summaryrefslogtreecommitdiffhomepage
path: root/pkg/sentry/loader
diff options
context:
space:
mode:
Diffstat (limited to 'pkg/sentry/loader')
-rw-r--r--pkg/sentry/loader/BUILD4
-rw-r--r--pkg/sentry/loader/elf.go40
-rw-r--r--pkg/sentry/loader/loader.go41
-rw-r--r--pkg/sentry/loader/vdso.go67
4 files changed, 50 insertions, 102 deletions
diff --git a/pkg/sentry/loader/BUILD b/pkg/sentry/loader/BUILD
index c6aa65f28..34bdb0b69 100644
--- a/pkg/sentry/loader/BUILD
+++ b/pkg/sentry/loader/BUILD
@@ -30,9 +30,6 @@ go_library(
"//pkg/rand",
"//pkg/safemem",
"//pkg/sentry/arch",
- "//pkg/sentry/fs",
- "//pkg/sentry/fs/anon",
- "//pkg/sentry/fs/fsutil",
"//pkg/sentry/fsbridge",
"//pkg/sentry/kernel/auth",
"//pkg/sentry/limits",
@@ -45,6 +42,5 @@ go_library(
"//pkg/syserr",
"//pkg/syserror",
"//pkg/usermem",
- "//pkg/waiter",
],
)
diff --git a/pkg/sentry/loader/elf.go b/pkg/sentry/loader/elf.go
index 616fafa2c..98af2cc38 100644
--- a/pkg/sentry/loader/elf.go
+++ b/pkg/sentry/loader/elf.go
@@ -90,14 +90,23 @@ type elfInfo struct {
sharedObject bool
}
+// fullReader interface extracts the ReadFull method from fsbridge.File so that
+// client code does not need to define an entire fsbridge.File when only read
+// functionality is needed.
+//
+// TODO(gvisor.dev/issue/1035): Once VFS2 ships, rewrite this to wrap
+// vfs.FileDescription's PRead/Read instead.
+type fullReader interface {
+ // ReadFull is the same as fsbridge.File.ReadFull.
+ ReadFull(ctx context.Context, dst usermem.IOSequence, offset int64) (int64, error)
+}
+
// parseHeader parse the ELF header, verifying that this is a supported ELF
// file and returning the ELF program headers.
//
// This is similar to elf.NewFile, except that it is more strict about what it
// accepts from the ELF, and it doesn't parse unnecessary parts of the file.
-//
-// ctx may be nil if f does not need it.
-func parseHeader(ctx context.Context, f fsbridge.File) (elfInfo, error) {
+func parseHeader(ctx context.Context, f fullReader) (elfInfo, error) {
// Check ident first; it will tell us the endianness of the rest of the
// structs.
var ident [elf.EI_NIDENT]byte
@@ -185,6 +194,10 @@ func parseHeader(ctx context.Context, f fsbridge.File) (elfInfo, error) {
log.Infof("Too many phdrs (%d): total size %d > %d", hdr.Phnum, totalPhdrSize, maxTotalPhdrSize)
return elfInfo{}, syserror.ENOEXEC
}
+ if int64(hdr.Phoff) < 0 || int64(hdr.Phoff+uint64(totalPhdrSize)) < 0 {
+ ctx.Infof("Unsupported phdr offset %d", hdr.Phoff)
+ return elfInfo{}, syserror.ENOEXEC
+ }
phdrBuf := make([]byte, totalPhdrSize)
_, err = f.ReadFull(ctx, usermem.BytesIOSequence(phdrBuf), int64(hdr.Phoff))
@@ -272,7 +285,7 @@ func mapSegment(ctx context.Context, m *mm.MemoryManager, f fsbridge.File, phdr
}
defer func() {
if mopts.MappingIdentity != nil {
- mopts.MappingIdentity.DecRef()
+ mopts.MappingIdentity.DecRef(ctx)
}
}()
if err := f.ConfigureMMap(ctx, &mopts); err != nil {
@@ -393,8 +406,7 @@ type loadedELF struct {
//
// It does not load the ELF interpreter, or return any auxv entries.
//
-// Preconditions:
-// * f is an ELF file
+// Preconditions: f is an ELF file.
func loadParsedELF(ctx context.Context, m *mm.MemoryManager, f fsbridge.File, info elfInfo, sharedLoadOffset usermem.Addr) (loadedELF, error) {
first := true
var start, end usermem.Addr
@@ -429,6 +441,10 @@ func loadParsedELF(ctx context.Context, m *mm.MemoryManager, f fsbridge.File, in
ctx.Infof("PT_INTERP path too big: %v", phdr.Filesz)
return loadedELF{}, syserror.ENOEXEC
}
+ if int64(phdr.Off) < 0 || int64(phdr.Off+phdr.Filesz) < 0 {
+ ctx.Infof("Unsupported PT_INTERP offset %d", phdr.Off)
+ return loadedELF{}, syserror.ENOEXEC
+ }
path := make([]byte, phdr.Filesz)
_, err := f.ReadFull(ctx, usermem.BytesIOSequence(path), int64(phdr.Off))
@@ -562,8 +578,8 @@ func loadParsedELF(ctx context.Context, m *mm.MemoryManager, f fsbridge.File, in
// It does not load the ELF interpreter, or return any auxv entries.
//
// Preconditions:
-// * f is an ELF file
-// * f is the first ELF loaded into m
+// * f is an ELF file.
+// * f is the first ELF loaded into m.
func loadInitialELF(ctx context.Context, m *mm.MemoryManager, fs *cpuid.FeatureSet, f fsbridge.File) (loadedELF, arch.Context, error) {
info, err := parseHeader(ctx, f)
if err != nil {
@@ -600,8 +616,7 @@ func loadInitialELF(ctx context.Context, m *mm.MemoryManager, fs *cpuid.FeatureS
//
// It does not return any auxv entries.
//
-// Preconditions:
-// * f is an ELF file
+// Preconditions: f is an ELF file.
func loadInterpreterELF(ctx context.Context, m *mm.MemoryManager, f fsbridge.File, initial loadedELF) (loadedELF, error) {
info, err := parseHeader(ctx, f)
if err != nil {
@@ -631,8 +646,7 @@ func loadInterpreterELF(ctx context.Context, m *mm.MemoryManager, f fsbridge.Fil
// If loadELF returns ErrSwitchFile it should be called again with the returned
// path and argv.
//
-// Preconditions:
-// * args.File is an ELF file
+// Preconditions: args.File is an ELF file.
func loadELF(ctx context.Context, args LoadArgs) (loadedELF, arch.Context, error) {
bin, ac, err := loadInitialELF(ctx, args.MemoryManager, args.Features, args.File)
if err != nil {
@@ -654,7 +668,7 @@ func loadELF(ctx context.Context, args LoadArgs) (loadedELF, arch.Context, error
ctx.Infof("Error opening interpreter %s: %v", bin.interpreter, err)
return loadedELF{}, nil, err
}
- defer intFile.DecRef()
+ defer intFile.DecRef(ctx)
interp, err = loadInterpreterELF(ctx, args.MemoryManager, intFile, bin)
if err != nil {
diff --git a/pkg/sentry/loader/loader.go b/pkg/sentry/loader/loader.go
index 88449fe95..c69b62db9 100644
--- a/pkg/sentry/loader/loader.go
+++ b/pkg/sentry/loader/loader.go
@@ -27,7 +27,6 @@ import (
"gvisor.dev/gvisor/pkg/cpuid"
"gvisor.dev/gvisor/pkg/rand"
"gvisor.dev/gvisor/pkg/sentry/arch"
- "gvisor.dev/gvisor/pkg/sentry/fs"
"gvisor.dev/gvisor/pkg/sentry/fsbridge"
"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
"gvisor.dev/gvisor/pkg/sentry/mm"
@@ -80,22 +79,6 @@ type LoadArgs struct {
Features *cpuid.FeatureSet
}
-// readFull behaves like io.ReadFull for an *fs.File.
-func readFull(ctx context.Context, f *fs.File, dst usermem.IOSequence, offset int64) (int64, error) {
- var total int64
- for dst.NumBytes() > 0 {
- n, err := f.Preadv(ctx, dst, offset+total)
- total += n
- if err == io.EOF && total != 0 {
- return total, io.ErrUnexpectedEOF
- } else if err != nil {
- return total, err
- }
- dst = dst.DropFirst64(n)
- }
- return total, nil
-}
-
// openPath opens args.Filename and checks that it is valid for loading.
//
// openPath returns an *fs.Dirent and *fs.File for args.Filename, which is not
@@ -139,7 +122,7 @@ func allocStack(ctx context.Context, m *mm.MemoryManager, a arch.Context) (*arch
if err != nil {
return nil, err
}
- return &arch.Stack{a, m, ar.End}, nil
+ return &arch.Stack{Arch: a, IO: m, Bottom: ar.End}, nil
}
const (
@@ -171,7 +154,7 @@ func loadExecutable(ctx context.Context, args LoadArgs) (loadedELF, arch.Context
return loadedELF{}, nil, nil, nil, err
}
// Ensure file is release in case the code loops or errors out.
- defer args.File.DecRef()
+ defer args.File.DecRef(ctx)
} else {
if err := checkIsRegularFile(ctx, args.File, args.Filename); err != nil {
return loadedELF{}, nil, nil, nil, err
@@ -232,20 +215,20 @@ func loadExecutable(ctx context.Context, args LoadArgs) (loadedELF, arch.Context
// path and argv.
//
// Preconditions:
-// * The Task MemoryManager is empty.
-// * Load is called on the Task goroutine.
+// * The Task MemoryManager is empty.
+// * Load is called on the Task goroutine.
func Load(ctx context.Context, args LoadArgs, extraAuxv []arch.AuxEntry, vdso *VDSO) (abi.OS, arch.Context, string, *syserr.Error) {
// Load the executable itself.
loaded, ac, file, newArgv, err := loadExecutable(ctx, args)
if err != nil {
- return 0, nil, "", syserr.NewDynamic(fmt.Sprintf("Failed to load %s: %v", args.Filename, err), syserr.FromError(err).ToLinux())
+ return 0, nil, "", syserr.NewDynamic(fmt.Sprintf("failed to load %s: %v", args.Filename, err), syserr.FromError(err).ToLinux())
}
- defer file.DecRef()
+ defer file.DecRef(ctx)
// Load the VDSO.
vdsoAddr, err := loadVDSO(ctx, args.MemoryManager, vdso, loaded)
if err != nil {
- return 0, nil, "", syserr.NewDynamic(fmt.Sprintf("Error loading VDSO: %v", err), syserr.FromError(err).ToLinux())
+ return 0, nil, "", syserr.NewDynamic(fmt.Sprintf("error loading VDSO: %v", err), syserr.FromError(err).ToLinux())
}
// Setup the heap. brk starts at the next page after the end of the
@@ -264,20 +247,20 @@ func Load(ctx context.Context, args LoadArgs, extraAuxv []arch.AuxEntry, vdso *V
}
// Push the original filename to the stack, for AT_EXECFN.
- execfn, err := stack.Push(args.Filename)
- if err != nil {
+ if _, err := stack.PushNullTerminatedByteSlice([]byte(args.Filename)); err != nil {
return 0, nil, "", syserr.NewDynamic(fmt.Sprintf("Failed to push exec filename: %v", err), syserr.FromError(err).ToLinux())
}
+ execfn := stack.Bottom
// Push 16 random bytes on the stack which AT_RANDOM will point to.
var b [16]byte
if _, err := rand.Read(b[:]); err != nil {
return 0, nil, "", syserr.NewDynamic(fmt.Sprintf("Failed to read random bytes: %v", err), syserr.FromError(err).ToLinux())
}
- random, err := stack.Push(b)
- if err != nil {
+ if _, err = stack.PushNullTerminatedByteSlice(b[:]); err != nil {
return 0, nil, "", syserr.NewDynamic(fmt.Sprintf("Failed to push random bytes: %v", err), syserr.FromError(err).ToLinux())
}
+ random := stack.Bottom
c := auth.CredentialsFromContext(ctx)
@@ -309,7 +292,7 @@ func Load(ctx context.Context, args LoadArgs, extraAuxv []arch.AuxEntry, vdso *V
m.SetEnvvStart(sl.EnvvStart)
m.SetEnvvEnd(sl.EnvvEnd)
m.SetAuxv(auxv)
- m.SetExecutable(file)
+ m.SetExecutable(ctx, file)
symbolValue, err := getSymbolValueFromVDSO("rt_sigreturn")
if err != nil {
diff --git a/pkg/sentry/loader/vdso.go b/pkg/sentry/loader/vdso.go
index 00977fc08..241d87835 100644
--- a/pkg/sentry/loader/vdso.go
+++ b/pkg/sentry/loader/vdso.go
@@ -26,10 +26,6 @@ import (
"gvisor.dev/gvisor/pkg/log"
"gvisor.dev/gvisor/pkg/safemem"
"gvisor.dev/gvisor/pkg/sentry/arch"
- "gvisor.dev/gvisor/pkg/sentry/fs"
- "gvisor.dev/gvisor/pkg/sentry/fs/anon"
- "gvisor.dev/gvisor/pkg/sentry/fs/fsutil"
- "gvisor.dev/gvisor/pkg/sentry/fsbridge"
"gvisor.dev/gvisor/pkg/sentry/memmap"
"gvisor.dev/gvisor/pkg/sentry/mm"
"gvisor.dev/gvisor/pkg/sentry/pgalloc"
@@ -37,7 +33,6 @@ import (
"gvisor.dev/gvisor/pkg/sentry/usage"
"gvisor.dev/gvisor/pkg/syserror"
"gvisor.dev/gvisor/pkg/usermem"
- "gvisor.dev/gvisor/pkg/waiter"
)
const vdsoPrelink = 0xffffffffff700000
@@ -55,52 +50,11 @@ func (f *fileContext) Value(key interface{}) interface{} {
}
}
-// byteReader implements fs.FileOperations for reading from a []byte source.
-type byteReader struct {
- fsutil.FileNoFsync `state:"nosave"`
- fsutil.FileNoIoctl `state:"nosave"`
- fsutil.FileNoMMap `state:"nosave"`
- fsutil.FileNoSplice `state:"nosave"`
- fsutil.FileNoopFlush `state:"nosave"`
- fsutil.FileNoopRelease `state:"nosave"`
- fsutil.FileNotDirReaddir `state:"nosave"`
- fsutil.FilePipeSeek `state:"nosave"`
- fsutil.FileUseInodeUnstableAttr `state:"nosave"`
- waiter.AlwaysReady `state:"nosave"`
-
+type byteFullReader struct {
data []byte
}
-var _ fs.FileOperations = (*byteReader)(nil)
-
-// newByteReaderFile creates a fake file to read data from.
-//
-// TODO(gvisor.dev/issue/1623): Convert to VFS2.
-func newByteReaderFile(ctx context.Context, data []byte) *fs.File {
- // Create a fake inode.
- inode := fs.NewInode(
- ctx,
- &fsutil.SimpleFileInode{},
- fs.NewPseudoMountSource(ctx),
- fs.StableAttr{
- Type: fs.Anonymous,
- DeviceID: anon.PseudoDevice.DeviceID(),
- InodeID: anon.PseudoDevice.NextIno(),
- BlockSize: usermem.PageSize,
- })
-
- // Use the fake inode to create a fake dirent.
- dirent := fs.NewTransientDirent(inode)
- defer dirent.DecRef()
-
- // Use the fake dirent to make a fake file.
- flags := fs.FileFlags{Read: true, Pread: true}
- return fs.NewFile(&fileContext{Context: context.Background()}, dirent, flags, &byteReader{
- data: data,
- })
-}
-
-func (b *byteReader) Read(ctx context.Context, file *fs.File, dst usermem.IOSequence, offset int64) (int64, error) {
+func (b *byteFullReader) ReadFull(ctx context.Context, dst usermem.IOSequence, offset int64) (int64, error) {
if offset < 0 {
return 0, syserror.EINVAL
}
@@ -111,10 +65,6 @@ func (b *byteReader) Read(ctx context.Context, file *fs.File, dst usermem.IOSequ
return int64(n), err
}
-func (b *byteReader) Write(ctx context.Context, file *fs.File, src usermem.IOSequence, offset int64) (int64, error) {
- panic("Write not supported")
-}
-
// validateVDSO checks that the VDSO can be loaded by loadVDSO.
//
// VDSOs are special (see below). Since we are going to map the VDSO directly
@@ -130,7 +80,7 @@ func (b *byteReader) Write(ctx context.Context, file *fs.File, src usermem.IOSeq
// * PT_LOAD segments don't extend beyond the end of the file.
//
// ctx may be nil if f does not need it.
-func validateVDSO(ctx context.Context, f fsbridge.File, size uint64) (elfInfo, error) {
+func validateVDSO(ctx context.Context, f fullReader, size uint64) (elfInfo, error) {
info, err := parseHeader(ctx, f)
if err != nil {
log.Infof("Unable to parse VDSO header: %v", err)
@@ -248,13 +198,12 @@ func getSymbolValueFromVDSO(symbol string) (uint64, error) {
// PrepareVDSO validates the system VDSO and returns a VDSO, containing the
// param page for updating by the kernel.
-func PrepareVDSO(ctx context.Context, mfp pgalloc.MemoryFileProvider) (*VDSO, error) {
- vdsoFile := fsbridge.NewFSFile(newByteReaderFile(ctx, vdsoBin))
+func PrepareVDSO(mfp pgalloc.MemoryFileProvider) (*VDSO, error) {
+ vdsoFile := &byteFullReader{data: vdsoBin}
// First make sure the VDSO is valid. vdsoFile does not use ctx, so a
// nil context can be passed.
info, err := validateVDSO(nil, vdsoFile, uint64(len(vdsoBin)))
- vdsoFile.DecRef()
if err != nil {
return nil, err
}
@@ -431,3 +380,9 @@ func loadVDSO(ctx context.Context, m *mm.MemoryManager, v *VDSO, bin loadedELF)
return vdsoAddr, nil
}
+
+// Release drops references on mappings held by v.
+func (v *VDSO) Release(ctx context.Context) {
+ v.ParamPage.DecRef(ctx)
+ v.vdso.DecRef(ctx)
+}
generated by cgit v1.2.3 (git 2.39.1) at 2025-05-30 18:58:59 +0000