From 2d51d57a71659b063ddcb21cc50845d05d39708b Mon Sep 17 00:00:00 2001
From: Aleksandr Nogikh <nogikh@google.com>
Date: Fri, 1 Apr 2022 13:16:03 +0000
Subject: all: run strace on each found reproducer

If `strace_bin` is specified, syzkaller will invoke a reproducer with it
and save the output. This should help in debugging.

If syz-manager is attached to a dashboard, upload the strace-powered output
and report.
---
 tools/syz-crush/crush.go |  7 +++++++
 tools/syz-repro/repro.go | 18 ++++++++++++++++++
 2 files changed, 25 insertions(+)

(limited to 'tools')

diff --git a/tools/syz-crush/crush.go b/tools/syz-crush/crush.go
index 36424c61a..a88041a37 100644
--- a/tools/syz-crush/crush.go
+++ b/tools/syz-crush/crush.go
@@ -31,6 +31,7 @@ var (
 	flagDebug       = flag.Bool("debug", false, "dump all VM output to console")
 	flagRestartTime = flag.Duration("restart_time", 0, "how long to run the test")
 	flagInfinite    = flag.Bool("infinite", true, "by default test is run for ever, -infinite=false to stop on crash")
+	flagStrace      = flag.Bool("strace", false, "run under strace (binary must be set in the config file")
 )
 
 type FileType int
@@ -59,6 +60,9 @@ func main() {
 	} else {
 		log.Printf("running until crash is found or till %v", *flagRestartTime)
 	}
+	if *flagStrace && cfg.StraceBin == "" {
+		log.Fatalf("strace_bin must not be empty in order to run with -strace")
+	}
 
 	vmPool, err := vm.Create(cfg, *flagDebug)
 	if err != nil {
@@ -160,6 +164,9 @@ func runInstance(cfg *mgrconfig.Config, reporter *report.Reporter,
 	optArgs := &instance.OptionalConfig{
 		ExitCondition: vm.ExitTimeout,
 	}
+	if *flagStrace {
+		optArgs.StraceBin = cfg.StraceBin
+	}
 	var err error
 	inst, err := instance.CreateExecProgInstance(vmPool, index, cfg, reporter, optArgs)
 	if err != nil {
diff --git a/tools/syz-repro/repro.go b/tools/syz-repro/repro.go
index 6622b8203..247cc11cd 100644
--- a/tools/syz-repro/repro.go
+++ b/tools/syz-repro/repro.go
@@ -25,6 +25,7 @@ var (
 	flagDebug  = flag.Bool("debug", false, "print debug output")
 	flagOutput = flag.String("output", filepath.Join(".", "repro.txt"), "output description file (output.txt)")
 	flagCRepro = flag.String("crepro", filepath.Join(".", "repro.c"), "output c file (repro.c)")
+	flagStrace = flag.String("strace", "", "output strace log (strace_bin must be set)")
 )
 
 func main() {
@@ -104,4 +105,21 @@ func main() {
 			log.Logf(0, "failed to write C repro to file: %v", err)
 		}
 	}
+	if *flagStrace != "" {
+		result := repro.RunStrace(res, cfg, reporter, vmPool, vmIndexes[0])
+		if result.Error != nil {
+			log.Logf(0, "failed to run strace: %v", result.Error)
+		} else {
+			if result.Report != nil {
+				log.Logf(0, "under strace repro crashed with title: %s", result.Report.Title)
+			} else {
+				log.Logf(0, "repro didn't crash under strace")
+			}
+			if err := osutil.WriteFile(*flagStrace, result.Output); err == nil {
+				fmt.Printf("C file saved to %s\n", *flagStrace)
+			} else {
+				log.Logf(0, "failed to write strace output to file: %v", err)
+			}
+		}
+	}
 }
-- 
cgit mrf-deployment