tree 091acfafe3c5991fd357a319847bb4827f3f9bbc
parent 90bb72c6a62fc269895ed9a55948f49fc905493b
author Adam Langley <alangley@gmail.com> 1588099436 -0700
committer CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org> 1588358142 +0000

fork_detect: be robust to qemu.

fork_detect needs to know whether |MADV_WIPEONFORK| is supported by the
kernel or not. However, current versions of qemu ignore madvise calls
and just return zero, making it seems like it's supported when it's
actually not. Therefore, try an madvise with -1 to ensure that clearly
bogus values actually produce and error before trusting the result of
calling with |MADV_WIPEONFORK|.

Change-Id: I7f72714d5794274acabd0bee0b0ac470e1933774
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/41024
Reviewed-by: Adam Langley <agl@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: Adam Langley <agl@google.com>