chore(events): decrease SO loader error log level to debug (#4041)

Errors from the SO loader are pretty frequent because of race conditions.
As the user has nothing to do with it, the log level should be lowered from WARN.

pkg/events/derive/symbols_collision.go

@@ -1,6 +1,8 @@
 package derive
 
 import (
+	"errors"
+
 	"github.com/hashicorp/golang-lru/simplelru"
 	"golang.org/x/exp/maps"
 
@@ -182,15 +184,19 @@ func (gen *SymbolsCollisionArgsGenerator) findShObjsCollisions(
 		// get exported symbols from the shared object BEING loaded
 		loadingShObj.exportedSymbols, err = gen.soLoader.GetExportedSymbols(loadingShObj.ObjInfo)
 		if err != nil {
+			// High level languages like Java might load non-ELF files
+			// There is no need to log errors for such cases
+			var notElfErr *sharedobjs.UnsupportedFileError
+			if errors.As(err, &notElfErr) {
+				return nil, nil
+			}
 			// TODO: rate limit frequent errors for overloaded envs
 			_, ok := gen.returnedErrorsMap[err.Error()]
 			if !ok {
 				gen.returnedErrorsMap[err.Error()] = true
-				logger.Warnw("symbols_loaded", "object loaded", loadingShObj.ObjInfo, "error", err.Error())
-			} else {
 				logger.Debugw("symbols_loaded", "object loaded", loadingShObj.ObjInfo, "error", err.Error())
 			}
-			return nil, errfmt.WrapError(err)
+			return nil, nil
 		}
 		loadingShObj.FilterSymbols(gen.symbolsBlacklistMap)    // del symbols NOT in blacklist
 		loadingShObj.FilterOutSymbols(gen.symbolsWhitelistMap) // del symbols IN the white list

pkg/events/derive/symbols_loaded.go

@@ -144,8 +144,6 @@ func (symbsLoadedGen *symbolsLoadedEventGenerator) deriveArgs(
 		_, ok := symbsLoadedGen.returnedErrors[err.Error()]
 		if !ok {
 			symbsLoadedGen.returnedErrors[err.Error()] = true
-			logger.Warnw("symbols_loaded", "object loaded", loadingObjectInfo, "error", err.Error())
-		} else {
 			logger.Debugw("symbols_loaded", "object loaded", loadingObjectInfo, "error", err.Error())
 		}
 		return nil, nil

pkg/events/derive/symbols_loaded_test.go

@@ -202,32 +202,30 @@ func TestDeriveSharedObjectExportWatchedSymbols(t *testing.T) {
 			mockLoader := initLoaderMock(errors.New("loading error"))
 			gen := initSymbolsLoadedEventGenerator(mockLoader, nil, nil)
 
-			// First error should be always returned
+			// First error should always be logged for debug
 			eventArgs, err := gen.deriveArgs(generateSOLoadedEvent(pid, sharedobjs.ObjInfo{Id: sharedobjs.ObjID{Inode: 1}, Path: "1.so"}))
 			assert.NoError(t, err)
 			assert.Nil(t, eventArgs)
 			assert.NotEmpty(t, errChan)
 			<-errChan
 			assert.Empty(t, errChan)
 
-			// Debug mode should return errors always
+			// Error should be suppressed
 			eventArgs, err = gen.deriveArgs(generateSOLoadedEvent(pid, sharedobjs.ObjInfo{Id: sharedobjs.ObjID{Inode: 1}, Path: "1.so"}))
 			assert.NoError(t, err)
 			assert.Nil(t, eventArgs)
-			assert.NotEmpty(t, errChan)
+			assert.Empty(t, errChan)
 		})
 		t.Run("No debug", func(t *testing.T) {
 			errChan := setMockLogger(logger.WarnLevel)
 			defer logger.SetLogger(baseLogger)
 			mockLoader := initLoaderMock(errors.New("loading error"))
 			gen := initSymbolsLoadedEventGenerator(mockLoader, nil, nil)
 
-			// First error should create warning
+			// First error should create debug log, so we won't see it
 			eventArgs, err := gen.deriveArgs(generateSOLoadedEvent(pid, sharedobjs.ObjInfo{Id: sharedobjs.ObjID{Inode: 1}, Path: "1.so"}))
 			assert.NoError(t, err)
 			assert.Nil(t, eventArgs)
-			assert.NotEmpty(t, errChan)
-			<-errChan
 			assert.Empty(t, errChan)
 
 			// Error should be suppressed
@@ -236,7 +234,7 @@ func TestDeriveSharedObjectExportWatchedSymbols(t *testing.T) {
 			assert.Nil(t, eventArgs)
 			assert.Empty(t, errChan)
 		})
-		t.Run("Non-ELF", func(t *testing.T) {
+		t.Run("Non-ELF error", func(t *testing.T) {
 			errChan := setMockLogger(logger.DebugLevel)
 			defer logger.SetLogger(baseLogger)
 			mockLoader := initLoaderMock(sharedobjs.InitUnsupportedFileError(nil))