pkg/bpf: move maps memlock retrieval from bugtool to bpf

These operations might eventually be taken care of by cilium/ebpf directly and we can remove this. I moved this to the bpf package as it made little sense to import pkg/bugtool to just perform those operations on maps. Signed-off-by: Mahe Tardy <mahe.tardy@gmail.com>
cilium · Oct 8, 2024 · 3f7f1f6 · 3f7f1f6
1 parent 3897867
commit 3f7f1f6
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Showing 3 changed files with 119 additions and 85 deletions.
diff --git a/pkg/bpf/maps.go b/pkg/bpf/maps.go
@@ -0,0 +1,100 @@
+// SPDX-License-Identifier: Apache-2.0
+// Copyright Authors of Tetragon
+
+package bpf
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"os"
+	"strconv"
+	"strings"
+
+	"github.com/cilium/ebpf"
+)
+
+type ExtendedMapInfo struct {
+	ebpf.MapInfo
+	Memlock int
+}
+
+func ExtendedInfoFromMapID(id int) (ExtendedMapInfo, error) {
+	m, err := ebpf.NewMapFromID(ebpf.MapID(id))
+	if err != nil {
+		return ExtendedMapInfo{}, fmt.Errorf("failed creating a map FD from ID: %w", err)
+	}
+	defer m.Close()
+
+	xInfo, err := ExtendedInfoFromMap(m)
+	if err != nil {
+		return ExtendedMapInfo{}, fmt.Errorf("failed to retrieve extended info from map %v: %w", m, err)
+	}
+
+	return xInfo, nil
+}
+
+func ExtendedInfoFromMap(m *ebpf.Map) (ExtendedMapInfo, error) {
+	info, err := m.Info()
+	if err != nil {
+		return ExtendedMapInfo{}, fmt.Errorf("failed to retrieve map info: %w", err)
+	}
+
+	memlock, err := ParseMemlockFromFDInfo(m.FD())
+	if err != nil {
+		return ExtendedMapInfo{}, fmt.Errorf("failed to parse memlock from fd (%d) info: %w", m.FD(), err)
+	}
+	return ExtendedMapInfo{
+		MapInfo: *info,
+		Memlock: memlock,
+	}, nil
+}
+
+func MemlockInfoFromMapID(id int) (ExtendedMapInfo, error) {
+	m, err := ebpf.NewMapFromID(ebpf.MapID(id))
+	if err != nil {
+		return ExtendedMapInfo{}, fmt.Errorf("failed creating a map FD from ID: %w", err)
+	}
+	defer m.Close()
+	memlock, err := ParseMemlockFromFDInfo(m.FD())
+	if err != nil {
+		return ExtendedMapInfo{}, fmt.Errorf("failed parsing fdinfo for memlock: %w", err)
+	}
+	info, err := m.Info()
+	if err != nil {
+		return ExtendedMapInfo{}, fmt.Errorf("failed retrieving info from map: %w", err)
+	}
+
+	return ExtendedMapInfo{
+		MapInfo: *info,
+		Memlock: memlock,
+	}, nil
+}
+
+func ParseMemlockFromFDInfo(fd int) (int, error) {
+	path := fmt.Sprintf("/proc/self/fdinfo/%d", fd)
+	file, err := os.Open(path)
+	if err != nil {
+		return 0, fmt.Errorf("failed to open file %q: %w", path, err)
+	}
+	defer file.Close()
+	return parseMemlockFromFDInfoReader(file)
+}
+
+func parseMemlockFromFDInfoReader(r io.Reader) (int, error) {
+	scanner := bufio.NewScanner(r)
+	for scanner.Scan() {
+		fields := strings.Fields(scanner.Text())
+		if len(fields) > 1 && fields[0] == "memlock:" {
+			memlock, err := strconv.Atoi(fields[1])
+			if err != nil {
+				return 0, fmt.Errorf("failed converting memlock to int: %w", err)
+			}
+			return memlock, nil
+		}
+	}
+	if err := scanner.Err(); err != nil {
+		return 0, fmt.Errorf("failed to scan: %w", err)
+	}
+	return 0, fmt.Errorf("didn't find memlock field")
+}
diff --git a/pkg/bugtool/maps_test.go → pkg/bpf/maps_test.go b/pkg/bugtool/maps_test.go → pkg/bpf/maps_test.go
@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: Apache-2.0
 // Copyright Authors of Tetragon
 
-package bugtool
+package bpf
 
 import (
 	"io"

diff --git a/pkg/bugtool/maps.go b/pkg/bugtool/maps.go
@@ -4,29 +4,21 @@
 package bugtool
 
 import (
-	"bufio"
 	"errors"
 	"fmt"
-	"io"
 	"io/fs"
 	"os"
 	"path/filepath"
 	"sort"
-	"strconv"
-	"strings"
 	"syscall"
 
 	"github.com/cilium/ebpf"
+	"github.com/cilium/tetragon/pkg/bpf"
 	"golang.org/x/exp/maps"
 )
 
-type ExtendedMapInfo struct {
-	ebpf.MapInfo
-	Memlock int
-}
-
 // TotalMemlockBytes iterates over the extend map info and sums the memlock field.
-func TotalMemlockBytes(infos []ExtendedMapInfo) int {
+func TotalMemlockBytes(infos []bpf.ExtendedMapInfo) int {
 	var sum int
 	for _, info := range infos {
 		sum += info.Memlock
@@ -37,14 +29,14 @@ func TotalMemlockBytes(infos []ExtendedMapInfo) int {
 // FindMapsUsedByPinnedProgs returns all info of maps used by the prog pinned
 // under the path specified as argument. It also retrieve all the maps
 // referenced in progs referenced in program array maps (tail calls).
-func FindMapsUsedByPinnedProgs(path string) ([]ExtendedMapInfo, error) {
+func FindMapsUsedByPinnedProgs(path string) ([]bpf.ExtendedMapInfo, error) {
 	mapIDs, err := mapIDsFromPinnedProgs(path)
 	if err != nil {
 		return nil, fmt.Errorf("failed retrieving map IDs: %w", err)
 	}
-	mapInfos := []ExtendedMapInfo{}
+	mapInfos := []bpf.ExtendedMapInfo{}
 	for _, mapID := range mapIDs {
-		memlockInfo, err := memlockInfoFromMapID(mapID)
+		memlockInfo, err := bpf.ExtendedInfoFromMapID(mapID)
 		if err != nil {
 			return nil, fmt.Errorf("failed retrieving map memlock from ID: %w", err)
 		}
@@ -55,10 +47,10 @@ func FindMapsUsedByPinnedProgs(path string) ([]ExtendedMapInfo, error) {
 
 // FindAllMaps iterates over all maps loaded on the host using MapGetNextID and
 // parses fdinfo to look for memlock.
-func FindAllMaps() ([]ExtendedMapInfo, error) {
+func FindAllMaps() ([]bpf.ExtendedMapInfo, error) {
 	var mapID ebpf.MapID
 	var err error
-	mapInfos := []ExtendedMapInfo{}
+	mapInfos := []bpf.ExtendedMapInfo{}
 
 	for {
 		mapID, err = ebpf.MapGetNextID(mapID)
@@ -79,12 +71,12 @@ func FindAllMaps() ([]ExtendedMapInfo, error) {
 			return nil, fmt.Errorf("failed to retrieve map info: %w", err)
 		}
 
-		memlock, err := parseMemlockFromFDInfo(m.FD())
+		memlock, err := bpf.ParseMemlockFromFDInfo(m.FD())
 		if err != nil {
 			return nil, fmt.Errorf("failed parsing fdinfo to retrieve memlock: %w", err)
 		}
 
-		mapInfos = append(mapInfos, ExtendedMapInfo{
+		mapInfos = append(mapInfos, bpf.ExtendedMapInfo{
 			MapInfo: *info,
 			Memlock: memlock,
 		})
@@ -93,8 +85,8 @@ func FindAllMaps() ([]ExtendedMapInfo, error) {
 
 // FindPinnedMaps returns all info of maps pinned under the path
 // specified as argument.
-func FindPinnedMaps(path string) ([]ExtendedMapInfo, error) {
-	var infos []ExtendedMapInfo
+func FindPinnedMaps(path string) ([]bpf.ExtendedMapInfo, error) {
+	var infos []bpf.ExtendedMapInfo
 	err := filepath.WalkDir(path, func(path string, d fs.DirEntry, _ error) error {
 		if d.IsDir() {
 			return nil // skip directories
@@ -116,20 +108,11 @@ func FindPinnedMaps(path string) ([]ExtendedMapInfo, error) {
 			return nil // skip non map
 		}
 
-		info, err := m.Info()
-		if err != nil {
-			return fmt.Errorf("failed to retrieve map info: %w", err)
-		}
-
-		memlock, err := parseMemlockFromFDInfo(m.FD())
+		xInfo, err := bpf.ExtendedInfoFromMap(m)
 		if err != nil {
-			return fmt.Errorf("failed to parse memlock from fd (%d) info: %w", m.FD(), err)
+			return fmt.Errorf("failed to retrieve extended info from map %v: %w", m, err)
 		}
-
-		infos = append(infos, ExtendedMapInfo{
-			MapInfo: *info,
-			Memlock: memlock,
-		})
+		infos = append(infos, xInfo)
 		return nil
 	})
 	if err != nil {
@@ -257,55 +240,6 @@ func mapIDsFromPinnedProgs(path string) ([]int, error) {
 	return maps.Keys(mapSet), nil
 }
 
-func memlockInfoFromMapID(id int) (ExtendedMapInfo, error) {
-	m, err := ebpf.NewMapFromID(ebpf.MapID(id))
-	if err != nil {
-		return ExtendedMapInfo{}, fmt.Errorf("failed creating a map FD from ID: %w", err)
-	}
-	defer m.Close()
-	memlock, err := parseMemlockFromFDInfo(m.FD())
-	if err != nil {
-		return ExtendedMapInfo{}, fmt.Errorf("failed parsing fdinfo for memlock: %w", err)
-	}
-	info, err := m.Info()
-	if err != nil {
-		return ExtendedMapInfo{}, fmt.Errorf("failed retrieving info from map: %w", err)
-	}
-
-	return ExtendedMapInfo{
-		MapInfo: *info,
-		Memlock: memlock,
-	}, nil
-}
-
-func parseMemlockFromFDInfo(fd int) (int, error) {
-	path := fmt.Sprintf("/proc/self/fdinfo/%d", fd)
-	file, err := os.Open(path)
-	if err != nil {
-		return 0, fmt.Errorf("failed to open file %q: %w", path, err)
-	}
-	defer file.Close()
-	return parseMemlockFromFDInfoReader(file)
-}
-
-func parseMemlockFromFDInfoReader(r io.Reader) (int, error) {
-	scanner := bufio.NewScanner(r)
-	for scanner.Scan() {
-		fields := strings.Fields(scanner.Text())
-		if len(fields) > 1 && fields[0] == "memlock:" {
-			memlock, err := strconv.Atoi(fields[1])
-			if err != nil {
-				return 0, fmt.Errorf("failed converting memlock to int: %w", err)
-			}
-			return memlock, nil
-		}
-	}
-	if err := scanner.Err(); err != nil {
-		return 0, fmt.Errorf("failed to scan: %w", err)
-	}
-	return 0, fmt.Errorf("didn't find memlock field")
-}
-
 func isProg(fd int) (bool, error) {
 	return isBPFObject("prog", fd)
 }
@@ -395,7 +329,7 @@ func RunMapsChecks(path string) (*MapsChecksOutput, error) {
 	out.TotalMemlockBytes.PinnedMaps = TotalMemlockBytes(pinnedMaps)
 
 	// details on map distribution
-	pinnedProgsMapsSet := map[int]ExtendedMapInfo{}
+	pinnedProgsMapsSet := map[int]bpf.ExtendedMapInfo{}
 	for _, info := range pinnedProgsMaps {
 		id, ok := info.ID()
 		if !ok {
@@ -404,7 +338,7 @@ func RunMapsChecks(path string) (*MapsChecksOutput, error) {
 		pinnedProgsMapsSet[int(id)] = info
 	}
 
-	pinnedMapsSet := map[int]ExtendedMapInfo{}
+	pinnedMapsSet := map[int]bpf.ExtendedMapInfo{}
 	for _, info := range pinnedMaps {
 		id, ok := info.ID()
 		if !ok {
@@ -442,7 +376,7 @@ func RunMapsChecks(path string) (*MapsChecksOutput, error) {
 
 	// aggregates maps total memory use
 	aggregatedMapsSet := map[string]struct {
-		ExtendedMapInfo
+		bpf.ExtendedMapInfo
 		count int
 	}{}
 	var total int
@@ -454,7 +388,7 @@ func RunMapsChecks(path string) (*MapsChecksOutput, error) {
 			aggregatedMapsSet[m.Name] = e
 		} else {
 			aggregatedMapsSet[m.Name] = struct {
-				ExtendedMapInfo
+				bpf.ExtendedMapInfo
 				count int
 			}{m, 1}
 		}