Give plug-in processes an executable heap and disable PIE/ASLR for Native

Give plug-in processes an executable heap and disable PIE/ASLR for Native
Client loader processes.

Some plug-ins depend on having an executable heap. They write code to data
pages and attempt to execute it without calling mprotect to mark this code
as executable.

Native Client needs to allocate a contiguous 1GB of address space. ASLR may
interfere with there being a "hole" this large in the address space by the
time NaCl makes its request.

Non-executable heaps are only available in 10.7 and later for 32-bit
processes.

PIE/ASLR was formerly disabled for all processes other than the browser
process. This change reenables it for all processes other than the NaCl
loader. PIE/ASLR is available on 10.5 and later, although the implementation
is stronger in 10.7 than in earlier releases.

This change results in two new helpers in addition to the existing
Chromium Helper.app: Chromium Helper EH.app (for executable heaps) and
Chromium Helper NP.app (for no PIE). libplugin_carbon_interpose.dylib moves
out of the helper .app and directly into the versioned directory. The
InfoPlist.strings have been removed from the helper app, but empty .lproj
directories remain.

BUG=90221, 93551
TEST=everything
Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=97984

[TVL, 2011-08-24 01:21:33]

what about breakpad symbols for the newly named binaries?  Do we need to just
clone the DSYM and then tweak the official build scripts or will we need to do
more?

http://codereview.chromium.org/7714018/diff/5082/chrome/tools/build/mac/make_...
File chrome/tools/build/mac/make_more_helpers.sh (right):

http://codereview.chromium.org/7714018/diff/5082/chrome/tools/build/mac/make_...
chrome/tools/build/mac/make_more_helpers.sh:54: $(dirname
"${0}")/../../../../build/mac/change_mach_o_flags.py"
the quotes here seem odd to me at the moment.

http://codereview.chromium.org/7714018/diff/5082/content/common/child_process...
File content/common/child_process_host.h (right):

http://codereview.chromium.org/7714018/diff/5082/content/common/child_process...
content/common/child_process_host.h:47: // You will generally want to set this
to true, except when there is an
"to true" here isn't right.  needs a tweak since it's now on a flag.

[Mark Mentovai, 2011-08-24 01:28:15]

> what about breakpad symbols for the newly named binaries?  Do we need to just
> clone the DSYM and then tweak the official build scripts or will we need to do
> more?

The beauty of this scheme is that I’m just copying the helper executable and
flipping one bit. Its symbols are identified by the LC_UUID contained in the
executable file, and that stays the same. I don’t need to generate any more
.dSYMs or breakpad symbol dumps. All three of the helpers wind up consulting the
same symbols.

http://codereview.chromium.org/7714018/diff/5082/chrome/tools/build/mac/make_...
File chrome/tools/build/mac/make_more_helpers.sh (right):

http://codereview.chromium.org/7714018/diff/5082/chrome/tools/build/mac/make_...
chrome/tools/build/mac/make_more_helpers.sh:54: $(dirname
"${0}")/../../../../build/mac/change_mach_o_flags.py"
TVL wrote:
> the quotes here seem odd to me at the moment.

They’re right, though. If you’re unconvinced we can talk.

[TVL, 2011-08-24 01:36:08]

lgtm.

nice job.

[TVL, 2011-08-24 02:06:05]

main changes lgtm