c943ed32aa
The allocations from Lgetxattr were #1 in the tar extract allocation profile (caused by security.capability lookups). No more! $ benchstat old.txt new.txt name old time/op new time/op delta Lgetxattr-4 15.2µs ± 0% 1.8µs ± 0% ~ (p=1.000 n=1+1) $ ./benchmark.bash Testing gocryptfs at /tmp/benchmark.bash.H8p: gocryptfs v2.0-beta1-4-g95ea738-dirty; go-fuse v2.0.4-0.20200908172753-0b6cbc515082 => github.com/rfjakob/go-fuse/v2 v2.0.4-0.20201015204057-88b12c99f8af; 2020-10-18 go1.15.3 linux/amd64 /tmp/benchmark.bash.H8p.mnt is a mountpoint WRITE: 262144000 bytes (262 MB, 250 MiB) copied, 0,520109 s, 504 MB/s READ: 262144000 bytes (262 MB, 250 MiB) copied, 0,255672 s, 1,0 GB/s UNTAR: 30,238 MD5: 12,721 LS: 10,038 RM: 16,536
324 lines
7.5 KiB
Go
324 lines
7.5 KiB
Go
package syscallcompat
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import (
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"bytes"
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"os"
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"runtime"
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"syscall"
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"testing"
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"golang.org/x/sys/unix"
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)
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func TestReadlinkat(t *testing.T) {
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for _, targetLen := range []int{100, 500, 4000} {
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target := string(bytes.Repeat([]byte("x"), targetLen))
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err := syscall.Symlink(target, tmpDir+"/readlinkat")
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if err != nil {
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if targetLen > 1000 {
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// Symlinks longer than 1024 (?) bytes are not supported on
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// MacOS and XFS
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t.Logf("skipping targetLen=%d: %v", targetLen, err)
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continue
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}
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t.Fatalf("targetLen=%d: %v", targetLen, err)
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}
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target2, err := Readlinkat(tmpDirFd, "readlinkat")
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if err != nil {
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t.Fatal(err)
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}
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if target != target2 {
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t.Errorf("target=%q != target2=%q", target, target2)
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}
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err = syscall.Unlink(tmpDir + "/readlinkat")
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if err != nil {
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t.Fatal(err)
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}
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}
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}
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func TestOpenat(t *testing.T) {
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// Always pass O_NOFOLLOW to avoid this warning:
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// Openat: O_NOFOLLOW missing: flags = 0x0"
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_, err := Openat(tmpDirFd, "testOpenAt", syscall.O_NOFOLLOW, 0)
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if err == nil {
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t.Errorf("should have failed")
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}
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fd, err := os.Create(tmpDir + "/testOpenAt")
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if err != nil {
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t.Fatal(err)
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}
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fd.Close()
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rawFd, err := Openat(tmpDirFd, "testOpenAt", syscall.O_NOFOLLOW, 0)
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if err != nil {
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t.Fatal(err)
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}
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defer syscall.Close(rawFd)
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if rawFd < 0 {
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t.Fatalf("rawFd=%d", rawFd)
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}
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// Test with absolute path
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rawFd, err = Openat(-1, tmpDir+"/testOpenAt", syscall.O_NOFOLLOW, 0)
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if err != nil {
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t.Fatal(err)
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}
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defer syscall.Close(rawFd)
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if rawFd < 0 {
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t.Fatalf("rawFd=%d", rawFd)
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}
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}
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func TestRenameat(t *testing.T) {
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os.Mkdir(tmpDir+"/dir1", 0700)
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dir1, err := os.Open(tmpDir + "/dir1")
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if err != nil {
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t.Fatal(err)
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}
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defer dir1.Close()
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os.Mkdir(tmpDir+"/dir2", 0700)
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dir2, err := os.Open(tmpDir + "/dir2")
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if err != nil {
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t.Fatal(err)
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}
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defer dir2.Close()
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fd, err := os.Create(tmpDir + "/dir1/f1")
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if err != nil {
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t.Fatal(err)
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}
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fd.Close()
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err = Renameat(int(dir1.Fd()), "f1", int(dir2.Fd()), "f2")
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if err != nil {
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t.Fatal(err)
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}
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_, err = os.Stat(tmpDir + "/dir2/f2")
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if err != nil {
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t.Fatal(err)
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}
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// Test with absolute path
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err = Renameat(-1, tmpDir+"/dir2/f2", -1, tmpDir+"/dir2/f1")
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if err != nil {
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t.Fatal(err)
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}
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_, err = os.Stat(tmpDir + "/dir2/f1")
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if err != nil {
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t.Fatal(err)
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}
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}
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func TestUnlinkat(t *testing.T) {
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os.Mkdir(tmpDir+"/unlink1", 0700)
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dirfd, err := os.Open(tmpDir + "/unlink1")
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if err != nil {
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t.Fatal(err)
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}
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defer dirfd.Close()
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// Try to delete file
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fd, err := os.Create(tmpDir + "/unlink1/f1")
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if err != nil {
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t.Fatal(err)
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}
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fd.Close()
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err = Unlinkat(int(dirfd.Fd()), "f1", 0)
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if err != nil {
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t.Fatal(err)
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}
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_, err = os.Stat(tmpDir + "/unlink1/f1")
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if err == nil {
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t.Fatalf("file not deleted!")
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}
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// Try to delete dir
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err = os.Mkdir(tmpDir+"/unlink1/d1", 0700)
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if err != nil {
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t.Fatal(err)
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}
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err = Unlinkat(int(dirfd.Fd()), "d1", 0)
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if err == nil {
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t.Fatalf("this should fail due to missing AT_REMOVEDIR flag")
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}
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err = Unlinkat(int(dirfd.Fd()), "d1", unix.AT_REMOVEDIR)
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if err != nil {
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t.Fatal(err)
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}
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_, err = os.Stat(tmpDir + "/unlink1/d1")
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if err == nil {
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t.Fatalf("dir not deleted!")
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}
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// Test with absolute path
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err = os.Mkdir(tmpDir+"/unlink1/d1", 0700)
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if err != nil {
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t.Fatal(err)
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}
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err = Unlinkat(-1, tmpDir+"/unlink1/d1", unix.AT_REMOVEDIR)
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if err != nil {
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t.Fatal(err)
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}
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_, err = os.Stat(tmpDir + "/unlink1/d1")
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if err == nil {
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t.Fatalf("dir not deleted!")
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}
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}
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func TestFchmodatNofollow(t *testing.T) {
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regular := "TestFchmodat_Regular"
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f, err := os.OpenFile(tmpDir+"/"+regular, os.O_CREATE|os.O_WRONLY, 0000)
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if err != nil {
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t.Fatal(err)
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}
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f.Close()
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symlink := "TestFchmodat_Symlink"
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err = syscall.Symlink(regular, tmpDir+"/"+symlink)
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if err != nil {
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t.Fatal(err)
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}
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dirfd, err := syscall.Open(tmpDir, syscall.O_RDONLY, 0)
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if err != nil {
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t.Fatal(err)
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}
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defer syscall.Close(dirfd)
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// Check that chmod on a regular file works ok
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err = FchmodatNofollow(dirfd, regular, 0111)
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if err != nil {
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t.Fatal(err)
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}
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var st syscall.Stat_t
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syscall.Lstat(tmpDir+"/"+regular, &st)
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st.Mode &= 0777
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if st.Mode != 0111 {
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t.Errorf("wrong mode: %#0o", st.Mode)
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}
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err = FchmodatNofollow(dirfd, regular, 0000)
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if err != nil {
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t.Error(err)
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}
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syscall.Lstat(tmpDir+"/"+regular, &st)
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st.Mode &= 0777
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if st.Mode != 0000 {
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t.Errorf("wrong mode: %#0o", st.Mode)
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}
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// Check what happens on a symlink
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err = FchmodatNofollow(dirfd, symlink, 0333)
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// On Darwin, permissions on symlinks are significant and can be changed. On
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// Linux they are ignored, and FchmodatNofollow rejects attempts to change
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// them.
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if err == nil && runtime.GOOS == "linux" {
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syscall.Lstat(tmpDir+"/"+symlink, &st)
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st.Mode &= 0777
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t.Errorf("chmod on symlink should have failed, but did not. New mode=%#0o", st.Mode)
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}
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syscall.Lstat(tmpDir+"/"+regular, &st)
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st.Mode &= 0777
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if st.Mode != 0000 {
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t.Errorf("chmod on symlink affected symlink target: New mode=%#0o", st.Mode)
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}
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}
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// symlinkCheckMode looks if the mode bits in "st" say that this is a symlink.
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// Calls t.Fatal() if not.
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func symlinkCheckMode(t *testing.T, st syscall.Stat_t) {
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if runtime.GOOS == "darwin" {
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// On MacOS, symlinks don't carry their own permissions, so
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// only check the file type.
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if st.Mode&syscall.S_IFMT != syscall.S_IFLNK {
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t.Fatalf("This is not a symlink: mode = 0%o", st.Mode)
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}
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return
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}
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if st.Mode != 0120777 {
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t.Fatalf("Wrong mode, have 0%o, want 0120777", st.Mode)
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}
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}
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func TestSymlinkat(t *testing.T) {
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err := Symlinkat("/foo/bar/baz", tmpDirFd, "symlink1")
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if err != nil {
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t.Fatal(err)
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}
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var st syscall.Stat_t
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err = syscall.Lstat(tmpDir+"/symlink1", &st)
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if err != nil {
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t.Fatal(err)
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}
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symlinkCheckMode(t, st)
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// Test with absolute path
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err = Symlinkat("/foo/bar/baz", -1, tmpDir+"/symlink2")
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if err != nil {
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t.Fatal(err)
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}
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err = syscall.Lstat(tmpDir+"/symlink2", &st)
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if err != nil {
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t.Fatal(err)
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}
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symlinkCheckMode(t, st)
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}
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func TestMkdirat(t *testing.T) {
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err := Mkdirat(tmpDirFd, "mkdirat", 0700)
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if err != nil {
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t.Fatal(err)
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}
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fi, err := os.Stat(tmpDir + "/mkdirat")
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if err != nil {
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t.Fatal(err)
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}
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if !fi.IsDir() {
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t.Fatalf("mkdirat did not create a directory")
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}
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// Test with absolute path
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err = Mkdirat(-1, tmpDir+"/mkdirat2", 0700)
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if err != nil {
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t.Fatal(err)
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}
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fi, err = os.Stat(tmpDir + "/mkdirat2")
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if err != nil {
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t.Fatal(err)
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}
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if !fi.IsDir() {
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t.Fatalf("mkdirat did not create a directory")
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}
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}
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func TestFstatat(t *testing.T) {
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var st unix.Stat_t
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// stat a normal file (size 3)
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f, err := os.Create(tmpDir + "/fstatat")
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if err != nil {
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t.Fatal(err)
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}
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_, err = f.Write([]byte("foo"))
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if err != nil {
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t.Fatal(err)
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}
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f.Close()
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err = Fstatat(tmpDirFd, "fstatat", &st, unix.AT_SYMLINK_NOFOLLOW)
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if err != nil {
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t.Fatal(err)
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}
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if st.Size != 3 {
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t.Errorf("wrong file size: %d", st.Size)
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}
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// stat a symlink and check that the size matches the length of the
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// symlink target. This proves that we have stat'ed the symlink itself.
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err = os.Symlink(tmpDir+"/fstatat", tmpDir+"/fstatatSymlink")
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if err != nil {
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t.Fatal(err)
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}
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err = Fstatat(tmpDirFd, "fstatatSymlink", &st, unix.AT_SYMLINK_NOFOLLOW)
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if err != nil {
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t.Fatal(err)
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}
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expectedSize := int64(len(tmpDir + "/fstatat"))
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if st.Size != expectedSize {
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t.Errorf("symlink size: expected=%d, got=%d", expectedSize, st.Size)
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}
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}
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// BenchmarkLgetxattr benchmarks Lgetxattr. Lgetxattr is very hot as the kernel
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// queries security.capabilities for every file access.
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func BenchmarkLgetxattr(b *testing.B) {
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for i := 0; i < b.N; i++ {
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Lgetxattr("/", "user.this.attr.does.not.exist")
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}
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}
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