syscall: use correct cmsg alignment for netbsd/arm64

tklauser · tklauser · commit 069aef406748 · 2020-10-01T13:23:43.000Z
netbsd/arm64 requires 128-bit alignment for cmsgs. Re-submit of CL 258437 which was dropped due to #41718. Change-Id: I898043d79f513bebe1a5eb931e7ebd8e291a5aec Reviewed-on: https://go-review.googlesource.com/c/go/+/258677 Trust: Tobias Klauser <tobias.klauser@gmail.com> Trust: Benny Siegert <bsiegert@gmail.com> Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Benny Siegert <bsiegert@gmail.com>
diff --git a/src/syscall/sockcmsg_unix_other.go b/src/syscall/sockcmsg_unix_other.go
@@ -32,6 +32,10 @@ func cmsgAlignOf(salen int) int {
 		if runtime.GOARCH == "arm" {
 			salign = 8
 		}
+		// NetBSD aarch64 requires 128-bit alignment.
+		if runtime.GOOS == "netbsd" && runtime.GOARCH == "arm64" {
+			salign = 16
+		}
 	}
 
 	return (salen + salign - 1) & ^(salign - 1)

Original file line number	Diff line number	Diff line change
`@@ -32,6 +32,10 @@ func cmsgAlignOf(salen int) int {`
`32`	`32`	`if runtime.GOARCH == "arm" {`
`33`	`33`	`salign = 8`
`34`	`34`	`}`
	`35`	`+ // NetBSD aarch64 requires 128-bit alignment.`
	`36`	`+ if runtime.GOOS == "netbsd" && runtime.GOARCH == "arm64" {`
	`37`	`+ salign = 16`
	`38`	`+ }`
`35`	`39`	`}`
`36`	`40`
`37`	`41`	`return (salen + salign - 1) & ^(salign - 1)`