diff options
Diffstat (limited to 'arch/x86/kernel')
50 files changed, 968 insertions, 362 deletions
diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index dbaf14d69ebd..4817d743c263 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -344,9 +344,12 @@ done: static void __init_or_module noinline optimize_nops(struct alt_instr *a, u8 *instr) { unsigned long flags; + int i; - if (instr[0] != 0x90) - return; + for (i = 0; i < a->padlen; i++) { + if (instr[i] != 0x90) + return; + } local_irq_save(flags); add_nops(instr + (a->instrlen - a->padlen), a->padlen); diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index 6e272f3ea984..25ddf02598d2 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -1286,6 +1286,55 @@ static int __init apic_intr_mode_select(void) return APIC_SYMMETRIC_IO; } +/* + * An initial setup of the virtual wire mode. + */ +void __init init_bsp_APIC(void) +{ + unsigned int value; + + /* + * Don't do the setup now if we have a SMP BIOS as the + * through-I/O-APIC virtual wire mode might be active. + */ + if (smp_found_config || !boot_cpu_has(X86_FEATURE_APIC)) + return; + + /* + * Do not trust the local APIC being empty at bootup. + */ + clear_local_APIC(); + + /* + * Enable APIC. + */ + value = apic_read(APIC_SPIV); + value &= ~APIC_VECTOR_MASK; + value |= APIC_SPIV_APIC_ENABLED; + +#ifdef CONFIG_X86_32 + /* This bit is reserved on P4/Xeon and should be cleared */ + if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) && + (boot_cpu_data.x86 == 15)) + value &= ~APIC_SPIV_FOCUS_DISABLED; + else +#endif + value |= APIC_SPIV_FOCUS_DISABLED; + value |= SPURIOUS_APIC_VECTOR; + apic_write(APIC_SPIV, value); + + /* + * Set up the virtual wire mode. + */ + apic_write(APIC_LVT0, APIC_DM_EXTINT); + value = APIC_DM_NMI; + if (!lapic_is_integrated()) /* 82489DX */ + value |= APIC_LVT_LEVEL_TRIGGER; + if (apic_extnmi == APIC_EXTNMI_NONE) + value |= APIC_LVT_MASKED; + apic_write(APIC_LVT1, value); +} + /* Init the interrupt delivery mode for the BSP */ void __init apic_intr_mode_init(void) { @@ -2626,11 +2675,13 @@ static int __init apic_set_verbosity(char *arg) apic_verbosity = APIC_DEBUG; else if (strcmp("verbose", arg) == 0) apic_verbosity = APIC_VERBOSE; +#ifdef CONFIG_X86_64 else { pr_warning("APIC Verbosity level %s not recognised" " use apic=verbose or apic=debug\n", arg); return -EINVAL; } +#endif return 0; } diff --git a/arch/x86/kernel/apic/apic_flat_64.c b/arch/x86/kernel/apic/apic_flat_64.c index aa85690e9b64..25a87028cb3f 100644 --- a/arch/x86/kernel/apic/apic_flat_64.c +++ b/arch/x86/kernel/apic/apic_flat_64.c @@ -151,7 +151,7 @@ static struct apic apic_flat __ro_after_init = { .apic_id_valid = default_apic_id_valid, .apic_id_registered = flat_apic_id_registered, - .irq_delivery_mode = dest_LowestPrio, + .irq_delivery_mode = dest_Fixed, .irq_dest_mode = 1, /* logical */ .disable_esr = 0, diff --git a/arch/x86/kernel/apic/apic_noop.c b/arch/x86/kernel/apic/apic_noop.c index 7b659c4480c9..5078b5ce63a7 100644 --- a/arch/x86/kernel/apic/apic_noop.c +++ b/arch/x86/kernel/apic/apic_noop.c @@ -110,7 +110,7 @@ struct apic apic_noop __ro_after_init = { .apic_id_valid = default_apic_id_valid, .apic_id_registered = noop_apic_id_registered, - .irq_delivery_mode = dest_LowestPrio, + .irq_delivery_mode = dest_Fixed, /* logical delivery broadcast to all CPUs: */ .irq_dest_mode = 1, diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c index 201579dc5242..8a7963421460 100644 --- a/arch/x86/kernel/apic/io_apic.c +++ b/arch/x86/kernel/apic/io_apic.c @@ -2988,7 +2988,7 @@ void mp_irqdomain_free(struct irq_domain *domain, unsigned int virq, } int mp_irqdomain_activate(struct irq_domain *domain, - struct irq_data *irq_data, bool early) + struct irq_data *irq_data, bool reserve) { unsigned long flags; diff --git a/arch/x86/kernel/apic/msi.c b/arch/x86/kernel/apic/msi.c index 9b18be764422..ce503c99f5c4 100644 --- a/arch/x86/kernel/apic/msi.c +++ b/arch/x86/kernel/apic/msi.c @@ -39,17 +39,13 @@ static void irq_msi_compose_msg(struct irq_data *data, struct msi_msg *msg) ((apic->irq_dest_mode == 0) ? MSI_ADDR_DEST_MODE_PHYSICAL : MSI_ADDR_DEST_MODE_LOGICAL) | - ((apic->irq_delivery_mode != dest_LowestPrio) ? - MSI_ADDR_REDIRECTION_CPU : - MSI_ADDR_REDIRECTION_LOWPRI) | + MSI_ADDR_REDIRECTION_CPU | MSI_ADDR_DEST_ID(cfg->dest_apicid); msg->data = MSI_DATA_TRIGGER_EDGE | MSI_DATA_LEVEL_ASSERT | - ((apic->irq_delivery_mode != dest_LowestPrio) ? - MSI_DATA_DELIVERY_FIXED : - MSI_DATA_DELIVERY_LOWPRI) | + MSI_DATA_DELIVERY_FIXED | MSI_DATA_VECTOR(cfg->vector); } diff --git a/arch/x86/kernel/apic/probe_32.c b/arch/x86/kernel/apic/probe_32.c index fa22017de806..02e8acb134f8 100644 --- a/arch/x86/kernel/apic/probe_32.c +++ b/arch/x86/kernel/apic/probe_32.c @@ -105,7 +105,7 @@ static struct apic apic_default __ro_after_init = { .apic_id_valid = default_apic_id_valid, .apic_id_registered = default_apic_id_registered, - .irq_delivery_mode = dest_LowestPrio, + .irq_delivery_mode = dest_Fixed, /* logical delivery broadcast to all CPUs: */ .irq_dest_mode = 1, diff --git a/arch/x86/kernel/apic/vector.c b/arch/x86/kernel/apic/vector.c index 6a823a25eaff..3cc471beb50b 100644 --- a/arch/x86/kernel/apic/vector.c +++ b/arch/x86/kernel/apic/vector.c @@ -184,6 +184,7 @@ static void reserve_irq_vector_locked(struct irq_data *irqd) irq_matrix_reserve(vector_matrix); apicd->can_reserve = true; apicd->has_reserved = true; + irqd_set_can_reserve(irqd); trace_vector_reserve(irqd->irq, 0); vector_assign_managed_shutdown(irqd); } @@ -368,8 +369,18 @@ static int activate_reserved(struct irq_data *irqd) int ret; ret = assign_irq_vector_any_locked(irqd); - if (!ret) + if (!ret) { apicd->has_reserved = false; + /* + * Core might have disabled reservation mode after + * allocating the irq descriptor. Ideally this should + * happen before allocation time, but that would require + * completely convoluted ways of transporting that + * information. + */ + if (!irqd_can_reserve(irqd)) + apicd->can_reserve = false; + } return ret; } @@ -398,21 +409,21 @@ static int activate_managed(struct irq_data *irqd) } static int x86_vector_activate(struct irq_domain *dom, struct irq_data *irqd, - bool early) + bool reserve) { struct apic_chip_data *apicd = apic_chip_data(irqd); unsigned long flags; int ret = 0; trace_vector_activate(irqd->irq, apicd->is_managed, - apicd->can_reserve, early); + apicd->can_reserve, reserve); /* Nothing to do for fixed assigned vectors */ if (!apicd->can_reserve && !apicd->is_managed) return 0; raw_spin_lock_irqsave(&vector_lock, flags); - if (early || irqd_is_managed_and_shutdown(irqd)) + if (reserve || irqd_is_managed_and_shutdown(irqd)) vector_assign_managed_shutdown(irqd); else if (apicd->is_managed) ret = activate_managed(irqd); @@ -478,6 +489,7 @@ static bool vector_configure_legacy(unsigned int virq, struct irq_data *irqd, } else { /* Release the vector */ apicd->can_reserve = true; + irqd_set_can_reserve(irqd); clear_irq_vector(irqd); realloc = true; } @@ -530,20 +542,23 @@ static int x86_vector_alloc_irqs(struct irq_domain *domain, unsigned int virq, err = assign_irq_vector_policy(irqd, info); trace_vector_setup(virq + i, false, err); - if (err) + if (err) { + irqd->chip_data = NULL; + free_apic_chip_data(apicd); goto error; + } } return 0; error: - x86_vector_free_irqs(domain, virq, i + 1); + x86_vector_free_irqs(domain, virq, i); return err; } #ifdef CONFIG_GENERIC_IRQ_DEBUGFS -void x86_vector_debug_show(struct seq_file *m, struct irq_domain *d, - struct irq_data *irqd, int ind) +static void x86_vector_debug_show(struct seq_file *m, struct irq_domain *d, + struct irq_data *irqd, int ind) { unsigned int cpu, vector, prev_cpu, prev_vector; struct apic_chip_data *apicd; diff --git a/arch/x86/kernel/apic/x2apic_cluster.c b/arch/x86/kernel/apic/x2apic_cluster.c index 622f13ca8a94..8b04234e010b 100644 --- a/arch/x86/kernel/apic/x2apic_cluster.c +++ b/arch/x86/kernel/apic/x2apic_cluster.c @@ -184,7 +184,7 @@ static struct apic apic_x2apic_cluster __ro_after_init = { .apic_id_valid = x2apic_apic_id_valid, .apic_id_registered = x2apic_apic_id_registered, - .irq_delivery_mode = dest_LowestPrio, + .irq_delivery_mode = dest_Fixed, .irq_dest_mode = 1, /* logical */ .disable_esr = 0, diff --git a/arch/x86/kernel/asm-offsets.c b/arch/x86/kernel/asm-offsets.c index 8ea78275480d..76417a9aab73 100644 --- a/arch/x86/kernel/asm-offsets.c +++ b/arch/x86/kernel/asm-offsets.c @@ -17,6 +17,7 @@ #include <asm/sigframe.h> #include <asm/bootparam.h> #include <asm/suspend.h> +#include <asm/tlbflush.h> #ifdef CONFIG_XEN #include <xen/interface/xen.h> @@ -93,4 +94,13 @@ void common(void) { BLANK(); DEFINE(PTREGS_SIZE, sizeof(struct pt_regs)); + + /* TLB state for the entry code */ + OFFSET(TLB_STATE_user_pcid_flush_mask, tlb_state, user_pcid_flush_mask); + + /* Layout info for cpu_entry_area */ + OFFSET(CPU_ENTRY_AREA_tss, cpu_entry_area, tss); + OFFSET(CPU_ENTRY_AREA_entry_trampoline, cpu_entry_area, entry_trampoline); + OFFSET(CPU_ENTRY_AREA_entry_stack, cpu_entry_area, entry_stack_page); + DEFINE(SIZEOF_entry_stack, sizeof(struct entry_stack)); } diff --git a/arch/x86/kernel/asm-offsets_32.c b/arch/x86/kernel/asm-offsets_32.c index dedf428b20b6..fa1261eefa16 100644 --- a/arch/x86/kernel/asm-offsets_32.c +++ b/arch/x86/kernel/asm-offsets_32.c @@ -47,13 +47,8 @@ void foo(void) BLANK(); /* Offset from the sysenter stack to tss.sp0 */ - DEFINE(TSS_sysenter_sp0, offsetof(struct tss_struct, x86_tss.sp0) - - offsetofend(struct tss_struct, SYSENTER_stack)); - - /* Offset from cpu_tss to SYSENTER_stack */ - OFFSET(CPU_TSS_SYSENTER_stack, tss_struct, SYSENTER_stack); - /* Size of SYSENTER_stack */ - DEFINE(SIZEOF_SYSENTER_stack, sizeof(((struct tss_struct *)0)->SYSENTER_stack)); + DEFINE(TSS_sysenter_sp0, offsetof(struct cpu_entry_area, tss.x86_tss.sp0) - + offsetofend(struct cpu_entry_area, entry_stack_page.stack)); #ifdef CONFIG_CC_STACKPROTECTOR BLANK(); diff --git a/arch/x86/kernel/asm-offsets_64.c b/arch/x86/kernel/asm-offsets_64.c index 630212fa9b9d..bf51e51d808d 100644 --- a/arch/x86/kernel/asm-offsets_64.c +++ b/arch/x86/kernel/asm-offsets_64.c @@ -23,6 +23,9 @@ int main(void) #ifdef CONFIG_PARAVIRT OFFSET(PV_CPU_usergs_sysret64, pv_cpu_ops, usergs_sysret64); OFFSET(PV_CPU_swapgs, pv_cpu_ops, swapgs); +#ifdef CONFIG_DEBUG_ENTRY + OFFSET(PV_IRQ_save_fl, pv_irq_ops, save_fl); +#endif BLANK(); #endif @@ -63,6 +66,7 @@ int main(void) OFFSET(TSS_ist, tss_struct, x86_tss.ist); OFFSET(TSS_sp0, tss_struct, x86_tss.sp0); + OFFSET(TSS_sp1, tss_struct, x86_tss.sp1); BLANK(); #ifdef CONFIG_CC_STACKPROTECTOR diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index d58184b7cd44..ea831c858195 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -804,8 +804,11 @@ static void init_amd(struct cpuinfo_x86 *c) case 0x17: init_amd_zn(c); break; } - /* Enable workaround for FXSAVE leak */ - if (c->x86 >= 6) + /* + * Enable workaround for FXSAVE leak on CPUs + * without a XSaveErPtr feature + */ + if ((c->x86 >= 6) && (!cpu_has(c, X86_FEATURE_XSAVEERPTR))) set_cpu_bug(c, X86_BUG_FXSAVE_LEAK); cpu_detect_cache_sizes(c); @@ -826,8 +829,32 @@ static void init_amd(struct cpuinfo_x86 *c) set_cpu_cap(c, X86_FEATURE_K8); if (cpu_has(c, X86_FEATURE_XMM2)) { - /* MFENCE stops RDTSC speculation */ - set_cpu_cap(c, X86_FEATURE_MFENCE_RDTSC); + unsigned long long val; + int ret; + + /* + * A serializing LFENCE has less overhead than MFENCE, so + * use it for execution serialization. On families which + * don't have that MSR, LFENCE is already serializing. + * msr_set_bit() uses the safe accessors, too, even if the MSR + * is not present. + */ + msr_set_bit(MSR_F10H_DECFG, + MSR_F10H_DECFG_LFENCE_SERIALIZE_BIT); + + /* + * Verify that the MSR write was successful (could be running + * under a hypervisor) and only then assume that LFENCE is + * serializing. + */ + ret = rdmsrl_safe(MSR_F10H_DECFG, &val); + if (!ret && (val & MSR_F10H_DECFG_LFENCE_SERIALIZE)) { + /* A serializing LFENCE stops RDTSC speculation */ + set_cpu_cap(c, X86_FEATURE_LFENCE_RDTSC); + } else { + /* MFENCE stops RDTSC speculation */ + set_cpu_cap(c, X86_FEATURE_MFENCE_RDTSC); + } } /* diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index ba0b2424c9b0..390b3dc3d438 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -10,6 +10,10 @@ */ #include <linux/init.h> #include <linux/utsname.h> +#include <linux/cpu.h> + +#include <asm/nospec-branch.h> +#include <asm/cmdline.h> #include <asm/bugs.h> #include <asm/processor.h> #include <asm/processor-flags.h> @@ -19,6 +23,9 @@ #include <asm/alternative.h> #include <asm/pgtable.h> #include <asm/set_memory.h> +#include <asm/intel-family.h> + +static void __init spectre_v2_select_mitigation(void); void __init check_bugs(void) { @@ -29,6 +36,9 @@ void __init check_bugs(void) print_cpu_info(&boot_cpu_data); } + /* Select the proper spectre mitigation before patching alternatives */ + spectre_v2_select_mitigation(); + #ifdef CONFIG_X86_32 /* * Check whether we are able to run this kernel safely on SMP. @@ -60,3 +70,214 @@ void __init check_bugs(void) set_memory_4k((unsigned long)__va(0), 1); #endif } + +/* The kernel command line selection */ +enum spectre_v2_mitigation_cmd { + SPECTRE_V2_CMD_NONE, + SPECTRE_V2_CMD_AUTO, + SPECTRE_V2_CMD_FORCE, + SPECTRE_V2_CMD_RETPOLINE, + SPECTRE_V2_CMD_RETPOLINE_GENERIC, + SPECTRE_V2_CMD_RETPOLINE_AMD, +}; + +static const char *spectre_v2_strings[] = { + [SPECTRE_V2_NONE] = "Vulnerable", + [SPECTRE_V2_RETPOLINE_MINIMAL] = "Vulnerable: Minimal generic ASM retpoline", + [SPECTRE_V2_RETPOLINE_MINIMAL_AMD] = "Vulnerable: Minimal AMD ASM retpoline", + [SPECTRE_V2_RETPOLINE_GENERIC] = "Mitigation: Full generic retpoline", + [SPECTRE_V2_RETPOLINE_AMD] = "Mitigation: Full AMD retpoline", +}; + +#undef pr_fmt +#define pr_fmt(fmt) "Spectre V2 mitigation: " fmt + +static enum spectre_v2_mitigation spectre_v2_enabled = SPECTRE_V2_NONE; + +static void __init spec2_print_if_insecure(const char *reason) +{ + if (boot_cpu_has_bug(X86_BUG_SPECTRE_V2)) + pr_info("%s\n", reason); +} + +static void __init spec2_print_if_secure(const char *reason) +{ + if (!boot_cpu_has_bug(X86_BUG_SPECTRE_V2)) + pr_info("%s\n", reason); +} + +static inline bool retp_compiler(void) +{ + return __is_defined(RETPOLINE); +} + +static inline bool match_option(const char *arg, int arglen, const char *opt) +{ + int len = strlen(opt); + + return len == arglen && !strncmp(arg, opt, len); +} + +static enum spectre_v2_mitigation_cmd __init spectre_v2_parse_cmdline(void) +{ + char arg[20]; + int ret; + + ret = cmdline_find_option(boot_command_line, "spectre_v2", arg, + sizeof(arg)); + if (ret > 0) { + if (match_option(arg, ret, "off")) { + goto disable; + } else if (match_option(arg, ret, "on")) { + spec2_print_if_secure("force enabled on command line."); + return SPECTRE_V2_CMD_FORCE; + } else if (match_option(arg, ret, "retpoline")) { + spec2_print_if_insecure("retpoline selected on command line."); + return SPECTRE_V2_CMD_RETPOLINE; + } else if (match_option(arg, ret, "retpoline,amd")) { + if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD) { + pr_err("retpoline,amd selected but CPU is not AMD. Switching to AUTO select\n"); + return SPECTRE_V2_CMD_AUTO; + } + spec2_print_if_insecure("AMD retpoline selected on command line."); + return SPECTRE_V2_CMD_RETPOLINE_AMD; + } else if (match_option(arg, ret, "retpoline,generic")) { + spec2_print_if_insecure("generic retpoline selected on command line."); + return SPECTRE_V2_CMD_RETPOLINE_GENERIC; + } else if (match_option(arg, ret, "auto")) { + return SPECTRE_V2_CMD_AUTO; + } + } + + if (!cmdline_find_option_bool(boot_command_line, "nospectre_v2")) + return SPECTRE_V2_CMD_AUTO; +disable: + spec2_print_if_insecure("disabled on command line."); + return SPECTRE_V2_CMD_NONE; +} + +/* Check for Skylake-like CPUs (for RSB handling) */ +static bool __init is_skylake_era(void) +{ + if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL && + boot_cpu_data.x86 == 6) { + switch (boot_cpu_data.x86_model) { + case INTEL_FAM6_SKYLAKE_MOBILE: + case INTEL_FAM6_SKYLAKE_DESKTOP: + case INTEL_FAM6_SKYLAKE_X: + case INTEL_FAM6_KABYLAKE_MOBILE: + case INTEL_FAM6_KABYLAKE_DESKTOP: + return true; + } + } + return false; +} + +static void __init spectre_v2_select_mitigation(void) +{ + enum spectre_v2_mitigation_cmd cmd = spectre_v2_parse_cmdline(); + enum spectre_v2_mitigation mode = SPECTRE_V2_NONE; + + /* + * If the CPU is not affected and the command line mode is NONE or AUTO + * then nothing to do. + */ + if (!boot_cpu_has_bug(X86_BUG_SPECTRE_V2) && + (cmd == SPECTRE_V2_CMD_NONE || cmd == SPECTRE_V2_CMD_AUTO)) + return; + + switch (cmd) { + case SPECTRE_V2_CMD_NONE: + return; + + case SPECTRE_V2_CMD_FORCE: + /* FALLTRHU */ + case SPECTRE_V2_CMD_AUTO: + goto retpoline_auto; + + case SPECTRE_V2_CMD_RETPOLINE_AMD: + if (IS_ENABLED(CONFIG_RETPOLINE)) + goto retpoline_amd; + break; + case SPECTRE_V2_CMD_RETPOLINE_GENERIC: + if (IS_ENABLED(CONFIG_RETPOLINE)) + goto retpoline_generic; + break; + case SPECTRE_V2_CMD_RETPOLINE: + if (IS_ENABLED(CONFIG_RETPOLINE)) + goto retpoline_auto; + break; + } + pr_err("kernel not compiled with retpoline; no mitigation available!"); + return; + +retpoline_auto: + if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD) { + retpoline_amd: + if (!boot_cpu_has(X86_FEATURE_LFENCE_RDTSC)) { + pr_err("LFENCE not serializing. Switching to generic retpoline\n"); + goto retpoline_generic; + } + mode = retp_compiler() ? SPECTRE_V2_RETPOLINE_AMD : + SPECTRE_V2_RETPOLINE_MINIMAL_AMD; + setup_force_cpu_cap(X86_FEATURE_RETPOLINE_AMD); + setup_force_cpu_cap(X86_FEATURE_RETPOLINE); + } else { + retpoline_generic: + mode = retp_compiler() ? SPECTRE_V2_RETPOLINE_GENERIC : + SPECTRE_V2_RETPOLINE_MINIMAL; + setup_force_cpu_cap(X86_FEATURE_RETPOLINE); + } + + spectre_v2_enabled = mode; + pr_info("%s\n", spectre_v2_strings[mode]); + + /* + * If neither SMEP or KPTI are available, there is a risk of + * hitting userspace addresses in the RSB after a context switch + * from a shallow call stack to a deeper one. To prevent this fill + * the entire RSB, even when using IBRS. + * + * Skylake era CPUs have a separate issue with *underflow* of the + * RSB, when they will predict 'ret' targets from the generic BTB. + * The proper mitigation for this is IBRS. If IBRS is not supported + * or deactivated in favour of retpolines the RSB fill on context + * switch is required. + */ + if ((!boot_cpu_has(X86_FEATURE_PTI) && + !boot_cpu_has(X86_FEATURE_SMEP)) || is_skylake_era()) { + setup_force_cpu_cap(X86_FEATURE_RSB_CTXSW); + pr_info("Filling RSB on context switch\n"); + } +} + +#undef pr_fmt + +#ifdef CONFIG_SYSFS +ssize_t cpu_show_meltdown(struct device *dev, + struct device_attribute *attr, char *buf) +{ + if (!boot_cpu_has_bug(X86_BUG_CPU_MELTDOWN)) + return sprintf(buf, "Not affected\n"); + if (boot_cpu_has(X86_FEATURE_PTI)) + return sprintf(buf, "Mitigation: PTI\n"); + return sprintf(buf, "Vulnerable\n"); +} + +ssize_t cpu_show_spectre_v1(struct device *dev, + struct device_attribute *attr, char *buf) +{ + if (!boot_cpu_has_bug(X86_BUG_SPECTRE_V1)) + return sprintf(buf, "Not affected\n"); + return sprintf(buf, "Vulnerable\n"); +} + +ssize_t cpu_show_spectre_v2(struct device *dev, + struct device_attribute *attr, char *buf) +{ + if (!boot_cpu_has_bug(X86_BUG_SPECTRE_V2)) + return sprintf(buf, "Not affected\n"); + + return sprintf(buf, "%s\n", spectre_v2_strings[spectre_v2_enabled]); +} +#endif diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index fa998ca8aa5a..ef29ad001991 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -476,8 +476,8 @@ static const char *table_lookup_model(struct cpuinfo_x86 *c) return NULL; /* Not found */ } -__u32 cpu_caps_cleared[NCAPINTS]; -__u32 cpu_caps_set[NCAPINTS]; +__u32 cpu_caps_cleared[NCAPINTS + NBUGINTS]; +__u32 cpu_caps_set[NCAPINTS + NBUGINTS]; void load_percpu_segment(int cpu) { @@ -490,28 +490,23 @@ void load_percpu_segment(int cpu) load_stack_canary_segment(); } -/* Setup the fixmap mapping only once per-processor */ -static inline void setup_fixmap_gdt(int cpu) -{ -#ifdef CONFIG_X86_64 - /* On 64-bit systems, we use a read-only fixmap GDT. */ - pgprot_t prot = PAGE_KERNEL_RO; -#else - /* - * On native 32-bit systems, the GDT cannot be read-only because - * our double fault handler uses a task gate, and entering through - * a task gate needs to change an available TSS to busy. If the GDT - * is read-only, that will triple fault. - * - * On Xen PV, the GDT must be read-only because the hypervisor requires - * it. - */ - pgprot_t prot = boot_cpu_has(X86_FEATURE_XENPV) ? - PAGE_KERNEL_RO : PAGE_KERNEL; +#ifdef CONFIG_X86_32 +/* The 32-bit entry code needs to find cpu_entry_area. */ +DEFINE_PER_CPU(struct cpu_entry_area *, cpu_entry_area); #endif - __set_fixmap(get_cpu_gdt_ro_index(cpu), get_cpu_gdt_paddr(cpu), prot); -} +#ifdef CONFIG_X86_64 +/* + * Special IST stacks which the CPU switches to when it calls + * an IST-marked descriptor entry. Up to 7 stacks (hardware + * limit), all of them are 4K, except the debug stack which + * is 8K. + */ +static const unsigned int exception_stack_sizes[N_EXCEPTION_STACKS] = { + [0 ... N_EXCEPTION_STACKS - 1] = EXCEPTION_STKSZ, + [DEBUG_STACK - 1] = DEBUG_STKSZ +}; +#endif /* Load the original GDT from the per-cpu structure */ void load_direct_gdt(int cpu) @@ -747,7 +742,7 @@ static void apply_forced_caps(struct cpuinfo_x86 *c) { int i; - for (i = 0; i < NCAPINTS; i++) { + for (i = 0; i < NCAPINTS + NBUGINTS; i++) { c->x86_capability[i] &= ~cpu_caps_cleared[i]; c->x86_capability[i] |= cpu_caps_set[i]; } @@ -927,6 +922,13 @@ static void __init early_identify_cpu(struct cpuinfo_x86 *c) } setup_force_cpu_cap(X86_FEATURE_ALWAYS); + + if (c->x86_vendor != X86_VENDOR_AMD) + setup_force_cpu_bug(X86_BUG_CPU_MELTDOWN); + + setup_force_cpu_bug(X86_BUG_SPECTRE_V1); + setup_force_cpu_bug(X86_BUG_SPECTRE_V2); + fpu__init_system(c); #ifdef CONFIG_X86_32 @@ -1250,7 +1252,7 @@ void enable_sep_cpu(void) return; cpu = get_cpu(); - tss = &per_cpu(cpu_tss, cpu); + tss = &per_cpu(cpu_tss_rw, cpu); /* * We cache MSR_IA32_SYSENTER_CS's value in the TSS's ss1 field -- @@ -1259,11 +1261,7 @@ void enable_sep_cpu(void) tss->x86_tss.ss1 = __KERNEL_CS; wrmsr(MSR_IA32_SYSENTER_CS, tss->x86_tss.ss1, 0); - - wrmsr(MSR_IA32_SYSENTER_ESP, - (unsigned long)tss + offsetofend(struct tss_struct, SYSENTER_stack), - 0); - + wrmsr(MSR_IA32_SYSENTER_ESP, (unsigned long)(cpu_entry_stack(cpu) + 1), 0); wrmsr(MSR_IA32_SYSENTER_EIP, (unsigned long)entry_SYSENTER_32, 0); put_cpu(); @@ -1357,25 +1355,22 @@ DEFINE_PER_CPU(unsigned int, irq_count) __visible = -1; DEFINE_PER_CPU(int, __preempt_count) = INIT_PREEMPT_COUNT; EXPORT_PER_CPU_SYMBOL(__preempt_count); -/* - * Special IST stacks which the CPU switches to when it calls - * an IST-marked descriptor entry. Up to 7 stacks (hardware - * limit), all of them are 4K, except the debug stack which - * is 8K. - */ -static const unsigned int exception_stack_sizes[N_EXCEPTION_STACKS] = { - [0 ... N_EXCEPTION_STACKS - 1] = EXCEPTION_STKSZ, - [DEBUG_STACK - 1] = DEBUG_STKSZ -}; - -static DEFINE_PER_CPU_PAGE_ALIGNED(char, exception_stacks - [(N_EXCEPTION_STACKS - 1) * EXCEPTION_STKSZ + DEBUG_STKSZ]); - /* May not be marked __init: used by software suspend */ void syscall_init(void) { + extern char _entry_trampoline[]; + extern char entry_SYSCALL_64_trampoline[]; + + int cpu = smp_processor_id(); + unsigned long SYSCALL64_entry_trampoline = + (unsigned long)get_cpu_entry_area(cpu)->entry_trampoline + + (entry_SYSCALL_64_trampoline - _entry_trampoline); + wrmsr(MSR_STAR, 0, (__USER32_CS << 16) | __KERNEL_CS); - wrmsrl(MSR_LSTAR, (unsigned long)entry_SYSCALL_64); + if (static_cpu_has(X86_FEATURE_PTI)) + wrmsrl(MSR_LSTAR, SYSCALL64_entry_trampoline); + else + wrmsrl(MSR_LSTAR, (unsigned long)entry_SYSCALL_64); #ifdef CONFIG_IA32_EMULATION wrmsrl(MSR_CSTAR, (unsigned long)entry_SYSCALL_compat); @@ -1386,7 +1381,7 @@ void syscall_init(void) * AMD doesn't allow SYSENTER in long mode (either 32- or 64-bit). */ wrmsrl_safe(MSR_IA32_SYSENTER_CS, (u64)__KERNEL_CS); - wrmsrl_safe(MSR_IA32_SYSENTER_ESP, 0ULL); + wrmsrl_safe(MSR_IA32_SYSENTER_ESP, (unsigned long)(cpu_entry_stack(cpu) + 1)); wrmsrl_safe(MSR_IA32_SYSENTER_EIP, (u64)entry_SYSENTER_compat); #else wrmsrl(MSR_CSTAR, (unsigned long)ignore_sysret); @@ -1530,7 +1525,7 @@ void cpu_init(void) if (cpu) load_ucode_ap(); - t = &per_cpu(cpu_tss, cpu); + t = &per_cpu(cpu_tss_rw, cpu); oist = &per_cpu(orig_ist, cpu); #ifdef CONFIG_NUMA @@ -1569,7 +1564,7 @@ void cpu_init(void) * set up and load the per-CPU TSS */ if (!oist->ist[0]) { - char *estacks = per_cpu(exception_stacks, cpu); + char *estacks = get_cpu_entry_area(cpu)->exception_stacks; for (v = 0; v < N_EXCEPTION_STACKS; v++) { estacks += exception_stack_sizes[v]; @@ -1580,7 +1575,7 @@ void cpu_init(void) } } - t->x86_tss.io_bitmap_base = offsetof(struct tss_struct, io_bitmap); + t->x86_tss.io_bitmap_base = IO_BITMAP_OFFSET; /* * <= is required because the CPU will access up to @@ -1596,11 +1591,12 @@ void cpu_init(void) enter_lazy_tlb(&init_mm, me); /* - * Initialize the TSS. Don't bother initializing sp0, as the initial - * task never enters user mode. + * Initialize the TSS. sp0 points to the entry trampoline stack + * regardless of what task is running. */ - set_tss_desc(cpu, t); + set_tss_desc(cpu, &get_cpu_entry_area(cpu)->tss.x86_tss); load_TR_desc(); + load_sp0((unsigned long)(cpu_entry_stack(cpu) + 1)); load_mm_ldt(&init_mm); @@ -1612,7 +1608,6 @@ void cpu_init(void) if (is_uv_system()) uv_cpu_init(); - setup_fixmap_gdt(cpu); load_fixmap_gdt(cpu); } @@ -1622,7 +1617,7 @@ void cpu_init(void) { int cpu = smp_processor_id(); struct task_struct *curr = current; - struct tss_struct *t = &per_cpu(cpu_tss, cpu); + struct tss_struct *t = &per_cpu(cpu_tss_rw, cpu); wait_for_master_cpu(cpu); @@ -1657,12 +1652,12 @@ void cpu_init(void) * Initialize the TSS. Don't bother initializing sp0, as the initial * task never enters user mode. */ - set_tss_desc(cpu, t); + set_tss_desc(cpu, &get_cpu_entry_area(cpu)->tss.x86_tss); load_TR_desc(); load_mm_ldt(&init_mm); - t->x86_tss.io_bitmap_base = offsetof(struct tss_struct, io_bitmap); + t->x86_tss.io_bitmap_base = IO_BITMAP_OFFSET; #ifdef CONFIG_DOUBLEFAULT /* Set up doublefault TSS pointer in the GDT */ @@ -1674,7 +1669,6 @@ void cpu_init(void) fpu__init_cpu(); - setup_fixmap_gdt(cpu); load_fixmap_gdt(cpu); } #endif diff --git a/arch/x86/kernel/cpu/intel_rdt.c b/arch/x86/kernel/cpu/intel_rdt.c index 88dcf8479013..99442370de40 100644 --- a/arch/x86/kernel/cpu/intel_rdt.c +++ b/arch/x86/kernel/cpu/intel_rdt.c @@ -525,10 +525,6 @@ static void domain_remove_cpu(int cpu, struct rdt_resource *r) */ if (static_branch_unlikely(&rdt_mon_enable_key)) rmdir_mondata_subdir_allrdtgrp(r, d->id); - kfree(d->ctrl_val); - kfree(d->rmid_busy_llc); - kfree(d->mbm_total); - kfree(d->mbm_local); list_del(&d->list); if (is_mbm_enabled()) cancel_delayed_work(&d->mbm_over); @@ -545,6 +541,10 @@ static void domain_remove_cpu(int cpu, struct rdt_resource *r) cancel_delayed_work(&d->cqm_limbo); } + kfree(d->ctrl_val); + kfree(d->rmid_busy_llc); + kfree(d->mbm_total); + kfree(d->mbm_local); kfree(d); return; } diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c index b1d616d08eee..868e412b4f0c 100644 --- a/arch/x86/kernel/cpu/mcheck/mce.c +++ b/arch/x86/kernel/cpu/mcheck/mce.c @@ -1785,6 +1785,11 @@ static void unexpected_machine_check(struct pt_regs *regs, long error_code) void (*machine_check_vector)(struct pt_regs *, long error_code) = unexpected_machine_check; +dotraplinkage void do_mce(struct pt_regs *regs, long error_code) +{ + machine_check_vector(regs, error_code); +} + /* * Called for each booted CPU to set up machine checks. * Must be called with preempt off: diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c index c6daec4bdba5..330b8462d426 100644 --- a/arch/x86/kernel/cpu/microcode/amd.c +++ b/arch/x86/kernel/cpu/microcode/amd.c @@ -470,6 +470,7 @@ static unsigned int verify_patch_size(u8 family, u32 patch_size, #define F14H_MPB_MAX_SIZE 1824 #define F15H_MPB_MAX_SIZE 4096 #define F16H_MPB_MAX_SIZE 3458 +#define F17H_MPB_MAX_SIZE 3200 switch (family) { case 0x14: @@ -481,6 +482,9 @@ static unsigned int verify_patch_size(u8 family, u32 patch_size, case 0x16: max_size = F16H_MPB_MAX_SIZE; break; + case 0x17: + max_size = F17H_MPB_MAX_SIZE; + break; default: max_size = F1XH_MPB_MAX_SIZE; break; diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c index 7dbcb7adf797..d9e460fc7a3b 100644 --- a/arch/x86/kernel/cpu/microcode/intel.c +++ b/arch/x86/kernel/cpu/microcode/intel.c @@ -565,15 +565,6 @@ static void print_ucode(struct ucode_cpu_info *uci) } #else -/* - * Flush global tlb. We only do this in x86_64 where paging has been enabled - * already and PGE should be enabled as well. - */ -static inline void flush_tlb_early(void) -{ - __native_flush_tlb_global_irq_disabled(); -} - static inline void print_ucode(struct ucode_cpu_info *uci) { struct microcode_intel *mc; @@ -602,10 +593,6 @@ static int apply_microcode_early(struct ucode_cpu_info *uci, bool early) if (rev != mc->hdr.rev) return -1; -#ifdef CONFIG_X86_64 - /* Flush global tlb. This is precaution. */ - flush_tlb_early(); -#endif uci->cpu_sig.rev = rev; if (early) @@ -923,8 +910,17 @@ static bool is_blacklisted(unsigned int cpu) { struct cpuinfo_x86 *c = &cpu_data(cpu); - if (c->x86 == 6 && c->x86_model == INTEL_FAM6_BROADWELL_X) { - pr_err_once("late loading on model 79 is disabled.\n"); + /* + * Late loading on model 79 with microcode revision less than 0x0b000021 + * may result in a system hang. This behavior is documented in item + * BDF90, #334165 (Intel Xeon Processor E7-8800/4800 v4 Product Family). + */ + if (c->x86 == 6 && + c->x86_model == INTEL_FAM6_BROADWELL_X && + c->x86_mask == 0x01 && + c->microcode < 0x0b000021) { + pr_err_once("Erratum BDF90: late loading with revision < 0x0b000021 (0x%x) disabled.\n", c->microcode); + pr_err_once("Please consider either early loading through initrd/built-in or a potential BIOS update.\n"); return true; } diff --git a/arch/x86/kernel/cpu/scattered.c b/arch/x86/kernel/cpu/scattered.c index 05459ad3db46..d0e69769abfd 100644 --- a/arch/x86/kernel/cpu/scattered.c +++ b/arch/x86/kernel/cpu/scattered.c @@ -21,7 +21,6 @@ struct cpuid_bit { static const struct cpuid_bit cpuid_bits[] = { { X86_FEATURE_APERFMPERF, CPUID_ECX, 0, 0x00000006, 0 }, { X86_FEATURE_EPB, CPUID_ECX, 3, 0x00000006, 0 }, - { X86_FEATURE_INTEL_PT, CPUID_EBX, 25, 0x00000007, 0 }, { X86_FEATURE_AVX512_4VNNIW, CPUID_EDX, 2, 0x00000007, 0 }, { X86_FEATURE_AVX512_4FMAPS, CPUID_EDX, 3, 0x00000007, 0 }, { X86_FEATURE_CAT_L3, CPUID_EBX, 1, 0x00000010, 0 }, diff --git a/arch/x86/kernel/doublefault.c b/arch/x86/kernel/doublefault.c index 0e662c55ae90..0b8cedb20d6d 100644 --- a/arch/x86/kernel/doublefault.c +++ b/arch/x86/kernel/doublefault.c @@ -50,25 +50,23 @@ static void doublefault_fn(void) cpu_relax(); } -struct tss_struct doublefault_tss __cacheline_aligned = { - .x86_tss = { - .sp0 = STACK_START, - .ss0 = __KERNEL_DS, - .ldt = 0, - .io_bitmap_base = INVALID_IO_BITMAP_OFFSET, - - .ip = (unsigned long) doublefault_fn, - /* 0x2 bit is always set */ - .flags = X86_EFLAGS_SF | 0x2, - .sp = STACK_START, - .es = __USER_DS, - .cs = __KERNEL_CS, - .ss = __KERNEL_DS, - .ds = __USER_DS, - .fs = __KERNEL_PERCPU, - - .__cr3 = __pa_nodebug(swapper_pg_dir), - } +struct x86_hw_tss doublefault_tss __cacheline_aligned = { + .sp0 = STACK_START, + .ss0 = __KERNEL_DS, + .ldt = 0, + .io_bitmap_base = INVALID_IO_BITMAP_OFFSET, + + .ip = (unsigned long) doublefault_fn, + /* 0x2 bit is always set */ + .flags = X86_EFLAGS_SF | 0x2, + .sp = STACK_START, + .es = __USER_DS, + .cs = __KERNEL_CS, + .ss = __KERNEL_DS, + .ds = __USER_DS, + .fs = __KERNEL_PERCPU, + + .__cr3 = __pa_nodebug(swapper_pg_dir), }; /* dummy for do_double_fault() call */ diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c index f13b4c00a5de..afbecff161d1 100644 --- a/arch/x86/kernel/dumpstack.c +++ b/arch/x86/kernel/dumpstack.c @@ -18,6 +18,7 @@ #include <linux/nmi.h> #include <linux/sysfs.h> +#include <asm/cpu_entry_area.h> #include <asm/stacktrace.h> #include <asm/unwind.h> @@ -43,6 +44,24 @@ bool in_task_stack(unsigned long *stack, struct task_struct *task, return true; } +bool in_entry_stack(unsigned long *stack, struct stack_info *info) +{ + struct entry_stack *ss = cpu_entry_stack(smp_processor_id()); + + void *begin = ss; + void *end = ss + 1; + + if ((void *)stack < begin || (void *)stack >= end) + return false; + + info->type = STACK_TYPE_ENTRY; + info->begin = begin; + info->end = end; + info->next_sp = NULL; + + return true; +} + static void printk_stack_address(unsigned long address, int reliable, char *log_lvl) { @@ -50,6 +69,39 @@ static void printk_stack_address(unsigned long address, int reliable, printk("%s %s%pB\n", log_lvl, reliable ? "" : "? ", (void *)address); } +void show_iret_regs(struct pt_regs *regs) +{ + printk(KERN_DEFAULT "RIP: %04x:%pS\n", (int)regs->cs, (void *)regs->ip); + printk(KERN_DEFAULT "RSP: %04x:%016lx EFLAGS: %08lx", (int)regs->ss, + regs->sp, regs->flags); +} + +static void show_regs_if_on_stack(struct stack_info *info, struct pt_regs *regs, + bool partial) +{ + /* + * These on_stack() checks aren't strictly necessary: the unwind code + * has already validated the 'regs' pointer. The checks are done for + * ordering reasons: if the registers are on the next stack, we don't + * want to print them out yet. Otherwise they'll be shown as part of + * the wrong stack. Later, when show_trace_log_lvl() switches to the + * next stack, this function will be called again with the same regs so + * they can be printed in the right context. + */ + if (!partial && on_stack(info, regs, sizeof(*regs))) { + __show_regs(regs, 0); + + } else if (partial && on_stack(info, (void *)regs + IRET_FRAME_OFFSET, + IRET_FRAME_SIZE)) { + /* + * When an interrupt or exception occurs in entry code, the + * full pt_regs might not have been saved yet. In that case + * just print the iret frame. + */ + show_iret_regs(regs); + } +} + void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs, unsigned long *stack, char *log_lvl) { @@ -57,11 +109,13 @@ void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs, struct stack_info stack_info = {0}; unsigned long visit_mask = 0; int graph_idx = 0; + bool partial; printk("%sCall Trace:\n", log_lvl); unwind_start(&state, task, regs, stack); stack = stack ? : get_stack_pointer(task, regs); + regs = unwind_get_entry_regs(&state, &partial); /* * Iterate through the stacks, starting with the current stack pointer. @@ -71,31 +125,35 @@ void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs, * - task stack * - interrupt stack * - HW exception stacks (double fault, nmi, debug, mce) + * - entry stack * - * x86-32 can have up to three stacks: + * x86-32 can have up to four stacks: * - task stack * - softirq stack * - hardirq stack + * - entry stack */ - for (regs = NULL; stack; stack = PTR_ALIGN(stack_info.next_sp, sizeof(long))) { + for ( ; stack; stack = PTR_ALIGN(stack_info.next_sp, sizeof(long))) { const char *stack_name; - /* - * If we overflowed the task stack into a guard page, jump back - * to the bottom of the usable stack. - */ - if (task_stack_page(task) - (void *)stack < PAGE_SIZE) - stack = task_stack_page(task); - - if (get_stack_info(stack, task, &stack_info, &visit_mask)) - break; + if (get_stack_info(stack, task, &stack_info, &visit_mask)) { + /* + * We weren't on a valid stack. It's possible that + * we overflowed a valid stack into a guard page. + * See if the next page up is valid so that we can + * generate some kind of backtrace if this happens. + */ + stack = (unsigned long *)PAGE_ALIGN((unsigned long)stack); + if (get_stack_info(stack, task, &stack_info, &visit_mask)) + break; + } stack_name = stack_type_name(stack_info.type); if (stack_name) printk("%s <%s>\n", log_lvl, stack_name); - if (regs && on_stack(&stack_info, regs, sizeof(*regs))) - __show_regs(regs, 0); + if (regs) + show_regs_if_on_stack(&stack_info, regs, partial); /* * Scan the stack, printing any text addresses we find. At the @@ -119,7 +177,7 @@ void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs, /* * Don't print regs->ip again if it was already printed - * by __show_regs() below. + * by show_regs_if_on_stack(). */ if (regs && stack == ®s->ip) goto next; @@ -154,9 +212,9 @@ next: unwind_next_frame(&state); /* if the frame has entry regs, print them */ - regs = unwind_get_entry_regs(&state); - if (regs && on_stack(&stack_info, regs, sizeof(*regs))) - __show_regs(regs, 0); + regs = unwind_get_entry_regs(&state, &partial); + if (regs) + show_regs_if_on_stack(&stack_info, regs, partial); } if (stack_name) @@ -252,11 +310,13 @@ int __die(const char *str, struct pt_regs *regs, long err) unsigned long sp; #endif printk(KERN_DEFAULT - "%s: %04lx [#%d]%s%s%s%s\n", str, err & 0xffff, ++die_counter, + "%s: %04lx [#%d]%s%s%s%s%s\n", str, err & 0xffff, ++die_counter, IS_ENABLED(CONFIG_PREEMPT) ? " PREEMPT" : "", IS_ENABLED(CONFIG_SMP) ? " SMP" : "", debug_pagealloc_enabled() ? " DEBUG_PAGEALLOC" : "", - IS_ENABLED(CONFIG_KASAN) ? " KASAN" : ""); + IS_ENABLED(CONFIG_KASAN) ? " KASAN" : "", + IS_ENABLED(CONFIG_PAGE_TABLE_ISOLATION) ? + (boot_cpu_has(X86_FEATURE_PTI) ? " PTI" : " NOPTI") : ""); if (notify_die(DIE_OOPS, str, regs, err, current->thread.trap_nr, SIGSEGV) == NOTIFY_STOP) diff --git a/arch/x86/kernel/dumpstack_32.c b/arch/x86/kernel/dumpstack_32.c index daefae83a3aa..04170f63e3a1 100644 --- a/arch/x86/kernel/dumpstack_32.c +++ b/arch/x86/kernel/dumpstack_32.c @@ -26,6 +26,9 @@ const char *stack_type_name(enum stack_type type) if (type == STACK_TYPE_SOFTIRQ) return "SOFTIRQ"; + if (type == STACK_TYPE_ENTRY) + return "ENTRY_TRAMPOLINE"; + return NULL; } @@ -93,6 +96,9 @@ int get_stack_info(unsigned long *stack, struct task_struct *task, if (task != current) goto unknown; + if (in_entry_stack(stack, info)) + goto recursion_check; + if (in_hardirq_stack(stack, info)) goto recursion_check; diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c index 88ce2ffdb110..563e28d14f2c 100644 --- a/arch/x86/kernel/dumpstack_64.c +++ b/arch/x86/kernel/dumpstack_64.c @@ -37,6 +37,15 @@ const char *stack_type_name(enum stack_type type) if (type == STACK_TYPE_IRQ) return "IRQ"; + if (type == STACK_TYPE_ENTRY) { + /* + * On 64-bit, we have a generic entry stack that we + * use for all the kernel entry points, including + * SYSENTER. + */ + return "ENTRY_TRAMPOLINE"; + } + if (type >= STACK_TYPE_EXCEPTION && type <= STACK_TYPE_EXCEPTION_LAST) return exception_stack_names[type - STACK_TYPE_EXCEPTION]; @@ -115,6 +124,9 @@ int get_stack_info(unsigned long *stack, struct task_struct *task, if (in_irq_stack(stack, info)) goto recursion_check; + if (in_entry_stack(stack, info)) + goto recursion_check; + goto unknown; recursion_check: diff --git a/arch/x86/kernel/ftrace_32.S b/arch/x86/kernel/ftrace_32.S index b6c6468e10bc..4c8440de3355 100644 --- a/arch/x86/kernel/ftrace_32.S +++ b/arch/x86/kernel/ftrace_32.S @@ -8,6 +8,7 @@ #include <asm/segment.h> #include <asm/export.h> #include <asm/ftrace.h> +#include <asm/nospec-branch.h> #ifdef CC_USING_FENTRY # define function_hook __fentry__ @@ -197,7 +198,8 @@ ftrace_stub: movl 0x4(%ebp), %edx subl $MCOUNT_INSN_SIZE, %eax - call *ftrace_trace_function + movl ftrace_trace_function, %ecx + CALL_NOSPEC %ecx popl %edx popl %ecx @@ -241,5 +243,5 @@ return_to_handler: movl %eax, %ecx popl %edx popl %eax - jmp *%ecx + JMP_NOSPEC %ecx #endif diff --git a/arch/x86/kernel/ftrace_64.S b/arch/x86/kernel/ftrace_64.S index c832291d948a..7cb8ba08beb9 100644 --- a/arch/x86/kernel/ftrace_64.S +++ b/arch/x86/kernel/ftrace_64.S @@ -7,7 +7,7 @@ #include <asm/ptrace.h> #include <asm/ftrace.h> #include <asm/export.h> - +#include <asm/nospec-branch.h> .code64 .section .entry.text, "ax" @@ -286,8 +286,8 @@ trace: * ip and parent ip are used and the list function is called when * function tracing is enabled. */ - call *ftrace_trace_function - + movq ftrace_trace_function, %r8 + CALL_NOSPEC %r8 restore_mcount_regs jmp fgraph_trace @@ -329,5 +329,5 @@ GLOBAL(return_to_handler) movq 8(%rsp), %rdx movq (%rsp), %rax addq $24, %rsp - jmp *%rdi + JMP_NOSPEC %rdi #endif diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c index 6a5d757b9cfd..7ba5d819ebe3 100644 --- a/arch/x86/kernel/head64.c +++ b/arch/x86/kernel/head64.c @@ -157,8 +157,8 @@ unsigned long __head __startup_64(unsigned long physaddr, p = fixup_pointer(&phys_base, physaddr); *p += load_delta - sme_get_me_mask(); - /* Encrypt the kernel (if SME is active) */ - sme_encrypt_kernel(); + /* Encrypt the kernel and related (if SME is active) */ + sme_encrypt_kernel(bp); /* * Return the SME encryption mask (if SME is active) to be used as a diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index 7dca675fe78d..04a625f0fcda 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -341,6 +341,27 @@ GLOBAL(early_recursion_flag) .balign PAGE_SIZE; \ GLOBAL(name) +#ifdef CONFIG_PAGE_TABLE_ISOLATION +/* + * Each PGD needs to be 8k long and 8k aligned. We do not + * ever go out to userspace with these, so we do not + * strictly *need* the second page, but this allows us to + * have a single set_pgd() implementation that does not + * need to worry about whether it has 4k or 8k to work + * with. + * + * This ensures PGDs are 8k long: + */ +#define PTI_USER_PGD_FILL 512 +/* This ensures they are 8k-aligned: */ +#define NEXT_PGD_PAGE(name) \ + .balign 2 * PAGE_SIZE; \ +GLOBAL(name) +#else +#define NEXT_PGD_PAGE(name) NEXT_PAGE(name) +#define PTI_USER_PGD_FILL 0 +#endif + /* Automate the creation of 1 to 1 mapping pmd entries */ #define PMDS(START, PERM, COUNT) \ i = 0 ; \ @@ -350,13 +371,14 @@ GLOBAL(name) .endr __INITDATA -NEXT_PAGE(early_top_pgt) +NEXT_PGD_PAGE(early_top_pgt) .fill 511,8,0 #ifdef CONFIG_X86_5LEVEL .quad level4_kernel_pgt - __START_KERNEL_map + _PAGE_TABLE_NOENC #else .quad level3_kernel_pgt - __START_KERNEL_map + _PAGE_TABLE_NOENC #endif + .fill PTI_USER_PGD_FILL,8,0 NEXT_PAGE(early_dynamic_pgts) .fill 512*EARLY_DYNAMIC_PAGE_TABLES,8,0 @@ -364,13 +386,14 @@ NEXT_PAGE(early_dynamic_pgts) .data #if defined(CONFIG_XEN_PV) || defined(CONFIG_XEN_PVH) -NEXT_PAGE(init_top_pgt) +NEXT_PGD_PAGE(init_top_pgt) .quad level3_ident_pgt - __START_KERNEL_map + _KERNPG_TABLE_NOENC .org init_top_pgt + PGD_PAGE_OFFSET*8, 0 .quad level3_ident_pgt - __START_KERNEL_map + _KERNPG_TABLE_NOENC .org init_top_pgt + PGD_START_KERNEL*8, 0 /* (2^48-(2*1024*1024*1024))/(2^39) = 511 */ .quad level3_kernel_pgt - __START_KERNEL_map + _PAGE_TABLE_NOENC + .fill PTI_USER_PGD_FILL,8,0 NEXT_PAGE(level3_ident_pgt) .quad level2_ident_pgt - __START_KERNEL_map + _KERNPG_TABLE_NOENC @@ -381,8 +404,9 @@ NEXT_PAGE(level2_ident_pgt) */ PMDS(0, __PAGE_KERNEL_IDENT_LARGE_EXEC, PTRS_PER_PMD) #else -NEXT_PAGE(init_top_pgt) +NEXT_PGD_PAGE(init_top_pgt) .fill 512,8,0 + .fill PTI_USER_PGD_FILL,8,0 #endif #ifdef CONFIG_X86_5LEVEL diff --git a/arch/x86/kernel/idt.c b/arch/x86/kernel/idt.c index d985cef3984f..56d99be3706a 100644 --- a/arch/x86/kernel/idt.c +++ b/arch/x86/kernel/idt.c @@ -56,7 +56,7 @@ struct idt_data { * Early traps running on the DEFAULT_STACK because the other interrupt * stacks work only after cpu_init(). */ -static const __initdata struct idt_data early_idts[] = { +static const __initconst struct idt_data early_idts[] = { INTG(X86_TRAP_DB, debug), SYSG(X86_TRAP_BP, int3), #ifdef CONFIG_X86_32 @@ -70,7 +70,7 @@ static const __initdata struct idt_data early_idts[] = { * the traps which use them are reinitialized with IST after cpu_init() has * set up TSS. */ -static const __initdata struct idt_data def_idts[] = { +static const __initconst struct idt_data def_idts[] = { INTG(X86_TRAP_DE, divide_error), INTG(X86_TRAP_NMI, nmi), INTG(X86_TRAP_BR, bounds), @@ -108,7 +108,7 @@ static const __initdata struct idt_data def_idts[] = { /* * The APIC and SMP idt entries */ -static const __initdata struct idt_data apic_idts[] = { +static const __initconst struct idt_data apic_idts[] = { #ifdef CONFIG_SMP INTG(RESCHEDULE_VECTOR, reschedule_interrupt), INTG(CALL_FUNCTION_VECTOR, call_function_interrupt), @@ -150,7 +150,7 @@ static const __initdata struct idt_data apic_idts[] = { * Early traps running on the DEFAULT_STACK because the other interrupt * stacks work only after cpu_init(). */ -static const __initdata struct idt_data early_pf_idts[] = { +static const __initconst struct idt_data early_pf_idts[] = { INTG(X86_TRAP_PF, page_fault), }; @@ -158,7 +158,7 @@ static const __initdata struct idt_data early_pf_idts[] = { * Override for the debug_idt. Same as the default, but with interrupt * stack set to DEFAULT_STACK (0). Required for NMI trap handling. */ -static const __initdata struct idt_data dbg_idts[] = { +static const __initconst struct idt_data dbg_idts[] = { INTG(X86_TRAP_DB, debug), INTG(X86_TRAP_BP, int3), }; @@ -180,7 +180,7 @@ gate_desc debug_idt_table[IDT_ENTRIES] __page_aligned_bss; * The exceptions which use Interrupt stacks. They are setup after * cpu_init() when the TSS has been initialized. */ -static const __initdata struct idt_data ist_idts[] = { +static const __initconst struct idt_data ist_idts[] = { ISTG(X86_TRAP_DB, debug, DEBUG_STACK), ISTG(X86_TRAP_NMI, nmi, NMI_STACK), SISTG(X86_TRAP_BP, int3, DEBUG_STACK), diff --git a/arch/x86/kernel/ioport.c b/arch/x86/kernel/ioport.c index 3feb648781c4..2f723301eb58 100644 --- a/arch/x86/kernel/ioport.c +++ b/arch/x86/kernel/ioport.c @@ -67,7 +67,7 @@ asmlinkage long sys_ioperm(unsigned long from, unsigned long num, int turn_on) * because the ->io_bitmap_max value must match the bitmap * contents: */ - tss = &per_cpu(cpu_tss, get_cpu()); + tss = &per_cpu(cpu_tss_rw, get_cpu()); if (turn_on) bitmap_clear(t->io_bitmap_ptr, from, num); diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c index 49cfd9fe7589..68e1867cca80 100644 --- a/arch/x86/kernel/irq.c +++ b/arch/x86/kernel/irq.c @@ -219,18 +219,6 @@ __visible unsigned int __irq_entry do_IRQ(struct pt_regs *regs) /* high bit used in ret_from_ code */ unsigned vector = ~regs->orig_ax; - /* - * NB: Unlike exception entries, IRQ entries do not reliably - * handle context tracking in the low-level entry code. This is - * because syscall entries execute briefly with IRQs on before - * updating context tracking state, so we can take an IRQ from - * kernel mode with CONTEXT_USER. The low-level entry code only - * updates the context if we came from user mode, so we won't - * switch to CONTEXT_KERNEL. We'll fix that once the syscall - * code is cleaned up enough that we can cleanly defer enabling - * IRQs. - */ - entering_irq(); /* entering_irq() tells RCU that we're not quiescent. Check it. */ diff --git a/arch/x86/kernel/irq_32.c b/arch/x86/kernel/irq_32.c index a83b3346a0e1..c1bdbd3d3232 100644 --- a/arch/x86/kernel/irq_32.c +++ b/arch/x86/kernel/irq_32.c @@ -20,6 +20,7 @@ #include <linux/mm.h> #include <asm/apic.h> +#include <asm/nospec-branch.h> #ifdef CONFIG_DEBUG_STACKOVERFLOW @@ -55,11 +56,11 @@ DEFINE_PER_CPU(struct irq_stack *, softirq_stack); static void call_on_stack(void *func, void *stack) { asm volatile("xchgl %%ebx,%%esp \n" - "call *%%edi \n" + CALL_NOSPEC "movl %%ebx,%%esp \n" : "=b" (stack) : "0" (stack), - "D"(func) + [thunk_target] "D"(func) : "memory", "cc", "edx", "ecx", "eax"); } @@ -95,11 +96,11 @@ static inline int execute_on_irq_stack(int overflow, struct irq_desc *desc) call_on_stack(print_stack_overflow, isp); asm volatile("xchgl %%ebx,%%esp \n" - "call *%%edi \n" + CALL_NOSPEC "movl %%ebx,%%esp \n" : "=a" (arg1), "=b" (isp) : "0" (desc), "1" (isp), - "D" (desc->handle_irq) + [thunk_target] "D" (desc->handle_irq) : "memory", "cc", "ecx"); return 1; } diff --git a/arch/x86/kernel/irq_64.c b/arch/x86/kernel/irq_64.c index 020efbf5786b..d86e344f5b3d 100644 --- a/arch/x86/kernel/irq_64.c +++ b/arch/x86/kernel/irq_64.c @@ -57,10 +57,10 @@ static inline void stack_overflow_check(struct pt_regs *regs) if (regs->sp >= estack_top && regs->sp <= estack_bottom) return; - WARN_ONCE(1, "do_IRQ(): %s has overflown the kernel stack (cur:%Lx,sp:%lx,irq stk top-bottom:%Lx-%Lx,exception stk top-bottom:%Lx-%Lx)\n", + WARN_ONCE(1, "do_IRQ(): %s has overflown the kernel stack (cur:%Lx,sp:%lx,irq stk top-bottom:%Lx-%Lx,exception stk top-bottom:%Lx-%Lx,ip:%pF)\n", current->comm, curbase, regs->sp, irq_stack_top, irq_stack_bottom, - estack_top, estack_bottom); + estack_top, estack_bottom, (void *)regs->ip); if (sysctl_panic_on_stackoverflow) panic("low stack detected by irq handler - check messages\n"); diff --git a/arch/x86/kernel/irqinit.c b/arch/x86/kernel/irqinit.c index 8da3e909e967..a539410c4ea9 100644 --- a/arch/x86/kernel/irqinit.c +++ b/arch/x86/kernel/irqinit.c @@ -61,6 +61,9 @@ void __init init_ISA_irqs(void) struct irq_chip *chip = legacy_pic->chip; int i; +#if defined(CONFIG_X86_64) || defined(CONFIG_X86_LOCAL_APIC) + init_bsp_APIC(); +#endif legacy_pic->init(0); for (i = 0; i < nr_legacy_irqs(); i++) diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c index e941136e24d8..203d398802a3 100644 --- a/arch/x86/kernel/kprobes/opt.c +++ b/arch/x86/kernel/kprobes/opt.c @@ -40,6 +40,7 @@ #include <asm/debugreg.h> #include <asm/set_memory.h> #include <asm/sections.h> +#include <asm/nospec-branch.h> #include "common.h" @@ -203,7 +204,7 @@ static int copy_optimized_instructions(u8 *dest, u8 *src, u8 *real) } /* Check whether insn is indirect jump */ -static int insn_is_indirect_jump(struct insn *insn) +static int __insn_is_indirect_jump(struct insn *insn) { return ((insn->opcode.bytes[0] == 0xff && (X86_MODRM_REG(insn->modrm.value) & 6) == 4) || /* Jump */ @@ -237,6 +238,26 @@ static int insn_jump_into_range(struct insn *insn, unsigned long start, int len) return (start <= target && target <= start + len); } +static int insn_is_indirect_jump(struct insn *insn) +{ + int ret = __insn_is_indirect_jump(insn); + +#ifdef CONFIG_RETPOLINE + /* + * Jump to x86_indirect_thunk_* is treated as an indirect jump. + * Note that even with CONFIG_RETPOLINE=y, the kernel compiled with + * older gcc may use indirect jump. So we add this check instead of + * replace indirect-jump check. + */ + if (!ret) + ret = insn_jump_into_range(insn, + (unsigned long)__indirect_thunk_start, + (unsigned long)__indirect_thunk_end - + (unsigned long)__indirect_thunk_start); +#endif + return ret; +} + /* Decode whole function to ensure any instructions don't jump into target */ static int can_optimize(unsigned long paddr) { diff --git a/arch/x86/kernel/ldt.c b/arch/x86/kernel/ldt.c index 1c1eae961340..26d713ecad34 100644 --- a/arch/x86/kernel/ldt.c +++ b/arch/x86/kernel/ldt.c @@ -5,6 +5,11 @@ * Copyright (C) 2002 Andi Kleen * * This handles calls from both 32bit and 64bit mode. + * + * Lock order: + * contex.ldt_usr_sem + * mmap_sem + * context.lock */ #include <linux/errno.h> @@ -19,6 +24,7 @@ #include <linux/uaccess.h> #include <asm/ldt.h> +#include <asm/tlb.h> #include <asm/desc.h> #include <asm/mmu_context.h> #include <asm/syscalls.h> @@ -42,17 +48,15 @@ static void refresh_ldt_segments(void) #endif } -/* context.lock is held for us, so we don't need any locking. */ +/* context.lock is held by the task which issued the smp function call */ static void flush_ldt(void *__mm) { struct mm_struct *mm = __mm; - mm_context_t *pc; if (this_cpu_read(cpu_tlbstate.loaded_mm) != mm) return; - pc = &mm->context; - set_ldt(pc->ldt->entries, pc->ldt->nr_entries); + load_mm_ldt(mm); refresh_ldt_segments(); } @@ -89,25 +93,143 @@ static struct ldt_struct *alloc_ldt_struct(unsigned int num_entries) return NULL; } + /* The new LDT isn't aliased for PTI yet. */ + new_ldt->slot = -1; + new_ldt->nr_entries = num_entries; return new_ldt; } +/* + * If PTI is enabled, this maps the LDT into the kernelmode and + * usermode tables for the given mm. + * + * There is no corresponding unmap function. Even if the LDT is freed, we + * leave the PTEs around until the slot is reused or the mm is destroyed. + * This is harmless: the LDT is always in ordinary memory, and no one will + * access the freed slot. + * + * If we wanted to unmap freed LDTs, we'd also need to do a flush to make + * it useful, and the flush would slow down modify_ldt(). + */ +static int +map_ldt_struct(struct mm_struct *mm, struct ldt_struct *ldt, int slot) +{ +#ifdef CONFIG_PAGE_TABLE_ISOLATION + bool is_vmalloc, had_top_level_entry; + unsigned long va; + spinlock_t *ptl; + pgd_t *pgd; + int i; + + if (!static_cpu_has(X86_FEATURE_PTI)) + return 0; + + /* + * Any given ldt_struct should have map_ldt_struct() called at most + * once. + */ + WARN_ON(ldt->slot != -1); + + /* + * Did we already have the top level entry allocated? We can't + * use pgd_none() for this because it doens't do anything on + * 4-level page table kernels. + */ + pgd = pgd_offset(mm, LDT_BASE_ADDR); + had_top_level_entry = (pgd->pgd != 0); + + is_vmalloc = is_vmalloc_addr(ldt->entries); + + for (i = 0; i * PAGE_SIZE < ldt->nr_entries * LDT_ENTRY_SIZE; i++) { + unsigned long offset = i << PAGE_SHIFT; + const void *src = (char *)ldt->entries + offset; + unsigned long pfn; + pte_t pte, *ptep; + + va = (unsigned long)ldt_slot_va(slot) + offset; + pfn = is_vmalloc ? vmalloc_to_pfn(src) : + page_to_pfn(virt_to_page(src)); + /* + * Treat the PTI LDT range as a *userspace* range. + * get_locked_pte() will allocate all needed pagetables + * and account for them in this mm. + */ + ptep = get_locked_pte(mm, va, &ptl); + if (!ptep) + return -ENOMEM; + /* + * Map it RO so the easy to find address is not a primary + * target via some kernel interface which misses a + * permission check. + */ + pte = pfn_pte(pfn, __pgprot(__PAGE_KERNEL_RO & ~_PAGE_GLOBAL)); + set_pte_at(mm, va, ptep, pte); + pte_unmap_unlock(ptep, ptl); + } + + if (mm->context.ldt) { + /* + * We already had an LDT. The top-level entry should already + * have been allocated and synchronized with the usermode + * tables. + */ + WARN_ON(!had_top_level_entry); + if (static_cpu_has(X86_FEATURE_PTI)) + WARN_ON(!kernel_to_user_pgdp(pgd)->pgd); + } else { + /* + * This is the first time we're mapping an LDT for this process. + * Sync the pgd to the usermode tables. + */ + WARN_ON(had_top_level_entry); + if (static_cpu_has(X86_FEATURE_PTI)) { + WARN_ON(kernel_to_user_pgdp(pgd)->pgd); + set_pgd(kernel_to_user_pgdp(pgd), *pgd); + } + } + + va = (unsigned long)ldt_slot_va(slot); + flush_tlb_mm_range(mm, va, va + LDT_SLOT_STRIDE, 0); + + ldt->slot = slot; +#endif + return 0; +} + +static void free_ldt_pgtables(struct mm_struct *mm) +{ +#ifdef CONFIG_PAGE_TABLE_ISOLATION + struct mmu_gather tlb; + unsigned long start = LDT_BASE_ADDR; + unsigned long end = start + (1UL << PGDIR_SHIFT); + + if (!static_cpu_has(X86_FEATURE_PTI)) + return; + + tlb_gather_mmu(&tlb, mm, start, end); + free_pgd_range(&tlb, start, end, start, end); + tlb_finish_mmu(&tlb, start, end); +#endif +} + /* After calling this, the LDT is immutable. */ static void finalize_ldt_struct(struct ldt_struct *ldt) { paravirt_alloc_ldt(ldt->entries, ldt->nr_entries); } -/* context.lock is held */ -static void install_ldt(struct mm_struct *current_mm, - struct ldt_struct *ldt) +static void install_ldt(struct mm_struct *mm, struct ldt_struct *ldt) { + mutex_lock(&mm->context.lock); + /* Synchronizes with READ_ONCE in load_mm_ldt. */ - smp_store_release(¤t_mm->context.ldt, ldt); + smp_store_release(&mm->context.ldt, ldt); - /* Activate the LDT for all CPUs using current_mm. */ - on_each_cpu_mask(mm_cpumask(current_mm), flush_ldt, current_mm, true); + /* Activate the LDT for all CPUs using currents mm. */ + on_each_cpu_mask(mm_cpumask(mm), flush_ldt, mm, true); + + mutex_unlock(&mm->context.lock); } static void free_ldt_struct(struct ldt_struct *ldt) @@ -124,27 +246,20 @@ static void free_ldt_struct(struct ldt_struct *ldt) } /* - * we do not have to muck with descriptors here, that is - * done in switch_mm() as needed. + * Called on fork from arch_dup_mmap(). Just copy the current LDT state, + * the new task is not running, so nothing can be installed. */ -int init_new_context_ldt(struct task_struct *tsk, struct mm_struct *mm) +int ldt_dup_context(struct mm_struct *old_mm, struct mm_struct *mm) { struct ldt_struct *new_ldt; - struct mm_struct *old_mm; int retval = 0; - mutex_init(&mm->context.lock); - old_mm = current->mm; - if (!old_mm) { - mm->context.ldt = NULL; + if (!old_mm) return 0; - } mutex_lock(&old_mm->context.lock); - if (!old_mm->context.ldt) { - mm->context.ldt = NULL; + if (!old_mm->context.ldt) goto out_unlock; - } new_ldt = alloc_ldt_struct(old_mm->context.ldt->nr_entries); if (!new_ldt) { @@ -156,6 +271,12 @@ int init_new_context_ldt(struct task_struct *tsk, struct mm_struct *mm) new_ldt->nr_entries * LDT_ENTRY_SIZE); finalize_ldt_struct(new_ldt); + retval = map_ldt_struct(mm, new_ldt, 0); + if (retval) { + free_ldt_pgtables(mm); + free_ldt_struct(new_ldt); + goto out_unlock; + } mm->context.ldt = new_ldt; out_unlock: @@ -174,13 +295,18 @@ void destroy_context_ldt(struct mm_struct *mm) mm->context.ldt = NULL; } +void ldt_arch_exit_mmap(struct mm_struct *mm) +{ + free_ldt_pgtables(mm); +} + static int read_ldt(void __user *ptr, unsigned long bytecount) { struct mm_struct *mm = current->mm; unsigned long entries_size; int retval; - mutex_lock(&mm->context.lock); + down_read(&mm->context.ldt_usr_sem); if (!mm->context.ldt) { retval = 0; @@ -209,7 +335,7 @@ static int read_ldt(void __user *ptr, unsigned long bytecount) retval = bytecount; out_unlock: - mutex_unlock(&mm->context.lock); + up_read(&mm->context.ldt_usr_sem); return retval; } @@ -269,7 +395,8 @@ static int write_ldt(void __user *ptr, unsigned long bytecount, int oldmode) ldt.avl = 0; } - mutex_lock(&mm->context.lock); + if (down_write_killable(&mm->context.ldt_usr_sem)) + return -EINTR; old_ldt = mm->context.ldt; old_nr_entries = old_ldt ? old_ldt->nr_entries : 0; @@ -286,12 +413,31 @@ static int write_ldt(void __user *ptr, unsigned long bytecount, int oldmode) new_ldt->entries[ldt_info.entry_number] = ldt; finalize_ldt_struct(new_ldt); + /* + * If we are using PTI, map the new LDT into the userspace pagetables. + * If there is already an LDT, use the other slot so that other CPUs + * will continue to use the old LDT until install_ldt() switches + * them over to the new LDT. + */ + error = map_ldt_struct(mm, new_ldt, old_ldt ? !old_ldt->slot : 0); + if (error) { + /* + * This only can fail for the first LDT setup. If an LDT is + * already installed then the PTE page is already + * populated. Mop up a half populated page table. + */ + if (!WARN_ON_ONCE(old_ldt)) + free_ldt_pgtables(mm); + free_ldt_struct(new_ldt); + goto out_unlock; + } + install_ldt(mm, new_ldt); free_ldt_struct(old_ldt); error = 0; out_unlock: - mutex_unlock(&mm->context.lock); + up_write(&mm->context.ldt_usr_sem); out: return error; } diff --git a/arch/x86/kernel/machine_kexec_32.c b/arch/x86/kernel/machine_kexec_32.c index 00bc751c861c..edfede768688 100644 --- a/arch/x86/kernel/machine_kexec_32.c +++ b/arch/x86/kernel/machine_kexec_32.c @@ -48,8 +48,6 @@ static void load_segments(void) "\tmovl $"STR(__KERNEL_DS)",%%eax\n" "\tmovl %%eax,%%ds\n" "\tmovl %%eax,%%es\n" - "\tmovl %%eax,%%fs\n" - "\tmovl %%eax,%%gs\n" "\tmovl %%eax,%%ss\n" : : : "eax", "memory"); #undef STR @@ -232,8 +230,8 @@ void machine_kexec(struct kimage *image) * The gdt & idt are now invalid. * If you want to load them you must set up your own idt & gdt. */ - set_gdt(phys_to_virt(0), 0); idt_invalidate(phys_to_virt(0)); + set_gdt(phys_to_virt(0), 0); /* now call it */ image->start = relocate_kernel_ptr((unsigned long)image->head, diff --git a/arch/x86/kernel/paravirt_patch_64.c b/arch/x86/kernel/paravirt_patch_64.c index ac0be8283325..9edadabf04f6 100644 --- a/arch/x86/kernel/paravirt_patch_64.c +++ b/arch/x86/kernel/paravirt_patch_64.c @@ -10,7 +10,6 @@ DEF_NATIVE(pv_irq_ops, save_fl, "pushfq; popq %rax"); DEF_NATIVE(pv_mmu_ops, read_cr2, "movq %cr2, %rax"); DEF_NATIVE(pv_mmu_ops, read_cr3, "movq %cr3, %rax"); DEF_NATIVE(pv_mmu_ops, write_cr3, "movq %rdi, %cr3"); -DEF_NATIVE(pv_mmu_ops, flush_tlb_single, "invlpg (%rdi)"); DEF_NATIVE(pv_cpu_ops, wbinvd, "wbinvd"); DEF_NATIVE(pv_cpu_ops, usergs_sysret64, "swapgs; sysretq"); @@ -60,7 +59,6 @@ unsigned native_patch(u8 type, u16 clobbers, void *ibuf, PATCH_SITE(pv_mmu_ops, read_cr2); PATCH_SITE(pv_mmu_ops, read_cr3); PATCH_SITE(pv_mmu_ops, write_cr3); - PATCH_SITE(pv_mmu_ops, flush_tlb_single); PATCH_SITE(pv_cpu_ops, wbinvd); #if defined(CONFIG_PARAVIRT_SPINLOCKS) case PARAVIRT_PATCH(pv_lock_ops.queued_spin_unlock): diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 97fb3e5737f5..cb368c2a22ab 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -47,7 +47,7 @@ * section. Since TSS's are completely CPU-local, we want them * on exact cacheline boundaries, to eliminate cacheline ping-pong. */ -__visible DEFINE_PER_CPU_SHARED_ALIGNED(struct tss_struct, cpu_tss) = { +__visible DEFINE_PER_CPU_PAGE_ALIGNED(struct tss_struct, cpu_tss_rw) = { .x86_tss = { /* * .sp0 is only used when entering ring 0 from a lower @@ -56,6 +56,16 @@ __visible DEFINE_PER_CPU_SHARED_ALIGNED(struct tss_struct, cpu_tss) = { * Poison it. */ .sp0 = (1UL << (BITS_PER_LONG-1)) + 1, + +#ifdef CONFIG_X86_64 + /* + * .sp1 is cpu_current_top_of_stack. The init task never + * runs user code, but cpu_current_top_of_stack should still + * be well defined before the first context switch. + */ + .sp1 = TOP_OF_INIT_STACK, +#endif + #ifdef CONFIG_X86_32 .ss0 = __KERNEL_DS, .ss1 = __KERNEL_CS, @@ -71,11 +81,8 @@ __visible DEFINE_PER_CPU_SHARED_ALIGNED(struct tss_struct, cpu_tss) = { */ .io_bitmap = { [0 ... IO_BITMAP_LONGS] = ~0 }, #endif -#ifdef CONFIG_X86_32 - .SYSENTER_stack_canary = STACK_END_MAGIC, -#endif }; -EXPORT_PER_CPU_SYMBOL(cpu_tss); +EXPORT_PER_CPU_SYMBOL(cpu_tss_rw); DEFINE_PER_CPU(bool, __tss_limit_invalid); EXPORT_PER_CPU_SYMBOL_GPL(__tss_limit_invalid); @@ -104,7 +111,7 @@ void exit_thread(struct task_struct *tsk) struct fpu *fpu = &t->fpu; if (bp) { - struct tss_struct *tss = &per_cpu(cpu_tss, get_cpu()); + struct tss_struct *tss = &per_cpu(cpu_tss_rw, get_cpu()); t->io_bitmap_ptr = NULL; clear_thread_flag(TIF_IO_BITMAP); @@ -299,7 +306,7 @@ void __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p, } if ((tifp ^ tifn) & _TIF_NOTSC) - cr4_toggle_bits(X86_CR4_TSD); + cr4_toggle_bits_irqsoff(X86_CR4_TSD); if ((tifp ^ tifn) & _TIF_NOCPUID) set_cpuid_faulting(!!(tifn & _TIF_NOCPUID)); @@ -373,19 +380,24 @@ void stop_this_cpu(void *dummy) disable_local_APIC(); mcheck_cpu_clear(this_cpu_ptr(&cpu_info)); + /* + * Use wbinvd on processors that support SME. This provides support + * for performing a successful kexec when going from SME inactive + * to SME active (or vice-versa). The cache must be cleared so that + * if there are entries with the same physical address, both with and + * without the encryption bit, they don't race each other when flushed + * and potentially end up with the wrong entry being committed to + * memory. + */ + if (boot_cpu_has(X86_FEATURE_SME)) + native_wbinvd(); for (;;) { /* - * Use wbinvd followed by hlt to stop the processor. This - * provides support for kexec on a processor that supports - * SME. With kexec, going from SME inactive to SME active - * requires clearing cache entries so that addresses without - * the encryption bit set don't corrupt the same physical - * address that has the encryption bit set when caches are - * flushed. To achieve this a wbinvd is performed followed by - * a hlt. Even if the processor is not in the kexec/SME - * scenario this only adds a wbinvd to a halting processor. + * Use native_halt() so that memory contents don't change + * (stack usage and variables) after possibly issuing the + * native_wbinvd() above. */ - asm volatile("wbinvd; hlt" : : : "memory"); + native_halt(); } } diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c index 45bf0c5f93e1..5224c6099184 100644 --- a/arch/x86/kernel/process_32.c +++ b/arch/x86/kernel/process_32.c @@ -234,7 +234,7 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) struct fpu *prev_fpu = &prev->fpu; struct fpu *next_fpu = &next->fpu; int cpu = smp_processor_id(); - struct tss_struct *tss = &per_cpu(cpu_tss, cpu); + struct tss_struct *tss = &per_cpu(cpu_tss_rw, cpu); /* never put a printk in __switch_to... printk() calls wake_up*() indirectly */ diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index eeeb34f85c25..c75466232016 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -69,9 +69,8 @@ void __show_regs(struct pt_regs *regs, int all) unsigned int fsindex, gsindex; unsigned int ds, cs, es; - printk(KERN_DEFAULT "RIP: %04lx:%pS\n", regs->cs, (void *)regs->ip); - printk(KERN_DEFAULT "RSP: %04lx:%016lx EFLAGS: %08lx", regs->ss, - regs->sp, regs->flags); + show_iret_regs(regs); + if (regs->orig_ax != -1) pr_cont(" ORIG_RAX: %016lx\n", regs->orig_ax); else @@ -88,6 +87,9 @@ void __show_regs(struct pt_regs *regs, int all) printk(KERN_DEFAULT "R13: %016lx R14: %016lx R15: %016lx\n", regs->r13, regs->r14, regs->r15); + if (!all) + return; + asm("movl %%ds,%0" : "=r" (ds)); asm("movl %%cs,%0" : "=r" (cs)); asm("movl %%es,%0" : "=r" (es)); @@ -98,9 +100,6 @@ void __show_regs(struct pt_regs *regs, int all) rdmsrl(MSR_GS_BASE, gs); rdmsrl(MSR_KERNEL_GS_BASE, shadowgs); - if (!all) - return; - cr0 = read_cr0(); cr2 = read_cr2(); cr3 = __read_cr3(); @@ -400,7 +399,7 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) struct fpu *prev_fpu = &prev->fpu; struct fpu *next_fpu = &next->fpu; int cpu = smp_processor_id(); - struct tss_struct *tss = &per_cpu(cpu_tss, cpu); + struct tss_struct *tss = &per_cpu(cpu_tss_rw, cpu); WARN_ON_ONCE(IS_ENABLED(CONFIG_DEBUG_ENTRY) && this_cpu_read(irq_count) != -1); @@ -462,6 +461,7 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) * Switch the PDA and FPU contexts. */ this_cpu_write(current_task, next_p); + this_cpu_write(cpu_current_top_of_stack, task_top_of_stack(next_p)); /* Reload sp0. */ update_sp0(next_p); diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index 8af2e8d0c0a1..68d7ab81c62f 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -364,16 +364,6 @@ static void __init reserve_initrd(void) !ramdisk_image || !ramdisk_size) return; /* No initrd provided by bootloader */ - /* - * If SME is active, this memory will be marked encrypted by the - * kernel when it is accessed (including relocation). However, the - * ramdisk image was loaded decrypted by the bootloader, so make - * sure that it is encrypted before accessing it. For SEV the - * ramdisk will already be encrypted, so only do this for SME. - */ - if (sme_active()) - sme_early_encrypt(ramdisk_image, ramdisk_end - ramdisk_image); - initrd_start = 0; mapped_size = memblock_mem_size(max_pfn_mapped); @@ -906,9 +896,6 @@ void __init setup_arch(char **cmdline_p) set_bit(EFI_BOOT, &efi.flags); set_bit(EFI_64BIT, &efi.flags); } - - if (efi_enabled(EFI_BOOT)) - efi_memblock_x86_reserve_range(); #endif x86_init.oem.arch_setup(); @@ -962,6 +949,8 @@ void __init setup_arch(char **cmdline_p) parse_early_param(); + if (efi_enabled(EFI_BOOT)) + efi_memblock_x86_reserve_range(); #ifdef CONFIG_MEMORY_HOTPLUG /* * Memory used by the kernel cannot be hot-removed because Linux diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 3d01df7d7cf6..ed556d50d7ed 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -106,7 +106,7 @@ EXPORT_SYMBOL(__max_logical_packages); static unsigned int logical_packages __read_mostly; /* Maximum number of SMT threads on any online core */ -int __max_smt_threads __read_mostly; +int __read_mostly __max_smt_threads = 1; /* Flag to indicate if a complete sched domain rebuild is required */ bool x86_topology_update; @@ -126,14 +126,10 @@ static inline void smpboot_setup_warm_reset_vector(unsigned long start_eip) spin_lock_irqsave(&rtc_lock, flags); CMOS_WRITE(0xa, 0xf); spin_unlock_irqrestore(&rtc_lock, flags); - local_flush_tlb(); - pr_debug("1.\n"); *((volatile unsigned short *)phys_to_virt(TRAMPOLINE_PHYS_HIGH)) = start_eip >> 4; - pr_debug("2.\n"); *((volatile unsigned short *)phys_to_virt(TRAMPOLINE_PHYS_LOW)) = start_eip & 0xf; - pr_debug("3.\n"); } static inline void smpboot_restore_warm_reset_vector(void) @@ -141,11 +137,6 @@ static inline void smpboot_restore_warm_reset_vector(void) unsigned long flags; /* - * Install writable page 0 entry to set BIOS data area. - */ - local_flush_tlb(); - - /* * Paranoid: Set warm reset code and vector here back * to default values. */ @@ -237,7 +228,7 @@ static void notrace start_secondary(void *unused) load_cr3(swapper_pg_dir); __flush_tlb_all(); #endif - + load_current_idt(); cpu_init(); x86_cpuinit.early_percpu_clock_init(); preempt_disable(); @@ -932,12 +923,8 @@ static int do_boot_cpu(int apicid, int cpu, struct task_struct *idle, initial_code = (unsigned long)start_secondary; initial_stack = idle->thread.sp; - /* - * Enable the espfix hack for this CPU - */ -#ifdef CONFIG_X86_ESPFIX64 + /* Enable the espfix hack for this CPU */ init_espfix_ap(cpu); -#endif /* So we see what's up */ announce_cpu(cpu, apicid); @@ -1304,7 +1291,7 @@ void __init native_smp_cpus_done(unsigned int max_cpus) * Today neither Intel nor AMD support heterogenous systems so * extrapolate the boot cpu's data to all packages. */ - ncpus = cpu_data(0).booted_cores * smp_num_siblings; + ncpus = cpu_data(0).booted_cores * topology_max_smt_threads(); __max_logical_packages = DIV_ROUND_UP(nr_cpu_ids, ncpus); pr_info("Max logical packages: %u\n", __max_logical_packages); diff --git a/arch/x86/kernel/stacktrace.c b/arch/x86/kernel/stacktrace.c index 77835bc021c7..093f2ea5dd56 100644 --- a/arch/x86/kernel/stacktrace.c +++ b/arch/x86/kernel/stacktrace.c @@ -102,7 +102,7 @@ __save_stack_trace_reliable(struct stack_trace *trace, for (unwind_start(&state, task, NULL, NULL); !unwind_done(&state); unwind_next_frame(&state)) { - regs = unwind_get_entry_regs(&state); + regs = unwind_get_entry_regs(&state, NULL); if (regs) { /* * Kernel mode registers on the stack indicate an @@ -164,8 +164,12 @@ int save_stack_trace_tsk_reliable(struct task_struct *tsk, { int ret; + /* + * If the task doesn't have a stack (e.g., a zombie), the stack is + * "reliably" empty. + */ if (!try_get_task_stack(tsk)) - return -EINVAL; + return 0; ret = __save_stack_trace_reliable(trace, tsk); diff --git a/arch/x86/kernel/tboot.c b/arch/x86/kernel/tboot.c index a4eb27918ceb..a2486f444073 100644 --- a/arch/x86/kernel/tboot.c +++ b/arch/x86/kernel/tboot.c @@ -138,6 +138,17 @@ static int map_tboot_page(unsigned long vaddr, unsigned long pfn, return -1; set_pte_at(&tboot_mm, vaddr, pte, pfn_pte(pfn, prot)); pte_unmap(pte); + + /* + * PTI poisons low addresses in the kernel page tables in the + * name of making them unusable for userspace. To execute + * code at such a low address, the poison must be cleared. + * + * Note: 'pgd' actually gets set in p4d_alloc() _or_ + * pud_alloc() depending on 4/5-level paging. + */ + pgd->pgd &= ~_PAGE_NX; + return 0; } diff --git a/arch/x86/kernel/tls.c b/arch/x86/kernel/tls.c index 9a9c9b076955..a5b802a12212 100644 --- a/arch/x86/kernel/tls.c +++ b/arch/x86/kernel/tls.c @@ -93,17 +93,10 @@ static void set_tls_desc(struct task_struct *p, int idx, cpu = get_cpu(); while (n-- > 0) { - if (LDT_empty(info) || LDT_zero(info)) { + if (LDT_empty(info) || LDT_zero(info)) memset(desc, 0, sizeof(*desc)); - } else { + else fill_ldt(desc, info); - - /* - * Always set the accessed bit so that the CPU - * doesn't try to write to the (read-only) GDT. - */ - desc->type |= 1; - } ++info; ++desc; } diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 989514c94a55..446c9ef8cfc3 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -51,6 +51,7 @@ #include <asm/traps.h> #include <asm/desc.h> #include <asm/fpu/internal.h> +#include <asm/cpu_entry_area.h> #include <asm/mce.h> #include <asm/fixmap.h> #include <asm/mach_traps.h> @@ -348,23 +349,42 @@ dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code) /* * If IRET takes a non-IST fault on the espfix64 stack, then we - * end up promoting it to a doublefault. In that case, modify - * the stack to make it look like we just entered the #GP - * handler from user space, similar to bad_iret. + * end up promoting it to a doublefault. In that case, take + * advantage of the fact that we're not using the normal (TSS.sp0) + * stack right now. We can write a fake #GP(0) frame at TSS.sp0 + * and then modify our own IRET frame so that, when we return, + * we land directly at the #GP(0) vector with the stack already + * set up according to its expectations. + * + * The net result is that our #GP handler will think that we + * entered from usermode with the bad user context. * * No need for ist_enter here because we don't use RCU. */ - if (((long)regs->sp >> PGDIR_SHIFT) == ESPFIX_PGD_ENTRY && + if (((long)regs->sp >> P4D_SHIFT) == ESPFIX_PGD_ENTRY && regs->cs == __KERNEL_CS && regs->ip == (unsigned long)native_irq_return_iret) { - struct pt_regs *normal_regs = task_pt_regs(current); + struct pt_regs *gpregs = (struct pt_regs *)this_cpu_read(cpu_tss_rw.x86_tss.sp0) - 1; - /* Fake a #GP(0) from userspace. */ - memmove(&normal_regs->ip, (void *)regs->sp, 5*8); - normal_regs->orig_ax = 0; /* Missing (lost) #GP error code */ + /* + * regs->sp points to the failing IRET frame on the + * ESPFIX64 stack. Copy it to the entry stack. This fills + * in gpregs->ss through gpregs->ip. + * + */ + memmove(&gpregs->ip, (void *)regs->sp, 5*8); + gpregs->orig_ax = 0; /* Missing (lost) #GP error code */ + + /* + * Adjust our frame so that we return straight to the #GP + * vector with the expected RSP value. This is safe because + * we won't enable interupts or schedule before we invoke + * general_protection, so nothing will clobber the stack + * frame we just set up. + */ regs->ip = (unsigned long)general_protection; - regs->sp = (unsigned long)&normal_regs->orig_ax; + regs->sp = (unsigned long)&gpregs->orig_ax; return; } @@ -389,7 +409,7 @@ dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code) * * Processors update CR2 whenever a page fault is detected. If a * second page fault occurs while an earlier page fault is being - * deliv- ered, the faulting linear address of the second fault will + * delivered, the faulting linear address of the second fault will * overwrite the contents of CR2 (replacing the previous * address). These updates to CR2 occur even if the page fault * results in a double fault or occurs during the delivery of a @@ -605,14 +625,15 @@ NOKPROBE_SYMBOL(do_int3); #ifdef CONFIG_X86_64 /* - * Help handler running on IST stack to switch off the IST stack if the - * interrupted code was in user mode. The actual stack switch is done in - * entry_64.S + * Help handler running on a per-cpu (IST or entry trampoline) stack + * to switch to the normal thread stack if the interrupted code was in + * user mode. The actual stack switch is done in entry_64.S */ asmlinkage __visible notrace struct pt_regs *sync_regs(struct pt_regs *eregs) { - struct pt_regs *regs = task_pt_regs(current); - *regs = *eregs; + struct pt_regs *regs = (struct pt_regs *)this_cpu_read(cpu_current_top_of_stack) - 1; + if (regs != eregs) + *regs = *eregs; return regs; } NOKPROBE_SYMBOL(sync_regs); @@ -628,13 +649,13 @@ struct bad_iret_stack *fixup_bad_iret(struct bad_iret_stack *s) /* * This is called from entry_64.S early in handling a fault * caused by a bad iret to user mode. To handle the fault - * correctly, we want move our stack frame to task_pt_regs - * and we want to pretend that the exception came from the - * iret target. + * correctly, we want to move our stack frame to where it would + * be had we entered directly on the entry stack (rather than + * just below the IRET frame) and we want to pretend that the + * exception came from the IRET target. */ struct bad_iret_stack *new_stack = - container_of(task_pt_regs(current), - struct bad_iret_stack, regs); + (struct bad_iret_stack *)this_cpu_read(cpu_tss_rw.x86_tss.sp0) - 1; /* Copy the IRET target to the new stack. */ memmove(&new_stack->regs.ip, (void *)s->regs.sp, 5*8); @@ -795,14 +816,6 @@ dotraplinkage void do_debug(struct pt_regs *regs, long error_code) debug_stack_usage_dec(); exit: -#if defined(CONFIG_X86_32) - /* - * This is the most likely code path that involves non-trivial use - * of the SYSENTER stack. Check that we haven't overrun it. - */ - WARN(this_cpu_read(cpu_tss.SYSENTER_stack_canary) != STACK_END_MAGIC, - "Overran or corrupted SYSENTER stack\n"); -#endif ist_exit(regs); } NOKPROBE_SYMBOL(do_debug); @@ -929,6 +942,9 @@ dotraplinkage void do_iret_error(struct pt_regs *regs, long error_code) void __init trap_init(void) { + /* Init cpu_entry_area before IST entries are set up */ + setup_cpu_entry_areas(); + idt_setup_traps(); /* @@ -936,8 +952,9 @@ void __init trap_init(void) * "sidt" instruction will not leak the location of the kernel, and * to defend the IDT against arbitrary memory write vulnerabilities. * It will be reloaded in cpu_init() */ - __set_fixmap(FIX_RO_IDT, __pa_symbol(idt_table), PAGE_KERNEL_RO); - idt_descr.address = fix_to_virt(FIX_RO_IDT); + cea_set_pte(CPU_ENTRY_AREA_RO_IDT_VADDR, __pa_symbol(idt_table), + PAGE_KERNEL_RO); + idt_descr.address = CPU_ENTRY_AREA_RO_IDT; /* * Should be a barrier for any external CPU state: diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index 8ea117f8142e..e169e85db434 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -602,7 +602,6 @@ unsigned long native_calibrate_tsc(void) case INTEL_FAM6_KABYLAKE_DESKTOP: crystal_khz = 24000; /* 24.0 MHz */ break; - case INTEL_FAM6_SKYLAKE_X: case INTEL_FAM6_ATOM_DENVERTON: crystal_khz = 25000; /* 25.0 MHz */ break; @@ -612,6 +611,8 @@ unsigned long native_calibrate_tsc(void) } } + if (crystal_khz == 0) + return 0; /* * TSC frequency determined by CPUID is a "hardware reported" * frequency and is the most accurate one so far we have. This @@ -1315,6 +1316,12 @@ void __init tsc_init(void) (unsigned long)cpu_khz / 1000, (unsigned long)cpu_khz % 1000); + if (cpu_khz != tsc_khz) { + pr_info("Detected %lu.%03lu MHz TSC", + (unsigned long)tsc_khz / 1000, + (unsigned long)tsc_khz % 1000); + } + /* Sanitize TSC ADJUST before cyc2ns gets initialized */ tsc_store_and_check_tsc_adjust(true); diff --git a/arch/x86/kernel/unwind_orc.c b/arch/x86/kernel/unwind_orc.c index a3f973b2c97a..be86a865087a 100644 --- a/arch/x86/kernel/unwind_orc.c +++ b/arch/x86/kernel/unwind_orc.c @@ -253,22 +253,15 @@ unsigned long *unwind_get_return_address_ptr(struct unwind_state *state) return NULL; } -static bool stack_access_ok(struct unwind_state *state, unsigned long addr, +static bool stack_access_ok(struct unwind_state *state, unsigned long _addr, size_t len) { struct stack_info *info = &state->stack_info; + void *addr = (void *)_addr; - /* - * If the address isn't on the current stack, switch to the next one. - * - * We may have to traverse multiple stacks to deal with the possibility - * that info->next_sp could point to an empty stack and the address - * could be on a subsequent stack. - */ - while (!on_stack(info, (void *)addr, len)) - if (get_stack_info(info->next_sp, state->task, info, - &state->stack_mask)) - return false; + if (!on_stack(info, addr, len) && + (get_stack_info(addr, state->task, info, &state->stack_mask))) + return false; return true; } @@ -283,42 +276,32 @@ static bool deref_stack_reg(struct unwind_state *state, unsigned long addr, return true; } -#define REGS_SIZE (sizeof(struct pt_regs)) -#define SP_OFFSET (offsetof(struct pt_regs, sp)) -#define IRET_REGS_SIZE (REGS_SIZE - offsetof(struct pt_regs, ip)) -#define IRET_SP_OFFSET (SP_OFFSET - offsetof(struct pt_regs, ip)) - static bool deref_stack_regs(struct unwind_state *state, unsigned long addr, - unsigned long *ip, unsigned long *sp, bool full) + unsigned long *ip, unsigned long *sp) { - size_t regs_size = full ? REGS_SIZE : IRET_REGS_SIZE; - size_t sp_offset = full ? SP_OFFSET : IRET_SP_OFFSET; - struct pt_regs *regs = (struct pt_regs *)(addr + regs_size - REGS_SIZE); - - if (IS_ENABLED(CONFIG_X86_64)) { - if (!stack_access_ok(state, addr, regs_size)) - return false; + struct pt_regs *regs = (struct pt_regs *)addr; - *ip = regs->ip; - *sp = regs->sp; + /* x86-32 support will be more complicated due to the ®s->sp hack */ + BUILD_BUG_ON(IS_ENABLED(CONFIG_X86_32)); - return true; - } - - if (!stack_access_ok(state, addr, sp_offset)) + if (!stack_access_ok(state, addr, sizeof(struct pt_regs))) return false; *ip = regs->ip; + *sp = regs->sp; + return true; +} - if (user_mode(regs)) { - if (!stack_access_ok(state, addr + sp_offset, - REGS_SIZE - SP_OFFSET)) - return false; +static bool deref_stack_iret_regs(struct unwind_state *state, unsigned long addr, + unsigned long *ip, unsigned long *sp) +{ + struct pt_regs *regs = (void *)addr - IRET_FRAME_OFFSET; - *sp = regs->sp; - } else - *sp = (unsigned long)®s->sp; + if (!stack_access_ok(state, addr, IRET_FRAME_SIZE)) + return false; + *ip = regs->ip; + *sp = regs->sp; return true; } @@ -327,7 +310,6 @@ bool unwind_next_frame(struct unwind_state *state) unsigned long ip_p, sp, orig_ip, prev_sp = state->sp; enum stack_type prev_type = state->stack_info.type; struct orc_entry *orc; - struct pt_regs *ptregs; bool indirect = false; if (unwind_done(state)) @@ -435,7 +417,7 @@ bool unwind_next_frame(struct unwind_state *state) break; case ORC_TYPE_REGS: - if (!deref_stack_regs(state, sp, &state->ip, &state->sp, true)) { + if (!deref_stack_regs(state, sp, &state->ip, &state->sp)) { orc_warn("can't dereference registers at %p for ip %pB\n", (void *)sp, (void *)orig_ip); goto done; @@ -447,20 +429,14 @@ bool unwind_next_frame(struct unwind_state *state) break; case ORC_TYPE_REGS_IRET: - if (!deref_stack_regs(state, sp, &state->ip, &state->sp, false)) { + if (!deref_stack_iret_regs(state, sp, &state->ip, &state->sp)) { orc_warn("can't dereference iret registers at %p for ip %pB\n", (void *)sp, (void *)orig_ip); goto done; } - ptregs = container_of((void *)sp, struct pt_regs, ip); - if ((unsigned long)ptregs >= prev_sp && - on_stack(&state->stack_info, ptregs, REGS_SIZE)) { - state->regs = ptregs; - state->full_regs = false; - } else - state->regs = NULL; - + state->regs = (void *)sp - IRET_FRAME_OFFSET; + state->full_regs = false; state->signal = true; break; @@ -553,8 +529,18 @@ void __unwind_start(struct unwind_state *state, struct task_struct *task, } if (get_stack_info((unsigned long *)state->sp, state->task, - &state->stack_info, &state->stack_mask)) - return; + &state->stack_info, &state->stack_mask)) { + /* + * We weren't on a valid stack. It's possible that + * we overflowed a valid stack into a guard page. + * See if the next page up is valid so that we can + * generate some kind of backtrace if this happens. + */ + void *next_page = (void *)PAGE_ALIGN((unsigned long)state->sp); + if (get_stack_info(next_page, state->task, &state->stack_info, + &state->stack_mask)) + return; + } /* * The caller can provide the address of the first frame directly diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S index a4009fb9be87..9b138a06c1a4 100644 --- a/arch/x86/kernel/vmlinux.lds.S +++ b/arch/x86/kernel/vmlinux.lds.S @@ -61,11 +61,17 @@ jiffies_64 = jiffies; . = ALIGN(HPAGE_SIZE); \ __end_rodata_hpage_align = .; +#define ALIGN_ENTRY_TEXT_BEGIN . = ALIGN(PMD_SIZE); +#define ALIGN_ENTRY_TEXT_END . = ALIGN(PMD_SIZE); + #else #define X64_ALIGN_RODATA_BEGIN #define X64_ALIGN_RODATA_END +#define ALIGN_ENTRY_TEXT_BEGIN +#define ALIGN_ENTRY_TEXT_END + #endif PHDRS { @@ -102,11 +108,28 @@ SECTIONS CPUIDLE_TEXT LOCK_TEXT KPROBES_TEXT + ALIGN_ENTRY_TEXT_BEGIN ENTRY_TEXT IRQENTRY_TEXT + ALIGN_ENTRY_TEXT_END SOFTIRQENTRY_TEXT *(.fixup) *(.gnu.warning) + +#ifdef CONFIG_X86_64 + . = ALIGN(PAGE_SIZE); + _entry_trampoline = .; + *(.entry_trampoline) + . = ALIGN(PAGE_SIZE); + ASSERT(. - _entry_trampoline == PAGE_SIZE, "entry trampoline is too big"); +#endif + +#ifdef CONFIG_RETPOLINE + __indirect_thunk_start = .; + *(.text.__x86.indirect_thunk) + __indirect_thunk_end = .; +#endif + /* End of text section */ _etext = .; } :text = 0x9090 |