os: treat Getwd result of ENOMEM the same as ENAMETOOLONG

We can see ENOMEM on FreeBSD.

Also don't fail the test if we get an EPERM error when reading
all the way up the tree; on Android we get that, perhaps because
the root directory is unreadable.

Also accept an EFAULT from a stat of a long name on Dragonfly,
which we see on the builders.

Change-Id: If37e6bf414b7b568c9a06130f71e79af153bfb75
Reviewed-on: https://go-review.googlesource.com/c/go/+/610415
Auto-Submit: Ian Lance Taylor <iant@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Commit-Queue: Ian Lance Taylor <iant@google.com>
Reviewed-by: Keith Randall <khr@google.com>

diff --git a/src/os/error_errno.go b/src/os/error_errno.go
index c4d540cdff09445ad36830ca017993f61f52ba56..662258338bd92904e13051e09f5fb7c317432775 100644 (file)
--- a/src/os/error_errno.go
+++ b/src/os/error_errno.go
@@ -10,5 +10,8 @@ import "syscall"
 
 type syscallErrorType = syscall.Errno
 
-const errENOSYS = syscall.ENOSYS
-const errERANGE = syscall.ERANGE
+const (
+       errENOSYS = syscall.ENOSYS
+       errERANGE = syscall.ERANGE
+       errENOMEM = syscall.ENOMEM
+)

diff --git a/src/os/error_plan9.go b/src/os/error_plan9.go
index 61b56211b4917b38c5c3b97cf605576ecd179551..35026554c27bcb8e1ab68a3fee129060f9086f82 100644 (file)
--- a/src/os/error_plan9.go
+++ b/src/os/error_plan9.go
@@ -10,3 +10,4 @@ type syscallErrorType = syscall.ErrorString
 
 var errENOSYS = syscall.NewError("function not implemented")
 var errERANGE = syscall.NewError("out of range")
+var errENOMEM = syscall.NewError("cannot allocate memory")

diff --git a/src/os/getwd.go b/src/os/getwd.go
index 8dca70fc2e582ed60c604fed9bd9d75882b296f4..82f0d944df97de1c108e1d16eab0ab54b35aebae 100644 (file)
--- a/src/os/getwd.go
+++ b/src/os/getwd.go
@@ -60,9 +60,10 @@ func Getwd() (dir string, err error) {
                        }
                }
                // Linux returns ENAMETOOLONG if the result is too long.
-               // BSD systems appear to return EINVAL.
+               // Some BSD systems appear to return EINVAL.
+               // FreeBSD systems appear to use ENOMEM
                // Solaris appears to use ERANGE.
-               if err != syscall.ENAMETOOLONG && err != syscall.EINVAL && err != errERANGE {
+               if err != syscall.ENAMETOOLONG && err != syscall.EINVAL && err != errERANGE && err != errENOMEM {
                        return dir, NewSyscallError("getwd", err)
                }
        }

diff --git a/src/os/getwd_unix_test.go b/src/os/getwd_unix_test.go
index a0c4f5bef1e591ccafbcf198460e887b94b5d462..084344735cf2ca30a7558f180bd2d67f891a4d54 100644 (file)
--- a/src/os/getwd_unix_test.go
+++ b/src/os/getwd_unix_test.go
@@ -9,6 +9,7 @@ package os_test
 import (
        "errors"
        . "os"
+       "runtime"
        "strings"
        "syscall"
        "testing"
@@ -56,6 +57,12 @@ func testGetwdDeep(t *testing.T, setPWD bool) {
                wd, err := Getwd()
                t.Logf("Getwd len: %d", len(wd))
                if err != nil {
+                       // We can get an EPERM error if we can't read up
+                       // to root, which happens on the Android builders.
+                       if errors.Is(err, syscall.EPERM) {
+                               t.Logf("ignoring EPERM error: %v", err)
+                               break
+                       }
                        t.Fatal(err)
                }
                if setPWD && wd != dir {
@@ -72,7 +79,13 @@ func testGetwdDeep(t *testing.T, setPWD bool) {
                // all Unix platforms (4096, on Linux).
                if _, err := Stat(wd); err != nil || len(wd) > 4096 {
                        t.Logf("Done; len(wd)=%d", len(wd))
-                       if err != nil && !errors.Is(err, syscall.ENAMETOOLONG) {
+                       // Most systems return ENAMETOOLONG.
+                       // Dragonfly returns EFAULT.
+                       switch {
+                       case err == nil:
+                       case errors.Is(err, syscall.ENAMETOOLONG):
+                       case runtime.GOOS == "dragonfly" && errors.Is(err, syscall.EFAULT):
+                       default:
                                t.Fatalf("unexpected Stat error: %v", err)
                        }
                        break