all: add KernelModule cfg to show DLKM coverage

PC returned for dynamic loaded module (DLKM) is not
parsed in coverage page.
So the commit is to use DLKM modules' load address
to restore the PC and show coverage data of DLKM.

As the load address is written in cfg file, so kaslr
needs to be disabled.
And for linux target, load address is getting from
/proc/modules during instance setup.

For either manual or auto address setting case,
name and path are needed in config kernel_modules, where

name is module name on target.
path is module unstripped object path on host.
addr is decimal value of module load address on target.

Example of config:
 "kernel_modules": [
  {
    "name": "nf_nat",
    "path": "/usr/src/linux-source/net/netfilter/nf_nat.ko",
    "addr": 18446744072637911040
  }
 ]

2 files changed, 17 insertions, 10 deletions

diff --git a/pkg/symbolizer/symbolizer.go b/pkg/symbolizer/symbolizer.go
index 96b62fb95..87342e750 100644
--- a/pkg/symbolizer/symbolizer.go
+++ b/pkg/symbolizer/symbolizer.go
@@ -23,6 +23,7 @@ type Symbolizer struct {
 }
 
 type Frame struct {
+	Module string
 	PC     uint64
 	Func   string
 	File   string
@@ -43,15 +44,15 @@ func NewSymbolizer(target *targets.Target) *Symbolizer {
 }
 
 func (s *Symbolizer) Symbolize(bin string, pc uint64) ([]Frame, error) {
-	return s.SymbolizeArray(bin, []uint64{pc})
+	return s.SymbolizeArray("kernel", bin, []uint64{pc})
 }
 
-func (s *Symbolizer) SymbolizeArray(bin string, pcs []uint64) ([]Frame, error) {
+func (s *Symbolizer) SymbolizeArray(module, bin string, pcs []uint64) ([]Frame, error) {
 	sub, err := s.getSubprocess(bin)
 	if err != nil {
 		return nil, err
 	}
-	return symbolize(sub.input, sub.scanner, pcs)
+	return symbolize(sub.input, sub.scanner, pcs, module)
 }
 
 func (s *Symbolizer) Close() {
@@ -100,7 +101,7 @@ func (s *Symbolizer) getSubprocess(bin string) (*subprocess, error) {
 	return sub, nil
 }
 
-func symbolize(input *bufio.Writer, scanner *bufio.Scanner, pcs []uint64) ([]Frame, error) {
+func symbolize(input *bufio.Writer, scanner *bufio.Scanner, pcs []uint64, module string) ([]Frame, error) {
 	var frames []Frame
 	done := make(chan error, 1)
 	go func() {
@@ -116,7 +117,7 @@ func symbolize(input *bufio.Writer, scanner *bufio.Scanner, pcs []uint64) ([]Fra
 		}
 		for range pcs {
 			var frames1 []Frame
-			frames1, err = parse(scanner)
+			frames1, err = parse(scanner, module)
 			if err != nil {
 				return
 			}
@@ -145,7 +146,7 @@ func symbolize(input *bufio.Writer, scanner *bufio.Scanner, pcs []uint64) ([]Fra
 	return frames, nil
 }
 
-func parse(s *bufio.Scanner) ([]Frame, error) {
+func parse(s *bufio.Scanner, module string) ([]Frame, error) {
 	pc, err := strconv.ParseUint(s.Text(), 0, 64)
 	if err != nil {
 		return nil, fmt.Errorf("failed to parse pc '%v' in addr2line output: %v", s.Text(), err)
@@ -182,6 +183,7 @@ func parse(s *bufio.Scanner) ([]Frame, error) {
 			continue
 		}
 		frames = append(frames, Frame{
+			Module: module,
 			PC:     pc,
 			Func:   fn,
 			File:   file,
diff --git a/pkg/symbolizer/symbolizer_test.go b/pkg/symbolizer/symbolizer_test.go
index 0bddb2f71..cdbef8e6c 100644
--- a/pkg/symbolizer/symbolizer_test.go
+++ b/pkg/symbolizer/symbolizer_test.go
@@ -25,6 +25,7 @@ func TestParse(t *testing.T) {
 				"mm/kasan/report.c:320\n",
 			[]Frame{
 				{
+					Module: "kernel",
 					PC:     0xffffffff8180a42e,
 					Func:   "__asan_report_load2_noabort",
 					File:   "mm/kasan/report.c",
@@ -42,6 +43,7 @@ func TestParse(t *testing.T) {
 				"mm/kasan/report.c:320\n",
 			[]Frame{
 				{
+					Module: "kernel",
 					PC:     0xffffffff8180a42d,
 					Func:   "kasan_report",
 					File:   "mm/kasan/report.c",
@@ -49,6 +51,7 @@ func TestParse(t *testing.T) {
 					Inline: true,
 				},
 				{
+					Module: "kernel",
 					PC:     0xffffffff8180a42d,
 					Func:   "__asan_report_load2_noabort",
 					File:   "mm/kasan/report.c",
@@ -64,6 +67,7 @@ func TestParse(t *testing.T) {
 				"drivers/video/console/fbcon.c:2750\n",
 			[]Frame{
 				{
+					Module: "kernel",
 					PC:     0xffffffff82fdbe0b,
 					Func:   "fbcon_invert_region",
 					File:   "drivers/video/console/fbcon.c",
@@ -93,6 +97,7 @@ func TestParse(t *testing.T) {
 				"fs/devpts/inode.c:588 (discriminator 3)\n",
 			[]Frame{
 				{
+					Module: "kernel",
 					PC:     0xffffffff81a2aff9,
 					Func:   "devpts_get_priv",
 					File:   "fs/devpts/inode.c",
@@ -153,7 +158,7 @@ func TestParse(t *testing.T) {
 	var allPCs []uint64
 	var allFrames []Frame
 	for _, addr := range addresses {
-		frames, err := symbolize(input, scanner, []uint64{addr.pc})
+		frames, err := symbolize(input, scanner, []uint64{addr.pc}, "kernel")
 		if err != nil {
 			t.Fatalf("got error: %v", err)
 		}
@@ -166,11 +171,11 @@ func TestParse(t *testing.T) {
 
 	// Symbolize PCs in 2 groups.
 	for i := 0; i <= len(addresses); i++ {
-		frames, err := symbolize(input, scanner, allPCs[:i])
+		frames, err := symbolize(input, scanner, allPCs[:i], "kernel")
 		if err != nil {
 			t.Fatalf("got error: %v", err)
 		}
-		frames2, err := symbolize(input, scanner, allPCs[i:])
+		frames2, err := symbolize(input, scanner, allPCs[i:], "kernel")
 		if err != nil {
 			t.Fatalf("got error: %v", err)
 		}
@@ -185,7 +190,7 @@ func TestParse(t *testing.T) {
 	for i := range lots {
 		lots[i] = addresses[0].pc
 	}
-	frames, err := symbolize(input, scanner, lots)
+	frames, err := symbolize(input, scanner, lots, "kernel")
 	if err != nil {
 		t.Fatalf("got error: %v", err)
 	}