From: Thomas Gleixner <tglx@xxxxxxxxxxxxx> commit 6f059e634dcd0d725854514c94c114bbdd83950d upstream reload_store() is way too complicated. Split the inner workings out and make the following enhancements: - Taint the kernel only when the microcode was actually updated. If. e.g. the rendezvous fails, then nothing happened and there is no reason for tainting. - Return useful error codes Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Signed-off-by: Borislav Petkov (AMD) <bp@xxxxxxxxx> Reviewed-by: Nikolay Borisov <nik.borisov@xxxxxxxx> Link: https://lore.kernel.org/r/20231002115903.145048840@xxxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/x86/kernel/cpu/microcode/core.c | 41 ++++++++++++++++------------------- 1 file changed, 19 insertions(+), 22 deletions(-) --- a/arch/x86/kernel/cpu/microcode/core.c +++ b/arch/x86/kernel/cpu/microcode/core.c @@ -362,11 +362,11 @@ static int microcode_reload_late(void) pr_info("Reload succeeded, microcode revision: 0x%x -> 0x%x\n", old, boot_cpu_data.microcode); microcode_check(&prev_info); + add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_STILL_OK); } else { pr_info("Reload failed, current microcode revision: 0x%x\n", boot_cpu_data.microcode); } - return ret; } @@ -399,40 +399,37 @@ static bool ensure_cpus_are_online(void) return true; } +static int ucode_load_late_locked(void) +{ + if (!ensure_cpus_are_online()) + return -EBUSY; + + switch (microcode_ops->request_microcode_fw(0, µcode_pdev->dev)) { + case UCODE_NEW: + return microcode_reload_late(); + case UCODE_NFOUND: + return -ENOENT; + default: + return -EBADFD; + } +} + static ssize_t reload_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t size) { - enum ucode_state tmp_ret = UCODE_OK; - int bsp = boot_cpu_data.cpu_index; unsigned long val; - ssize_t ret = 0; + ssize_t ret; ret = kstrtoul(buf, 0, &val); if (ret || val != 1) return -EINVAL; cpus_read_lock(); - - if (!ensure_cpus_are_online()) { - ret = -EBUSY; - goto put; - } - - tmp_ret = microcode_ops->request_microcode_fw(bsp, µcode_pdev->dev); - if (tmp_ret != UCODE_NEW) - goto put; - - ret = microcode_reload_late(); -put: + ret = ucode_load_late_locked(); cpus_read_unlock(); - if (ret == 0) - ret = size; - - add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_STILL_OK); - - return ret; + return ret ? : size; } static DEVICE_ATTR_WO(reload); Patches currently in stable-queue which might be from tglx@xxxxxxxxxxxxx are queue-6.6/x86-microcode-intel-cleanup-code-further.patch queue-6.6/x86-microcode-intel-simplify-scan_microcode.patch queue-6.6/x86-microcode-mop-up-early-loading-leftovers.patch queue-6.6/x86-microcode-provide-new-control-functions.patch queue-6.6/x86-microcode-intel-save-the-microcode-only-after-a-successful-late-load.patch queue-6.6/x86-microcode-32-move-early-loading-after-paging-enable.patch queue-6.6/x86-microcode-intel-simplify-early-loading.patch queue-6.6/x86-microcode-add-per-cpu-control-field.patch queue-6.6/x86-microcode-add-per-cpu-result-state.patch queue-6.6/x86-microcode-prepare-for-minimal-revision-check.patch queue-6.6/x86-microcode-intel-simplify-and-rename-generic_load_microcode.patch queue-6.6/x86-microcode-amd-get-rid-of-the-_load_microcode_amd-forward-declaration.patch queue-6.6/x86-microcode-handle-offline-cpus-correctly.patch queue-6.6/x86-microcode-get-rid-of-the-schedule-work-indirection.patch queue-6.6/x86-microcode-intel-rework-intel_cpu_collect_info.patch queue-6.6/x86-microcode-amd-use-cached-microcode-for-ap-load.patch queue-6.6/x86-microcode-replace-the-all-in-one-rendevous-handler.patch queue-6.6/x86-microcode-amd-add-get_patch_level.patch queue-6.6/x86-apic-provide-apic_force_nmi_on_cpu.patch queue-6.6/sched-core-prevent-rescheduling-when-interrupts-are-disabled.patch queue-6.6/x86-cpu-fix-warm-boot-hang-regression-on-amd-sc1100-.patch queue-6.6/x86-microcode-intel-rework-intel_find_matching_signature.patch queue-6.6/x86-microcode-remove-pointless-apply-invocation.patch queue-6.6/x86-microcode-intel-reuse-intel_cpu_collect_info.patch queue-6.6/x86-microcode-amd-use-correct-per-cpu-ucode_cpu_info.patch queue-6.6/x86-microcode-amd-cache-builtin-initrd-microcode-early.patch queue-6.6/x86-microcode-protect-against-instrumentation.patch queue-6.6/x86-microcode-clean-up-mc_cpu_down_prep.patch queue-6.6/x86-microcode-amd-cache-builtin-microcode-too.patch queue-6.6/x86-microcode-amd-merge-early_apply_microcode-into-its-single-callsite.patch queue-6.6/x86-microcode-rendezvous-and-load-in-nmi.patch queue-6.6/x86-microcode-intel-rip-out-mixed-stepping-support-for-intel-cpus.patch queue-6.6/x86-microcode-intel-unify-microcode-apply-functions.patch queue-6.6/intel_idle-handle-older-cpus-which-stop-the-tsc-in-deeper-c-states-correctly.patch queue-6.6/x86-microcode-intel-switch-to-kvmalloc.patch queue-6.6/x86-microcode-clarify-the-late-load-logic.patch queue-6.6/x86-microcode-sanitize-__wait_for_cpus.patch queue-6.6/x86-microcode-rework-early-revisions-reporting.patch queue-6.6/rcuref-plug-slowpath-race-in-rcuref_put.patch queue-6.6/x86-microcode-handle-nosmt-correctly.patch
