Hi,
This series implements[1][2] the Linux Kernel Control Flow Integrity
ABI, which provides a function prototype based forward edge control flow
integrity protection by instrumenting every indirect call to check for
a hash value before the target function address. If the hash at the call
site and the hash at the target do not match, execution will trap.
I'd really like to be in a position where more people can test with GCC
snapshots, etc, and there can be some follow-up patches if people find
issues. Since I don't have commit access, who is the right person to
commit this?
Thanks!
-Kees
Changes since v13[3]:
- Strip name encoding when forming __cfi_ preamble labels to fix build
failure for functions with asm("name"); add new test.
- Link .kcfi_traps to the function's own text section under
-ffunction-sections so --gc-sections can't drop it (to match Clang);
add new test.
- Handle all remaining C type codes in the type-id mangler, adding
_BitInt, _Complex, nullptr_t, _FloatN/_DecimalN, fixed-point, and opaque
types; add new tests.
- Remove redundant IPA type-id caching pass, instead compute type-ids on
demand which also fixes LTO miscompile.
- Move the KCFI label counter into final.cc and give the NOP template
string an owned copy (xstrdup).
- Use GTY on the cached kcfi_type_id attribute identifier.
- Header and idiom cleanups: no <string>/config.h/system.h in headers,
use INCLUDE_STRING, tree_to_uhwi, dyn_cast.
- Docs: add Itanium C++ ABI link, note C/Objective-C availability, correct
the ARM 32-bit description and the whole-program offset-ABI note;
bump copyright to 2026.
[1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107048
[2] https://github.com/KSPP/linux/issues/369
[3]
https://inbox.sourceware.org/gcc-patches/[email protected]/
Kees Cook (7):
kcfi: Introduce KCFI typeinfo mangling API
kcfi: Add core Kernel Control Flow Integrity infrastructure
kcfi: Add regression test suite
x86: Add x86_64 Kernel Control Flow Integrity implementation
aarch64: Add AArch64 Kernel Control Flow Integrity implementation
arm: Add ARM 32-bit Kernel Control Flow Integrity implementation
riscv: Add RISC-V Kernel Control Flow Integrity implementation
gcc/kcfi.h | 59 ++
gcc/kcfi.cc | 632 ++++++++++++
gcc/config/aarch64/aarch64-protos.h | 4 +
gcc/config/arm/arm-protos.h | 4 +
gcc/config/i386/i386-protos.h | 2 +-
gcc/config/i386/i386.h | 3 +-
gcc/config/riscv/riscv-protos.h | 3 +
gcc/config/aarch64/aarch64.md | 56 +
gcc/config/arm/arm.md | 62 ++
gcc/config/i386/i386.md | 63 +-
gcc/config/riscv/riscv.md | 76 +-
gcc/config/aarch64/aarch64.cc | 127 +++
gcc/config/arm/arm.cc | 217 +++-
gcc/config/i386/i386-expand.cc | 28 +-
gcc/config/i386/i386.cc | 210 +++-
gcc/config/riscv/riscv.cc | 199 ++++
gcc/doc/extend.texi | 139 +++
gcc/doc/invoke.texi | 141 +++
gcc/doc/tm.texi | 32 +
gcc/testsuite/gcc.dg/kcfi/kcfi.exp | 51 +
gcc/testsuite/lib/target-supports.exp | 14 +
.../gcc.dg/builtin-typeinfo-bitint.c | 82 ++
gcc/testsuite/gcc.dg/builtin-typeinfo-c23.c | 72 ++
.../gcc.dg/builtin-typeinfo-errors.c | 28 +
gcc/testsuite/gcc.dg/builtin-typeinfo-fixed.c | 57 ++
gcc/testsuite/gcc.dg/builtin-typeinfo.c | 375 +++++++
.../gcc.dg/kcfi/kcfi-aarch64-ilp32.c | 7 +
gcc/testsuite/gcc.dg/kcfi/kcfi-adjacency.c | 142 +++
gcc/testsuite/gcc.dg/kcfi/kcfi-arm-fixed-ip.c | 15 +
.../gcc.dg/kcfi/kcfi-arm-fixed-r12.c | 15 +
.../gcc.dg/kcfi/kcfi-arm-sibcall-r3.c | 50 +
gcc/testsuite/gcc.dg/kcfi/kcfi-asm-name.c | 16 +
gcc/testsuite/gcc.dg/kcfi/kcfi-basics.c | 168 +++
gcc/testsuite/gcc.dg/kcfi/kcfi-call-sharing.c | 92 ++
.../gcc.dg/kcfi/kcfi-cold-partition.c | 126 +++
.../gcc.dg/kcfi/kcfi-complex-addressing.c | 206 ++++
.../gcc.dg/kcfi/kcfi-direct-call-shapes.c | 36 +
.../gcc.dg/kcfi/kcfi-ipa-robustness.c | 54 +
gcc/testsuite/gcc.dg/kcfi/kcfi-lto-offset.c | 26 +
.../gcc.dg/kcfi/kcfi-move-preservation.c | 138 +++
.../gcc.dg/kcfi/kcfi-no-sanitize-inline.c | 100 ++
gcc/testsuite/gcc.dg/kcfi/kcfi-no-sanitize.c | 41 +
.../gcc.dg/kcfi/kcfi-offset-validation.c | 40 +
.../gcc.dg/kcfi/kcfi-patchable-entry-only.c | 64 ++
.../gcc.dg/kcfi/kcfi-patchable-incompatible.c | 7 +
.../gcc.dg/kcfi/kcfi-patchable-large.c | 57 ++
.../gcc.dg/kcfi/kcfi-patchable-medium.c | 63 ++
.../gcc.dg/kcfi/kcfi-patchable-prefix-only.c | 64 ++
gcc/testsuite/gcc.dg/kcfi/kcfi-riscv-32bit.c | 7 +
.../gcc.dg/kcfi/kcfi-riscv-fixed-t1.c | 7 +
.../gcc.dg/kcfi/kcfi-riscv-fixed-t2.c | 7 +
.../gcc.dg/kcfi/kcfi-riscv-fixed-t3.c | 7 +
gcc/testsuite/gcc.dg/kcfi/kcfi-runtime.c | 276 +++++
gcc/testsuite/gcc.dg/kcfi/kcfi-tail-calls.c | 144 +++
.../gcc.dg/kcfi/kcfi-trap-encoding.c | 88 ++
.../gcc.dg/kcfi/kcfi-trap-section-per-func.c | 23 +
gcc/testsuite/gcc.dg/kcfi/kcfi-trap-section.c | 29 +
gcc/testsuite/gcc.dg/kcfi/kcfi-x86-32bit.c | 7 +
gcc/testsuite/gcc.dg/kcfi/kcfi-x86-arity.c | 93 ++
.../gcc.dg/kcfi/kcfi-x86-fixed-r10.c | 7 +
.../gcc.dg/kcfi/kcfi-x86-fixed-r11.c | 7 +
.../gcc.dg/kcfi/kcfi-x86-retpoline-r11.c | 40 +
gcc/Makefile.in | 3 +
gcc/c-family/c-common.h | 1 +
gcc/flag-types.h | 2 +
gcc/gimple.h | 22 +
gcc/kcfi-typeinfo.h | 31 +
gcc/selftest.h | 1 +
gcc/c-family/c-attribs.cc | 17 +-
gcc/c-family/c-common.cc | 2 +
gcc/c/c-parser.cc | 72 ++
gcc/common.opt | 8 +
gcc/df-scan.cc | 7 +
gcc/doc/tm.texi.in | 12 +
gcc/final.cc | 17 +
gcc/kcfi-typeinfo.cc | 967 ++++++++++++++++++
gcc/opts.cc | 5 +-
gcc/passes.cc | 1 +
gcc/rtl.def | 6 +
gcc/rtlanal.cc | 5 +
gcc/selftest-run-tests.cc | 1 +
gcc/target.def | 39 +
gcc/toplev.cc | 12 +
gcc/tree-inline.cc | 10 +
gcc/varasm.cc | 44 +-
85 files changed, 6234 insertions(+), 56 deletions(-)
create mode 100644 gcc/kcfi.h
create mode 100644 gcc/kcfi.cc
create mode 100644 gcc/testsuite/gcc.dg/kcfi/kcfi.exp
create mode 100644 gcc/testsuite/gcc.dg/builtin-typeinfo-bitint.c
create mode 100644 gcc/testsuite/gcc.dg/builtin-typeinfo-c23.c
create mode 100644 gcc/testsuite/gcc.dg/builtin-typeinfo-errors.c
create mode 100644 gcc/testsuite/gcc.dg/builtin-typeinfo-fixed.c
create mode 100644 gcc/testsuite/gcc.dg/builtin-typeinfo.c
create mode 100644 gcc/testsuite/gcc.dg/kcfi/kcfi-aarch64-ilp32.c
create mode 100644 gcc/testsuite/gcc.dg/kcfi/kcfi-adjacency.c
create mode 100644 gcc/testsuite/gcc.dg/kcfi/kcfi-arm-fixed-ip.c
create mode 100644 gcc/testsuite/gcc.dg/kcfi/kcfi-arm-fixed-r12.c
create mode 100644 gcc/testsuite/gcc.dg/kcfi/kcfi-arm-sibcall-r3.c
create mode 100644 gcc/testsuite/gcc.dg/kcfi/kcfi-asm-name.c
create mode 100644 gcc/testsuite/gcc.dg/kcfi/kcfi-basics.c
create mode 100644 gcc/testsuite/gcc.dg/kcfi/kcfi-call-sharing.c
create mode 100644 gcc/testsuite/gcc.dg/kcfi/kcfi-cold-partition.c
create mode 100644 gcc/testsuite/gcc.dg/kcfi/kcfi-complex-addressing.c
create mode 100644 gcc/testsuite/gcc.dg/kcfi/kcfi-direct-call-shapes.c
create mode 100644 gcc/testsuite/gcc.dg/kcfi/kcfi-ipa-robustness.c
create mode 100644 gcc/testsuite/gcc.dg/kcfi/kcfi-lto-offset.c
create mode 100644 gcc/testsuite/gcc.dg/kcfi/kcfi-move-preservation.c
create mode 100644 gcc/testsuite/gcc.dg/kcfi/kcfi-no-sanitize-inline.c
create mode 100644 gcc/testsuite/gcc.dg/kcfi/kcfi-no-sanitize.c
create mode 100644 gcc/testsuite/gcc.dg/kcfi/kcfi-offset-validation.c
create mode 100644 gcc/testsuite/gcc.dg/kcfi/kcfi-patchable-entry-only.c
create mode 100644 gcc/testsuite/gcc.dg/kcfi/kcfi-patchable-incompatible.c
create mode 100644 gcc/testsuite/gcc.dg/kcfi/kcfi-patchable-large.c
create mode 100644 gcc/testsuite/gcc.dg/kcfi/kcfi-patchable-medium.c
create mode 100644 gcc/testsuite/gcc.dg/kcfi/kcfi-patchable-prefix-only.c
create mode 100644 gcc/testsuite/gcc.dg/kcfi/kcfi-riscv-32bit.c
create mode 100644 gcc/testsuite/gcc.dg/kcfi/kcfi-riscv-fixed-t1.c
create mode 100644 gcc/testsuite/gcc.dg/kcfi/kcfi-riscv-fixed-t2.c
create mode 100644 gcc/testsuite/gcc.dg/kcfi/kcfi-riscv-fixed-t3.c
create mode 100644 gcc/testsuite/gcc.dg/kcfi/kcfi-runtime.c
create mode 100644 gcc/testsuite/gcc.dg/kcfi/kcfi-tail-calls.c
create mode 100644 gcc/testsuite/gcc.dg/kcfi/kcfi-trap-encoding.c
create mode 100644 gcc/testsuite/gcc.dg/kcfi/kcfi-trap-section-per-func.c
create mode 100644 gcc/testsuite/gcc.dg/kcfi/kcfi-trap-section.c
create mode 100644 gcc/testsuite/gcc.dg/kcfi/kcfi-x86-32bit.c
create mode 100644 gcc/testsuite/gcc.dg/kcfi/kcfi-x86-arity.c
create mode 100644 gcc/testsuite/gcc.dg/kcfi/kcfi-x86-fixed-r10.c
create mode 100644 gcc/testsuite/gcc.dg/kcfi/kcfi-x86-fixed-r11.c
create mode 100644 gcc/testsuite/gcc.dg/kcfi/kcfi-x86-retpoline-r11.c
create mode 100644 gcc/kcfi-typeinfo.h
create mode 100644 gcc/kcfi-typeinfo.cc
--
2.34.1
