sysinfo: hugepages: more validation checks

add more validations when checking for hugepages, reducing the chance to read random junk in the system. Signed-off-by: Francesco Romani <[email protected]>
k8stopologyawareschedwg · Dec 11, 2023 · 537a43d · 537a43d
1 parent e2a1d06
commit 537a43d
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Showing 3 changed files with 14 additions and 28 deletions.
diff --git a/pkg/sysinfo/hugepages.go b/pkg/sysinfo/hugepages.go
@@ -21,6 +21,8 @@ import (
 	"strconv"
 	"strings"
 
+	"k8s.io/klog/v2"
+
 	"k8s.io/apimachinery/pkg/api/resource"
 )
 
@@ -70,14 +72,18 @@ func HugepagesForNode(hnd Handle, nodeID int) ([]Hugepages, error) {
 	}
 	for _, entry := range entries {
 		entryName := entry.Name()
-		entryPath := filepath.Join(hpPath, entryName)
+		if !entry.IsDir() {
+			klog.Warningf("unexpected entry in %q: %q - skipped", hpPath, entryName)
+			continue
+		}
 
 		var hugepageSizeKB int
 		if n, err := fmt.Sscanf(entryName, "hugepages-%dkB", &hugepageSizeKB); n != 1 || err != nil {
 			return hugepages, fmt.Errorf("malformed hugepages entry %q", entryName)
 		}
 
-		totalCount, err := readIntFromFile(filepath.Join(entryPath, "nr_hugepages"))
+		entryPath := filepath.Join(hpPath, entryName)
+		hpCountPath, err := filepath.EvalSymlinks(filepath.Join(entryPath, "nr_hugepages"))
 		if err != nil {
 			return hugepages, fmt.Errorf("cannot clean %q: %w", entryPath, err)
 		}

diff --git a/pkg/sysinfo/hugepages_test.go b/pkg/sysinfo/hugepages_test.go
@@ -65,7 +65,7 @@ func TestHugepagesForNode(t *testing.T) {
 	}
 	defer os.RemoveAll(rootDir) // clean up
 
-	if err := makeTree(rootDir, 2); err != nil {
+	if err := makeMemoryTree(rootDir, 2); err != nil {
 		t.Errorf("failed to setup the fake tree on %q: %v", rootDir, err)
 	}
 	if err := setHPCount(rootDir, 0, HugepageSize2Mi, 6); err != nil {
@@ -92,34 +92,14 @@ func TestHugepagesForNode(t *testing.T) {
 	if len(hpCounters["hugepages-1Gi"]) != 2 {
 		t.Errorf("found unexpected 1Gi hugepages")
 	}
-	if hpCounters["hugepages-1Gi"][0] != 0 {
+	if hpCounters["hugepages-1Gi"][0] != 17179869184 { // from makeMemoryTree builtin
 		t.Errorf("found unexpected 1Gi hugepages for node 0: %v", hpCounters["hugepages-1Gi"][0])
 	}
-	if hpCounters["hugepages-1Gi"][1] != 0 {
+	if hpCounters["hugepages-1Gi"][1] != 17179869184 { // from makeMemoryTree builtin
 		t.Errorf("found unexpected 1Gi hugepages for node 1: %v", hpCounters["hugepages-1Gi"][1])
 	}
 }
 
-func makeTree(root string, numNodes int) error {
-	hnd := Handle{root}
-	for idx := 0; idx < numNodes; idx++ {
-		for _, size := range []int{HugepageSize2Mi, HugepageSize1Gi} {
-			path := filepath.Join(
-				hnd.SysDevicesNodesNodeNth(idx),
-				"hugepages",
-				fmt.Sprintf("hugepages-%dkB", size),
-			)
-			if err := os.MkdirAll(path, 0755); err != nil {
-				return err
-			}
-			if err := setHPCount(root, idx, size, 0); err != nil {
-				return err
-			}
-		}
-	}
-	return nil
-}
-
 func setHPCount(root string, nodeID, pageSize, numPages int) error {
 	hnd := Handle{root}
 	path := filepath.Join(

diff --git a/pkg/sysinfo/memory_test.go b/pkg/sysinfo/memory_test.go
@@ -13,6 +13,7 @@ limitations under the License.
 package sysinfo
 
 import (
+	"fmt"
 	"os"
 	"path/filepath"
 	"testing"
@@ -91,12 +92,11 @@ func makeMemoryTree(root string, numNodes int) error {
 			return err
 		}
 
-		hpPathSizes := []string{"hugepages-1048576kB", "hugepages-2048kB"}
-		for _, hpPathSize := range hpPathSizes {
+		for _, size := range []int{HugepageSize2Mi, HugepageSize1Gi} {
 			hpPath := filepath.Join(
 				hnd.SysDevicesNodesNodeNth(idx),
 				"hugepages",
-				hpPathSize,
+				fmt.Sprintf("hugepages-%dkB", size),
 			)
 			if err := os.MkdirAll(hpPath, 0755); err != nil {
 				return err