The DEXCR is a SPR that allows control over various execution 'aspects', such as indirect branch prediction and enabling the hashst/hashchk instructions. Further details are in ISA 3.1B Book 3 chapter 9.
This series adds static (compile time) support for initialising the DEXCR, and basic HASHKEYR bookkeeping. v3: * Address Russell's comments v2: * Add ptrace/coredump support Previous versions: v2: https://lore.kernel.org/all/20230330055040.434133-1-bg...@linux.ibm.com/ v1: https://lore.kernel.org/all/20230322054612.1340573-1-bg...@linux.ibm.com/ RFC: https://lore.kernel.org/all/20221128024458.46121-1-bg...@linux.ibm.com/ Benjamin Gray (12): powerpc/book3s: Add missing <linux/sched.h> include powerpc/ptrace: Add missing <linux/regset.h> include powerpc/dexcr: Add initial Dynamic Execution Control Register (DEXCR) support powerpc/dexcr: Handle hashchk exception powerpc/dexcr: Support userspace ROP protection powerpc/dexcr: Support custom default DEXCR value powerpc/ptrace: Expose DEXCR and HDEXCR registers to ptrace powerpc/ptrace: Expose HASHKEYR register to ptrace Documentation: Document PowerPC kernel DEXCR interface selftests/powerpc: Add more utility macros selftests/powerpc/dexcr: Add hashst/hashchk test selftests/powerpc/dexcr: Add DEXCR status utility lsdexcr Documentation/powerpc/dexcr.rst | 58 +++++ Documentation/powerpc/index.rst | 1 + arch/powerpc/Kconfig | 14 ++ arch/powerpc/include/asm/book3s/64/kexec.h | 5 + arch/powerpc/include/asm/book3s/64/kup.h | 1 + arch/powerpc/include/asm/cputable.h | 4 +- arch/powerpc/include/asm/ppc-opcode.h | 1 + arch/powerpc/include/asm/processor.h | 1 + arch/powerpc/include/asm/reg.h | 10 + arch/powerpc/include/uapi/asm/elf.h | 2 + arch/powerpc/kernel/cpu_setup_power.c | 9 + arch/powerpc/kernel/process.c | 17 ++ arch/powerpc/kernel/prom.c | 1 + arch/powerpc/kernel/ptrace/ptrace-decl.h | 6 + arch/powerpc/kernel/ptrace/ptrace-view.c | 67 +++++- arch/powerpc/kernel/traps.c | 16 ++ include/uapi/linux/elf.h | 2 + tools/testing/selftests/powerpc/Makefile | 1 + .../selftests/powerpc/dexcr/.gitignore | 2 + .../testing/selftests/powerpc/dexcr/Makefile | 9 + tools/testing/selftests/powerpc/dexcr/dexcr.c | 132 ++++++++++ tools/testing/selftests/powerpc/dexcr/dexcr.h | 49 ++++ .../selftests/powerpc/dexcr/hashchk_test.c | 227 ++++++++++++++++++ .../testing/selftests/powerpc/dexcr/lsdexcr.c | 141 +++++++++++ tools/testing/selftests/powerpc/include/reg.h | 4 + .../testing/selftests/powerpc/include/utils.h | 31 ++- .../powerpc/pmu/sampling_tests/misc.h | 2 - tools/testing/selftests/powerpc/utils.c | 24 ++ 28 files changed, 832 insertions(+), 5 deletions(-) create mode 100644 Documentation/powerpc/dexcr.rst create mode 100644 tools/testing/selftests/powerpc/dexcr/.gitignore create mode 100644 tools/testing/selftests/powerpc/dexcr/Makefile create mode 100644 tools/testing/selftests/powerpc/dexcr/dexcr.c create mode 100644 tools/testing/selftests/powerpc/dexcr/dexcr.h create mode 100644 tools/testing/selftests/powerpc/dexcr/hashchk_test.c create mode 100644 tools/testing/selftests/powerpc/dexcr/lsdexcr.c base-commit: 547124f858ea52b2f7e58e8c0d39170a9fa66b4b -- 2.40.1
