On Fri, Nov 2, 2018 at 11:39 AM Sudakshina Das <sudi....@arm.com> wrote: > > Hi > > This patch is part of a series that enables ARMv8.5-A in GCC and > adds Branch Target Identification Mechanism. > (https://developer.arm.com/products/architecture/cpu-architecture/a-profile/exploration-tools) > > This patch adds a new pass called "bti" which is triggered by the > command line argument -mbranch-protection whenever "bti" is turned on. > > The pass iterates through the instructions and adds appropriated BTI > instructions based on the following: > * Add a new "BTI C" at the beginning of a function, unless its already > protected by a "PACIASP/PACIBSP". We exempt the functions that are > only called directly.
Coming back to this because the check only_called_directly_p does not work if the linker will insert a veneer as the compiler does not know about that. This is recorded as https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671 . Thanks, Andrew Pinski > * Add a new "BTI J" for every target of an indirect jump, jump table > targets, non-local goto targets or labels that might be referenced > by variables, constant pools, etc (NOTE_INSN_DELETED_LABEL) > > Since we have already changed the use of indirect tail calls to only x16 > and x17, we do not have to use "BTI JC". > (check patch 3/6). > > Bootstrapped and regression tested with aarch64-none-linux-gnu. Added > new tests. > Is this ok for trunk? > > Thanks > Sudi > > *** gcc/ChangeLog *** > > 2018-xx-xx Sudakshina Das <sudi....@arm.com> > Ramana Radhakrishnan <ramana.radhakrish...@arm.com> > > * config.gcc (aarch64*-*-*): Add aarch64-bti-insert.o. > * gcc/config/aarch64/aarch64.h: Update comment for > TRAMPOLINE_SIZE. > * config/aarch64/aarch64.c (aarch64_asm_trampoline_template): > Update if bti is enabled. > * config/aarch64/aarch64-bti-insert.c: New file. > * config/aarch64/aarch64-passes.def (INSERT_PASS_BEFORE): Insert > bti pass. > * config/aarch64/aarch64-protos.h (make_pass_insert_bti): > Declare the new bti pass. > * config/aarch64/aarch64.md (bti_nop): Define. > * config/aarch64/t-aarch64: Add rule for aarch64-bti-insert.o. > > *** gcc/testsuite/ChangeLog *** > > 2018-xx-xx Sudakshina Das <sudi....@arm.com> > > * gcc.target/aarch64/bti-1.c: New test. > * gcc.target/aarch64/bti-2.c: New test. > * lib/target-supports.exp > (check_effective_target_aarch64_bti_hw): Add new check for > BTI hw. >
