The branch target identification extension does not yet have kernel or gcc support. It should be in shape for developing those though.
In system mode I do honor the GP bit from the page tables. In user-only mode, there is a way to pretend that the GP bit is always set. Further linux-user changes will have to track the ABI that gets developed. In the meantime, provide a statically linable make check-tcg test for the functionality. r~ Richard Henderson (11): target/arm: Introduce isar_feature_aa64_bti target/arm: Add PSTATE.BTYPE target/arm: Add BT and BTYPE to tb->flags target/arm: Record the GP bit for a page in MemTxAttrs target/arm: Default handling of BTYPE during translation target/arm: Reset btype for direct branches and syscalls target/arm: Set btype for indirect branches target/arm: Add guarded_pages cpu property for user-only target/arm: Enable BTI for -cpu max linux-user/aarch64: Reset btype for signal handlers tests/tcg/aarch64: Add bti smoke test include/exec/memattrs.h | 2 + target/arm/cpu.h | 22 +++- target/arm/internals.h | 6 + target/arm/translate.h | 9 ++ linux-user/aarch64/signal.c | 4 + target/arm/cpu64.c | 22 ++++ target/arm/helper.c | 28 +++-- target/arm/translate-a64.c | 196 +++++++++++++++++++++++++++++- tests/tcg/aarch64/bti-1.c | 61 ++++++++++ tests/tcg/aarch64/bti-crt.inc.c | 51 ++++++++ tests/tcg/aarch64/Makefile.target | 7 +- 11 files changed, 397 insertions(+), 11 deletions(-) create mode 100644 tests/tcg/aarch64/bti-1.c create mode 100644 tests/tcg/aarch64/bti-crt.inc.c -- 2.17.2
