unix: change Dup,Dup2,Dup3 to use Syscall, not RawSyscall

ianlancetaylor · ianlancetaylor · commit 5829c7488649 · 2015-03-26T17:59:35.000Z
This avoids hanging when a Go program uses a FUSE filesystem and the dup system call has to close a file descriptor. When dup uses RawSyscall then the goroutine calling dup will occupy a scheduler slot (a p structure) during the call, and may block waiting for some other goroutine to respond to the close call on the FUSE filesystem. Changing to Syscall avoids the problem. This makes Dup a tiny bit slower but is quite unlikely to make a difference for any real programs. Update golang/go#10202. Change-Id: I590c5c9a04e0a1281a85dc553c7592fa83949ac7 Reviewed-on: https://go-review.googlesource.com/8056 Reviewed-by: Rob Pike <r@golang.org>
diff --git a/unix/syscall_darwin.go b/unix/syscall_darwin.go
@@ -222,8 +222,8 @@ func Kill(pid int, signum syscall.Signal) (err error) { return kill(pid, int(sig
 //sys	Chown(path string, uid int, gid int) (err error)
 //sys	Chroot(path string) (err error)
 //sys	Close(fd int) (err error)
-//sysnb	Dup(fd int) (nfd int, err error)
-//sysnb	Dup2(from int, to int) (err error)
+//sys	Dup(fd int) (nfd int, err error)
+//sys	Dup2(from int, to int) (err error)
 //sys	Exchangedata(path1 string, path2 string, options int) (err error)
 //sys	Exit(code int)
 //sys	Fchdir(fd int) (err error)
diff --git a/unix/syscall_dragonfly.go b/unix/syscall_dragonfly.go
@@ -127,8 +127,8 @@ func Getfsstat(buf []Statfs_t, flags int) (n int, err error) {
 //sys	Chown(path string, uid int, gid int) (err error)
 //sys	Chroot(path string) (err error)
 //sys	Close(fd int) (err error)
-//sysnb	Dup(fd int) (nfd int, err error)
-//sysnb	Dup2(from int, to int) (err error)
+//sys	Dup(fd int) (nfd int, err error)
+//sys	Dup2(from int, to int) (err error)
 //sys	Exit(code int)
 //sys	Fchdir(fd int) (err error)
 //sys	Fchflags(fd int, flags int) (err error)
diff --git a/unix/syscall_freebsd.go b/unix/syscall_freebsd.go
@@ -379,8 +379,8 @@ func Llistxattr(link string, dest []byte) (sz int, err error) {
 //sys	Chown(path string, uid int, gid int) (err error)
 //sys	Chroot(path string) (err error)
 //sys	Close(fd int) (err error)
-//sysnb	Dup(fd int) (nfd int, err error)
-//sysnb	Dup2(from int, to int) (err error)
+//sys	Dup(fd int) (nfd int, err error)
+//sys	Dup2(from int, to int) (err error)
 //sys	Exit(code int)
 //sys	ExtattrGetFd(fd int, attrnamespace int, attrname string, data uintptr, nbytes int) (ret int, err error)
 //sys	ExtattrSetFd(fd int, attrnamespace int, attrname string, data uintptr, nbytes int) (ret int, err error)
diff --git a/unix/syscall_linux.go b/unix/syscall_linux.go
@@ -790,9 +790,9 @@ func Mount(source string, target string, fstype string, flags uintptr, data stri
 //sys	Chroot(path string) (err error)
 //sys	Close(fd int) (err error)
 //sys	Creat(path string, mode uint32) (fd int, err error)
-//sysnb	Dup(oldfd int) (fd int, err error)
-//sysnb	Dup2(oldfd int, newfd int) (err error)
-//sysnb	Dup3(oldfd int, newfd int, flags int) (err error)
+//sys	Dup(oldfd int) (fd int, err error)
+//sys	Dup2(oldfd int, newfd int) (err error)
+//sys	Dup3(oldfd int, newfd int, flags int) (err error)
 //sysnb	EpollCreate(size int) (fd int, err error)
 //sysnb	EpollCreate1(flag int) (fd int, err error)
 //sysnb	EpollCtl(epfd int, op int, fd int, event *EpollEvent) (err error)
diff --git a/unix/syscall_netbsd.go b/unix/syscall_netbsd.go
@@ -151,8 +151,8 @@ func sendfile(outfd int, infd int, offset *int64, count int) (written int, err e
 //sys	Chown(path string, uid int, gid int) (err error)
 //sys	Chroot(path string) (err error)
 //sys	Close(fd int) (err error)
-//sysnb	Dup(fd int) (nfd int, err error)
-//sysnb	Dup2(from int, to int) (err error)
+//sys	Dup(fd int) (nfd int, err error)
+//sys	Dup2(from int, to int) (err error)
 //sys	Exit(code int)
 //sys	Fchdir(fd int) (err error)
 //sys	Fchflags(fd int, flags int) (err error)
diff --git a/unix/syscall_openbsd.go b/unix/syscall_openbsd.go
@@ -129,8 +129,8 @@ func Getfsstat(buf []Statfs_t, flags int) (n int, err error) {
 //sys	Chown(path string, uid int, gid int) (err error)
 //sys	Chroot(path string) (err error)
 //sys	Close(fd int) (err error)
-//sysnb	Dup(fd int) (nfd int, err error)
-//sysnb	Dup2(from int, to int) (err error)
+//sys	Dup(fd int) (nfd int, err error)
+//sys	Dup2(from int, to int) (err error)
 //sys	Exit(code int)
 //sys	Fchdir(fd int) (err error)
 //sys	Fchflags(fd int, flags int) (err error)
diff --git a/unix/zsyscall_darwin_386.go b/unix/zsyscall_darwin_386.go
@@ -3,7 +3,12 @@
 
 package unix
 
-import "unsafe"
+import (
+	"syscall"
+	"unsafe"
+)
+
+var _ syscall.Errno
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
@@ -409,7 +414,7 @@ func Close(fd int) (err error) {
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Dup(fd int) (nfd int, err error) {
-	r0, _, e1 := RawSyscall(SYS_DUP, uintptr(fd), 0, 0)
+	r0, _, e1 := Syscall(SYS_DUP, uintptr(fd), 0, 0)
 	nfd = int(r0)
 	if e1 != 0 {
 		err = e1
@@ -420,7 +425,7 @@ func Dup(fd int) (nfd int, err error) {
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Dup2(from int, to int) (err error) {
-	_, _, e1 := RawSyscall(SYS_DUP2, uintptr(from), uintptr(to), 0)
+	_, _, e1 := Syscall(SYS_DUP2, uintptr(from), uintptr(to), 0)
 	if e1 != 0 {
 		err = e1
 	}
diff --git a/unix/zsyscall_darwin_amd64.go b/unix/zsyscall_darwin_amd64.go
@@ -3,7 +3,12 @@
 
 package unix
 
-import "unsafe"
+import (
+	"syscall"
+	"unsafe"
+)
+
+var _ syscall.Errno
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
@@ -409,7 +414,7 @@ func Close(fd int) (err error) {
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Dup(fd int) (nfd int, err error) {
-	r0, _, e1 := RawSyscall(SYS_DUP, uintptr(fd), 0, 0)
+	r0, _, e1 := Syscall(SYS_DUP, uintptr(fd), 0, 0)
 	nfd = int(r0)
 	if e1 != 0 {
 		err = e1
@@ -420,7 +425,7 @@ func Dup(fd int) (nfd int, err error) {
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Dup2(from int, to int) (err error) {
-	_, _, e1 := RawSyscall(SYS_DUP2, uintptr(from), uintptr(to), 0)
+	_, _, e1 := Syscall(SYS_DUP2, uintptr(from), uintptr(to), 0)
 	if e1 != 0 {
 		err = e1
 	}
diff --git a/unix/zsyscall_dragonfly_386.go b/unix/zsyscall_dragonfly_386.go
@@ -428,7 +428,7 @@ func Close(fd int) (err error) {
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Dup(fd int) (nfd int, err error) {
-	r0, _, e1 := RawSyscall(SYS_DUP, uintptr(fd), 0, 0)
+	r0, _, e1 := Syscall(SYS_DUP, uintptr(fd), 0, 0)
 	nfd = int(r0)
 	if e1 != 0 {
 		err = e1
@@ -439,7 +439,7 @@ func Dup(fd int) (nfd int, err error) {
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Dup2(from int, to int) (err error) {
-	_, _, e1 := RawSyscall(SYS_DUP2, uintptr(from), uintptr(to), 0)
+	_, _, e1 := Syscall(SYS_DUP2, uintptr(from), uintptr(to), 0)
 	if e1 != 0 {
 		err = e1
 	}
diff --git a/unix/zsyscall_dragonfly_amd64.go b/unix/zsyscall_dragonfly_amd64.go
@@ -428,7 +428,7 @@ func Close(fd int) (err error) {
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Dup(fd int) (nfd int, err error) {
-	r0, _, e1 := RawSyscall(SYS_DUP, uintptr(fd), 0, 0)
+	r0, _, e1 := Syscall(SYS_DUP, uintptr(fd), 0, 0)
 	nfd = int(r0)
 	if e1 != 0 {
 		err = e1
@@ -439,7 +439,7 @@ func Dup(fd int) (nfd int, err error) {
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Dup2(from int, to int) (err error) {
-	_, _, e1 := RawSyscall(SYS_DUP2, uintptr(from), uintptr(to), 0)
+	_, _, e1 := Syscall(SYS_DUP2, uintptr(from), uintptr(to), 0)
 	if e1 != 0 {
 		err = e1
 	}
diff --git a/unix/zsyscall_freebsd_386.go b/unix/zsyscall_freebsd_386.go
@@ -394,7 +394,7 @@ func Close(fd int) (err error) {
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Dup(fd int) (nfd int, err error) {
-	r0, _, e1 := RawSyscall(SYS_DUP, uintptr(fd), 0, 0)
+	r0, _, e1 := Syscall(SYS_DUP, uintptr(fd), 0, 0)
 	nfd = int(r0)
 	if e1 != 0 {
 		err = e1
@@ -405,7 +405,7 @@ func Dup(fd int) (nfd int, err error) {
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Dup2(from int, to int) (err error) {
-	_, _, e1 := RawSyscall(SYS_DUP2, uintptr(from), uintptr(to), 0)
+	_, _, e1 := Syscall(SYS_DUP2, uintptr(from), uintptr(to), 0)
 	if e1 != 0 {
 		err = e1
 	}
diff --git a/unix/zsyscall_freebsd_amd64.go b/unix/zsyscall_freebsd_amd64.go
@@ -394,7 +394,7 @@ func Close(fd int) (err error) {
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Dup(fd int) (nfd int, err error) {
-	r0, _, e1 := RawSyscall(SYS_DUP, uintptr(fd), 0, 0)
+	r0, _, e1 := Syscall(SYS_DUP, uintptr(fd), 0, 0)
 	nfd = int(r0)
 	if e1 != 0 {
 		err = e1
@@ -405,7 +405,7 @@ func Dup(fd int) (nfd int, err error) {
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Dup2(from int, to int) (err error) {
-	_, _, e1 := RawSyscall(SYS_DUP2, uintptr(from), uintptr(to), 0)
+	_, _, e1 := Syscall(SYS_DUP2, uintptr(from), uintptr(to), 0)
 	if e1 != 0 {
 		err = e1
 	}
diff --git a/unix/zsyscall_freebsd_arm.go b/unix/zsyscall_freebsd_arm.go
@@ -394,7 +394,7 @@ func Close(fd int) (err error) {
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Dup(fd int) (nfd int, err error) {
-	r0, _, e1 := RawSyscall(SYS_DUP, uintptr(fd), 0, 0)
+	r0, _, e1 := Syscall(SYS_DUP, uintptr(fd), 0, 0)
 	nfd = int(r0)
 	if e1 != 0 {
 		err = e1
@@ -405,7 +405,7 @@ func Dup(fd int) (nfd int, err error) {
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Dup2(from int, to int) (err error) {
-	_, _, e1 := RawSyscall(SYS_DUP2, uintptr(from), uintptr(to), 0)
+	_, _, e1 := Syscall(SYS_DUP2, uintptr(from), uintptr(to), 0)
 	if e1 != 0 {
 		err = e1
 	}
diff --git a/unix/zsyscall_linux_386.go b/unix/zsyscall_linux_386.go
@@ -309,7 +309,7 @@ func Creat(path string, mode uint32) (fd int, err error) {
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Dup(oldfd int) (fd int, err error) {
-	r0, _, e1 := RawSyscall(SYS_DUP, uintptr(oldfd), 0, 0)
+	r0, _, e1 := Syscall(SYS_DUP, uintptr(oldfd), 0, 0)
 	fd = int(r0)
 	if e1 != 0 {
 		err = e1
@@ -320,7 +320,7 @@ func Dup(oldfd int) (fd int, err error) {
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Dup2(oldfd int, newfd int) (err error) {
-	_, _, e1 := RawSyscall(SYS_DUP2, uintptr(oldfd), uintptr(newfd), 0)
+	_, _, e1 := Syscall(SYS_DUP2, uintptr(oldfd), uintptr(newfd), 0)
 	if e1 != 0 {
 		err = e1
 	}
@@ -330,7 +330,7 @@ func Dup2(oldfd int, newfd int) (err error) {
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Dup3(oldfd int, newfd int, flags int) (err error) {
-	_, _, e1 := RawSyscall(SYS_DUP3, uintptr(oldfd), uintptr(newfd), uintptr(flags))
+	_, _, e1 := Syscall(SYS_DUP3, uintptr(oldfd), uintptr(newfd), uintptr(flags))
 	if e1 != 0 {
 		err = e1
 	}
diff --git a/unix/zsyscall_linux_amd64.go b/unix/zsyscall_linux_amd64.go
@@ -309,7 +309,7 @@ func Creat(path string, mode uint32) (fd int, err error) {
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Dup(oldfd int) (fd int, err error) {
-	r0, _, e1 := RawSyscall(SYS_DUP, uintptr(oldfd), 0, 0)
+	r0, _, e1 := Syscall(SYS_DUP, uintptr(oldfd), 0, 0)
 	fd = int(r0)
 	if e1 != 0 {
 		err = e1
@@ -320,7 +320,7 @@ func Dup(oldfd int) (fd int, err error) {
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Dup2(oldfd int, newfd int) (err error) {
-	_, _, e1 := RawSyscall(SYS_DUP2, uintptr(oldfd), uintptr(newfd), 0)
+	_, _, e1 := Syscall(SYS_DUP2, uintptr(oldfd), uintptr(newfd), 0)
 	if e1 != 0 {
 		err = e1
 	}
@@ -330,7 +330,7 @@ func Dup2(oldfd int, newfd int) (err error) {
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Dup3(oldfd int, newfd int, flags int) (err error) {
-	_, _, e1 := RawSyscall(SYS_DUP3, uintptr(oldfd), uintptr(newfd), uintptr(flags))
+	_, _, e1 := Syscall(SYS_DUP3, uintptr(oldfd), uintptr(newfd), uintptr(flags))
 	if e1 != 0 {
 		err = e1
 	}
diff --git a/unix/zsyscall_linux_arm.go b/unix/zsyscall_linux_arm.go
@@ -309,7 +309,7 @@ func Creat(path string, mode uint32) (fd int, err error) {
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Dup(oldfd int) (fd int, err error) {
-	r0, _, e1 := RawSyscall(SYS_DUP, uintptr(oldfd), 0, 0)
+	r0, _, e1 := Syscall(SYS_DUP, uintptr(oldfd), 0, 0)
 	fd = int(r0)
 	if e1 != 0 {
 		err = e1
@@ -320,7 +320,7 @@ func Dup(oldfd int) (fd int, err error) {
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Dup2(oldfd int, newfd int) (err error) {
-	_, _, e1 := RawSyscall(SYS_DUP2, uintptr(oldfd), uintptr(newfd), 0)
+	_, _, e1 := Syscall(SYS_DUP2, uintptr(oldfd), uintptr(newfd), 0)
 	if e1 != 0 {
 		err = e1
 	}
@@ -330,7 +330,7 @@ func Dup2(oldfd int, newfd int) (err error) {
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Dup3(oldfd int, newfd int, flags int) (err error) {
-	_, _, e1 := RawSyscall(SYS_DUP3, uintptr(oldfd), uintptr(newfd), uintptr(flags))
+	_, _, e1 := Syscall(SYS_DUP3, uintptr(oldfd), uintptr(newfd), uintptr(flags))
 	if e1 != 0 {
 		err = e1
 	}
diff --git a/unix/zsyscall_netbsd_386.go b/unix/zsyscall_netbsd_386.go
@@ -411,7 +411,7 @@ func Close(fd int) (err error) {
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Dup(fd int) (nfd int, err error) {
-	r0, _, e1 := RawSyscall(SYS_DUP, uintptr(fd), 0, 0)
+	r0, _, e1 := Syscall(SYS_DUP, uintptr(fd), 0, 0)
 	nfd = int(r0)
 	if e1 != 0 {
 		err = e1
@@ -422,7 +422,7 @@ func Dup(fd int) (nfd int, err error) {
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Dup2(from int, to int) (err error) {
-	_, _, e1 := RawSyscall(SYS_DUP2, uintptr(from), uintptr(to), 0)
+	_, _, e1 := Syscall(SYS_DUP2, uintptr(from), uintptr(to), 0)
 	if e1 != 0 {
 		err = e1
 	}
diff --git a/unix/zsyscall_netbsd_amd64.go b/unix/zsyscall_netbsd_amd64.go
@@ -411,7 +411,7 @@ func Close(fd int) (err error) {
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Dup(fd int) (nfd int, err error) {
-	r0, _, e1 := RawSyscall(SYS_DUP, uintptr(fd), 0, 0)
+	r0, _, e1 := Syscall(SYS_DUP, uintptr(fd), 0, 0)
 	nfd = int(r0)
 	if e1 != 0 {
 		err = e1
@@ -422,7 +422,7 @@ func Dup(fd int) (nfd int, err error) {
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Dup2(from int, to int) (err error) {
-	_, _, e1 := RawSyscall(SYS_DUP2, uintptr(from), uintptr(to), 0)
+	_, _, e1 := Syscall(SYS_DUP2, uintptr(from), uintptr(to), 0)
 	if e1 != 0 {
 		err = e1
 	}
diff --git a/unix/zsyscall_netbsd_arm.go b/unix/zsyscall_netbsd_arm.go
diff --git a/unix/zsyscall_openbsd_386.go b/unix/zsyscall_openbsd_386.go
diff --git a/unix/zsyscall_openbsd_amd64.go b/unix/zsyscall_openbsd_amd64.go
