From f6c43faab72cc4d24c97287064030de97ab74f4a Mon Sep 17 00:00:00 2001
From: Aleksandr Nogikh <nogikh@google.com>
Date: Thu, 19 Aug 2021 13:09:46 +0000
Subject: pkg/report: return more information from opcode decompiler

Let decompiler also parse the exact command name. Perform right trim on
the full output line, as it may contain tabs and spaces at the end.

Introduce an "-update" flag to facilitate mass updating of opcode
decompilation tests after changes to this functionality.
---
 pkg/report/decompile.go                         | 9 ++++++---
 pkg/report/decompile_test.go                    | 5 +++++
 pkg/report/linux_test.go                        | 7 ++++++-
 pkg/report/testdata/linux/decompile/amd64/0.out | 2 +-
 pkg/report/testdata/linux/decompile/amd64/2.out | 6 +++---
 5 files changed, 21 insertions(+), 8 deletions(-)

(limited to 'pkg')

diff --git a/pkg/report/decompile.go b/pkg/report/decompile.go
index ea352fc29..6f5a6fe41 100644
--- a/pkg/report/decompile.go
+++ b/pkg/report/decompile.go
@@ -10,6 +10,7 @@ import (
 	"os"
 	"regexp"
 	"strconv"
+	"strings"
 	"time"
 
 	"github.com/google/syzkaller/pkg/osutil"
@@ -28,6 +29,7 @@ const objdumpCallTimeout = 10 * time.Second
 type DecompiledOpcode struct {
 	Offset          int
 	IsBad           bool
+	Instruction     string
 	FullDescription string
 }
 
@@ -80,11 +82,12 @@ func objdumpParseOutput(rawOutput []byte) []DecompiledOpcode {
 		if err != nil {
 			continue
 		}
-		const objdumpBadCommand = "(bad)"
+		const objdumpBadInstruction = "(bad)"
 		ret = append(ret, DecompiledOpcode{
 			Offset:          int(offset),
-			IsBad:           result[3] == objdumpBadCommand,
-			FullDescription: result[0],
+			IsBad:           result[3] == objdumpBadInstruction,
+			Instruction:     result[3],
+			FullDescription: strings.TrimRight(result[0], " \t"),
 		})
 	}
 	return ret
diff --git a/pkg/report/decompile_test.go b/pkg/report/decompile_test.go
index 15843de83..c89b88681 100644
--- a/pkg/report/decompile_test.go
+++ b/pkg/report/decompile_test.go
@@ -26,22 +26,27 @@ Disassembly of section .data:
 	expected := []DecompiledOpcode{
 		{
 			Offset:          0,
+			Instruction:     "push   %ebp",
 			FullDescription: "   0:   55                      push   %ebp",
 		},
 		{
 			Offset:          1,
+			Instruction:     "push   %ebx",
 			FullDescription: "   1:   53                      push   %ebx",
 		},
 		{
 			Offset:          2,
+			Instruction:     "xor    %eax,%eax",
 			FullDescription: "   2:   31 c0                   xor    %eax,%eax",
 		},
 		{
 			Offset:          4,
+			Instruction:     "call   0xfff7bffe",
 			FullDescription: "   4:   e8 f5 bf f7 ff          call   0xfff7bffe",
 		},
 		{
 			Offset:          9,
+			Instruction:     "(bad)",
 			IsBad:           true,
 			FullDescription: "   9:   ff                      (bad)",
 		},
diff --git a/pkg/report/linux_test.go b/pkg/report/linux_test.go
index ec5eb3c71..bba6326e0 100644
--- a/pkg/report/linux_test.go
+++ b/pkg/report/linux_test.go
@@ -14,6 +14,7 @@ import (
 	"testing"
 
 	"github.com/google/syzkaller/pkg/mgrconfig"
+	"github.com/google/syzkaller/pkg/osutil"
 	"github.com/google/syzkaller/pkg/symbolizer"
 	"github.com/google/syzkaller/sys/targets"
 )
@@ -421,12 +422,16 @@ func testDisassembly(t *testing.T, reporter *linux, testFilePrefix string) {
 		t.Fatalf("failed to read input file: %v", err)
 	}
 
+	result := reporter.decompileReportOpcodes(input)
+	if *flagUpdate {
+		osutil.WriteFile(testFilePrefix+".out", result)
+	}
+
 	output, err := ioutil.ReadFile(testFilePrefix + ".out")
 	if err != nil {
 		t.Fatalf("failed to read output file: %v", err)
 	}
 
-	result := reporter.decompileReportOpcodes(input)
 	if !bytes.Equal(output, result) {
 		t.Fatalf("Expected:\n%s\nGot:\n%s\n", output, result)
 	}
diff --git a/pkg/report/testdata/linux/decompile/amd64/0.out b/pkg/report/testdata/linux/decompile/amd64/0.out
index 1d50e885d..93f0dda98 100644
--- a/pkg/report/testdata/linux/decompile/amd64/0.out
+++ b/pkg/report/testdata/linux/decompile/amd64/0.out
@@ -57,7 +57,7 @@ Code disassembly (best guess), 2 bytes skipped:
   19:	e8 f4 c7 f6 fd       	callq  0xfdf6c812
   1e:	e9 e0 fb ff ff       	jmpq   0xfffffc03
   23:	e8 4a a8 b0 fd       	callq  0xfdb0a872
-  28:	0f 0b                	ud2     <-- trapping instruction
+  28:	0f 0b                	ud2 <-- trapping instruction
   2a:	e9 97 fb ff ff       	jmpq   0xfffffbc6
   2f:	4c 89 ff             	mov    %r15,%rdi
   32:	e8 0b c8 f6 fd       	callq  0xfdf6c842
diff --git a/pkg/report/testdata/linux/decompile/amd64/2.out b/pkg/report/testdata/linux/decompile/amd64/2.out
index 87de89e9e..b5c3e5f63 100644
--- a/pkg/report/testdata/linux/decompile/amd64/2.out
+++ b/pkg/report/testdata/linux/decompile/amd64/2.out
@@ -171,15 +171,15 @@ Code disassembly (best guess):
   13:	bf 01 00 00 00       	mov    $0x1,%edi
   18:	e8 15 2a 09 00       	callq  0x92a32
   1d:	e8 50 84 35 00       	callq  0x358472
-  22:	fb                   	sti    
+  22:	fb                   	sti
   23:	65 8b 05 88 91 bc 7e 	mov    %gs:0x7ebc9188(%rip),%eax        # 0x7ebc91b2
   2a:	85 c0                	test   %eax,%eax <-- trapping instruction
   2c:	74 58                	je     0x86
   2e:	5b                   	pop    %rbx
   2f:	5d                   	pop    %rbp
-  30:	c3                   	retq   
+  30:	c3                   	retq
   31:	65 8b 05 d6 98 bc 7e 	mov    %gs:0x7ebc98d6(%rip),%eax        # 0x7ebc990e
   38:	85 c0                	test   %eax,%eax
   3a:	75 a2                	jne    0xffffffde
-  3c:	0f 0b                	ud2    
+  3c:	0f 0b                	ud2
   3e:	eb 9e                	jmp    0xffffffde
-- 
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