Merge pull request #421 from parca-dev/fix-pprof-nil-pointer

pkg/storage: Fix nil pointer for locations that don't have a mapping

Author: brancz

README.md

@@ -74,4 +74,4 @@ Parca was originally developed by [Polar Signals](https://polarsignals.com/). Re
 ## Contributing
 
 Check out our [Contributing Guide](CONTRIBUTING.md) to get started!
-
+It explains how compile Parca, run it with Tilt as container in Kubernetes and send a Pull Request.

pkg/storage/pprof.go

@@ -140,11 +140,16 @@ func GeneratePprof(ctx context.Context, locationStore Locations, ip InstantProfi
 				}
 			}
 
-			location := &profile.Location{
-				ID:      uint64(len(p.Location) + 1),
-				Mapping: mapping,
+			addr := loc.Address
+			if mapping != nil {
 				// TODO: Is this right?
-				Address:  loc.Address + mapping.Offset,
+				addr += mapping.Offset
+			}
+
+			location := &profile.Location{
+				ID:       uint64(len(p.Location) + 1),
+				Mapping:  mapping,
+				Address:  addr,
 				Line:     lines,
 				IsFolded: loc.IsFolded,
 			}

pkg/storage/pprof_test.go

@@ -21,6 +21,7 @@ import (
 
 	"github.com/go-kit/log"
 	"github.com/google/pprof/profile"
+	"github.com/google/uuid"
 	"github.com/parca-dev/parca/pkg/storage/metastore"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/stretchr/testify/require"
@@ -63,3 +64,50 @@ func TestGeneratePprof(t *testing.T) {
 	require.NoError(t, f.Close())
 	require.NoError(t, resProf.CheckValid())
 }
+
+func TestGeneratePprofNilMapping(t *testing.T) {
+	ctx := context.Background()
+
+	pt := NewProfileTree()
+	pt.Insert(makeSample(2, []uuid.UUID{
+		uuid.MustParse("00000000-0000-0000-0000-000000000002"),
+		uuid.MustParse("00000000-0000-0000-0000-000000000001"),
+	}))
+
+	l := &fakeLocations{m: map[uuid.UUID]*metastore.Location{
+		uuid.MustParse("00000000-0000-0000-0000-000000000001"): {
+			ID: uuid.MustParse("00000000-0000-0000-0000-000000000001"),
+			Lines: []metastore.LocationLine{{
+				Function: &metastore.Function{
+					ID:          uuid.MustParse("00000000-0000-0000-0000-0000000000f1"),
+					FunctionKey: metastore.FunctionKey{Name: "1"},
+				},
+			}},
+		},
+		uuid.MustParse("00000000-0000-0000-0000-000000000002"): {
+			ID: uuid.MustParse("00000000-0000-0000-0000-000000000002"),
+			Lines: []metastore.LocationLine{{
+				Function: &metastore.Function{
+					ID:          uuid.MustParse("00000000-0000-0000-0000-0000000000f2"),
+					FunctionKey: metastore.FunctionKey{Name: "2"},
+				},
+			}},
+		},
+	}}
+
+	res, err := GeneratePprof(ctx, l, &Profile{Tree: pt})
+	require.NoError(t, err)
+
+	tmpfile, err := ioutil.TempFile("", "pprof")
+	defer os.Remove(tmpfile.Name())
+	require.NoError(t, err)
+	require.NoError(t, res.Write(tmpfile))
+	require.NoError(t, tmpfile.Close())
+
+	f, err := os.Open(tmpfile.Name())
+	require.NoError(t, err)
+	resProf, err := profile.Parse(f)
+	require.NoError(t, err)
+	require.NoError(t, f.Close())
+	require.NoError(t, resProf.CheckValid())
+}