All platforms except i386 will report the error and do no
instrumentation with -finstrument-control-flow option. i386
will provide the implementation based on a specification
published by Intel for a new technology called Control-flow
Enforcement Technology (CET). The spec is available at
https://software.intel.com/sites/default/files/managed/4d/2a/control-flow-enforcement-technology-preview.pdf
The implementation in this patch:
1) enables Control-flow Enforcement Technology (CET), published by
Intel. This part introduces i386 specific options -mcet, -mibt and
-mshstk, new instructions and intrinsics;
2) provides support for -fcf-protection option and 'nocf_check'
attribute by doing needed code instrumentation, which is based on
CET features.
gcc/
* common/config/i386/i386-common.c (OPTION_MASK_ISA_IBT_SET): New.
(OPTION_MASK_ISA_SHSTK_SET): Likewise.
(OPTION_MASK_ISA_IBT_UNSET): Likewise.
(OPTION_MASK_ISA_SHSTK_UNSET): Likewise.
(ix86_handle_option): Add -mibt, -mshstk, -mcet handling.
* config.gcc (extra_headers): Add cetintrin.h for x86 targets.
(extra_objs): Add cet.o for Linux/x86 targets.
(tmake_file): Add i386/t-cet for Linux/x86 targets.
* config/i386/cet.c: New file.
* config/i386/cetintrin.h: Likewise.
* config/i386/t-cet: Likewise.
* config/i386/cpuid.h (bit_SHSTK): New.
(bit_IBT): Likewise.
* config/i386/driver-i386.c (host_detect_local_cpu): Detect and
pass IBT and SHSTK bits.
* config/i386/i386-builtin-types.def
(VOID_FTYPE_UNSIGNED_PVOID): New.
(VOID_FTYPE_UINT64_PVOID): Likewise.
* config/i386/i386-builtin.def: Add CET intrinsics.
* config/i386/i386-c.c (ix86_target_macros_internal): Add
OPTION_MASK_ISA_IBT, OPTION_MASK_ISA_SHSTK handling.
* config/i386/i386-passes.def: Add pass_insert_endbranch pass.
* config/i386/i386-protos.h (make_pass_insert_endbranch): New
prototype.
* config/i386/i386.c (rest_of_insert_endbranch): New.
(pass_data_insert_endbranch): Likewise.
(pass_insert_endbranch): Likewise.
(make_pass_insert_endbranch): Likewise.
(ix86_notrack_prefixed_insn_p): Likewise.
(ix86_target_string): Add -mibt, -mshstk flags.
(ix86_option_override_internal): Add flag_cf_protection
processing.
(ix86_valid_target_attribute_inner_p): Set OPT_mibt, OPT_mshstk.
(ix86_print_operand): Add 'notrack' prefix output.
(ix86_init_mmx_sse_builtins): Add CET intrinsics.
(ix86_expand_builtin): Expand CET intrinsics.
(x86_output_mi_thunk): Add 'endbranch' instruction.
* config/i386/i386.h (TARGET_IBT): New.
(TARGET_IBT_P): Likewise.
(TARGET_SHSTK): Likewise.
(TARGET_SHSTK_P): Likewise.
* config/i386/i386.md (unspecv): Add UNSPECV_NOP_RDSSP,
UNSPECV_INCSSP, UNSPECV_SAVEPREVSSP, UNSPECV_RSTORSSP,
UNSPECV_WRSS, UNSPECV_WRUSS, UNSPECV_SETSSBSY, UNSPECV_CLRSSBSY.
(builtin_setjmp_setup): New pattern.
(builtin_longjmp): Likewise.
(rdssp<mode>): Likewise.
(incssp<mode>): Likewise.
(saveprevssp): Likewise.
(rstorssp): Likewise.
(wrss<mode>): Likewise.
(wruss<mode>): Likewise.
(setssbsy): Likewise.
(clrssbsy): Likewise.
(nop_endbr): Likewise.
* config/i386/i386.opt: Add -mcet, -mibt, -mshstk and -mcet-switch
options.
* config/i386/immintrin.h: Include <cetintrin.h>.
* config/i386/linux-common.h
(file_end_indicate_exec_stack_and_cet): New prototype.
(TARGET_ASM_FILE_END): New.
From-SVN: r253977
