strings.Contains(reason, "fd_epoll [epoll_create epoll_create1]") {
 			t.Fatalf("%v: wrong disable reason: %v", c.Name, reason)
 		}
 	}
diff --git a/syz-fuzzer/testing.go b/syz-fuzzer/testing.go
index ceecaf76a..a8783104e 100644
--- a/syz-fuzzer/testing.go
+++ b/syz-fuzzer/testing.go
@@ -298,17 +298,6 @@ func buildCallList(target *prog.Target, enabledCalls []int, sandbox string) (
 			delete(calls, c)
 		}
 	}
-	_, unsupported = target.TransitivelyEnabledCalls(calls)
-	for c := range calls {
-		if reason, ok := unsupported[c]; ok {
-			log.Logf(1, "transitively unsupported: %v(): %v", c.Name, reason)
-			disabled = append(disabled, rpctype.SyscallReason{
-				ID:     c.ID,
-				Reason: reason,
-			})
-			delete(calls, c)
-		}
-	}
 	for c := range calls {
 		enabled = append(enabled, c.ID)
 	}
diff --git a/syz-manager/rpc.go b/syz-manager/rpc.go
index 07533e078..183cda24e 100644
--- a/syz-manager/rpc.go
+++ b/syz-manager/rpc.go
@@ -7,6 +7,8 @@ import (
 	"bytes"
 	"fmt"
 	"net"
+	"sort"
+	"strings"
 	"sync"
 	"time"
 
@@ -189,23 +191,59 @@ func (serv *RPCServer) Check(a *rpctype.CheckArgs, r *rpctype.CheckRes) error {
 func (serv *RPCServer) check(a *rpctype.CheckArgs, modules []host.KernelModule) error {
 	// Note: need to print disbled syscalls before failing due to an error.
 	// This helps to debug "all system calls are disabled".
-	if len(serv.cfg.EnabledSyscalls) != 0 && len(a.DisabledCalls[serv.cfg.Sandbox]) != 0 {
-		disabled := make(map[string]string)
-		for _, dc := range a.DisabledCalls[serv.cfg.Sandbox] {
-			disabled[serv.cfg.Target.Syscalls[dc.ID].Name] = dc.Reason
+	enabledCalls := make(map[*prog.Syscall]bool)
+	for _, call := range a.EnabledCalls[serv.cfg.Sandbox] {
+		enabledCalls[serv.cfg.Target.Syscalls[call]] = true
+	}
+	disabledCalls := make(map[*prog.Syscall]string)
+	for _, dc := range a.DisabledCalls[serv.cfg.Sandbox] {
+		disabledCalls[serv.cfg.Target.Syscalls[dc.ID]] = dc.Reason
+	}
+	enabledCalls, transitivelyDisabled := serv.target.TransitivelyEnabledCalls(enabledCalls)
+	buf := new(bytes.Buffer)
+	if len(serv.cfg.EnabledSyscalls) != 0 || log.V(1) {
+		if len(disabledCalls) != 0 {
+			var lines []string
+			for call, reason := range disabledCalls {
+				lines = append(lines, fmt.Sprintf("%-44v: %v\n", call.Name, reason))
+			}
+			sort.Strings(lines)
+			fmt.Fprintf(buf, "disabled the following syscalls:\n%s\n", strings.Join(lines, ""))
 		}
-		for _, id := range serv.cfg.Syscalls {
-			name := serv.cfg.Target.Syscalls[id].Name
-			if reason := disabled[name]; reason != "" {
-				log.Logf(0, "disabling %v: %v", name, reason)
+		if len(transitivelyDisabled) != 0 {
+			var lines []string
+			for call, reason := range transitivelyDisabled {
+				lines = append(lines, fmt.Sprintf("%-44v: %v\n", call.Name, reason))
 			}
+			sort.Strings(lines)
+			fmt.Fprintf(buf, "transitively disabled the following syscalls"+
+				" (missing resource [creating syscalls]):\n%s\n",
+				strings.Join(lines, ""))
 		}
 	}
+	if len(enabledCalls) == 0 && a.Error == "" {
+		a.Error = "all system calls are disabled"
+	}
+	hasFileErrors := false
 	for _, file := range a.Files {
-		if file.Error != "" {
-			log.Logf(0, "failed to read %q: %v", file.Name, file.Error)
+		if file.Error == "" {
+			continue
+		}
+		if !hasFileErrors {
+			fmt.Fprintf(buf, "failed to read the following files in the VM:\n")
 		}
+		fmt.Fprintf(buf, "%-44v: %v\n", file.Name, file.Error)
+		hasFileErrors = true
 	}
+	if hasFileErrors {
+		fmt.Fprintf(buf, "\n")
+	}
+	fmt.Fprintf(buf, "%-24v: %v/%v\n", "syscalls", len(enabledCalls), len(serv.cfg.Target.Syscalls))
+	for _, feat := range a.Features.Supported() {
+		fmt.Fprintf(buf, "%-24v: %v\n", feat.Name, feat.Reason)
+	}
+	fmt.Fprintf(buf, "\n")
+	log.Logf(0, "machine check:\n%s", buf.Bytes())
 	if a.Error != "" {
 		log.Logf(0, "machine check failed: %v", a.Error)
 		serv.checkFailures++
@@ -214,15 +252,7 @@ func (serv *RPCServer) check(a *rpctype.CheckArgs, modules []host.KernelModule)
 		}
 		return fmt.Errorf("machine check failed: %v", a.Error)
 	}
-	serv.targetEnabledSyscalls = make(map[*prog.Syscall]bool)
-	for _, call := range a.EnabledCalls[serv.cfg.Sandbox] {
-		serv.targetEnabledSyscalls[serv.cfg.Target.Syscalls[call]] = true
-	}
-	log.Logf(0, "machine check:")
-	log.Logf(0, "%-24v: %v/%v", "syscalls", len(serv.targetEnabledSyscalls), len(serv.cfg.Target.Syscalls))
-	for _, feat := range a.Features.Supported() {
-		log.Logf(0, "%-24v: %v", feat.Name, feat.Reason)
-	}
+	serv.targetEnabledSyscalls = enabledCalls
 	serv.checkFeatures = a.Features
 	serv.canonicalModules = cover.NewCanonicalizer(modules, serv.cfg.Cover)
 	serv.mgr.machineChecked(a.Features, a.Globs, serv.targetEnabledSyscalls, modules)