These two options allow for ARM MTE to be enabled dynamically (instead
of at compile time via the ELF note). They are settable from a non-root
shell to allow device owners to test system binaries with MTE.
The following values may be set:
1. 'off' -> No MTE, uses TBI on compatible devices.
2. 'sync' -> SYNC MTE.
3. 'async' -> ASYNC MTE.
The following methods can be used to launch a process (sanitizer-status)
with configurable values:
1. adb shell MEMTAG_OPTIONS=async sanitizer-status
2. adb shell setprop arm64.memtag.process.sanitizer-status async && \
adb shell sanitizer-status
Note: The system server will require some special handing in the zygote
pre-fork to check the sysprops. The zygote should always have the ELF
note. TODO in a subsequent patch.
Bug: 135772972
Bug: 172365548
Test: Launching sanitizer-status above using both the settings.
Change-Id: Ic1dbf3985a3f23521ec86725ec482c8f6739c182
Now that the feature guarded by this flag has landed in Linux 5.10
we no longer need the flag, so we can remove it.
Bug: 135772972
Change-Id: I02fa50848cbd0486c23c8a229bb8f1ab5dd5a56f
It turns out that we need this on non-aarch64 more than I thought
we would, so let's start defining it everywhere.
Also expose platform headers to sanitizer-status.
Bug: 135772972
Change-Id: Ia7fd8a9bca0c123c4ca2ecd5f250f3a628a5513b
An upcoming change to scudo will cause us to start calling
android_unsafe_frame_pointer_chase() from within the allocator. Since this
function uses ScopedDisableMTE, this would otherwise make it unsafe to use
the allocator from within ScopedDisableMTE. This seems like an unreasonable
restriction, so make ScopedDisableMTE save the PSTATE.TCO state in the
constructor and restore it in the destructor.
Bug: 135772972
Change-Id: I47e18d5fb2929efd5a58676488180cd85731007b
mte_supported() lets code efficiently detect the presence of MTE, and
ScopedDisableMTE lets code disable MTE RAII-style in a particular region
of code.
Bug: 135772972
Change-Id: I628a054b50d79f67f39f35d44232b7a2ae166afb
