tree 307c3dcffbce74380d54cc35c43a267fbb017129
parent ab9391cb88a2a1daf1382e1ad7e355ce6207c891
author Elias Naur <elias.naur@gmail.com> 1485808593 +0100
committer Elias Naur <elias.naur@gmail.com> 1485894316 +0000

internal/mobileinit: preserve stdout and stderr file descriptors

To ensure correct command line behavior, the Go runtime crashes
when a SIGPIPE is received on either fd 1 or fd 2 (CL 18151).

At the same time, go mobile redirects stdout and stderr to the
Android logcat facility by replacing os.Stderr and os.Stdout with
the writer ends of two pipes.

This in turn allows the original os.Stderr and os.Stdout files to
be garbage finalized, closing fd 1 and 2.

If an Android app then happens to open a pipe or socket, fd 1 and 2
might be reused. If the pipe or socket ever receives a SIGPIPE, the
Go runtime will think the signal was for stdout or stderr and crash
the program.

This CL preserves fd 1 and fd 2 by using dup3 to redirect the file
descriptors.

Change-Id: I5058d729eca52503a43f0e8c87a9fd296ed3667e
Reviewed-on: https://go-review.googlesource.com/35961
Reviewed-by: David Crawshaw <crawshaw@golang.org>