Many Amlogic devices (e.g. FireTV 2nd gen Cube, Vero 4k+, MI Smart Speaker, etc.) are A-only with androidboot.slot_suffix=normal argument. I think "normal" actually means A-only in this case so just ignore it.
Fix topjohnwu#5806
The hijacked load node does not need to be a FIFO. A FIFO is only
required for blocking init's control flow, which is already achieved
by hijacking the enforce node.
Previously `read_string()` calls `std::string.resize()` with a int read from remote process. When I/O error occurs, -1 will be used for resizing the string, `std::bad_alloc` is thrown and since magisk is compiled with `-fno-exceptions`, it will crash the whole daemon process.
May fix topjohnwu#5681
Since Android 13, sepolicy are also loaded from APEX modules. Part
of the change is to run restorecon before SELinux is set to enforce.
In order to support this situation, we also hijack plat_file_contexts
if necessary to properly order our operations.
Original idea credits to @yujincheng08, close#5603
On older Android versions, pre-mounting selinuxfs will lead to errors,
so we have to use a different method to block init's control flow.
Since all devices that falls in this catagory must both:
1. Be Android 8.0 - 9.0
2. Have early mount fstab in its device tree
We can actually use the same FIFO trick, but this time not on selinuxfs,
but on the read-only device tree nodes in sysfs or procfs. By mocking
the fstab/compatible node in the device tree, we can block init when
it attempts to do early mount; at that point, we can then mock selinuxfs
as we normally would, successfully hijack and inject patched sepolicy.
