This is a note to let you know that I've just added the patch titled x86/entry: Remove skip_r11rcx to the 5.4-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-entry-remove-skip_r11rcx.patch and it can be found in the queue-5.4 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 Wed Oct 5 12:28:43 PM CEST 2022 From: Thadeu Lima de Souza Cascardo <cascardo@xxxxxxxxxxxxx> Date: Mon, 3 Oct 2022 10:10:12 -0300 Subject: x86/entry: Remove skip_r11rcx To: stable@xxxxxxxxxxxxxxx Cc: x86@xxxxxxxxxx, kvm@xxxxxxxxxxxxxxx, bp@xxxxxxxxx, pbonzini@xxxxxxxxxx, peterz@xxxxxxxxxxxxx, jpoimboe@xxxxxxxxxx Message-ID: <20221003131038.12645-12-cascardo@xxxxxxxxxxxxx> From: Peter Zijlstra <peterz@xxxxxxxxxxxxx> commit 1b331eeea7b8676fc5dbdf80d0a07e41be226177 upstream. Yes, r11 and rcx have been restored previously, but since they're being popped anyway (into rsi) might as well pop them into their own regs -- setting them to the value they already are. Less magical code. Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Signed-off-by: Borislav Petkov <bp@xxxxxxx> Link: https://lore.kernel.org/r/20220506121631.365070674@xxxxxxxxxxxxx Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/x86/entry/calling.h | 10 +--------- arch/x86/entry/entry_64.S | 3 +-- 2 files changed, 2 insertions(+), 11 deletions(-) --- a/arch/x86/entry/calling.h +++ b/arch/x86/entry/calling.h @@ -146,27 +146,19 @@ For 32-bit we have the following convent .endm -.macro POP_REGS pop_rdi=1 skip_r11rcx=0 +.macro POP_REGS pop_rdi=1 popq %r15 popq %r14 popq %r13 popq %r12 popq %rbp popq %rbx - .if \skip_r11rcx - popq %rsi - .else popq %r11 - .endif popq %r10 popq %r9 popq %r8 popq %rax - .if \skip_r11rcx - popq %rsi - .else popq %rcx - .endif popq %rdx popq %rsi .if \pop_rdi --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -248,8 +248,7 @@ GLOBAL(entry_SYSCALL_64_after_hwframe) * perf profiles. Nothing jumps here. */ syscall_return_via_sysret: - /* rcx and r11 are already restored (see code above) */ - POP_REGS pop_rdi=0 skip_r11rcx=1 + POP_REGS pop_rdi=0 /* * Now all regs are restored except RSP and RDI. Patches currently in stable-queue which might be from cascardo@xxxxxxxxxxxxx are queue-5.4/x86-speculation-disable-rrsba-behavior.patch queue-5.4/kvm-vmx-flatten-__vmx_vcpu_run.patch queue-5.4/x86-kvm-vmx-make-noinstr-clean.patch queue-5.4/revert-x86-speculation-add-rsb-vm-exit-protections.patch queue-5.4/kvm-vmx-fix-ibrs-handling-after-vmexit.patch queue-5.4/kvm-vmx-prevent-guest-rsb-poisoning-attacks-with-eibrs.patch queue-5.4/kvm-nvmx-use-__vmx_vcpu_run-in-nested_vmx_check_vmentry_hw.patch queue-5.4/x86-bugs-keep-a-per-cpu-ia32_spec_ctrl-value.patch queue-5.4/x86-cpu-amd-enumerate-btc_no.patch queue-5.4/x86-speculation-fix-firmware-entry-spec_ctrl-handling.patch queue-5.4/x86-speculation-add-spectre_v2-ibrs-option-to-support-kernel-ibrs.patch queue-5.4/x86-cpu-add-consistent-cpu-match-macros.patch queue-5.4/x86-speculation-remove-x86_spec_ctrl_mask.patch queue-5.4/x86-bugs-add-cannon-lake-to-retbleed-affected-cpu-list.patch queue-5.4/x86-bugs-warn-when-ibrs-mitigation-is-selected-on-enhanced-ibrs-parts.patch queue-5.4/x86-speculation-fill-rsb-on-vmexit-for-ibrs.patch queue-5.4/x86-cpu-add-a-steppings-field-to-struct-x86_cpu_id.patch queue-5.4/kvm-vmx-convert-launched-argument-to-flags.patch queue-5.4/x86-common-stamp-out-the-stepping-madness.patch queue-5.4/x86-bugs-split-spectre_v2_select_mitigation-and-spectre_v2_user_select_mitigation.patch queue-5.4/x86-bugs-report-intel-retbleed-vulnerability.patch queue-5.4/x86-speculation-change-fill_return_buffer-to-work-with-objtool.patch queue-5.4/x86-cpufeatures-move-retpoline-flags-to-word-11.patch queue-5.4/x86-speculation-fix-spec_ctrl-write-on-smt-state-change.patch queue-5.4/kvm-vmx-use-test-reg-reg-instead-of-cmp-0-reg-in-vmenter.s.patch queue-5.4/x86-bugs-optimize-spec_ctrl-msr-writes.patch queue-5.4/x86-bugs-report-amd-retbleed-vulnerability.patch queue-5.4/x86-speculation-fix-rsb-filling-with-config_retpoline-n.patch queue-5.4/intel_idle-disable-ibrs-during-long-idle.patch queue-5.4/x86-speculation-use-declare_per_cpu-for-x86_spec_ctrl_current.patch queue-5.4/x86-entry-remove-skip_r11rcx.patch queue-5.4/x86-speculation-use-cached-host-spec_ctrl-value-for-guest-entry-exit.patch queue-5.4/x86-devicetable-move-x86-specific-macro-out-of-generic-code.patch queue-5.4/x86-bugs-add-amd-retbleed-boot-parameter.patch queue-5.4/x86-entry-add-kernel-ibrs-implementation.patch queue-5.4/revert-x86-cpu-add-a-steppings-field-to-struct-x86_cpu_id.patch queue-5.4/x86-speculation-add-rsb-vm-exit-protections.patch