unix: fix Pause on linux-arm64

Pause is a legacy syscall not available on linux-arm64. Use ppoll with
all args as 0 to emulate - this is the way musl libc does Pause when the
pause syscall isn't available.

With the changes in syscall_linux* and regenerating zsyscall_linux*,
this calling Pause on linux-arm64 works and returns EINTR as expected.

Change-Id: I88236290313f18c742d826e759e86ff260a8b383
Reviewed-on: https://go-review.googlesource.com/22014
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

unix/syscall_linux.go

@@ -906,7 +906,6 @@ func Getpgrp() (pid int) {
 //sys	Mkdirat(dirfd int, path string, mode uint32) (err error)
 //sys	Mknodat(dirfd int, path string, mode uint32, dev int) (err error)
 //sys	Nanosleep(time *Timespec, leftover *Timespec) (err error)
-//sys	Pause() (err error)
 //sys	PivotRoot(newroot string, putold string) (err error) = SYS_PIVOT_ROOT
 //sysnb prlimit(pid int, resource int, old *Rlimit, newlimit *Rlimit) (err error) = SYS_PRLIMIT64
 //sys   Prctl(option int, arg2 uintptr, arg3 uintptr, arg4 uintptr, arg5 uintptr) (err error)

unix/syscall_linux_386.go

@@ -92,6 +92,7 @@ func Pipe2(p []int, flags int) (err error) {
 
 //sys	mmap2(addr uintptr, length uintptr, prot int, flags int, fd int, pageOffset uintptr) (xaddr uintptr, err error)
 //sys	EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error)
+//sys	Pause() (err error)
 
 func mmap(addr uintptr, length uintptr, prot int, flags int, fd int, offset int64) (xaddr uintptr, err error) {
 	page := uintptr(offset / 4096)

unix/syscall_linux_amd64.go

@@ -26,6 +26,7 @@ import "syscall"
 //sys	Lchown(path string, uid int, gid int) (err error)
 //sys	Listen(s int, n int) (err error)
 //sys	Lstat(path string, stat *Stat_t) (err error)
+//sys	Pause() (err error)
 //sys	Pread(fd int, p []byte, offset int64) (n int, err error) = SYS_PREAD64
 //sys	Pwrite(fd int, p []byte, offset int64) (n int, err error) = SYS_PWRITE64
 //sys	Seek(fd int, offset int64, whence int) (off int64, err error) = SYS_LSEEK

unix/syscall_linux_arm.go

@@ -109,6 +109,7 @@ func Seek(fd int, offset int64, whence int) (newoffset int64, err error) {
 // Vsyscalls on amd64.
 //sysnb	Gettimeofday(tv *Timeval) (err error)
 //sys	EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error)
+//sys	Pause() (err error)
 
 func Time(t *Time_t) (Time_t, error) {
 	var tv Timeval

unix/syscall_linux_arm64.go

@@ -155,6 +155,14 @@ func Dup2(oldfd int, newfd int) (err error) {
 	return Dup3(oldfd, newfd, 0)
 }
 
+func Pause() (err error) {
+	_, _, e1 := Syscall6(SYS_PPOLL, 0, 0, 0, 0, 0, 0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
 // TODO(dfc): constants that should be in zsysnum_linux_arm64.go, remove
 // these when the deprecated syscalls that the syscall package relies on
 // are removed.

unix/syscall_linux_mips64x.go

@@ -25,6 +25,7 @@ const _SYS_getdents = SYS_GETDENTS
 //sysnb	Getuid() (uid int)
 //sys	Lchown(path string, uid int, gid int) (err error)
 //sys	Listen(s int, n int) (err error)
+//sys	Pause() (err error)
 //sys	Pread(fd int, p []byte, offset int64) (n int, err error) = SYS_PREAD64
 //sys	Pwrite(fd int, p []byte, offset int64) (n int, err error) = SYS_PWRITE64
 //sys	Seek(fd int, offset int64, whence int) (off int64, err error) = SYS_LSEEK

unix/syscall_linux_ppc64x.go

@@ -23,6 +23,7 @@ package unix
 //sys	Lchown(path string, uid int, gid int) (err error)
 //sys	Listen(s int, n int) (err error)
 //sys	Lstat(path string, stat *Stat_t) (err error)
+//sys	Pause() (err error)
 //sys	Pread(fd int, p []byte, offset int64) (n int, err error) = SYS_PREAD64
 //sys	Pwrite(fd int, p []byte, offset int64) (n int, err error) = SYS_PWRITE64
 //sys	Seek(fd int, offset int64, whence int) (off int64, err error) = SYS_LSEEK

unix/zsyscall_linux_386.go

@@ -729,16 +729,6 @@ func Nanosleep(time *Timespec, leftover *Timespec) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Pause() (err error) {
-	_, _, e1 := Syscall(SYS_PAUSE, 0, 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func PivotRoot(newroot string, putold string) (err error) {
 	var _p0 *byte
 	_p0, err = BytePtrFromString(newroot)
@@ -1582,6 +1572,16 @@ func EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func Pause() (err error) {
+	_, _, e1 := Syscall(SYS_PAUSE, 0, 0, 0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func getrlimit(resource int, rlim *rlimit32) (err error) {
 	_, _, e1 := RawSyscall(SYS_GETRLIMIT, uintptr(resource), uintptr(unsafe.Pointer(rlim)), 0)
 	if e1 != 0 {

unix/zsyscall_linux_amd64.go

@@ -729,16 +729,6 @@ func Nanosleep(time *Timespec, leftover *Timespec) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Pause() (err error) {
-	_, _, e1 := Syscall(SYS_PAUSE, 0, 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func PivotRoot(newroot string, putold string) (err error) {
 	var _p0 *byte
 	_p0, err = BytePtrFromString(newroot)
@@ -1391,6 +1381,16 @@ func Lstat(path string, stat *Stat_t) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func Pause() (err error) {
+	_, _, e1 := Syscall(SYS_PAUSE, 0, 0, 0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func Pread(fd int, p []byte, offset int64) (n int, err error) {
 	var _p0 unsafe.Pointer
 	if len(p) > 0 {

unix/zsyscall_linux_arm.go

@@ -729,16 +729,6 @@ func Nanosleep(time *Timespec, leftover *Timespec) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Pause() (err error) {
-	_, _, e1 := Syscall(SYS_PAUSE, 0, 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func PivotRoot(newroot string, putold string) (err error) {
 	var _p0 *byte
 	_p0, err = BytePtrFromString(newroot)
@@ -1649,6 +1639,16 @@ func EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func Pause() (err error) {
+	_, _, e1 := Syscall(SYS_PAUSE, 0, 0, 0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func Pread(fd int, p []byte, offset int64) (n int, err error) {
 	var _p0 unsafe.Pointer
 	if len(p) > 0 {

unix/zsyscall_linux_arm64.go

@@ -729,16 +729,6 @@ func Nanosleep(time *Timespec, leftover *Timespec) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Pause() (err error) {
-	_, _, e1 := Syscall(SYS_PAUSE, 0, 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func PivotRoot(newroot string, putold string) (err error) {
 	var _p0 *byte
 	_p0, err = BytePtrFromString(newroot)

unix/zsyscall_linux_mips64.go

@@ -729,16 +729,6 @@ func Nanosleep(time *Timespec, leftover *Timespec) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Pause() (err error) {
-	_, _, e1 := Syscall(SYS_PAUSE, 0, 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func PivotRoot(newroot string, putold string) (err error) {
 	var _p0 *byte
 	_p0, err = BytePtrFromString(newroot)
@@ -1314,6 +1304,16 @@ func Listen(s int, n int) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func Pause() (err error) {
+	_, _, e1 := Syscall(SYS_PAUSE, 0, 0, 0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func Pread(fd int, p []byte, offset int64) (n int, err error) {
 	var _p0 unsafe.Pointer
 	if len(p) > 0 {

unix/zsyscall_linux_mips64le.go

@@ -729,16 +729,6 @@ func Nanosleep(time *Timespec, leftover *Timespec) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Pause() (err error) {
-	_, _, e1 := Syscall(SYS_PAUSE, 0, 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func PivotRoot(newroot string, putold string) (err error) {
 	var _p0 *byte
 	_p0, err = BytePtrFromString(newroot)
@@ -1314,6 +1304,16 @@ func Listen(s int, n int) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func Pause() (err error) {
+	_, _, e1 := Syscall(SYS_PAUSE, 0, 0, 0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func Pread(fd int, p []byte, offset int64) (n int, err error) {
 	var _p0 unsafe.Pointer
 	if len(p) > 0 {

unix/zsyscall_linux_ppc64.go

@@ -729,16 +729,6 @@ func Nanosleep(time *Timespec, leftover *Timespec) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Pause() (err error) {
-	_, _, e1 := Syscall(SYS_PAUSE, 0, 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func PivotRoot(newroot string, putold string) (err error) {
 	var _p0 *byte
 	_p0, err = BytePtrFromString(newroot)
@@ -1370,6 +1360,16 @@ func Lstat(path string, stat *Stat_t) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func Pause() (err error) {
+	_, _, e1 := Syscall(SYS_PAUSE, 0, 0, 0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func Pread(fd int, p []byte, offset int64) (n int, err error) {
 	var _p0 unsafe.Pointer
 	if len(p) > 0 {

unix/zsyscall_linux_ppc64le.go

@@ -729,16 +729,6 @@ func Nanosleep(time *Timespec, leftover *Timespec) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Pause() (err error) {
-	_, _, e1 := Syscall(SYS_PAUSE, 0, 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func PivotRoot(newroot string, putold string) (err error) {
 	var _p0 *byte
 	_p0, err = BytePtrFromString(newroot)
@@ -1370,6 +1360,16 @@ func Lstat(path string, stat *Stat_t) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func Pause() (err error) {
+	_, _, e1 := Syscall(SYS_PAUSE, 0, 0, 0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func Pread(fd int, p []byte, offset int64) (n int, err error) {
 	var _p0 unsafe.Pointer
 	if len(p) > 0 {