Linus Torvalds 7001052160 Add support for Intel CET-IBT, available since Tigerlake (11th gen), which is a ... coarse grained, hardware based, forward edge Control-Flow-Integrity mechanism where any indirect CALL/JMP must target an ENDBR instruction or suffer #CP. Additionally, since Alderlake (12th gen)/Sapphire-Rapids, speculation is limited to 2 instructions (and typically fewer) on branch targets not starting with ENDBR. CET-IBT also limits speculation of the next sequential instruction after the indirect CALL/JMP [1]. CET-IBT is fundamentally incompatible with retpolines, but provides, as described above, speculation limits itself. [1] https://www.intel.com/content/www/us/en/developer/articles/technical/software-security-guidance/technical-documentation/branch-history-injection.html -----BEGIN PGP SIGNATURE----- iQJJBAABCgAzFiEEv3OU3/byMaA0LqWJdkfhpEvA5LoFAmI/LI8VHHBldGVyekBp bmZyYWRlYWQub3JnAAoJEHZH4aRLwOS6ZnkP/2QCgQLTu6oRxv9O020CHwlaSEeD 1Hoy3loum5q5hAi1Ik3dR9p0H5u64c9qbrBVxaFoNKaLt5GKrtHaDSHNk2L/CFHX urpH65uvTLxbyZzcahkAahoJ71XU+m7PcrHLWMunw9sy10rExYVsUOlFyoyG6XCF BDCNZpdkC09ZM3vwlWGMZd5Pp+6HcZNPyoV9tpvWAS2l+WYFWAID7mflbpQ+tA8b y/hM6b3Ud0rT2ubuG1iUpopgNdwqQZ+HisMPGprh+wKZkYwS2l8pUTrz0MaBkFde go7fW16kFy2HQzGm6aIEBmfcg0palP/mFVaWP0zS62LwhJSWTn5G6xWBr3yxSsht 9gWCiI0oDZuTg698MedWmomdG2SK6yAuZuqmdKtLLoWfWgviPEi7TDFG/cKtZdAW ag8GM8T4iyYZzpCEcWO9GWbjo6TTGq30JBQefCBG47GjD0csv2ubXXx0Iey+jOwT x3E8wnv9dl8V9FSd/tMpTFmje8ges23yGrWtNpb5BRBuWTeuGiBPZED2BNyyIf+T dmewi2ufNMONgyNp27bDKopY81CPAQq9cVxqNm9Cg3eWPFnpOq2KGYEvisZ/rpEL EjMQeUBsy/C3AUFAleu1vwNnkwP/7JfKYpN00gnSyeQNZpqwxXBCKnHNgOMTXyJz beB/7u2KIUbKEkSN =jZfK -----END PGP SIGNATURE----- Merge tag 'x86_core_for_5.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 CET-IBT (Control-Flow-Integrity) support from Peter Zijlstra: "Add support for Intel CET-IBT, available since Tigerlake (11th gen), which is a coarse grained, hardware based, forward edge Control-Flow-Integrity mechanism where any indirect CALL/JMP must target an ENDBR instruction or suffer #CP. Additionally, since Alderlake (12th gen)/Sapphire-Rapids, speculation is limited to 2 instructions (and typically fewer) on branch targets not starting with ENDBR. CET-IBT also limits speculation of the next sequential instruction after the indirect CALL/JMP [1]. CET-IBT is fundamentally incompatible with retpolines, but provides, as described above, speculation limits itself" [1] https://www.intel.com/content/www/us/en/developer/articles/technical/software-security-guidance/technical-documentation/branch-history-injection.html * tag 'x86_core_for_5.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (53 commits) kvm/emulate: Fix SETcc emulation for ENDBR x86/Kconfig: Only allow CONFIG_X86_KERNEL_IBT with ld.lld >= 14.0.0 x86/Kconfig: Only enable CONFIG_CC_HAS_IBT for clang >= 14.0.0 kbuild: Fixup the IBT kbuild changes x86/Kconfig: Do not allow CONFIG_X86_X32_ABI=y with llvm-objcopy x86: Remove toolchain check for X32 ABI capability x86/alternative: Use .ibt_endbr_seal to seal indirect calls objtool: Find unused ENDBR instructions objtool: Validate IBT assumptions objtool: Add IBT/ENDBR decoding objtool: Read the NOENDBR annotation x86: Annotate idtentry_df() x86,objtool: Move the ASM_REACHABLE annotation to objtool.h x86: Annotate call_on_stack() objtool: Rework ASM_REACHABLE x86: Mark __invalid_creds() __noreturn exit: Mark do_group_exit() __noreturn x86: Mark stop_this_cpu() __noreturn objtool: Ignore extra-symbol code objtool: Rename --duplicate to --lto ...		2022-03-27 10:17:23 -07:00
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asm	Add support for Intel CET-IBT, available since Tigerlake (11th gen), which is a	2022-03-27 10:17:23 -07:00