test: add function to test processes memory pages reading features

This commit introduces a new function `readMemoryPages` that reads
the process arguments and environment variables from memory pages
and compares them with the `environ` and `cmdline` files of the process.

Signed-off-by: Kouame Behouba Manasse <[email protected]>

test/crit/Makefile

@@ -16,6 +16,8 @@ test-imgs: ../loop/loop
 	mkdir -p $@
 	$(CRIU) dump -v4 -o dump.log -D $@ -t $(PID)
 	$(CRIU) restore -v4 -o restore.log -D $@ -d
+	cp /proc/${PID}/environ $@
+	cp /proc/${PID}/cmdline $@
 	pkill -9 loop
 
 ../../crit/bin/crit:

test/crit/main.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"errors"
 	"fmt"
+	"io/ioutil"
 	"log"
 	"os"
 	"path/filepath"
@@ -12,6 +13,7 @@ import (
 
 	"github.com/checkpoint-restore/go-criu/v6/crit"
 	"github.com/checkpoint-restore/go-criu/v6/crit/cli"
+	"github.com/checkpoint-restore/go-criu/v6/crit/images/pstree"
 )
 
 const testImgDir = "test-imgs"
@@ -26,6 +28,11 @@ func main() {
 	if err = recodeImgs(imgs); err != nil {
 		log.Fatal(err)
 	}
+
+	// Run test for memory pages reading features
+	if err = readMemoryPages(); err != nil {
+		log.Fatal(err)
+	}
 	log.Println("=== PASS")
 }
 
@@ -124,3 +131,61 @@ nextFile:
 
 	return imgs, nil
 }
+
+// readMemoryPages reads and compares process arguments
+// and environment variables from memory pages and corresponding test files.
+func readMemoryPages() error {
+	psTreeFile, err := os.Open(filepath.Join(testImgDir, "pstree.img"))
+	if err != nil {
+		return err
+	}
+	defer psTreeFile.Close()
+
+	c := crit.New(psTreeFile, nil, testImgDir, false, true)
+
+	psTreeImg, err := c.Decode(&pstree.PstreeEntry{})
+	if err != nil {
+		return err
+	}
+
+	pid := psTreeImg.Entries[0].Message.(*pstree.PstreeEntry).GetPid()
+
+	mr, err := crit.NewMemoryReader(testImgDir, pid, os.Getpagesize())
+	if err != nil {
+		return err
+	}
+
+	// Retrieve process arguments from memory pages
+	argsBuff, err := mr.GetPsArgs()
+	if err != nil {
+		return err
+	}
+
+	// Read process environment variables from the environ test file
+	testFileArgs, err := ioutil.ReadFile(filepath.Join(testImgDir, "cmdline"))
+	if err != nil {
+		return err
+	}
+
+	if !bytes.Equal(testFileArgs, argsBuff.Bytes()) {
+		return errors.New("process arguments do not match")
+	}
+
+	// Retrieve process environment variables from memory pages
+	envVarsBuffer, err := mr.GetPsEnvVars()
+	if err != nil {
+		return err
+	}
+
+	// Read process environment variables from the environ test file
+	envVarsTestFile, err := ioutil.ReadFile(filepath.Join(testImgDir, "environ"))
+	if err != nil {
+		return err
+	}
+
+	if !bytes.Equal(envVarsTestFile, envVarsBuffer.Bytes()) {
+		return errors.New("process environment variables do not match")
+	}
+
+	return nil
+}