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-rw-r--r--pkg/fd/fd.go42
-rw-r--r--pkg/sentry/control/BUILD1
-rw-r--r--pkg/sentry/control/proc.go28
-rw-r--r--pkg/sentry/fdimport/BUILD1
-rw-r--r--pkg/sentry/fdimport/fdimport.go22
5 files changed, 56 insertions, 38 deletions
diff --git a/pkg/fd/fd.go b/pkg/fd/fd.go
index 83bcfe220..cc6b0cdf1 100644
--- a/pkg/fd/fd.go
+++ b/pkg/fd/fd.go
@@ -49,7 +49,7 @@ func fixCount(n int, err error) (int, error) {
// Read implements io.Reader.
func (r *ReadWriter) Read(b []byte) (int, error) {
- c, err := fixCount(syscall.Read(int(atomic.LoadInt64(&r.fd)), b))
+ c, err := fixCount(syscall.Read(r.FD(), b))
if c == 0 && len(b) > 0 && err == nil {
return 0, io.EOF
}
@@ -62,7 +62,7 @@ func (r *ReadWriter) Read(b []byte) (int, error) {
func (r *ReadWriter) ReadAt(b []byte, off int64) (c int, err error) {
for len(b) > 0 {
var m int
- m, err = fixCount(syscall.Pread(int(atomic.LoadInt64(&r.fd)), b, off))
+ m, err = fixCount(syscall.Pread(r.FD(), b, off))
if m == 0 && err == nil {
return c, io.EOF
}
@@ -82,7 +82,7 @@ func (r *ReadWriter) Write(b []byte) (int, error) {
var n, remaining int
for remaining = len(b); remaining > 0; {
woff := len(b) - remaining
- n, err = syscall.Write(int(atomic.LoadInt64(&r.fd)), b[woff:])
+ n, err = syscall.Write(r.FD(), b[woff:])
if n > 0 {
// syscall.Write wrote some bytes. This is the common case.
@@ -110,7 +110,7 @@ func (r *ReadWriter) Write(b []byte) (int, error) {
func (r *ReadWriter) WriteAt(b []byte, off int64) (c int, err error) {
for len(b) > 0 {
var m int
- m, err = fixCount(syscall.Pwrite(int(atomic.LoadInt64(&r.fd)), b, off))
+ m, err = fixCount(syscall.Pwrite(r.FD(), b, off))
if err != nil {
break
}
@@ -121,6 +121,16 @@ func (r *ReadWriter) WriteAt(b []byte, off int64) (c int, err error) {
return
}
+// FD returns the owned file descriptor. Ownership remains unchanged.
+func (r *ReadWriter) FD() int {
+ return int(atomic.LoadInt64(&r.fd))
+}
+
+// String implements Stringer.String().
+func (r *ReadWriter) String() string {
+ return fmt.Sprintf("FD: %d", r.FD())
+}
+
// FD owns a host file descriptor.
//
// It is similar to os.File, with a few important distinctions:
@@ -167,6 +177,23 @@ func NewFromFile(file *os.File) (*FD, error) {
return New(fd), nil
}
+// NewFromFiles creates new FDs for each file in the slice.
+func NewFromFiles(files []*os.File) ([]*FD, error) {
+ rv := make([]*FD, 0, len(files))
+ for _, f := range files {
+ new, err := NewFromFile(f)
+ if err != nil {
+ // Cleanup on error.
+ for _, fd := range rv {
+ fd.Close()
+ }
+ return nil, err
+ }
+ rv = append(rv, new)
+ }
+ return rv, nil
+}
+
// Open is equivalent to open(2).
func Open(path string, openmode int, perm uint32) (*FD, error) {
f, err := syscall.Open(path, openmode|syscall.O_LARGEFILE, perm)
@@ -204,11 +231,6 @@ func (f *FD) Release() int {
return int(atomic.SwapInt64(&f.fd, -1))
}
-// FD returns the file descriptor owned by FD. FD retains ownership.
-func (f *FD) FD() int {
- return int(atomic.LoadInt64(&f.fd))
-}
-
// File converts the FD to an os.File.
//
// FD does not transfer ownership of the file descriptor (it will be
@@ -219,7 +241,7 @@ func (f *FD) FD() int {
// This operation is somewhat expensive, so care should be taken to minimize
// its use.
func (f *FD) File() (*os.File, error) {
- fd, err := syscall.Dup(int(atomic.LoadInt64(&f.fd)))
+ fd, err := syscall.Dup(f.FD())
if err != nil {
return nil, err
}
diff --git a/pkg/sentry/control/BUILD b/pkg/sentry/control/BUILD
index 2c5d14be5..deaf5fa23 100644
--- a/pkg/sentry/control/BUILD
+++ b/pkg/sentry/control/BUILD
@@ -35,7 +35,6 @@ go_library(
"//pkg/sync",
"//pkg/tcpip/link/sniffer",
"//pkg/urpc",
- "@org_golang_x_sys//unix:go_default_library",
],
)
diff --git a/pkg/sentry/control/proc.go b/pkg/sentry/control/proc.go
index dfa936563..668f47802 100644
--- a/pkg/sentry/control/proc.go
+++ b/pkg/sentry/control/proc.go
@@ -23,8 +23,8 @@ import (
"text/tabwriter"
"time"
- "golang.org/x/sys/unix"
"gvisor.dev/gvisor/pkg/abi/linux"
+ "gvisor.dev/gvisor/pkg/fd"
"gvisor.dev/gvisor/pkg/sentry/fdimport"
"gvisor.dev/gvisor/pkg/sentry/fs"
"gvisor.dev/gvisor/pkg/sentry/fs/host"
@@ -203,27 +203,17 @@ func (proc *Proc) execAsync(args *ExecArgs) (*kernel.ThreadGroup, kernel.ThreadI
}
initArgs.Filename = resolved
- fds := make([]int, len(args.FilePayload.Files))
- for i, file := range args.FilePayload.Files {
- if kernel.VFS2Enabled {
- // Need to dup to remove ownership from os.File.
- dup, err := unix.Dup(int(file.Fd()))
- if err != nil {
- return nil, 0, nil, nil, fmt.Errorf("duplicating payload files: %w", err)
- }
- fds[i] = dup
- } else {
- // VFS1 dups the file on import.
- fds[i] = int(file.Fd())
- }
+ fds, err := fd.NewFromFiles(args.Files)
+ if err != nil {
+ return nil, 0, nil, nil, fmt.Errorf("duplicating payload files: %w", err)
}
+ defer func() {
+ for _, fd := range fds {
+ _ = fd.Close()
+ }
+ }()
ttyFile, ttyFileVFS2, err := fdimport.Import(ctx, fdTable, args.StdioIsPty, fds)
if err != nil {
- if kernel.VFS2Enabled {
- for _, fd := range fds {
- unix.Close(fd)
- }
- }
return nil, 0, nil, nil, err
}
diff --git a/pkg/sentry/fdimport/BUILD b/pkg/sentry/fdimport/BUILD
index 5e41ceb4e..6b4f8b0ed 100644
--- a/pkg/sentry/fdimport/BUILD
+++ b/pkg/sentry/fdimport/BUILD
@@ -10,6 +10,7 @@ go_library(
visibility = ["//pkg/sentry:internal"],
deps = [
"//pkg/context",
+ "//pkg/fd",
"//pkg/sentry/fs",
"//pkg/sentry/fs/host",
"//pkg/sentry/fsimpl/host",
diff --git a/pkg/sentry/fdimport/fdimport.go b/pkg/sentry/fdimport/fdimport.go
index 1b7cb94c0..314661475 100644
--- a/pkg/sentry/fdimport/fdimport.go
+++ b/pkg/sentry/fdimport/fdimport.go
@@ -18,6 +18,7 @@ import (
"fmt"
"gvisor.dev/gvisor/pkg/context"
+ "gvisor.dev/gvisor/pkg/fd"
"gvisor.dev/gvisor/pkg/sentry/fs"
"gvisor.dev/gvisor/pkg/sentry/fs/host"
hostvfs2 "gvisor.dev/gvisor/pkg/sentry/fsimpl/host"
@@ -27,8 +28,9 @@ import (
// Import imports a slice of FDs into the given FDTable. If console is true,
// sets up TTY for the first 3 FDs in the slice representing stdin, stdout,
-// stderr. Upon success, Import takes ownership of all FDs.
-func Import(ctx context.Context, fdTable *kernel.FDTable, console bool, fds []int) (*host.TTYFileOperations, *hostvfs2.TTYFileDescription, error) {
+// stderr. Used FDs are either closed or released. It's safe for the caller to
+// close any remaining files upon return.
+func Import(ctx context.Context, fdTable *kernel.FDTable, console bool, fds []*fd.FD) (*host.TTYFileOperations, *hostvfs2.TTYFileDescription, error) {
if kernel.VFS2Enabled {
ttyFile, err := importVFS2(ctx, fdTable, console, fds)
return nil, ttyFile, err
@@ -37,7 +39,7 @@ func Import(ctx context.Context, fdTable *kernel.FDTable, console bool, fds []in
return ttyFile, nil, err
}
-func importFS(ctx context.Context, fdTable *kernel.FDTable, console bool, fds []int) (*host.TTYFileOperations, error) {
+func importFS(ctx context.Context, fdTable *kernel.FDTable, console bool, fds []*fd.FD) (*host.TTYFileOperations, error) {
var ttyFile *fs.File
for appFD, hostFD := range fds {
var appFile *fs.File
@@ -46,11 +48,12 @@ func importFS(ctx context.Context, fdTable *kernel.FDTable, console bool, fds []
// Import the file as a host TTY file.
if ttyFile == nil {
var err error
- appFile, err = host.ImportFile(ctx, hostFD, true /* isTTY */)
+ appFile, err = host.ImportFile(ctx, hostFD.FD(), true /* isTTY */)
if err != nil {
return nil, err
}
defer appFile.DecRef(ctx)
+ _ = hostFD.Close() // FD is dup'd i ImportFile.
// Remember this in the TTY file, as we will
// use it for the other stdio FDs.
@@ -65,11 +68,12 @@ func importFS(ctx context.Context, fdTable *kernel.FDTable, console bool, fds []
} else {
// Import the file as a regular host file.
var err error
- appFile, err = host.ImportFile(ctx, hostFD, false /* isTTY */)
+ appFile, err = host.ImportFile(ctx, hostFD.FD(), false /* isTTY */)
if err != nil {
return nil, err
}
defer appFile.DecRef(ctx)
+ _ = hostFD.Close() // FD is dup'd i ImportFile.
}
// Add the file to the FD map.
@@ -84,7 +88,7 @@ func importFS(ctx context.Context, fdTable *kernel.FDTable, console bool, fds []
return ttyFile.FileOperations.(*host.TTYFileOperations), nil
}
-func importVFS2(ctx context.Context, fdTable *kernel.FDTable, console bool, stdioFDs []int) (*hostvfs2.TTYFileDescription, error) {
+func importVFS2(ctx context.Context, fdTable *kernel.FDTable, console bool, stdioFDs []*fd.FD) (*hostvfs2.TTYFileDescription, error) {
k := kernel.KernelFromContext(ctx)
if k == nil {
return nil, fmt.Errorf("cannot find kernel from context")
@@ -98,11 +102,12 @@ func importVFS2(ctx context.Context, fdTable *kernel.FDTable, console bool, stdi
// Import the file as a host TTY file.
if ttyFile == nil {
var err error
- appFile, err = hostvfs2.ImportFD(ctx, k.HostMount(), hostFD, true /* isTTY */)
+ appFile, err = hostvfs2.ImportFD(ctx, k.HostMount(), hostFD.FD(), true /* isTTY */)
if err != nil {
return nil, err
}
defer appFile.DecRef(ctx)
+ hostFD.Release() // FD is transfered to host FD.
// Remember this in the TTY file, as we will use it for the other stdio
// FDs.
@@ -115,11 +120,12 @@ func importVFS2(ctx context.Context, fdTable *kernel.FDTable, console bool, stdi
}
} else {
var err error
- appFile, err = hostvfs2.ImportFD(ctx, k.HostMount(), hostFD, false /* isTTY */)
+ appFile, err = hostvfs2.ImportFD(ctx, k.HostMount(), hostFD.FD(), false /* isTTY */)
if err != nil {
return nil, err
}
defer appFile.DecRef(ctx)
+ hostFD.Release() // FD is transfered to host FD.
}
if err := fdTable.NewFDAtVFS2(ctx, int32(appFD), appFile, kernel.FDFlags{}); err != nil {
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-24 01:32:30 +0000