os: always check for EINTR in calls to open

For golang#11180
For golang#20400
For golang#39237

Change-Id: I8de97517c8f92c08f0c8a51f651a17e31617979b
Reviewed-on: https://go-review.googlesource.com/c/go/+/236997
Reviewed-by: Bryan C. Mills <bcmills@google.com>

src/os/file_unix.go

@@ -202,10 +202,8 @@ func openFileNolog(name string, flag int, perm FileMode) (*File, error) {
 			break
 		}
 
-		// On OS X, sigaction(2) doesn't guarantee that SA_RESTART will cause
-		// open(2) to be restarted for regular files. This is easy to reproduce on
-		// fuse file systems (see https://golang.org/issue/11180).
-		if runtime.GOOS == "darwin" && e == syscall.EINTR {
+		// We have to check EINTR here, per issues 11180 and 39237.
+		if e == syscall.EINTR {
 			continue
 		}
 

src/os/removeall_at.go

@@ -9,7 +9,6 @@ package os
 import (
 	"internal/syscall/unix"
 	"io"
-	"runtime"
 	"syscall"
 )
 
@@ -178,7 +177,7 @@ func openFdAt(dirfd int, name string) (*File, error) {
 		}
 
 		// See comment in openFileNolog.
-		if runtime.GOOS == "darwin" && e == syscall.EINTR {
+		if e == syscall.EINTR {
 			continue
 		}