syscallcompat: Drop Fchownat emulation on macOS.

5 files changed, 10 insertions, 38 deletions

diff --git a/internal/syscallcompat/emulate.go b/internal/syscallcompat/emulate.go
index 8a538fb..dc8cf6d 100644
--- a/internal/syscallcompat/emulate.go
+++ b/internal/syscallcompat/emulate.go
@@ -30,26 +30,6 @@ func emulateMknodat(dirfd int, path string, mode uint32, dev int) error {
 	return syscall.Mknod(path, mode, dev)
 }
 
-// emulateFchownat emulates the syscall for platforms that don't have it
-// in the kernel (darwin).
-func emulateFchownat(dirfd int, path string, uid int, gid int, flags int) (err error) {
-	if !filepath.IsAbs(path) {
-		chdirMutex.Lock()
-		defer chdirMutex.Unlock()
-		cwd, err := syscall.Open(".", syscall.O_RDONLY, 0)
-		if err != nil {
-			return err
-		}
-		defer syscall.Close(cwd)
-		err = syscall.Fchdir(dirfd)
-		if err != nil {
-			return err
-		}
-		defer syscall.Fchdir(cwd)
-	}
-	return syscall.Lchown(path, uid, gid)
-}
-
 // emulateSymlinkat emulates the syscall for platforms that don't have it
 // in the kernel (darwin).
 func emulateSymlinkat(oldpath string, newdirfd int, newpath string) (err error) {
diff --git a/internal/syscallcompat/emulate_test.go b/internal/syscallcompat/emulate_test.go
index 3f23d91..6fe5f3e 100644
--- a/internal/syscallcompat/emulate_test.go
+++ b/internal/syscallcompat/emulate_test.go
@@ -29,10 +29,6 @@ func TestEmulateMknodat(t *testing.T) {
 	}
 }
 
-func TestEmulateFchownat(t *testing.T) {
-	t.Skipf("TODO")
-}
-
 // symlinkCheckMode looks if the mode bits in "st" say that this is a symlink.
 // Calls t.Fatal() if not.
 func symlinkCheckMode(t *testing.T, st syscall.Stat_t) {
diff --git a/internal/syscallcompat/sys_common.go b/internal/syscallcompat/sys_common.go
index 75d2509..9514830 100644
--- a/internal/syscallcompat/sys_common.go
+++ b/internal/syscallcompat/sys_common.go
@@ -72,6 +72,16 @@ func Unlinkat(dirfd int, path string, flags int) (err error) {
 	return unix.Unlinkat(dirfd, path, flags)
 }
 
+// Fchownat syscall.
+func Fchownat(dirfd int, path string, uid int, gid int, flags int) (err error) {
+	// Why would we ever want to call this without AT_SYMLINK_NOFOLLOW?
+	if flags&unix.AT_SYMLINK_NOFOLLOW == 0 {
+		tlog.Warn.Printf("Fchownat: adding missing AT_SYMLINK_NOFOLLOW flag")
+		flags |= unix.AT_SYMLINK_NOFOLLOW
+	}
+	return unix.Fchownat(dirfd, path, uid, gid, flags)
+}
+
 // Linkat exists both in Linux and in MacOS 10.10+.
 func Linkat(olddirfd int, oldpath string, newdirfd int, newpath string, flags int) (err error) {
 	return unix.Linkat(olddirfd, oldpath, newdirfd, newpath, flags)
diff --git a/internal/syscallcompat/sys_darwin.go b/internal/syscallcompat/sys_darwin.go
index 89d93e7..be85fee 100644
--- a/internal/syscallcompat/sys_darwin.go
+++ b/internal/syscallcompat/sys_darwin.go
@@ -102,10 +102,6 @@ func Fchmodat(dirfd int, path string, mode uint32, flags int) (err error) {
 	return unix.Fchmodat(dirfd, path, mode, flags)
 }
 
-func Fchownat(dirfd int, path string, uid int, gid int, flags int) (err error) {
-	return emulateFchownat(dirfd, path, uid, gid, flags)
-}
-
 func Symlinkat(oldpath string, newdirfd int, newpath string) (err error) {
 	return emulateSymlinkat(oldpath, newdirfd, newpath)
 }
diff --git a/internal/syscallcompat/sys_linux.go b/internal/syscallcompat/sys_linux.go
index 28a7149..cacec6a 100644
--- a/internal/syscallcompat/sys_linux.go
+++ b/internal/syscallcompat/sys_linux.go
@@ -154,16 +154,6 @@ func Fchmodat(dirfd int, path string, mode uint32, flags int) (err error) {
 	return syscall.Chmod(procPath, mode)
 }
 
-// Fchownat syscall.
-func Fchownat(dirfd int, path string, uid int, gid int, flags int) (err error) {
-	// Why would we ever want to call this without AT_SYMLINK_NOFOLLOW?
-	if flags&unix.AT_SYMLINK_NOFOLLOW == 0 {
-		tlog.Warn.Printf("Fchownat: adding missing AT_SYMLINK_NOFOLLOW flag")
-		flags |= unix.AT_SYMLINK_NOFOLLOW
-	}
-	return syscall.Fchownat(dirfd, path, uid, gid, flags)
-}
-
 // Symlinkat syscall.
 func Symlinkat(oldpath string, newdirfd int, newpath string) (err error) {
 	return unix.Symlinkat(oldpath, newdirfd, newpath)