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-rw-r--r--pkg/p9/client_file.go23
-rw-r--r--pkg/p9/file.go16
-rw-r--r--pkg/p9/handlers.go29
-rw-r--r--pkg/p9/messages.go129
-rw-r--r--pkg/p9/messages_test.go15
-rw-r--r--pkg/p9/p9.go4
-rw-r--r--pkg/sentry/fs/copy_up.go9
-rw-r--r--pkg/sentry/fs/file_overlay.go2
-rw-r--r--pkg/sentry/fs/fsutil/inode.go41
-rw-r--r--pkg/sentry/fs/gofer/context_file.go14
-rw-r--r--pkg/sentry/fs/gofer/inode.go18
-rw-r--r--pkg/sentry/fs/inode.go24
-rw-r--r--pkg/sentry/fs/inode_operations.go25
-rw-r--r--pkg/sentry/fs/inode_overlay.go30
-rw-r--r--pkg/sentry/fs/inode_overlay_test.go4
-rw-r--r--pkg/sentry/fs/tmpfs/tmpfs.go18
-rw-r--r--pkg/sentry/syscalls/linux/linux64_amd64.go4
-rw-r--r--pkg/sentry/syscalls/linux/linux64_arm64.go4
-rw-r--r--pkg/sentry/syscalls/linux/sys_xattr.go48
19 files changed, 364 insertions, 93 deletions
diff --git a/pkg/p9/client_file.go b/pkg/p9/client_file.go
index de9357389..04b584383 100644
--- a/pkg/p9/client_file.go
+++ b/pkg/p9/client_file.go
@@ -165,6 +165,29 @@ func (c *clientFile) SetAttr(valid SetAttrMask, attr SetAttr) error {
return c.client.sendRecv(&Tsetattr{FID: c.fid, Valid: valid, SetAttr: attr}, &Rsetattr{})
}
+// GetXattr implements File.GetXattr.
+func (c *clientFile) GetXattr(name string, size uint64) (string, error) {
+ if atomic.LoadUint32(&c.closed) != 0 {
+ return "", syscall.EBADF
+ }
+
+ rgetxattr := Rgetxattr{}
+ if err := c.client.sendRecv(&Tgetxattr{FID: c.fid, Name: name, Size: size}, &rgetxattr); err != nil {
+ return "", err
+ }
+
+ return rgetxattr.Value, nil
+}
+
+// SetXattr implements File.SetXattr.
+func (c *clientFile) SetXattr(name, value string, flags uint32) error {
+ if atomic.LoadUint32(&c.closed) != 0 {
+ return syscall.EBADF
+ }
+
+ return c.client.sendRecv(&Tsetxattr{FID: c.fid, Name: name, Value: value, Flags: flags}, &Rsetxattr{})
+}
+
// Allocate implements File.Allocate.
func (c *clientFile) Allocate(mode AllocateMode, offset, length uint64) error {
if atomic.LoadUint32(&c.closed) != 0 {
diff --git a/pkg/p9/file.go b/pkg/p9/file.go
index 96d1f2a8e..4607cfcdf 100644
--- a/pkg/p9/file.go
+++ b/pkg/p9/file.go
@@ -89,6 +89,22 @@ type File interface {
// On the server, SetAttr has a write concurrency guarantee.
SetAttr(valid SetAttrMask, attr SetAttr) error
+ // GetXattr returns extended attributes of this node.
+ //
+ // Size indicates the size of the buffer that has been allocated to hold the
+ // attribute value. If the value is larger than size, implementations may
+ // return ERANGE to indicate that the buffer is too small, but they are also
+ // free to ignore the hint entirely (i.e. the value returned may be larger
+ // than size). All size checking is done independently at the syscall layer.
+ //
+ // TODO(b/127675828): Determine concurrency guarantees once implemented.
+ GetXattr(name string, size uint64) (string, error)
+
+ // SetXattr sets extended attributes on this node.
+ //
+ // TODO(b/127675828): Determine concurrency guarantees once implemented.
+ SetXattr(name, value string, flags uint32) error
+
// Allocate allows the caller to directly manipulate the allocated disk space
// for the file. See fallocate(2) for more details.
Allocate(mode AllocateMode, offset, length uint64) error
diff --git a/pkg/p9/handlers.go b/pkg/p9/handlers.go
index b9582c07f..7d6653a07 100644
--- a/pkg/p9/handlers.go
+++ b/pkg/p9/handlers.go
@@ -913,6 +913,35 @@ func (t *Txattrcreate) handle(cs *connState) message {
}
// handle implements handler.handle.
+func (t *Tgetxattr) handle(cs *connState) message {
+ ref, ok := cs.LookupFID(t.FID)
+ if !ok {
+ return newErr(syscall.EBADF)
+ }
+ defer ref.DecRef()
+
+ val, err := ref.file.GetXattr(t.Name, t.Size)
+ if err != nil {
+ return newErr(err)
+ }
+ return &Rgetxattr{Value: val}
+}
+
+// handle implements handler.handle.
+func (t *Tsetxattr) handle(cs *connState) message {
+ ref, ok := cs.LookupFID(t.FID)
+ if !ok {
+ return newErr(syscall.EBADF)
+ }
+ defer ref.DecRef()
+
+ if err := ref.file.SetXattr(t.Name, t.Value, t.Flags); err != nil {
+ return newErr(err)
+ }
+ return &Rsetxattr{}
+}
+
+// handle implements handler.handle.
func (t *Treaddir) handle(cs *connState) message {
ref, ok := cs.LookupFID(t.Directory)
if !ok {
diff --git a/pkg/p9/messages.go b/pkg/p9/messages.go
index ffdd7e8c6..ceb723d86 100644
--- a/pkg/p9/messages.go
+++ b/pkg/p9/messages.go
@@ -1611,6 +1611,131 @@ func (r *Rxattrcreate) String() string {
return fmt.Sprintf("Rxattrcreate{}")
}
+// Tgetxattr is a getxattr request.
+type Tgetxattr struct {
+ // FID refers to the file for which to get xattrs.
+ FID FID
+
+ // Name is the xattr to get.
+ Name string
+
+ // Size is the buffer size for the xattr to get.
+ Size uint64
+}
+
+// Decode implements encoder.Decode.
+func (t *Tgetxattr) Decode(b *buffer) {
+ t.FID = b.ReadFID()
+ t.Name = b.ReadString()
+ t.Size = b.Read64()
+}
+
+// Encode implements encoder.Encode.
+func (t *Tgetxattr) Encode(b *buffer) {
+ b.WriteFID(t.FID)
+ b.WriteString(t.Name)
+ b.Write64(t.Size)
+}
+
+// Type implements message.Type.
+func (*Tgetxattr) Type() MsgType {
+ return MsgTgetxattr
+}
+
+// String implements fmt.Stringer.
+func (t *Tgetxattr) String() string {
+ return fmt.Sprintf("Tgetxattr{FID: %d, Name: %s, Size: %d}", t.FID, t.Name, t.Size)
+}
+
+// Rgetxattr is a getxattr response.
+type Rgetxattr struct {
+ // Value is the extended attribute value.
+ Value string
+}
+
+// Decode implements encoder.Decode.
+func (r *Rgetxattr) Decode(b *buffer) {
+ r.Value = b.ReadString()
+}
+
+// Encode implements encoder.Encode.
+func (r *Rgetxattr) Encode(b *buffer) {
+ b.WriteString(r.Value)
+}
+
+// Type implements message.Type.
+func (*Rgetxattr) Type() MsgType {
+ return MsgRgetxattr
+}
+
+// String implements fmt.Stringer.
+func (r *Rgetxattr) String() string {
+ return fmt.Sprintf("Rgetxattr{Value: %s}", r.Value)
+}
+
+// Tsetxattr sets extended attributes.
+type Tsetxattr struct {
+ // FID refers to the file on which to set xattrs.
+ FID FID
+
+ // Name is the attribute name.
+ Name string
+
+ // Value is the attribute value.
+ Value string
+
+ // Linux setxattr(2) flags.
+ Flags uint32
+}
+
+// Decode implements encoder.Decode.
+func (t *Tsetxattr) Decode(b *buffer) {
+ t.FID = b.ReadFID()
+ t.Name = b.ReadString()
+ t.Value = b.ReadString()
+ t.Flags = b.Read32()
+}
+
+// Encode implements encoder.Encode.
+func (t *Tsetxattr) Encode(b *buffer) {
+ b.WriteFID(t.FID)
+ b.WriteString(t.Name)
+ b.WriteString(t.Value)
+ b.Write32(t.Flags)
+}
+
+// Type implements message.Type.
+func (*Tsetxattr) Type() MsgType {
+ return MsgTsetxattr
+}
+
+// String implements fmt.Stringer.
+func (t *Tsetxattr) String() string {
+ return fmt.Sprintf("Tsetxattr{FID: %d, Name: %s, Value: %s, Flags: %d}", t.FID, t.Name, t.Value, t.Flags)
+}
+
+// Rsetxattr is a setxattr response.
+type Rsetxattr struct {
+}
+
+// Decode implements encoder.Decode.
+func (r *Rsetxattr) Decode(b *buffer) {
+}
+
+// Encode implements encoder.Encode.
+func (r *Rsetxattr) Encode(b *buffer) {
+}
+
+// Type implements message.Type.
+func (*Rsetxattr) Type() MsgType {
+ return MsgRsetxattr
+}
+
+// String implements fmt.Stringer.
+func (r *Rsetxattr) String() string {
+ return fmt.Sprintf("Rsetxattr{}")
+}
+
// Treaddir is a readdir request.
type Treaddir struct {
// Directory is the directory FID to read.
@@ -2363,6 +2488,10 @@ func init() {
msgRegistry.register(MsgRxattrwalk, func() message { return &Rxattrwalk{} })
msgRegistry.register(MsgTxattrcreate, func() message { return &Txattrcreate{} })
msgRegistry.register(MsgRxattrcreate, func() message { return &Rxattrcreate{} })
+ msgRegistry.register(MsgTgetxattr, func() message { return &Tgetxattr{} })
+ msgRegistry.register(MsgRgetxattr, func() message { return &Rgetxattr{} })
+ msgRegistry.register(MsgTsetxattr, func() message { return &Tsetxattr{} })
+ msgRegistry.register(MsgRsetxattr, func() message { return &Rsetxattr{} })
msgRegistry.register(MsgTreaddir, func() message { return &Treaddir{} })
msgRegistry.register(MsgRreaddir, func() message { return &Rreaddir{} })
msgRegistry.register(MsgTfsync, func() message { return &Tfsync{} })
diff --git a/pkg/p9/messages_test.go b/pkg/p9/messages_test.go
index 6ba6a1654..825c939da 100644
--- a/pkg/p9/messages_test.go
+++ b/pkg/p9/messages_test.go
@@ -194,6 +194,21 @@ func TestEncodeDecode(t *testing.T) {
Flags: 3,
},
&Rxattrcreate{},
+ &Tgetxattr{
+ FID: 1,
+ Name: "abc",
+ Size: 2,
+ },
+ &Rgetxattr{
+ Value: "xyz",
+ },
+ &Tsetxattr{
+ FID: 1,
+ Name: "abc",
+ Value: "xyz",
+ Flags: 2,
+ },
+ &Rsetxattr{},
&Treaddir{
Directory: 1,
Offset: 2,
diff --git a/pkg/p9/p9.go b/pkg/p9/p9.go
index d3090535a..5ab00d625 100644
--- a/pkg/p9/p9.go
+++ b/pkg/p9/p9.go
@@ -339,6 +339,10 @@ const (
MsgRxattrwalk = 31
MsgTxattrcreate = 32
MsgRxattrcreate = 33
+ MsgTgetxattr = 34
+ MsgRgetxattr = 35
+ MsgTsetxattr = 36
+ MsgRsetxattr = 37
MsgTreaddir = 40
MsgRreaddir = 41
MsgTfsync = 50
diff --git a/pkg/sentry/fs/copy_up.go b/pkg/sentry/fs/copy_up.go
index 734177e90..e03e3e417 100644
--- a/pkg/sentry/fs/copy_up.go
+++ b/pkg/sentry/fs/copy_up.go
@@ -18,6 +18,7 @@ import (
"fmt"
"io"
+ "gvisor.dev/gvisor/pkg/abi/linux"
"gvisor.dev/gvisor/pkg/log"
"gvisor.dev/gvisor/pkg/sentry/context"
"gvisor.dev/gvisor/pkg/sentry/memmap"
@@ -395,12 +396,12 @@ func copyContentsLocked(ctx context.Context, upper *Inode, lower *Inode, size in
// Size and permissions are set on upper when the file content is copied
// and when the file is created respectively.
func copyAttributesLocked(ctx context.Context, upper *Inode, lower *Inode) error {
- // Extract attributes fro the lower filesystem.
+ // Extract attributes from the lower filesystem.
lowerAttr, err := lower.UnstableAttr(ctx)
if err != nil {
return err
}
- lowerXattr, err := lower.Listxattr()
+ lowerXattr, err := lower.ListXattr(ctx)
if err != nil && err != syserror.EOPNOTSUPP {
return err
}
@@ -421,11 +422,11 @@ func copyAttributesLocked(ctx context.Context, upper *Inode, lower *Inode) error
if isXattrOverlay(name) {
continue
}
- value, err := lower.Getxattr(name)
+ value, err := lower.GetXattr(ctx, name, linux.XATTR_SIZE_MAX)
if err != nil {
return err
}
- if err := upper.InodeOperations.Setxattr(upper, name, value); err != nil {
+ if err := upper.InodeOperations.SetXattr(ctx, upper, name, value, 0 /* flags */); err != nil {
return err
}
}
diff --git a/pkg/sentry/fs/file_overlay.go b/pkg/sentry/fs/file_overlay.go
index 8a633b1ba..8991207b4 100644
--- a/pkg/sentry/fs/file_overlay.go
+++ b/pkg/sentry/fs/file_overlay.go
@@ -475,7 +475,7 @@ func readdirEntries(ctx context.Context, o *overlayEntry) (*SortedDentryMap, err
// Skip this name if it is a negative entry in the
// upper or there exists a whiteout for it.
if o.upper != nil {
- if overlayHasWhiteout(o.upper, name) {
+ if overlayHasWhiteout(ctx, o.upper, name) {
continue
}
}
diff --git a/pkg/sentry/fs/fsutil/inode.go b/pkg/sentry/fs/fsutil/inode.go
index adf5ec69c..df7b74855 100644
--- a/pkg/sentry/fs/fsutil/inode.go
+++ b/pkg/sentry/fs/fsutil/inode.go
@@ -15,6 +15,7 @@
package fsutil
import (
+ "gvisor.dev/gvisor/pkg/abi/linux"
"gvisor.dev/gvisor/pkg/sentry/context"
"gvisor.dev/gvisor/pkg/sentry/fs"
ktime "gvisor.dev/gvisor/pkg/sentry/kernel/time"
@@ -202,7 +203,7 @@ func (i *InodeSimpleAttributes) NotifyModificationAndStatusChange(ctx context.Co
}
// InodeSimpleExtendedAttributes implements
-// fs.InodeOperations.{Get,Set,List}xattr.
+// fs.InodeOperations.{Get,Set,List}Xattr.
//
// +stateify savable
type InodeSimpleExtendedAttributes struct {
@@ -211,8 +212,8 @@ type InodeSimpleExtendedAttributes struct {
xattrs map[string]string
}
-// Getxattr implements fs.InodeOperations.Getxattr.
-func (i *InodeSimpleExtendedAttributes) Getxattr(_ *fs.Inode, name string) (string, error) {
+// GetXattr implements fs.InodeOperations.GetXattr.
+func (i *InodeSimpleExtendedAttributes) GetXattr(_ context.Context, _ *fs.Inode, name string, _ uint64) (string, error) {
i.mu.RLock()
value, ok := i.xattrs[name]
i.mu.RUnlock()
@@ -222,19 +223,31 @@ func (i *InodeSimpleExtendedAttributes) Getxattr(_ *fs.Inode, name string) (stri
return value, nil
}
-// Setxattr implements fs.InodeOperations.Setxattr.
-func (i *InodeSimpleExtendedAttributes) Setxattr(_ *fs.Inode, name, value string) error {
+// SetXattr implements fs.InodeOperations.SetXattr.
+func (i *InodeSimpleExtendedAttributes) SetXattr(_ context.Context, _ *fs.Inode, name, value string, flags uint32) error {
i.mu.Lock()
+ defer i.mu.Unlock()
if i.xattrs == nil {
+ if flags&linux.XATTR_REPLACE != 0 {
+ return syserror.ENODATA
+ }
i.xattrs = make(map[string]string)
}
+
+ _, ok := i.xattrs[name]
+ if ok && flags&linux.XATTR_CREATE != 0 {
+ return syserror.EEXIST
+ }
+ if !ok && flags&linux.XATTR_REPLACE != 0 {
+ return syserror.ENODATA
+ }
+
i.xattrs[name] = value
- i.mu.Unlock()
return nil
}
-// Listxattr implements fs.InodeOperations.Listxattr.
-func (i *InodeSimpleExtendedAttributes) Listxattr(_ *fs.Inode) (map[string]struct{}, error) {
+// ListXattr implements fs.InodeOperations.ListXattr.
+func (i *InodeSimpleExtendedAttributes) ListXattr(context.Context, *fs.Inode) (map[string]struct{}, error) {
i.mu.RLock()
names := make(map[string]struct{}, len(i.xattrs))
for name := range i.xattrs {
@@ -436,18 +449,18 @@ func (InodeNotSymlink) Getlink(context.Context, *fs.Inode) (*fs.Dirent, error) {
// extended attributes.
type InodeNoExtendedAttributes struct{}
-// Getxattr implements fs.InodeOperations.Getxattr.
-func (InodeNoExtendedAttributes) Getxattr(*fs.Inode, string) (string, error) {
+// GetXattr implements fs.InodeOperations.GetXattr.
+func (InodeNoExtendedAttributes) GetXattr(context.Context, *fs.Inode, string, uint64) (string, error) {
return "", syserror.EOPNOTSUPP
}
-// Setxattr implements fs.InodeOperations.Setxattr.
-func (InodeNoExtendedAttributes) Setxattr(*fs.Inode, string, string) error {
+// SetXattr implements fs.InodeOperations.SetXattr.
+func (InodeNoExtendedAttributes) SetXattr(context.Context, *fs.Inode, string, string, uint32) error {
return syserror.EOPNOTSUPP
}
-// Listxattr implements fs.InodeOperations.Listxattr.
-func (InodeNoExtendedAttributes) Listxattr(*fs.Inode) (map[string]struct{}, error) {
+// ListXattr implements fs.InodeOperations.ListXattr.
+func (InodeNoExtendedAttributes) ListXattr(context.Context, *fs.Inode) (map[string]struct{}, error) {
return nil, syserror.EOPNOTSUPP
}
diff --git a/pkg/sentry/fs/gofer/context_file.go b/pkg/sentry/fs/gofer/context_file.go
index 44b72582a..2125dafef 100644
--- a/pkg/sentry/fs/gofer/context_file.go
+++ b/pkg/sentry/fs/gofer/context_file.go
@@ -59,6 +59,20 @@ func (c *contextFile) setAttr(ctx context.Context, valid p9.SetAttrMask, attr p9
return err
}
+func (c *contextFile) getXattr(ctx context.Context, name string, size uint64) (string, error) {
+ ctx.UninterruptibleSleepStart(false)
+ val, err := c.file.GetXattr(name, size)
+ ctx.UninterruptibleSleepFinish(false)
+ return val, err
+}
+
+func (c *contextFile) setXattr(ctx context.Context, name, value string, flags uint32) error {
+ ctx.UninterruptibleSleepStart(false)
+ err := c.file.SetXattr(name, value, flags)
+ ctx.UninterruptibleSleepFinish(false)
+ return err
+}
+
func (c *contextFile) allocate(ctx context.Context, mode p9.AllocateMode, offset, length uint64) error {
ctx.UninterruptibleSleepStart(false)
err := c.file.Allocate(mode, offset, length)
diff --git a/pkg/sentry/fs/gofer/inode.go b/pkg/sentry/fs/gofer/inode.go
index 245fe2ef1..98d1a8a48 100644
--- a/pkg/sentry/fs/gofer/inode.go
+++ b/pkg/sentry/fs/gofer/inode.go
@@ -38,8 +38,7 @@ import (
//
// +stateify savable
type inodeOperations struct {
- fsutil.InodeNotVirtual `state:"nosave"`
- fsutil.InodeNoExtendedAttributes `state:"nosave"`
+ fsutil.InodeNotVirtual `state:"nosave"`
// fileState implements fs.CachedFileObject. It exists
// to break a circular load dependency between inodeOperations
@@ -604,6 +603,21 @@ func (i *inodeOperations) Truncate(ctx context.Context, inode *fs.Inode, length
return i.fileState.file.setAttr(ctx, p9.SetAttrMask{Size: true}, p9.SetAttr{Size: uint64(length)})
}
+// GetXattr implements fs.InodeOperations.GetXattr.
+func (i *inodeOperations) GetXattr(ctx context.Context, inode *fs.Inode, name string, size uint64) (string, error) {
+ return i.fileState.file.getXattr(ctx, name, size)
+}
+
+// SetXattr implements fs.InodeOperations.SetXattr.
+func (i *inodeOperations) SetXattr(ctx context.Context, inode *fs.Inode, name string, value string, flags uint32) error {
+ return i.fileState.file.setXattr(ctx, name, value, flags)
+}
+
+// ListXattr implements fs.InodeOperations.ListXattr.
+func (i *inodeOperations) ListXattr(context.Context, *fs.Inode) (map[string]struct{}, error) {
+ return nil, syscall.EOPNOTSUPP
+}
+
// Allocate implements fs.InodeOperations.Allocate.
func (i *inodeOperations) Allocate(ctx context.Context, inode *fs.Inode, offset, length int64) error {
// This can only be called for files anyway.
diff --git a/pkg/sentry/fs/inode.go b/pkg/sentry/fs/inode.go
index 468043df0..ee9d301ef 100644
--- a/pkg/sentry/fs/inode.go
+++ b/pkg/sentry/fs/inode.go
@@ -261,28 +261,28 @@ func (i *Inode) UnstableAttr(ctx context.Context) (UnstableAttr, error) {
return i.InodeOperations.UnstableAttr(ctx, i)
}
-// Getxattr calls i.InodeOperations.Getxattr with i as the Inode.
-func (i *Inode) Getxattr(name string) (string, error) {
+// GetXattr calls i.InodeOperations.GetXattr with i as the Inode.
+func (i *Inode) GetXattr(ctx context.Context, name string, size uint64) (string, error) {
if i.overlay != nil {
- return overlayGetxattr(i.overlay, name)
+ return overlayGetXattr(ctx, i.overlay, name, size)
}
- return i.InodeOperations.Getxattr(i, name)
+ return i.InodeOperations.GetXattr(ctx, i, name, size)
}
-// Setxattr calls i.InodeOperations.Setxattr with i as the Inode.
-func (i *Inode) Setxattr(name, value string) error {
+// SetXattr calls i.InodeOperations.SetXattr with i as the Inode.
+func (i *Inode) SetXattr(ctx context.Context, name, value string, flags uint32) error {
if i.overlay != nil {
- return overlaySetxattr(i.overlay, name, value)
+ return overlaySetxattr(ctx, i.overlay, name, value, flags)
}
- return i.InodeOperations.Setxattr(i, name, value)
+ return i.InodeOperations.SetXattr(ctx, i, name, value, flags)
}
-// Listxattr calls i.InodeOperations.Listxattr with i as the Inode.
-func (i *Inode) Listxattr() (map[string]struct{}, error) {
+// ListXattr calls i.InodeOperations.ListXattr with i as the Inode.
+func (i *Inode) ListXattr(ctx context.Context) (map[string]struct{}, error) {
if i.overlay != nil {
- return overlayListxattr(i.overlay)
+ return overlayListXattr(ctx, i.overlay)
}
- return i.InodeOperations.Listxattr(i)
+ return i.InodeOperations.ListXattr(ctx, i)
}
// CheckPermission will check if the caller may access this file in the
diff --git a/pkg/sentry/fs/inode_operations.go b/pkg/sentry/fs/inode_operations.go
index 5cde9d215..13261cb81 100644
--- a/pkg/sentry/fs/inode_operations.go
+++ b/pkg/sentry/fs/inode_operations.go
@@ -170,20 +170,27 @@ type InodeOperations interface {
// file system events.
UnstableAttr(ctx context.Context, inode *Inode) (UnstableAttr, error)
- // Getxattr retrieves the value of extended attribute name. Inodes that
- // do not support extended attributes return EOPNOTSUPP. Inodes that
- // support extended attributes but don't have a value at name return
+ // GetXattr retrieves the value of extended attribute specified by name.
+ // Inodes that do not support extended attributes return EOPNOTSUPP. Inodes
+ // that support extended attributes but don't have a value at name return
// ENODATA.
- Getxattr(inode *Inode, name string) (string, error)
+ //
+ // If this is called through the getxattr(2) syscall, size indicates the
+ // size of the buffer that the application has allocated to hold the
+ // attribute value. If the value is larger than size, implementations may
+ // return ERANGE to indicate that the buffer is too small, but they are also
+ // free to ignore the hint entirely (i.e. the value returned may be larger
+ // than size). All size checking is done independently at the syscall layer.
+ GetXattr(ctx context.Context, inode *Inode, name string, size uint64) (string, error)
- // Setxattr sets the value of extended attribute name. Inodes that
- // do not support extended attributes return EOPNOTSUPP.
- Setxattr(inode *Inode, name, value string) error
+ // SetXattr sets the value of extended attribute specified by name. Inodes
+ // that do not support extended attributes return EOPNOTSUPP.
+ SetXattr(ctx context.Context, inode *Inode, name, value string, flags uint32) error
- // Listxattr returns the set of all extended attributes names that
+ // ListXattr returns the set of all extended attributes names that
// have values. Inodes that do not support extended attributes return
// EOPNOTSUPP.
- Listxattr(inode *Inode) (map[string]struct{}, error)
+ ListXattr(ctx context.Context, inode *Inode) (map[string]struct{}, error)
// Check determines whether an Inode can be accessed with the
// requested permission mask using the context (which gives access
diff --git a/pkg/sentry/fs/inode_overlay.go b/pkg/sentry/fs/inode_overlay.go
index 13d11e001..b90da20d0 100644
--- a/pkg/sentry/fs/inode_overlay.go
+++ b/pkg/sentry/fs/inode_overlay.go
@@ -25,13 +25,13 @@ import (
"gvisor.dev/gvisor/pkg/syserror"
)
-func overlayHasWhiteout(parent *Inode, name string) bool {
- s, err := parent.Getxattr(XattrOverlayWhiteout(name))
+func overlayHasWhiteout(ctx context.Context, parent *Inode, name string) bool {
+ s, err := parent.GetXattr(ctx, XattrOverlayWhiteout(name), 1)
return err == nil && s == "y"
}
-func overlayCreateWhiteout(parent *Inode, name string) error {
- return parent.InodeOperations.Setxattr(parent, XattrOverlayWhiteout(name), "y")
+func overlayCreateWhiteout(ctx context.Context, parent *Inode, name string) error {
+ return parent.InodeOperations.SetXattr(ctx, parent, XattrOverlayWhiteout(name), "y", 0 /* flags */)
}
func overlayWriteOut(ctx context.Context, o *overlayEntry) error {
@@ -89,7 +89,7 @@ func overlayLookup(ctx context.Context, parent *overlayEntry, inode *Inode, name
}
// Are we done?
- if overlayHasWhiteout(parent.upper, name) {
+ if overlayHasWhiteout(ctx, parent.upper, name) {
if upperInode == nil {
parent.copyMu.RUnlock()
if negativeUpperChild {
@@ -345,7 +345,7 @@ func overlayRemove(ctx context.Context, o *overlayEntry, parent *Dirent, child *
}
}
if child.Inode.overlay.lowerExists {
- if err := overlayCreateWhiteout(o.upper, child.name); err != nil {
+ if err := overlayCreateWhiteout(ctx, o.upper, child.name); err != nil {
return err
}
}
@@ -426,7 +426,7 @@ func overlayRename(ctx context.Context, o *overlayEntry, oldParent *Dirent, rena
return err
}
if renamed.Inode.overlay.lowerExists {
- if err := overlayCreateWhiteout(oldParent.Inode.overlay.upper, oldName); err != nil {
+ if err := overlayCreateWhiteout(ctx, oldParent.Inode.overlay.upper, oldName); err != nil {
return err
}
}
@@ -528,7 +528,7 @@ func overlayUnstableAttr(ctx context.Context, o *overlayEntry) (UnstableAttr, er
return attr, err
}
-func overlayGetxattr(o *overlayEntry, name string) (string, error) {
+func overlayGetXattr(ctx context.Context, o *overlayEntry, name string, size uint64) (string, error) {
// Hot path. This is how the overlay checks for whiteout files.
// Avoid defers.
var (
@@ -544,31 +544,31 @@ func overlayGetxattr(o *overlayEntry, name string) (string, error) {
o.copyMu.RLock()
if o.upper != nil {
- s, err = o.upper.Getxattr(name)
+ s, err = o.upper.GetXattr(ctx, name, size)
} else {
- s, err = o.lower.Getxattr(name)
+ s, err = o.lower.GetXattr(ctx, name, size)
}
o.copyMu.RUnlock()
return s, err
}
// TODO(b/146028302): Support setxattr for overlayfs.
-func overlaySetxattr(o *overlayEntry, name, value string) error {
+func overlaySetxattr(ctx context.Context, o *overlayEntry, name, value string, flags uint32) error {
return syserror.EOPNOTSUPP
}
-func overlayListxattr(o *overlayEntry) (map[string]struct{}, error) {
+func overlayListXattr(ctx context.Context, o *overlayEntry) (map[string]struct{}, error) {
o.copyMu.RLock()
defer o.copyMu.RUnlock()
var names map[string]struct{}
var err error
if o.upper != nil {
- names, err = o.upper.Listxattr()
+ names, err = o.upper.ListXattr(ctx)
} else {
- names, err = o.lower.Listxattr()
+ names, err = o.lower.ListXattr(ctx)
}
for name := range names {
- // Same as overlayGetxattr, we shouldn't forward along
+ // Same as overlayGetXattr, we shouldn't forward along
// overlay attributes.
if strings.HasPrefix(XattrOverlayPrefix, name) {
delete(names, name)
diff --git a/pkg/sentry/fs/inode_overlay_test.go b/pkg/sentry/fs/inode_overlay_test.go
index 8935aad65..493d98c36 100644
--- a/pkg/sentry/fs/inode_overlay_test.go
+++ b/pkg/sentry/fs/inode_overlay_test.go
@@ -382,8 +382,8 @@ type dir struct {
ReaddirCalled bool
}
-// Getxattr implements InodeOperations.Getxattr.
-func (d *dir) Getxattr(inode *fs.Inode, name string) (string, error) {
+// GetXattr implements InodeOperations.GetXattr.
+func (d *dir) GetXattr(_ context.Context, _ *fs.Inode, name string, _ uint64) (string, error) {
for _, n := range d.negative {
if name == fs.XattrOverlayWhiteout(n) {
return "y", nil
diff --git a/pkg/sentry/fs/tmpfs/tmpfs.go b/pkg/sentry/fs/tmpfs/tmpfs.go
index 69089c8a8..0f718e236 100644
--- a/pkg/sentry/fs/tmpfs/tmpfs.go
+++ b/pkg/sentry/fs/tmpfs/tmpfs.go
@@ -148,19 +148,19 @@ func (d *Dir) CreateFifo(ctx context.Context, dir *fs.Inode, name string, perms
return d.ramfsDir.CreateFifo(ctx, dir, name, perms)
}
-// Getxattr implements fs.InodeOperations.Getxattr.
-func (d *Dir) Getxattr(i *fs.Inode, name string) (string, error) {
- return d.ramfsDir.Getxattr(i, name)
+// GetXattr implements fs.InodeOperations.GetXattr.
+func (d *Dir) GetXattr(ctx context.Context, i *fs.Inode, name string, size uint64) (string, error) {
+ return d.ramfsDir.GetXattr(ctx, i, name, size)
}
-// Setxattr implements fs.InodeOperations.Setxattr.
-func (d *Dir) Setxattr(i *fs.Inode, name, value string) error {
- return d.ramfsDir.Setxattr(i, name, value)
+// SetXattr implements fs.InodeOperations.SetXattr.
+func (d *Dir) SetXattr(ctx context.Context, i *fs.Inode, name, value string, flags uint32) error {
+ return d.ramfsDir.SetXattr(ctx, i, name, value, flags)
}
-// Listxattr implements fs.InodeOperations.Listxattr.
-func (d *Dir) Listxattr(i *fs.Inode) (map[string]struct{}, error) {
- return d.ramfsDir.Listxattr(i)
+// ListXattr implements fs.InodeOperations.ListXattr.
+func (d *Dir) ListXattr(ctx context.Context, i *fs.Inode) (map[string]struct{}, error) {
+ return d.ramfsDir.ListXattr(ctx, i)
}
// Lookup implements fs.InodeOperations.Lookup.
diff --git a/pkg/sentry/syscalls/linux/linux64_amd64.go b/pkg/sentry/syscalls/linux/linux64_amd64.go
index 479c5f6ff..6b2920900 100644
--- a/pkg/sentry/syscalls/linux/linux64_amd64.go
+++ b/pkg/sentry/syscalls/linux/linux64_amd64.go
@@ -228,10 +228,10 @@ var AMD64 = &kernel.SyscallTable{
185: syscalls.Error("security", syserror.ENOSYS, "Not implemented in Linux.", nil),
186: syscalls.Supported("gettid", Gettid),
187: syscalls.Supported("readahead", Readahead),
- 188: syscalls.PartiallySupported("setxattr", Setxattr, "Only supported for tmpfs.", nil),
+ 188: syscalls.PartiallySupported("setxattr", SetXattr, "Only supported for tmpfs.", nil),
189: syscalls.Error("lsetxattr", syserror.ENOTSUP, "Requires filesystem support.", nil),
190: syscalls.Error("fsetxattr", syserror.ENOTSUP, "Requires filesystem support.", nil),
- 191: syscalls.PartiallySupported("getxattr", Getxattr, "Only supported for tmpfs.", nil),
+ 191: syscalls.PartiallySupported("getxattr", GetXattr, "Only supported for tmpfs.", nil),
192: syscalls.ErrorWithEvent("lgetxattr", syserror.ENOTSUP, "Requires filesystem support.", nil),
193: syscalls.ErrorWithEvent("fgetxattr", syserror.ENOTSUP, "Requires filesystem support.", nil),
194: syscalls.ErrorWithEvent("listxattr", syserror.ENOTSUP, "Requires filesystem support.", nil),
diff --git a/pkg/sentry/syscalls/linux/linux64_arm64.go b/pkg/sentry/syscalls/linux/linux64_arm64.go
index d3f61f5e8..8c1b20911 100644
--- a/pkg/sentry/syscalls/linux/linux64_arm64.go
+++ b/pkg/sentry/syscalls/linux/linux64_arm64.go
@@ -41,10 +41,10 @@ var ARM64 = &kernel.SyscallTable{
2: syscalls.PartiallySupported("io_submit", IoSubmit, "Generally supported with exceptions. User ring optimizations are not implemented.", []string{"gvisor.dev/issue/204"}),
3: syscalls.PartiallySupported("io_cancel", IoCancel, "Generally supported with exceptions. User ring optimizations are not implemented.", []string{"gvisor.dev/issue/204"}),
4: syscalls.PartiallySupported("io_getevents", IoGetevents, "Generally supported with exceptions. User ring optimizations are not implemented.", []string{"gvisor.dev/issue/204"}),
- 5: syscalls.PartiallySupported("setxattr", Setxattr, "Only supported for tmpfs.", nil),
+ 5: syscalls.PartiallySupported("setxattr", SetXattr, "Only supported for tmpfs.", nil),
6: syscalls.Error("lsetxattr", syserror.ENOTSUP, "Requires filesystem support.", nil),
7: syscalls.Error("fsetxattr", syserror.ENOTSUP, "Requires filesystem support.", nil),
- 8: syscalls.PartiallySupported("getxattr", Getxattr, "Only supported for tmpfs.", nil),
+ 8: syscalls.PartiallySupported("getxattr", GetXattr, "Only supported for tmpfs.", nil),
9: syscalls.ErrorWithEvent("lgetxattr", syserror.ENOTSUP, "Requires filesystem support.", nil),
10: syscalls.ErrorWithEvent("fgetxattr", syserror.ENOTSUP, "Requires filesystem support.", nil),
11: syscalls.ErrorWithEvent("listxattr", syserror.ENOTSUP, "Requires filesystem support.", nil),
diff --git a/pkg/sentry/syscalls/linux/sys_xattr.go b/pkg/sentry/syscalls/linux/sys_xattr.go
index 97d9a65ea..816352218 100644
--- a/pkg/sentry/syscalls/linux/sys_xattr.go
+++ b/pkg/sentry/syscalls/linux/sys_xattr.go
@@ -25,12 +25,12 @@ import (
"gvisor.dev/gvisor/pkg/syserror"
)
-// Getxattr implements linux syscall getxattr(2).
-func Getxattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+// GetXattr implements linux syscall getxattr(2).
+func GetXattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
pathAddr := args[0].Pointer()
nameAddr := args[1].Pointer()
valueAddr := args[2].Pointer()
- size := args[3].SizeT()
+ size := uint64(args[3].SizeT())
path, dirPath, err := copyInPath(t, pathAddr, false /* allowEmpty */)
if err != nil {
@@ -39,22 +39,28 @@ func Getxattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysc
valueLen := 0
err = fileOpOn(t, linux.AT_FDCWD, path, true /* resolve */, func(root *fs.Dirent, d *fs.Dirent, _ uint) error {
- value, err := getxattr(t, d, dirPath, nameAddr)
+ // If getxattr(2) is called with size 0, the size of the value will be
+ // returned successfully even if it is nonzero. In that case, we need to
+ // retrieve the entire attribute value so we can return the correct size.
+ requestedSize := size
+ if size == 0 || size > linux.XATTR_SIZE_MAX {
+ requestedSize = linux.XATTR_SIZE_MAX
+ }
+
+ value, err := getXattr(t, d, dirPath, nameAddr, uint64(requestedSize))
if err != nil {
return err
}
valueLen = len(value)
- if size == 0 {
- return nil
- }
- if size > linux.XATTR_SIZE_MAX {
- size = linux.XATTR_SIZE_MAX
- }
- if valueLen > int(size) {
+ if uint64(valueLen) > requestedSize {
return syserror.ERANGE
}
+ // Skip copying out the attribute value if size is 0.
+ if size == 0 {
+ return nil
+ }
_, err = t.CopyOutBytes(valueAddr, []byte(value))
return err
})
@@ -64,8 +70,8 @@ func Getxattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysc
return uintptr(valueLen), nil, nil
}
-// getxattr implements getxattr from the given *fs.Dirent.
-func getxattr(t *kernel.Task, d *fs.Dirent, dirPath bool, nameAddr usermem.Addr) (string, error) {
+// getXattr implements getxattr(2) from the given *fs.Dirent.
+func getXattr(t *kernel.Task, d *fs.Dirent, dirPath bool, nameAddr usermem.Addr, size uint64) (string, error) {
if dirPath && !fs.IsDir(d.Inode.StableAttr) {
return "", syserror.ENOTDIR
}
@@ -83,15 +89,15 @@ func getxattr(t *kernel.Task, d *fs.Dirent, dirPath bool, nameAddr usermem.Addr)
return "", syserror.EOPNOTSUPP
}
- return d.Inode.Getxattr(name)
+ return d.Inode.GetXattr(t, name, size)
}
-// Setxattr implements linux syscall setxattr(2).
-func Setxattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+// SetXattr implements linux syscall setxattr(2).
+func SetXattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
pathAddr := args[0].Pointer()
nameAddr := args[1].Pointer()
valueAddr := args[2].Pointer()
- size := args[3].SizeT()
+ size := uint64(args[3].SizeT())
flags := args[4].Uint()
path, dirPath, err := copyInPath(t, pathAddr, false /* allowEmpty */)
@@ -104,12 +110,12 @@ func Setxattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysc
}
return 0, nil, fileOpOn(t, linux.AT_FDCWD, path, true /* resolve */, func(root *fs.Dirent, d *fs.Dirent, _ uint) error {
- return setxattr(t, d, dirPath, nameAddr, valueAddr, size, flags)
+ return setXattr(t, d, dirPath, nameAddr, valueAddr, uint64(size), flags)
})
}
-// setxattr implements setxattr from the given *fs.Dirent.
-func setxattr(t *kernel.Task, d *fs.Dirent, dirPath bool, nameAddr, valueAddr usermem.Addr, size uint, flags uint32) error {
+// setXattr implements setxattr(2) from the given *fs.Dirent.
+func setXattr(t *kernel.Task, d *fs.Dirent, dirPath bool, nameAddr, valueAddr usermem.Addr, size uint64, flags uint32) error {
if dirPath && !fs.IsDir(d.Inode.StableAttr) {
return syserror.ENOTDIR
}
@@ -136,7 +142,7 @@ func setxattr(t *kernel.Task, d *fs.Dirent, dirPath bool, nameAddr, valueAddr us
return syserror.EOPNOTSUPP
}
- return d.Inode.Setxattr(name, value)
+ return d.Inode.SetXattr(t, name, value, flags)
}
func copyInXattrName(t *kernel.Task, nameAddr usermem.Addr) (string, error) {
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-18 22:18:47 +0000