On Mon, Nov 28, 2022 at 10:40 PM Martin Liška <mli...@suse.cz> wrote: > > On 11/11/22 02:26, liuhongt via Gcc-patches wrote: > > 2 years ago, ARM folks support HWASAN[1] in GCC[2], and introduced > > several > > target hooks(Many thanks to their work) so other backends can do similar > > things if they have similar feature. > > Intel LAM(linear Address Masking)[3 Charpter 14] supports similar > > feature with > > the upper bits of pointers can be used as metadata, LAM support two modes: > > LAM_U48:bits 48-62 can be used as metadata > > LAM_U57:bits 57-62 can be used as metedata. > > > > These 2 patches mainly support those target hooks, but HWASAN is not really > > enabled until the final decision for the LAM kernel interface which may take > > quite a long time. We have verified our patches with a "fake" interface > > locally[4], and > > decided to push the backend patches to the GCC13 to make other HWASAN > > developper's work > > easy. > > Hello. > > A few random comments I noticed: > > 1) please document the new target -mlam in extend.texi I will. > 2) the description speaks about bits [48-62] or [57-62], can explain why the > patch contains: > Kernel will use bit 63 for special purposes, and here we want to extract the tag by shifting right the pointer 57 bits, and need to manually mask off bit63. > + /* Mask off bit63 when LAM_U57. */ > + if (ix86_lam_type == lam_u57) > ? > > 3) Shouldn't the -lman option emit GNU_PROPERTY_X86_FEATURE_1_LAM_U57 or > GNU_PROPERTY_X86_FEATURE_1_LAM_U48 > .gnu.property note? > > 4) Can you please explain Florian's comment here: > https://gitlab.com/x86-psABIs/x86-64-ABI/-/merge_requests/13#note_1181396487 > > Thanks, > Martin > > > > > [1] https://clang.llvm.org/docs/HardwareAssistedAddressSanitizerDesign.html > > [2] https://gcc.gnu.org/pipermail/gcc-patches/2020-November/557857.html > > [3] > > https://www.intel.com/content/dam/develop/external/us/en/documents/architecture-instruction-set-extensions-programming-reference.pdf > > [4] https://gitlab.com/x86-gcc/gcc/-/tree/users/intel/lam/master > > > > > > Bootstrapped and regtested on x86_64-pc-linux-gnu{-m32,}. > > Ok for trunk? > > > > liuhongt (2): > > Implement hwasan target_hook. > > Enable hwasan for x86-64. > > > > gcc/config/i386/i386-expand.cc | 12 ++++ > > gcc/config/i386/i386-options.cc | 3 + > > gcc/config/i386/i386-opts.h | 6 ++ > > gcc/config/i386/i386-protos.h | 2 + > > gcc/config/i386/i386.cc | 123 ++++++++++++++++++++++++++++++++ > > gcc/config/i386/i386.opt | 16 +++++ > > libsanitizer/configure.tgt | 1 + > > 7 files changed, 163 insertions(+) > > >
-- BR, Hongtao
