compiler_wrapper: work around gcc failing due to a kernel bug

Very rarely on old GCCs, we'll complaints about GCC itself being handed
ERESTARTSYS. Retry the compilation in those cases. Similarly, we'll
sometimes see `run()` give us random errors with things like `waitid()`,
so handle those.

BUG=chromium:1166017
TEST=CQ

Change-Id: If9b6fdc523f60719608739da0eefa94c82164ae7
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/toolchain-utils/+/2648090
Reviewed-by: Manoj Gupta <manojgupta@chromium.org>
Tested-by: George Burgess <gbiv@chromium.org>

1 files changed, 25 insertions, 0 deletions

diff --git a/compiler_wrapper/kernel_bug.go b/compiler_wrapper/kernel_bug.go
new file mode 100644
index 00000000..55817cb6
--- /dev/null
+++ b/compiler_wrapper/kernel_bug.go
@@ -0,0 +1,25 @@
+// Copyright 2021 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+package main
+
+import (
+	"bytes"
+	"strings"
+)
+
+// crbug.com/1166017
+
+const kernelBugRetryLimit = 25
+
+// GCC will sometimes fail to wait on subprocesses due to this kernel bug. It always fails the
+// compilation and prints "Unknown error 512" in that case.
+func containsTracesOfKernelBug(buf []byte) bool {
+	return bytes.Contains(buf, []byte("Unknown error 512"))
+}
+
+func errorContainsTracesOfKernelBug(err error) bool {
+	// We'll get errors that look like "waitid: errno 512." Presumably, this isn't specific to
+	// waitid, so just try to match the "errno 512" ending.
+	return err != nil && strings.HasSuffix(err.Error(), "errno 512")
+}