Linux sandbox: restrict clock_gettime() and clock_getres()

Linux sandbox: restrict clock_gettime() and clock_getres()

In the baseline policy, we restrict the |clk_id| parameter allowed in
clock_gettime(). This applies to all sandboxed process types.

In the renderer policy, we similarly restrict the |clk_id| parameter for
clock_getres().

BUG=413469, 413855
Committed: https://crrev.com/3f43ba638732da04c922605827ad3e7e603d41e0
Cr-Commit-Position: refs/heads/master@{#294751}

[jln (very slow on Chromium), 2014-09-12 23:31:09]

jln@chromium.org changed reviewers:
+ bmeurer@chromium.org, mdempsky@chromium.org

[jln (very slow on Chromium), 2014-09-12 23:32:26]

Matthew: PTAL!

bmeurer: mostly FYI. It doesn't seem like V8 is using any fancy clock we don't
allow at the moment. If it wants to, it can be added to
sandbox/linux/seccomp-bpf-helpers/syscall_parameters_restrictions.cc

[mdempsky, 2014-09-13 01:05:50]

lgtm

[jln (very slow on Chromium), 2014-09-13 17:15:09]

The CQ bit was checked by jln@chromium.org

[commit-bot: I haz the power, 2014-09-13 17:15:45]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patchset/566083002/1

[commit-bot: I haz the power, 2014-09-13 20:40:56]

Committed patchset #1 (id:1) as c9d37c1bb79271e170a49d0ac236aba7eb00a693

[commit-bot: I haz the power, 2014-09-13 20:44:27]

Patchset 1 (id:??) landed as
https://crrev.com/3f43ba638732da04c922605827ad3e7e603d41e0
Cr-Commit-Position: refs/heads/master@{#294751}