tree 1a48ada4a610b0662d3f6d88740931fd19b27c3a
parent 1540f601be32bdd4af8e8c13bdf2bc06bdaa76f1
author Colin Cross <ccross@android.com> 1371403156 -0700
committer Colin Cross <ccross@android.com> 1372116941 -0700

bionic: prevent root processes from calling __system_property_add

If a root process other than init calls __system_property_add, which
it should never do, it will break the design assumption that there is
only one mutator.

Pass O_EXCL to open() in map_prop_region_rw to ensure that only one
process ever has the property pages open for write.

(cherry picked from commit fb9b7b436f3ef94385f1b0c55ab81f246f0d96b8)

Change-Id: I6df3afedbfb5d07891b095aa24b78278381a5aaf