Combine file mode and isDir arguments

Updates #1035

PiperOrigin-RevId: 303021328

2 files changed, 17 insertions, 15 deletions

diff --git a/pkg/sentry/fsimpl/tmpfs/filesystem.go b/pkg/sentry/fsimpl/tmpfs/filesystem.go
index 75d01b853..12cc64385 100644
--- a/pkg/sentry/fsimpl/tmpfs/filesystem.go
+++ b/pkg/sentry/fsimpl/tmpfs/filesystem.go
@@ -41,7 +41,7 @@ func stepLocked(rp *vfs.ResolvingPath, d *dentry) (*dentry, error) {
 	if !d.inode.isDir() {
 		return nil, syserror.ENOTDIR
 	}
-	if err := d.inode.checkPermissions(rp.Credentials(), vfs.MayExec, true); err != nil {
+	if err := d.inode.checkPermissions(rp.Credentials(), vfs.MayExec); err != nil {
 		return nil, err
 	}
 afterSymlink:
@@ -125,7 +125,7 @@ func (fs *filesystem) doCreateAt(rp *vfs.ResolvingPath, dir bool, create func(pa
 	if err != nil {
 		return err
 	}
-	if err := parent.inode.checkPermissions(rp.Credentials(), vfs.MayWrite|vfs.MayExec, true /* isDir */); err != nil {
+	if err := parent.inode.checkPermissions(rp.Credentials(), vfs.MayWrite|vfs.MayExec); err != nil {
 		return err
 	}
 	name := rp.Component()
@@ -163,7 +163,7 @@ func (fs *filesystem) AccessAt(ctx context.Context, rp *vfs.ResolvingPath, creds
 	if err != nil {
 		return err
 	}
-	return d.inode.checkPermissions(creds, ats, d.inode.isDir())
+	return d.inode.checkPermissions(creds, ats)
 }
 
 // GetDentryAt implements vfs.FilesystemImpl.GetDentryAt.
@@ -178,7 +178,7 @@ func (fs *filesystem) GetDentryAt(ctx context.Context, rp *vfs.ResolvingPath, op
 		if !d.inode.isDir() {
 			return nil, syserror.ENOTDIR
 		}
-		if err := d.inode.checkPermissions(rp.Credentials(), vfs.MayExec, true /* isDir */); err != nil {
+		if err := d.inode.checkPermissions(rp.Credentials(), vfs.MayExec); err != nil {
 			return nil, err
 		}
 	}
@@ -301,7 +301,7 @@ afterTrailingSymlink:
 		return nil, err
 	}
 	// Check for search permission in the parent directory.
-	if err := parent.inode.checkPermissions(rp.Credentials(), vfs.MayExec, true); err != nil {
+	if err := parent.inode.checkPermissions(rp.Credentials(), vfs.MayExec); err != nil {
 		return nil, err
 	}
 	// Reject attempts to open directories with O_CREAT.
@@ -316,7 +316,7 @@ afterTrailingSymlink:
 	child, err := stepLocked(rp, parent)
 	if err == syserror.ENOENT {
 		// Already checked for searchability above; now check for writability.
-		if err := parent.inode.checkPermissions(rp.Credentials(), vfs.MayWrite, true); err != nil {
+		if err := parent.inode.checkPermissions(rp.Credentials(), vfs.MayWrite); err != nil {
 			return nil, err
 		}
 		if err := rp.Mount().CheckBeginWrite(); err != nil {
@@ -347,7 +347,7 @@ afterTrailingSymlink:
 func (d *dentry) open(ctx context.Context, rp *vfs.ResolvingPath, opts *vfs.OpenOptions, afterCreate bool) (*vfs.FileDescription, error) {
 	ats := vfs.AccessTypesForOpenFlags(opts)
 	if !afterCreate {
-		if err := d.inode.checkPermissions(rp.Credentials(), ats, d.inode.isDir()); err != nil {
+		if err := d.inode.checkPermissions(rp.Credentials(), ats); err != nil {
 			return nil, err
 		}
 	}
@@ -428,7 +428,7 @@ func (fs *filesystem) RenameAt(ctx context.Context, rp *vfs.ResolvingPath, oldPa
 	defer mnt.EndWrite()
 
 	oldParent := oldParentVD.Dentry().Impl().(*dentry)
-	if err := oldParent.inode.checkPermissions(rp.Credentials(), vfs.MayWrite|vfs.MayExec, true /* isDir */); err != nil {
+	if err := oldParent.inode.checkPermissions(rp.Credentials(), vfs.MayWrite|vfs.MayExec); err != nil {
 		return err
 	}
 	// Call vfs.Dentry.Child() instead of stepLocked() or rp.ResolveChild(),
@@ -445,7 +445,7 @@ func (fs *filesystem) RenameAt(ctx context.Context, rp *vfs.ResolvingPath, oldPa
 		}
 		if oldParent != newParent {
 			// Writability is needed to change renamed's "..".
-			if err := renamed.inode.checkPermissions(rp.Credentials(), vfs.MayWrite, true /* isDir */); err != nil {
+			if err := renamed.inode.checkPermissions(rp.Credentials(), vfs.MayWrite); err != nil {
 				return err
 			}
 		}
@@ -455,7 +455,7 @@ func (fs *filesystem) RenameAt(ctx context.Context, rp *vfs.ResolvingPath, oldPa
 		}
 	}
 
-	if err := newParent.inode.checkPermissions(rp.Credentials(), vfs.MayWrite|vfs.MayExec, true /* isDir */); err != nil {
+	if err := newParent.inode.checkPermissions(rp.Credentials(), vfs.MayWrite|vfs.MayExec); err != nil {
 		return err
 	}
 	replacedVFSD := newParent.vfsd.Child(newName)
@@ -528,7 +528,7 @@ func (fs *filesystem) RmdirAt(ctx context.Context, rp *vfs.ResolvingPath) error
 	if err != nil {
 		return err
 	}
-	if err := parent.inode.checkPermissions(rp.Credentials(), vfs.MayWrite|vfs.MayExec, true /* isDir */); err != nil {
+	if err := parent.inode.checkPermissions(rp.Credentials(), vfs.MayWrite|vfs.MayExec); err != nil {
 		return err
 	}
 	name := rp.Component()
@@ -621,7 +621,7 @@ func (fs *filesystem) UnlinkAt(ctx context.Context, rp *vfs.ResolvingPath) error
 	if err != nil {
 		return err
 	}
-	if err := parent.inode.checkPermissions(rp.Credentials(), vfs.MayWrite|vfs.MayExec, true /* isDir */); err != nil {
+	if err := parent.inode.checkPermissions(rp.Credentials(), vfs.MayWrite|vfs.MayExec); err != nil {
 		return err
 	}
 	name := rp.Component()
diff --git a/pkg/sentry/fsimpl/tmpfs/tmpfs.go b/pkg/sentry/fsimpl/tmpfs/tmpfs.go
index 2d5070a46..2f9e6c876 100644
--- a/pkg/sentry/fsimpl/tmpfs/tmpfs.go
+++ b/pkg/sentry/fsimpl/tmpfs/tmpfs.go
@@ -245,8 +245,9 @@ func (i *inode) decRef() {
 	}
 }
 
-func (i *inode) checkPermissions(creds *auth.Credentials, ats vfs.AccessTypes, isDir bool) error {
-	return vfs.GenericCheckPermissions(creds, ats, isDir, uint16(atomic.LoadUint32(&i.mode)), auth.KUID(atomic.LoadUint32(&i.uid)), auth.KGID(atomic.LoadUint32(&i.gid)))
+func (i *inode) checkPermissions(creds *auth.Credentials, ats vfs.AccessTypes) error {
+	mode := linux.FileMode(atomic.LoadUint32(&i.mode))
+	return vfs.GenericCheckPermissions(creds, ats, mode, auth.KUID(atomic.LoadUint32(&i.uid)), auth.KGID(atomic.LoadUint32(&i.gid)))
 }
 
 // Go won't inline this function, and returning linux.Statx (which is quite
@@ -299,7 +300,8 @@ func (i *inode) setStat(ctx context.Context, creds *auth.Credentials, stat *linu
 	if stat.Mask&^(linux.STATX_MODE|linux.STATX_UID|linux.STATX_GID|linux.STATX_ATIME|linux.STATX_MTIME|linux.STATX_CTIME|linux.STATX_SIZE) != 0 {
 		return syserror.EPERM
 	}
-	if err := vfs.CheckSetStat(ctx, creds, stat, uint16(atomic.LoadUint32(&i.mode))&^linux.S_IFMT, auth.KUID(atomic.LoadUint32(&i.uid)), auth.KGID(atomic.LoadUint32(&i.gid))); err != nil {
+	mode := linux.FileMode(atomic.LoadUint32(&i.mode))
+	if err := vfs.CheckSetStat(ctx, creds, stat, mode, auth.KUID(atomic.LoadUint32(&i.uid)), auth.KGID(atomic.LoadUint32(&i.gid))); err != nil {
 		return err
 	}
 	i.mu.Lock()