1 files changed, 27 insertions, 105 deletions
diff --git a/pkg/sentry/control/proc.go b/pkg/sentry/control/proc.go
index 2ed17ee09..dfa936563 100644
--- a/pkg/sentry/control/proc.go
+++ b/pkg/sentry/control/proc.go
@@ -18,7 +18,6 @@ import (
 	"bytes"
 	"encoding/json"
 	"fmt"
-	"path"
 	"sort"
 	"strings"
 	"text/tabwriter"
@@ -26,13 +25,10 @@ import (
 
 	"golang.org/x/sys/unix"
 	"gvisor.dev/gvisor/pkg/abi/linux"
-	"gvisor.dev/gvisor/pkg/context"
-	"gvisor.dev/gvisor/pkg/fspath"
-	"gvisor.dev/gvisor/pkg/log"
 	"gvisor.dev/gvisor/pkg/sentry/fdimport"
 	"gvisor.dev/gvisor/pkg/sentry/fs"
 	"gvisor.dev/gvisor/pkg/sentry/fs/host"
-	"gvisor.dev/gvisor/pkg/sentry/fsbridge"
+	"gvisor.dev/gvisor/pkg/sentry/fs/user"
 	hostvfs2 "gvisor.dev/gvisor/pkg/sentry/fsimpl/host"
 	"gvisor.dev/gvisor/pkg/sentry/kernel"
 	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
@@ -40,7 +36,6 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/limits"
 	"gvisor.dev/gvisor/pkg/sentry/usage"
 	"gvisor.dev/gvisor/pkg/sentry/vfs"
-	"gvisor.dev/gvisor/pkg/syserror"
 	"gvisor.dev/gvisor/pkg/urpc"
 )
 
@@ -108,6 +103,9 @@ type ExecArgs struct {
 
 // String prints the arguments as a string.
 func (args ExecArgs) String() string {
+	if len(args.Argv) == 0 {
+		return args.Filename
+	}
 	a := make([]string, len(args.Argv))
 	copy(a, args.Argv)
 	if args.Filename != "" {
@@ -141,7 +139,6 @@ func ExecAsync(proc *Proc, args *ExecArgs) (*kernel.ThreadGroup, kernel.ThreadID
 func (proc *Proc) execAsync(args *ExecArgs) (*kernel.ThreadGroup, kernel.ThreadID, *host.TTYFileOperations, *hostvfs2.TTYFileDescription, error) {
 	// Import file descriptors.
 	fdTable := proc.Kernel.NewFDTable()
-	defer fdTable.DecRef()
 
 	creds := auth.NewUserCredentials(
 		args.KUID,
@@ -179,43 +176,32 @@ func (proc *Proc) execAsync(args *ExecArgs) (*kernel.ThreadGroup, kernel.ThreadI
 		initArgs.MountNamespaceVFS2.IncRef()
 	}
 	ctx := initArgs.NewContext(proc.Kernel)
+	defer fdTable.DecRef(ctx)
+
+	if kernel.VFS2Enabled {
+		// Get the full path to the filename from the PATH env variable.
+		if initArgs.MountNamespaceVFS2 == nil {
+			// Set initArgs so that 'ctx' returns the namespace.
+			//
+			// MountNamespaceVFS2 adds a reference to the namespace, which is
+			// transferred to the new process.
+			initArgs.MountNamespaceVFS2 = proc.Kernel.GlobalInit().Leader().MountNamespaceVFS2()
+		}
+	} else {
+		if initArgs.MountNamespace == nil {
+			// Set initArgs so that 'ctx' returns the namespace.
+			initArgs.MountNamespace = proc.Kernel.GlobalInit().Leader().MountNamespace()
 
-	if initArgs.Filename == "" {
-		if kernel.VFS2Enabled {
-			// Get the full path to the filename from the PATH env variable.
-			if initArgs.MountNamespaceVFS2 == nil {
-				// Set initArgs so that 'ctx' returns the namespace.
-				//
-				// MountNamespaceVFS2 adds a reference to the namespace, which is
-				// transferred to the new process.
-				initArgs.MountNamespaceVFS2 = proc.Kernel.GlobalInit().Leader().MountNamespaceVFS2()
-			}
-
-			paths := fs.GetPath(initArgs.Envv)
-			vfsObj := proc.Kernel.VFS()
-			file, err := ResolveExecutablePath(ctx, vfsObj, initArgs.WorkingDirectory, initArgs.Argv[0], paths)
-			if err != nil {
-				return nil, 0, nil, nil, fmt.Errorf("error finding executable %q in PATH %v: %v", initArgs.Argv[0], paths, err)
-			}
-			initArgs.File = fsbridge.NewVFSFile(file)
-		} else {
-			// Get the full path to the filename from the PATH env variable.
-			paths := fs.GetPath(initArgs.Envv)
-			if initArgs.MountNamespace == nil {
-				// Set initArgs so that 'ctx' returns the namespace.
-				initArgs.MountNamespace = proc.Kernel.GlobalInit().Leader().MountNamespace()
-
-				// initArgs must hold a reference on MountNamespace, which will
-				// be donated to the new process in CreateProcess.
-				initArgs.MountNamespace.IncRef()
-			}
-			f, err := initArgs.MountNamespace.ResolveExecutablePath(ctx, initArgs.WorkingDirectory, initArgs.Argv[0], paths)
-			if err != nil {
-				return nil, 0, nil, nil, fmt.Errorf("error finding executable %q in PATH %v: %v", initArgs.Argv[0], paths, err)
-			}
-			initArgs.Filename = f
+			// initArgs must hold a reference on MountNamespace, which will
+			// be donated to the new process in CreateProcess.
+			initArgs.MountNamespace.IncRef()
 		}
 	}
+	resolved, err := user.ResolveExecutablePath(ctx, &initArgs)
+	if err != nil {
+		return nil, 0, nil, nil, err
+	}
+	initArgs.Filename = resolved
 
 	fds := make([]int, len(args.FilePayload.Files))
 	for i, file := range args.FilePayload.Files {
@@ -428,67 +414,3 @@ func ttyName(tty *kernel.TTY) string {
 	}
 	return fmt.Sprintf("pts/%d", tty.Index)
 }
-
-// ResolveExecutablePath resolves the given executable name given a set of
-// paths that might contain it.
-func ResolveExecutablePath(ctx context.Context, vfsObj *vfs.VirtualFilesystem, wd, name string, paths []string) (*vfs.FileDescription, error) {
-	root := vfs.RootFromContext(ctx)
-	defer root.DecRef()
-	creds := auth.CredentialsFromContext(ctx)
-
-	// Absolute paths can be used directly.
-	if path.IsAbs(name) {
-		return openExecutable(ctx, vfsObj, creds, root, name)
-	}
-
-	// Paths with '/' in them should be joined to the working directory, or
-	// to the root if working directory is not set.
-	if strings.IndexByte(name, '/') > 0 {
-		if len(wd) == 0 {
-			wd = "/"
-		}
-		if !path.IsAbs(wd) {
-			return nil, fmt.Errorf("working directory %q must be absolute", wd)
-		}
-		return openExecutable(ctx, vfsObj, creds, root, path.Join(wd, name))
-	}
-
-	// Otherwise, we must lookup the name in the paths, starting from the
-	// calling context's root directory.
-	for _, p := range paths {
-		if !path.IsAbs(p) {
-			// Relative paths aren't safe, no one should be using them.
-			log.Warningf("Skipping relative path %q in $PATH", p)
-			continue
-		}
-
-		binPath := path.Join(p, name)
-		f, err := openExecutable(ctx, vfsObj, creds, root, binPath)
-		if err != nil {
-			return nil, err
-		}
-		if f == nil {
-			continue // Not found/no access.
-		}
-		return f, nil
-	}
-	return nil, syserror.ENOENT
-}
-
-func openExecutable(ctx context.Context, vfsObj *vfs.VirtualFilesystem, creds *auth.Credentials, root vfs.VirtualDentry, path string) (*vfs.FileDescription, error) {
-	pop := vfs.PathOperation{
-		Root:               root,
-		Start:              root, // binPath is absolute, Start can be anything.
-		Path:               fspath.Parse(path),
-		FollowFinalSymlink: true,
-	}
-	opts := &vfs.OpenOptions{
-		Flags:    linux.O_RDONLY,
-		FileExec: true,
-	}
-	f, err := vfsObj.OpenAt(ctx, creds, &pop, opts)
-	if err == syserror.ENOENT || err == syserror.EACCES {
-		return nil, nil
-	}
-	return f, err
-}