runtime: fix errno sign for some mmap and mincore cases
The caller of mmap expects it to return a positive errno value, but the
linux-arm64 and nacl-386 system calls returned a negative errno value.
Correct them to negate the errno value.
The caller of mincore expects it to return a negative errno value (yes,
this is inconsistent), but the linux-mips64x and linux-ppc64x system
call returned a positive errno value. Correct them to negate the errno
value.
Add a test that mmap returns errno with the correct sign. Brad added a
test for mincore's errno value in https://golang.org/cl/19457.
Fixes #14297.
Change-Id: I2b93f32e679bd1eae1c9aef9ae7bcf0ba39521b5
Reviewed-on: https://go-review.googlesource.com/19455
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
diff --git a/src/runtime/runtime_mmap_test.go b/src/runtime/runtime_mmap_test.go
new file mode 100644
index 0000000..ff5e733
--- /dev/null
+++ b/src/runtime/runtime_mmap_test.go
@@ -0,0 +1,30 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build darwin dragonfly freebsd linux nacl netbsd openbsd solaris
+
+package runtime_test
+
+import (
+ "runtime"
+ "runtime/internal/sys"
+ "testing"
+)
+
+// Test that the error value returned by mmap is positive, as that is
+// what the code in mem_bsd.go, mem_darwin.go, and mem_linux.go expects.
+// See the uses of ENOMEM in sysMap in those files.
+func TestMmapErrorSign(t *testing.T) {
+ p := runtime.Mmap(nil, ^uintptr(0)&^(sys.PhysPageSize-1), 0, runtime.MAP_ANON|runtime.MAP_PRIVATE, -1, 0)
+
+ // The runtime.mmap function is nosplit, but t.Errorf is not.
+ // Reset the pointer so that we don't get an "invalid stack
+ // pointer" error from t.Errorf if we call it.
+ v := uintptr(p)
+ p = nil
+
+ if v != runtime.ENOMEM {
+ t.Errorf("mmap = %v, want %v", v, runtime.ENOMEM)
+ }
+}
