"nonplat" was renamed to "vendor" in Android Pie, but was retained
here for Treble compatibility.
We're now outside of the compatbility window for these devices so
it can safely be removed.
Test: build boot cuttlefish device. adb remount, modify
/system/etc/selinux/plat_sepolicy_and_mapping.sha256 to force
on-device policy compilation. reboot. Verify that device boots
without new selinux denials.
Change-Id: I663a524670120ee19dfe785aa5f89b3981bdd378
This benchmarks mapping property prefixes to property contexts with
two algorithms: the 'Legacy' method used before Android P and the
'Trie' used afterwards (the code in this directory).
It uses input mappings from both Oreo and the latest in AOSP ('S').
Note that there is nearly a 10x increase in the number of mappings in
S as there was in Oreo, which was predicted when the trie was
designed.
Results on cuttlefish:
-----------------------------------------------------------
Benchmark Time CPU Iterations
-----------------------------------------------------------
LegacyLookupOreo 683576 ns 673538 ns 1060
LegacyLookupS 5683109 ns 5596982 ns 124
TrieLookupOreo 299851 ns 295696 ns 2378
TrieLookupS 584831 ns 576801 ns 1204
The results show that the legacy look up uses 8.3x more CPU time to
handle the number of mappings added through S, whereas the Trie lookup
uses less than 2x more CPU time, showing that the trie scales better
with added mappings.
Test: run this benchmark
Change-Id: I35c3aa4429f049e327a891f9cbe1901d8855d7ba
1) "fix the system properties design" is written for the old protocol,
so we've already changed the design. There are no other further
planned changes.
2) "don't drag in all the macros, just the types." is not likely to
happen or be particularly impactful.
3) "Find a location suitable for these functions ..." is refering to
legacy code. More likely that this code will be removed before we
find a serious reason to fix this TODO.
4) "(73062966) We still don't have a good way ..." is stale; we fixed
this bug and added the appropriate mechanism.
Test: n/a
Change-Id: I23991692cdeb81ad00844a6a1680900ff384208b
Reinitializing system properties can result in crashes later in the
program, and is generally not recommended or even supported. This
change moves the actual logic for system properties into a class that
can be tested in isolation, without reinitializing the actual system
property area used in libc.
Bug: 62197783
Test: boot devices, ensure properties work
Test: system property unit tests and benchmarks
Change-Id: I9ae6e1b56c62f51a4d3fdb5b62b8926cef545649
pa_size should be static to prop_area, so make it so.
__system_property_area__ was reused for various purposes, but
realistically is a deprecated symbol and this finally separates us
from it.
Bug: 36001741
Test: boot bullhead, system property unit tests
Change-Id: I39663cc3b613093fa4c728b21d8ba58754f8e105
system_properties.cpp is a little bit unmanageable in its current
form, and is overdue for a refactoring into more clearly defined
components.
Of particular interest, is creating of a Contexts interface that
handles mapping of system property name -> SEContext and its
associated prop_area, and creating two classes that implement the
current and legacy functionality. This is needed as there will likely
be a third even newer way to do this mapping.
Bug: 36001741
Test: boot bullhead, system property unit tests
Change-Id: Ie75ec6fea1a95f90813918f54669d533e51327c6
Jeff Vander Stoep
Tom Cherry
Ryan Prichard
Bowgo Tsai