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authorWei Zhang <zhangwei198900@gmail.com>2019-04-02 14:50:09 -0700
committerShentubot <shentubot@google.com>2019-04-02 14:51:07 -0700
commit1fcd40719dd89d92213c6ba5b4872b79198c309f (patch)
tree261a006da63fc17c155854982f015276a5271de4 /pkg/sentry/fs/dev
parenta40ee4f4b8a6874157759723583d6489bbac7f23 (diff)
device: fix device major/minor
Current gvisor doesn't give devices a right major and minor number. When testing golang supporting of gvisor, I run the test case below: ``` $ docker run -ti --runtime runsc golang:1.12.1 bash -c "cd /usr/local/go/src && ./run.bash " ``` And it reports some errors, one of them is: "--- FAIL: TestDevices (0.00s) --- FAIL: TestDevices//dev/null_1:3 (0.00s) dev_linux_test.go:45: for /dev/null Major(0x0) == 0, want 1 dev_linux_test.go:48: for /dev/null Minor(0x0) == 0, want 3 dev_linux_test.go:51: for /dev/null Mkdev(1, 3) == 0x103, want 0x0 --- FAIL: TestDevices//dev/zero_1:5 (0.00s) dev_linux_test.go:45: for /dev/zero Major(0x0) == 0, want 1 dev_linux_test.go:48: for /dev/zero Minor(0x0) == 0, want 5 dev_linux_test.go:51: for /dev/zero Mkdev(1, 5) == 0x105, want 0x0 --- FAIL: TestDevices//dev/random_1:8 (0.00s) dev_linux_test.go:45: for /dev/random Major(0x0) == 0, want 1 dev_linux_test.go:48: for /dev/random Minor(0x0) == 0, want 8 dev_linux_test.go:51: for /dev/random Mkdev(1, 8) == 0x108, want 0x0 --- FAIL: TestDevices//dev/full_1:7 (0.00s) dev_linux_test.go:45: for /dev/full Major(0x0) == 0, want 1 dev_linux_test.go:48: for /dev/full Minor(0x0) == 0, want 7 dev_linux_test.go:51: for /dev/full Mkdev(1, 7) == 0x107, want 0x0 --- FAIL: TestDevices//dev/urandom_1:9 (0.00s) dev_linux_test.go:45: for /dev/urandom Major(0x0) == 0, want 1 dev_linux_test.go:48: for /dev/urandom Minor(0x0) == 0, want 9 dev_linux_test.go:51: for /dev/urandom Mkdev(1, 9) == 0x109, want 0x0 " So I think we'd better assign to them correct major/minor numbers following linux spec. Signed-off-by: Wei Zhang <zhangwei198900@gmail.com> Change-Id: I4521ee7884b4e214fd3a261929e3b6dac537ada9 PiperOrigin-RevId: 241609021
Diffstat (limited to 'pkg/sentry/fs/dev')
-rw-r--r--pkg/sentry/fs/dev/dev.go34
1 files changed, 29 insertions, 5 deletions
diff --git a/pkg/sentry/fs/dev/dev.go b/pkg/sentry/fs/dev/dev.go
index e1eaa08cb..fbc750a71 100644
--- a/pkg/sentry/fs/dev/dev.go
+++ b/pkg/sentry/fs/dev/dev.go
@@ -27,6 +27,19 @@ import (
"gvisor.googlesource.com/gvisor/pkg/sentry/usermem"
)
+// Memory device numbers are from Linux's drivers/char/mem.c
+const (
+ // Mem device major.
+ memDevMajor uint16 = 1
+
+ // Mem device minors.
+ nullDevMinor uint32 = 3
+ zeroDevMinor uint32 = 5
+ fullDevMinor uint32 = 7
+ randomDevMinor uint32 = 8
+ urandomDevMinor uint32 = 9
+)
+
func newCharacterDevice(iops fs.InodeOperations, msrc *fs.MountSource) *fs.Inode {
return fs.NewInode(iops, msrc, fs.StableAttr{
DeviceID: devDevice.DeviceID(),
@@ -36,6 +49,17 @@ func newCharacterDevice(iops fs.InodeOperations, msrc *fs.MountSource) *fs.Inode
})
}
+func newMemDevice(iops fs.InodeOperations, msrc *fs.MountSource, minor uint32) *fs.Inode {
+ return fs.NewInode(iops, msrc, fs.StableAttr{
+ DeviceID: devDevice.DeviceID(),
+ InodeID: devDevice.NextIno(),
+ BlockSize: usermem.PageSize,
+ Type: fs.CharacterDevice,
+ DeviceFileMajor: memDevMajor,
+ DeviceFileMinor: minor,
+ })
+}
+
func newDirectory(ctx context.Context, msrc *fs.MountSource) *fs.Inode {
iops := ramfs.NewDir(ctx, nil, fs.RootOwner, fs.FilePermsFromMode(0555))
return fs.NewInode(iops, msrc, fs.StableAttr{
@@ -64,17 +88,17 @@ func New(ctx context.Context, msrc *fs.MountSource, binderEnabled bool, ashmemEn
"stdout": newSymlink(ctx, "/proc/self/fd/1", msrc),
"stderr": newSymlink(ctx, "/proc/self/fd/2", msrc),
- "null": newCharacterDevice(newNullDevice(ctx, fs.RootOwner, 0666), msrc),
- "zero": newCharacterDevice(newZeroDevice(ctx, fs.RootOwner, 0666), msrc),
- "full": newCharacterDevice(newFullDevice(ctx, fs.RootOwner, 0666), msrc),
+ "null": newMemDevice(newNullDevice(ctx, fs.RootOwner, 0666), msrc, nullDevMinor),
+ "zero": newMemDevice(newZeroDevice(ctx, fs.RootOwner, 0666), msrc, zeroDevMinor),
+ "full": newMemDevice(newFullDevice(ctx, fs.RootOwner, 0666), msrc, fullDevMinor),
// This is not as good as /dev/random in linux because go
// runtime uses sys_random and /dev/urandom internally.
// According to 'man 4 random', this will be sufficient unless
// application uses this to generate long-lived GPG/SSL/SSH
// keys.
- "random": newCharacterDevice(newRandomDevice(ctx, fs.RootOwner, 0444), msrc),
- "urandom": newCharacterDevice(newRandomDevice(ctx, fs.RootOwner, 0444), msrc),
+ "random": newMemDevice(newRandomDevice(ctx, fs.RootOwner, 0444), msrc, randomDevMinor),
+ "urandom": newMemDevice(newRandomDevice(ctx, fs.RootOwner, 0444), msrc, urandomDevMinor),
"shm": tmpfs.NewDir(ctx, nil, fs.RootOwner, fs.FilePermsFromMode(0777), msrc),