diff options
Diffstat (limited to 'arch/x86/kernel/cpu')
| -rw-r--r-- | arch/x86/kernel/cpu/amd.c | 9 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/bugs.c | 37 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/intel_rdt_rdtgroup.c | 26 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/microcode/amd.c | 53 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/microcode/core.c | 6 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/microcode/intel.c | 8 |
6 files changed, 85 insertions, 54 deletions
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index e017f64e0..c8979f8cb 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -199,6 +199,15 @@ static void init_amd_k6(struct cpuinfo_x86 *c) return; } #endif + /* + * Work around Erratum 1386. The XSAVES instruction malfunctions in + * certain circumstances on Zen1/2 uarch, and not all parts have had + * updated microcode at the time of writing (March 2023). + * + * Affected parts all have no supervisor XSAVE states, meaning that + * the XSAVEC instruction (which works fine) is equivalent. + */ + clear_cpu_cap(c, X86_FEATURE_XSAVES); } static void init_amd_k7(struct cpuinfo_x86 *c) diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index f1f57acca..680fa070e 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -135,9 +135,17 @@ void __init check_bugs(void) * have unknown values. AMD64_LS_CFG MSR is cached in the early AMD * init code as it is not enumerated and depends on the family. */ - if (boot_cpu_has(X86_FEATURE_MSR_SPEC_CTRL)) + if (cpu_feature_enabled(X86_FEATURE_MSR_SPEC_CTRL)) { rdmsrl(MSR_IA32_SPEC_CTRL, x86_spec_ctrl_base); + /* + * Previously running kernel (kexec), may have some controls + * turned ON. Clear them and let the mitigations setup below + * rediscover them based on configuration. + */ + x86_spec_ctrl_base &= ~SPEC_CTRL_MITIGATIONS_MASK; + } + /* Select the proper CPU mitigations before patching alternatives: */ spectre_v1_select_mitigation(); spectre_v2_select_mitigation(); @@ -975,14 +983,18 @@ spectre_v2_parse_user_cmdline(void) return SPECTRE_V2_USER_CMD_AUTO; } -static inline bool spectre_v2_in_ibrs_mode(enum spectre_v2_mitigation mode) +static inline bool spectre_v2_in_eibrs_mode(enum spectre_v2_mitigation mode) { - return mode == SPECTRE_V2_IBRS || - mode == SPECTRE_V2_EIBRS || + return mode == SPECTRE_V2_EIBRS || mode == SPECTRE_V2_EIBRS_RETPOLINE || mode == SPECTRE_V2_EIBRS_LFENCE; } +static inline bool spectre_v2_in_ibrs_mode(enum spectre_v2_mitigation mode) +{ + return spectre_v2_in_eibrs_mode(mode) || mode == SPECTRE_V2_IBRS; +} + static void __init spectre_v2_user_select_mitigation(void) { @@ -1045,12 +1057,19 @@ spectre_v2_user_select_mitigation(void) } /* - * If no STIBP, IBRS or enhanced IBRS is enabled, or SMT impossible, - * STIBP is not required. + * If no STIBP, enhanced IBRS is enabled, or SMT impossible, STIBP + * is not required. + * + * Enhanced IBRS also protects against cross-thread branch target + * injection in user-mode as the IBRS bit remains always set which + * implicitly enables cross-thread protections. However, in legacy IBRS + * mode, the IBRS bit is set only on kernel entry and cleared on return + * to userspace. This disables the implicit cross-thread protection, + * so allow for STIBP to be selected in that case. */ if (!boot_cpu_has(X86_FEATURE_STIBP) || !smt_possible || - spectre_v2_in_ibrs_mode(spectre_v2_enabled)) + spectre_v2_in_eibrs_mode(spectre_v2_enabled)) return; /* @@ -1778,6 +1797,8 @@ static int ib_prctl_set(struct task_struct *task, unsigned long ctrl) if (ctrl == PR_SPEC_FORCE_DISABLE) task_set_spec_ib_force_disable(task); task_update_spec_tif(task); + if (task == current) + indirect_branch_prediction_barrier(); break; default: return -ERANGE; @@ -2100,7 +2121,7 @@ static ssize_t mmio_stale_data_show_state(char *buf) static char *stibp_state(void) { - if (spectre_v2_in_ibrs_mode(spectre_v2_enabled)) + if (spectre_v2_in_eibrs_mode(spectre_v2_enabled)) return ""; switch (spectre_v2_user_stibp) { diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c index f406e3b85..1125f752f 100644 --- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c +++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c @@ -585,8 +585,10 @@ static int __rdtgroup_move_task(struct task_struct *tsk, /* * Ensure the task's closid and rmid are written before determining if * the task is current that will decide if it will be interrupted. + * This pairs with the full barrier between the rq->curr update and + * resctrl_sched_in() during context switch. */ - barrier(); + smp_mb(); /* * By now, the task's closid and rmid are set. If the task is current @@ -2140,19 +2142,23 @@ static void rdt_move_group_tasks(struct rdtgroup *from, struct rdtgroup *to, t->closid = to->closid; t->rmid = to->mon.rmid; -#ifdef CONFIG_SMP /* - * This is safe on x86 w/o barriers as the ordering - * of writing to task_cpu() and t->on_cpu is - * reverse to the reading here. The detection is - * inaccurate as tasks might move or schedule - * before the smp function call takes place. In - * such a case the function call is pointless, but + * Order the closid/rmid stores above before the loads + * in task_curr(). This pairs with the full barrier + * between the rq->curr update and resctrl_sched_in() + * during context switch. + */ + smp_mb(); + + /* + * If the task is on a CPU, set the CPU in the mask. + * The detection is inaccurate as tasks might move or + * schedule before the smp function call takes place. + * In such a case the function call is pointless, but * there is no other side effect. */ - if (mask && t->on_cpu) + if (IS_ENABLED(CONFIG_SMP) && mask && task_curr(t)) cpumask_set_cpu(task_cpu(t), mask); -#endif } } read_unlock(&tasklist_lock); diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c index 8396c77e9..b33e4fe9d 100644 --- a/arch/x86/kernel/cpu/microcode/amd.c +++ b/arch/x86/kernel/cpu/microcode/amd.c @@ -54,7 +54,9 @@ struct cont_desc { }; static u32 ucode_new_rev; -static u8 amd_ucode_patch[PATCH_MAX_SIZE]; + +/* One blob per node. */ +static u8 amd_ucode_patch[MAX_NUMNODES][PATCH_MAX_SIZE]; /* * Microcode patch container file is prepended to the initrd in cpio @@ -210,7 +212,7 @@ apply_microcode_early_amd(u32 cpuid_1_eax, void *ucode, size_t size, bool save_p patch = (u8 (*)[PATCH_MAX_SIZE])__pa_nodebug(&amd_ucode_patch); #else new_rev = &ucode_new_rev; - patch = &amd_ucode_patch; + patch = &amd_ucode_patch[0]; #endif desc.cpuid_1_eax = cpuid_1_eax; @@ -329,8 +331,7 @@ void load_ucode_amd_ap(unsigned int cpuid_1_eax) apply_microcode_early_amd(cpuid_1_eax, cp.data, cp.size, false); } -static enum ucode_state -load_microcode_amd(bool save, u8 family, const u8 *data, size_t size); +static enum ucode_state load_microcode_amd(u8 family, const u8 *data, size_t size); int __init save_microcode_in_initrd_amd(unsigned int cpuid_1_eax) { @@ -348,19 +349,19 @@ int __init save_microcode_in_initrd_amd(unsigned int cpuid_1_eax) if (!desc.mc) return -EINVAL; - ret = load_microcode_amd(true, x86_family(cpuid_1_eax), desc.data, desc.size); + ret = load_microcode_amd(x86_family(cpuid_1_eax), desc.data, desc.size); if (ret > UCODE_UPDATED) return -EINVAL; return 0; } -void reload_ucode_amd(void) +void reload_ucode_amd(unsigned int cpu) { - struct microcode_amd *mc; u32 rev, dummy; + struct microcode_amd *mc; - mc = (struct microcode_amd *)amd_ucode_patch; + mc = (struct microcode_amd *)amd_ucode_patch[cpu_to_node(cpu)]; rdmsr(MSR_AMD64_PATCH_LEVEL, rev, dummy); @@ -698,9 +699,10 @@ static enum ucode_state __load_microcode_amd(u8 family, const u8 *data, return UCODE_OK; } -static enum ucode_state -load_microcode_amd(bool save, u8 family, const u8 *data, size_t size) +static enum ucode_state load_microcode_amd(u8 family, const u8 *data, size_t size) { + struct cpuinfo_x86 *c; + unsigned int nid, cpu; struct ucode_patch *p; enum ucode_state ret; @@ -713,22 +715,22 @@ load_microcode_amd(bool save, u8 family, const u8 *data, size_t size) return ret; } - p = find_patch(0); - if (!p) { - return ret; - } else { - if (boot_cpu_data.microcode >= p->patch_id) - return ret; + for_each_node(nid) { + cpu = cpumask_first(cpumask_of_node(nid)); + c = &cpu_data(cpu); - ret = UCODE_NEW; - } + p = find_patch(cpu); + if (!p) + continue; - /* save BSP's matching patch for early load */ - if (!save) - return ret; + if (c->microcode >= p->patch_id) + continue; - memset(amd_ucode_patch, 0, PATCH_MAX_SIZE); - memcpy(amd_ucode_patch, p->data, min_t(u32, ksize(p->data), PATCH_MAX_SIZE)); + ret = UCODE_NEW; + + memset(&amd_ucode_patch[nid], 0, PATCH_MAX_SIZE); + memcpy(&amd_ucode_patch[nid], p->data, min_t(u32, ksize(p->data), PATCH_MAX_SIZE)); + } return ret; } @@ -754,12 +756,11 @@ static enum ucode_state request_microcode_amd(int cpu, struct device *device, { char fw_name[36] = "amd-ucode/microcode_amd.bin"; struct cpuinfo_x86 *c = &cpu_data(cpu); - bool bsp = c->cpu_index == boot_cpu_data.cpu_index; enum ucode_state ret = UCODE_NFOUND; const struct firmware *fw; /* reload ucode container only on the boot cpu */ - if (!refresh_fw || !bsp) + if (!refresh_fw) return UCODE_OK; if (c->x86 >= 0x15) @@ -776,7 +777,7 @@ static enum ucode_state request_microcode_amd(int cpu, struct device *device, goto fw_release; } - ret = load_microcode_amd(bsp, c->x86, fw->data, fw->size); + ret = load_microcode_amd(c->x86, fw->data, fw->size); fw_release: release_firmware(fw); diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c index 985ef98c8..963b98971 100644 --- a/arch/x86/kernel/cpu/microcode/core.c +++ b/arch/x86/kernel/cpu/microcode/core.c @@ -326,7 +326,7 @@ struct cpio_data find_microcode_in_initrd(const char *path, bool use_pa) #endif } -void reload_early_microcode(void) +void reload_early_microcode(unsigned int cpu) { int vendor, family; @@ -340,7 +340,7 @@ void reload_early_microcode(void) break; case X86_VENDOR_AMD: if (family >= 0x10) - reload_ucode_amd(); + reload_ucode_amd(cpu); break; default: break; @@ -783,7 +783,7 @@ void microcode_bsp_resume(void) if (uci->valid && uci->mc) microcode_ops->apply_microcode(cpu); else if (!uci->mc) - reload_early_microcode(); + reload_early_microcode(cpu); } static struct syscore_ops mc_syscore_ops = { diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c index 3aa0e5a45..31ad79a0c 100644 --- a/arch/x86/kernel/cpu/microcode/intel.c +++ b/arch/x86/kernel/cpu/microcode/intel.c @@ -662,7 +662,6 @@ void load_ucode_intel_ap(void) else iup = &intel_ucode_patch; -reget: if (!*iup) { patch = __load_ucode_intel(&uci); if (!patch) @@ -673,12 +672,7 @@ reget: uci.mc = *iup; - if (apply_microcode_early(&uci, true)) { - /* Mixed-silicon system? Try to refetch the proper patch: */ - *iup = NULL; - - goto reget; - } + apply_microcode_early(&uci, true); } static struct microcode_intel *find_patch(struct ucode_cpu_info *uci) |