This is a note to let you know that I've just added the patch titled x86/bugs: Split spectre_v2_select_mitigation() and spectre_v2_user_select_mitigation() to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: x86-bugs-split-spectre_v2_select_mitigation-and-spectre_v2_user_select_mitigation.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Tue Jul 12 05:07:35 PM CEST 2022 From: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Date: Tue, 14 Jun 2022 23:15:56 +0200 Subject: x86/bugs: Split spectre_v2_select_mitigation() and spectre_v2_user_select_mitigation() From: Peter Zijlstra <peterz@xxxxxxxxxxxxx> commit 166115c08a9b0b846b783088808a27d739be6e8d upstream. retbleed will depend on spectre_v2, while spectre_v2_user depends on retbleed. Break this cycle. Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Signed-off-by: Borislav Petkov <bp@xxxxxxx> Reviewed-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx> Signed-off-by: Borislav Petkov <bp@xxxxxxx> Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@xxxxxxxxxxxxx> Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/x86/kernel/cpu/bugs.c | 25 +++++++++++++++++-------- 1 file changed, 17 insertions(+), 8 deletions(-) --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -37,8 +37,9 @@ #include "cpu.h" static void __init spectre_v1_select_mitigation(void); -static void __init retbleed_select_mitigation(void); static void __init spectre_v2_select_mitigation(void); +static void __init retbleed_select_mitigation(void); +static void __init spectre_v2_user_select_mitigation(void); static void __init ssb_select_mitigation(void); static void __init l1tf_select_mitigation(void); static void __init mds_select_mitigation(void); @@ -137,13 +138,19 @@ void __init check_bugs(void) /* Select the proper CPU mitigations before patching alternatives: */ spectre_v1_select_mitigation(); + spectre_v2_select_mitigation(); + /* + * retbleed_select_mitigation() relies on the state set by + * spectre_v2_select_mitigation(); specifically it wants to know about + * spectre_v2=ibrs. + */ retbleed_select_mitigation(); /* - * spectre_v2_select_mitigation() relies on the state set by + * spectre_v2_user_select_mitigation() relies on the state set by * retbleed_select_mitigation(); specifically the STIBP selection is * forced for UNRET. */ - spectre_v2_select_mitigation(); + spectre_v2_user_select_mitigation(); ssb_select_mitigation(); l1tf_select_mitigation(); md_clear_select_mitigation(); @@ -969,13 +976,15 @@ static void __init spec_v2_user_print_co pr_info("spectre_v2_user=%s forced on command line.\n", reason); } +static __ro_after_init enum spectre_v2_mitigation_cmd spectre_v2_cmd; + static enum spectre_v2_user_cmd __init -spectre_v2_parse_user_cmdline(enum spectre_v2_mitigation_cmd v2_cmd) +spectre_v2_parse_user_cmdline(void) { char arg[20]; int ret, i; - switch (v2_cmd) { + switch (spectre_v2_cmd) { case SPECTRE_V2_CMD_NONE: return SPECTRE_V2_USER_CMD_NONE; case SPECTRE_V2_CMD_FORCE: @@ -1010,7 +1019,7 @@ static inline bool spectre_v2_in_ibrs_mo } static void __init -spectre_v2_user_select_mitigation(enum spectre_v2_mitigation_cmd v2_cmd) +spectre_v2_user_select_mitigation(void) { enum spectre_v2_user_mitigation mode = SPECTRE_V2_USER_NONE; bool smt_possible = IS_ENABLED(CONFIG_SMP); @@ -1023,7 +1032,7 @@ spectre_v2_user_select_mitigation(enum s cpu_smt_control == CPU_SMT_NOT_SUPPORTED) smt_possible = false; - cmd = spectre_v2_parse_user_cmdline(v2_cmd); + cmd = spectre_v2_parse_user_cmdline(); switch (cmd) { case SPECTRE_V2_USER_CMD_NONE: goto set_mode; @@ -1347,7 +1356,7 @@ static void __init spectre_v2_select_mit } /* Set up IBPB and STIBP depending on the general spectre V2 command */ - spectre_v2_user_select_mitigation(cmd); + spectre_v2_cmd = cmd; } static void update_stibp_msr(void * __unused) Patches currently in stable-queue which might be from peterz@xxxxxxxxxxxxx are queue-5.10/objtool-cache-instruction-relocs.patch queue-5.10/x86-sev-avoid-using-__x86_return_thunk.patch queue-5.10/objtool-add-elf_create_undef_symbol.patch queue-5.10/x86-ftrace-use-alternative-ret-encoding.patch queue-5.10/objtool-re-add-unwind_hint_-save_restore.patch queue-5.10/x86-bugs-add-retbleed-ibpb.patch queue-5.10/x86-bugs-enable-stibp-for-jmp2ret.patch queue-5.10/x86-retpoline-cleanup-some-ifdefery.patch queue-5.10/objtool-handle-__sanitize_cov-tail-calls.patch queue-5.10/x86-prepare-asm-files-for-straight-line-speculation.patch queue-5.10/kvm-vmx-flatten-__vmx_vcpu_run.patch queue-5.10/x86-kvm-vmx-make-noinstr-clean.patch queue-5.10/objtool-x86-replace-alternatives-with-.retpoline_sites.patch queue-5.10/objtool-skip-magical-retpoline-.altinstr_replacement.patch queue-5.10/x86-retbleed-add-fine-grained-kconfig-knobs.patch queue-5.10/x86-cpu-amd-add-spectral-chicken.patch queue-5.10/objtool-add-straight-line-speculation-validation.patch queue-5.10/kvm-vmx-fix-ibrs-handling-after-vmexit.patch queue-5.10/kvm-vmx-prevent-guest-rsb-poisoning-attacks-with-eibrs.patch queue-5.10/x86-vsyscall_emu-64-don-t-use-ret-in-vsyscall-emulation.patch queue-5.10/tools-arch-update-arch-x86-lib-mem-cpy-set-_64.s-copies-used-in-perf-bench-mem-memcpy.patch queue-5.10/x86-add-straight-line-speculation-mitigation.patch queue-5.10/x86-add-magic-amd-return-thunk.patch queue-5.10/x86-bugs-keep-a-per-cpu-ia32_spec_ctrl-value.patch queue-5.10/x86-alternatives-optimize-optimize_nops.patch queue-5.10/x86-objtool-create-.return_sites.patch queue-5.10/crypto-x86-poly1305-fixup-sls.patch queue-5.10/x86-alternative-handle-jcc-__x86_indirect_thunk_-reg.patch queue-5.10/x86-kvm-fix-setcc-emulation-for-return-thunks.patch queue-5.10/objtool-fix-objtool-regression-on-x32-systems.patch queue-5.10/x86-alternative-relax-text_poke_bp-constraint.patch queue-5.10/x86-retpoline-swizzle-retpoline-thunk.patch queue-5.10/objtool-rework-the-elf_rebuild_reloc_section-logic.patch queue-5.10/x86-speculation-fix-firmware-entry-spec_ctrl-handling.patch queue-5.10/x86-retpoline-remove-unused-replacement-symbols.patch queue-5.10/objtool-fix-symbol-creation.patch queue-5.10/x86-speculation-add-spectre_v2-ibrs-option-to-support-kernel-ibrs.patch queue-5.10/bpf-x86-respect-x86_feature_retpoline.patch queue-5.10/objtool-fix-type-of-reloc-addend.patch queue-5.10/objtool-x86-rewrite-retpoline-thunk-calls.patch queue-5.10/x86-undo-return-thunk-damage.patch queue-5.10/x86-prepare-inline-asm-for-straight-line-speculation.patch queue-5.10/x86-alternative-support-alternative_ternary.patch queue-5.10/kvm-emulate-fix-setcc-emulation-function-offsets-with-sls.patch queue-5.10/objtool-handle-per-arch-retpoline-naming.patch queue-5.10/x86-retpoline-create-a-retpoline-thunk-array.patch queue-5.10/x86-retpoline-simplify-retpolines.patch queue-5.10/x86-asm-fix-register-order.patch queue-5.10/x86-speculation-fill-rsb-on-vmexit-for-ibrs.patch queue-5.10/objtool-add-entry-unret-validation.patch queue-5.10/objtool-keep-track-of-retpoline-call-sites.patch queue-5.10/kvm-vmx-convert-launched-argument-to-flags.patch queue-5.10/objtool-add-elf_create_reloc-helper.patch queue-5.10/objtool-make-.altinstructions-section-entry-size-consistent.patch queue-5.10/x86-bpf-use-alternative-ret-encoding.patch queue-5.10/x86-common-stamp-out-the-stepping-madness.patch queue-5.10/x86-bugs-split-spectre_v2_select_mitigation-and-spectre_v2_user_select_mitigation.patch queue-5.10/x86-bugs-report-intel-retbleed-vulnerability.patch queue-5.10/bpf-x86-simplify-computing-label-offsets.patch queue-5.10/x86-cpufeatures-move-retpoline-flags-to-word-11.patch queue-5.10/x86-speculation-fix-spec_ctrl-write-on-smt-state-change.patch queue-5.10/x86-retpoline-use-mfunction-return.patch queue-5.10/x86-xen-rename-sys-entry-points.patch queue-5.10/objtool-only-rewrite-unconditional-retpoline-thunk-calls.patch queue-5.10/x86-bugs-optimize-spec_ctrl-msr-writes.patch queue-5.10/x86-alternative-optimize-single-byte-nops-at-an-arbitrary-position.patch queue-5.10/objtool-fix-code-relocs-vs-weak-symbols.patch queue-5.10/x86-bugs-report-amd-retbleed-vulnerability.patch queue-5.10/x86-static_call-use-alternative-ret-encoding.patch queue-5.10/x86-speculation-fix-rsb-filling-with-config_retpoline-n.patch queue-5.10/x86-asm-fixup-odd-gen-for-each-reg.h-usage.patch queue-5.10/x86-alternative-add-debug-prints-to-apply_retpolines.patch queue-5.10/objtool-extract-elf_symbol_add.patch queue-5.10/x86-use-return-thunk-in-asm-code.patch queue-5.10/objtool-remove-reloc-symbol-type-checks-in-get_alt_entry.patch queue-5.10/objtool-classify-symbols.patch queue-5.10/intel_idle-disable-ibrs-during-long-idle.patch queue-5.10/objtool-correctly-handle-retpoline-thunk-calls.patch queue-5.10/objtool-fix-.symtab_shndx-handling-for-elf_create_undef_symbol.patch queue-5.10/x86-retpoline-move-the-retpoline-thunk-declarations-to-nospec-branch.h.patch queue-5.10/objtool-support-asm-jump-tables.patch queue-5.10/x86-alternative-implement-.retpoline_sites-support.patch queue-5.10/objtool-x86-ignore-__x86_indirect_alt_-symbols.patch queue-5.10/objtool-fix-sls-validation-for-kcov-tail-call-replacement.patch queue-5.10/x86-alternative-try-inline-spectre_v2-retpoline-amd.patch queue-5.10/x86-entry-remove-skip_r11rcx.patch queue-5.10/objtool-explicitly-avoid-self-modifying-code-in-.altinstr_replacement.patch queue-5.10/x86-speculation-use-cached-host-spec_ctrl-value-for-guest-entry-exit.patch queue-5.10/x86-bugs-add-amd-retbleed-boot-parameter.patch queue-5.10/objtool-create-reloc-sections-implicitly.patch queue-5.10/x86-entry-add-kernel-ibrs-implementation.patch queue-5.10/objtool-treat-.text.__x86.-as-noinstr.patch queue-5.10/x86-lib-atomic64_386_32-rename-things.patch queue-5.10/objtool-introduce-cfi-hash.patch queue-5.10/objtool-default-ignore-int3-for-unreachable.patch queue-5.10/objtool-extract-elf_strtab_concat.patch queue-5.10/objtool-teach-get_alt_entry-about-more-relocation-types.patch queue-5.10/objtool-update-retpoline-validation.patch