[AARCH64] GP bit (BTI) lost during two stages translation
Description of problem:
I noticed that the BTI faults were not reported.
That's because the GP (guarded page) information is lost during the two stages translation in get_phys_addr_twostage().
The "guarded" information is correctly retrieved by the first call to get_phys_addr_nogpc() but overwritten by the the second call to get_phys_addr_nogpc().
The call to combine_cacheattrs() copies cacheattrs1.guarded but this field is never modified.

The attached patch fixes the issue for me.
[get_phys_addr_twostage_bti_gp_bit_lost_master.patch](/uploads/2fbe8090f92c43a63e39ee66ab2daf47/get_phys_addr_twostage_bti_gp_bit_lost_master.patch)