Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 78928f5..8bf6489 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -32,9 +32,15 @@
#include <asm/e820/api.h>
#include <asm/hypervisor.h>
+#include "cpu.h"
+
+static void __init spectre_v1_select_mitigation(void);
static void __init spectre_v2_select_mitigation(void);
static void __init ssb_select_mitigation(void);
static void __init l1tf_select_mitigation(void);
+static void __init mds_select_mitigation(void);
+static void __init mds_print_mitigation(void);
+static void __init taa_select_mitigation(void);
/* The base value of the SPEC_CTRL MSR that always has to be preserved. */
u64 x86_spec_ctrl_base;
@@ -54,13 +60,20 @@
u64 __ro_after_init x86_amd_ls_cfg_base;
u64 __ro_after_init x86_amd_ls_cfg_ssbd_mask;
-/* Control conditional STIPB in switch_to() */
+/* Control conditional STIBP in switch_to() */
DEFINE_STATIC_KEY_FALSE(switch_to_cond_stibp);
/* Control conditional IBPB in switch_mm() */
DEFINE_STATIC_KEY_FALSE(switch_mm_cond_ibpb);
/* Control unconditional IBPB in switch_mm() */
DEFINE_STATIC_KEY_FALSE(switch_mm_always_ibpb);
+/* Control MDS CPU buffer clear before returning to user space */
+DEFINE_STATIC_KEY_FALSE(mds_user_clear);
+EXPORT_SYMBOL_GPL(mds_user_clear);
+/* Control MDS CPU buffer clear before idling (halt, mwait) */
+DEFINE_STATIC_KEY_FALSE(mds_idle_clear);
+EXPORT_SYMBOL_GPL(mds_idle_clear);
+
void __init check_bugs(void)
{
identify_boot_cpu();
@@ -69,7 +82,7 @@
* identify_boot_cpu() initialized SMT support information, let the
* core code know.
*/
- cpu_smt_check_topology_early();
+ cpu_smt_check_topology();
if (!IS_ENABLED(CONFIG_SMP)) {
pr_info("CPU: ");
@@ -88,16 +101,21 @@
if (boot_cpu_has(X86_FEATURE_STIBP))
x86_spec_ctrl_mask |= SPEC_CTRL_STIBP;
- /* Select the proper spectre mitigation before patching alternatives */
+ /* Select the proper CPU mitigations before patching alternatives: */
+ spectre_v1_select_mitigation();
spectre_v2_select_mitigation();
+ ssb_select_mitigation();
+ l1tf_select_mitigation();
+ mds_select_mitigation();
+ taa_select_mitigation();
/*
- * Select proper mitigation for any exposure to the Speculative Store
- * Bypass vulnerability.
+ * As MDS and TAA mitigations are inter-related, print MDS
+ * mitigation until after TAA mitigation selection is done.
*/
- ssb_select_mitigation();
+ mds_print_mitigation();
- l1tf_select_mitigation();
+ arch_smt_update();
#ifdef CONFIG_X86_32
/*
@@ -205,6 +223,266 @@
}
#undef pr_fmt
+#define pr_fmt(fmt) "MDS: " fmt
+
+/* Default mitigation for MDS-affected CPUs */
+static enum mds_mitigations mds_mitigation __ro_after_init = MDS_MITIGATION_FULL;
+static bool mds_nosmt __ro_after_init = false;
+
+static const char * const mds_strings[] = {
+ [MDS_MITIGATION_OFF] = "Vulnerable",
+ [MDS_MITIGATION_FULL] = "Mitigation: Clear CPU buffers",
+ [MDS_MITIGATION_VMWERV] = "Vulnerable: Clear CPU buffers attempted, no microcode",
+};
+
+static void __init mds_select_mitigation(void)
+{
+ if (!boot_cpu_has_bug(X86_BUG_MDS) || cpu_mitigations_off()) {
+ mds_mitigation = MDS_MITIGATION_OFF;
+ return;
+ }
+
+ if (mds_mitigation == MDS_MITIGATION_FULL) {
+ if (!boot_cpu_has(X86_FEATURE_MD_CLEAR))
+ mds_mitigation = MDS_MITIGATION_VMWERV;
+
+ static_branch_enable(&mds_user_clear);
+
+ if (!boot_cpu_has(X86_BUG_MSBDS_ONLY) &&
+ (mds_nosmt || cpu_mitigations_auto_nosmt()))
+ cpu_smt_disable(false);
+ }
+}
+
+static void __init mds_print_mitigation(void)
+{
+ if (!boot_cpu_has_bug(X86_BUG_MDS) || cpu_mitigations_off())
+ return;
+
+ pr_info("%s\n", mds_strings[mds_mitigation]);
+}
+
+static int __init mds_cmdline(char *str)
+{
+ if (!boot_cpu_has_bug(X86_BUG_MDS))
+ return 0;
+
+ if (!str)
+ return -EINVAL;
+
+ if (!strcmp(str, "off"))
+ mds_mitigation = MDS_MITIGATION_OFF;
+ else if (!strcmp(str, "full"))
+ mds_mitigation = MDS_MITIGATION_FULL;
+ else if (!strcmp(str, "full,nosmt")) {
+ mds_mitigation = MDS_MITIGATION_FULL;
+ mds_nosmt = true;
+ }
+
+ return 0;
+}
+early_param("mds", mds_cmdline);
+
+#undef pr_fmt
+#define pr_fmt(fmt) "TAA: " fmt
+
+/* Default mitigation for TAA-affected CPUs */
+static enum taa_mitigations taa_mitigation __ro_after_init = TAA_MITIGATION_VERW;
+static bool taa_nosmt __ro_after_init;
+
+static const char * const taa_strings[] = {
+ [TAA_MITIGATION_OFF] = "Vulnerable",
+ [TAA_MITIGATION_UCODE_NEEDED] = "Vulnerable: Clear CPU buffers attempted, no microcode",
+ [TAA_MITIGATION_VERW] = "Mitigation: Clear CPU buffers",
+ [TAA_MITIGATION_TSX_DISABLED] = "Mitigation: TSX disabled",
+};
+
+static void __init taa_select_mitigation(void)
+{
+ u64 ia32_cap;
+
+ if (!boot_cpu_has_bug(X86_BUG_TAA)) {
+ taa_mitigation = TAA_MITIGATION_OFF;
+ return;
+ }
+
+ /* TSX previously disabled by tsx=off */
+ if (!boot_cpu_has(X86_FEATURE_RTM)) {
+ taa_mitigation = TAA_MITIGATION_TSX_DISABLED;
+ goto out;
+ }
+
+ if (cpu_mitigations_off()) {
+ taa_mitigation = TAA_MITIGATION_OFF;
+ return;
+ }
+
+ /*
+ * TAA mitigation via VERW is turned off if both
+ * tsx_async_abort=off and mds=off are specified.
+ */
+ if (taa_mitigation == TAA_MITIGATION_OFF &&
+ mds_mitigation == MDS_MITIGATION_OFF)
+ goto out;
+
+ if (boot_cpu_has(X86_FEATURE_MD_CLEAR))
+ taa_mitigation = TAA_MITIGATION_VERW;
+ else
+ taa_mitigation = TAA_MITIGATION_UCODE_NEEDED;
+
+ /*
+ * VERW doesn't clear the CPU buffers when MD_CLEAR=1 and MDS_NO=1.
+ * A microcode update fixes this behavior to clear CPU buffers. It also
+ * adds support for MSR_IA32_TSX_CTRL which is enumerated by the
+ * ARCH_CAP_TSX_CTRL_MSR bit.
+ *
+ * On MDS_NO=1 CPUs if ARCH_CAP_TSX_CTRL_MSR is not set, microcode
+ * update is required.
+ */
+ ia32_cap = x86_read_arch_cap_msr();
+ if ( (ia32_cap & ARCH_CAP_MDS_NO) &&
+ !(ia32_cap & ARCH_CAP_TSX_CTRL_MSR))
+ taa_mitigation = TAA_MITIGATION_UCODE_NEEDED;
+
+ /*
+ * TSX is enabled, select alternate mitigation for TAA which is
+ * the same as MDS. Enable MDS static branch to clear CPU buffers.
+ *
+ * For guests that can't determine whether the correct microcode is
+ * present on host, enable the mitigation for UCODE_NEEDED as well.
+ */
+ static_branch_enable(&mds_user_clear);
+
+ if (taa_nosmt || cpu_mitigations_auto_nosmt())
+ cpu_smt_disable(false);
+
+ /*
+ * Update MDS mitigation, if necessary, as the mds_user_clear is
+ * now enabled for TAA mitigation.
+ */
+ if (mds_mitigation == MDS_MITIGATION_OFF &&
+ boot_cpu_has_bug(X86_BUG_MDS)) {
+ mds_mitigation = MDS_MITIGATION_FULL;
+ mds_select_mitigation();
+ }
+out:
+ pr_info("%s\n", taa_strings[taa_mitigation]);
+}
+
+static int __init tsx_async_abort_parse_cmdline(char *str)
+{
+ if (!boot_cpu_has_bug(X86_BUG_TAA))
+ return 0;
+
+ if (!str)
+ return -EINVAL;
+
+ if (!strcmp(str, "off")) {
+ taa_mitigation = TAA_MITIGATION_OFF;
+ } else if (!strcmp(str, "full")) {
+ taa_mitigation = TAA_MITIGATION_VERW;
+ } else if (!strcmp(str, "full,nosmt")) {
+ taa_mitigation = TAA_MITIGATION_VERW;
+ taa_nosmt = true;
+ }
+
+ return 0;
+}
+early_param("tsx_async_abort", tsx_async_abort_parse_cmdline);
+
+#undef pr_fmt
+#define pr_fmt(fmt) "Spectre V1 : " fmt
+
+enum spectre_v1_mitigation {
+ SPECTRE_V1_MITIGATION_NONE,
+ SPECTRE_V1_MITIGATION_AUTO,
+};
+
+static enum spectre_v1_mitigation spectre_v1_mitigation __ro_after_init =
+ SPECTRE_V1_MITIGATION_AUTO;
+
+static const char * const spectre_v1_strings[] = {
+ [SPECTRE_V1_MITIGATION_NONE] = "Vulnerable: __user pointer sanitization and usercopy barriers only; no swapgs barriers",
+ [SPECTRE_V1_MITIGATION_AUTO] = "Mitigation: usercopy/swapgs barriers and __user pointer sanitization",
+};
+
+/*
+ * Does SMAP provide full mitigation against speculative kernel access to
+ * userspace?
+ */
+static bool smap_works_speculatively(void)
+{
+ if (!boot_cpu_has(X86_FEATURE_SMAP))
+ return false;
+
+ /*
+ * On CPUs which are vulnerable to Meltdown, SMAP does not
+ * prevent speculative access to user data in the L1 cache.
+ * Consider SMAP to be non-functional as a mitigation on these
+ * CPUs.
+ */
+ if (boot_cpu_has(X86_BUG_CPU_MELTDOWN))
+ return false;
+
+ return true;
+}
+
+static void __init spectre_v1_select_mitigation(void)
+{
+ if (!boot_cpu_has_bug(X86_BUG_SPECTRE_V1) || cpu_mitigations_off()) {
+ spectre_v1_mitigation = SPECTRE_V1_MITIGATION_NONE;
+ return;
+ }
+
+ if (spectre_v1_mitigation == SPECTRE_V1_MITIGATION_AUTO) {
+ /*
+ * With Spectre v1, a user can speculatively control either
+ * path of a conditional swapgs with a user-controlled GS
+ * value. The mitigation is to add lfences to both code paths.
+ *
+ * If FSGSBASE is enabled, the user can put a kernel address in
+ * GS, in which case SMAP provides no protection.
+ *
+ * [ NOTE: Don't check for X86_FEATURE_FSGSBASE until the
+ * FSGSBASE enablement patches have been merged. ]
+ *
+ * If FSGSBASE is disabled, the user can only put a user space
+ * address in GS. That makes an attack harder, but still
+ * possible if there's no SMAP protection.
+ */
+ if (!smap_works_speculatively()) {
+ /*
+ * Mitigation can be provided from SWAPGS itself or
+ * PTI as the CR3 write in the Meltdown mitigation
+ * is serializing.
+ *
+ * If neither is there, mitigate with an LFENCE to
+ * stop speculation through swapgs.
+ */
+ if (boot_cpu_has_bug(X86_BUG_SWAPGS) &&
+ !boot_cpu_has(X86_FEATURE_PTI))
+ setup_force_cpu_cap(X86_FEATURE_FENCE_SWAPGS_USER);
+
+ /*
+ * Enable lfences in the kernel entry (non-swapgs)
+ * paths, to prevent user entry from speculatively
+ * skipping swapgs.
+ */
+ setup_force_cpu_cap(X86_FEATURE_FENCE_SWAPGS_KERNEL);
+ }
+ }
+
+ pr_info("%s\n", spectre_v1_strings[spectre_v1_mitigation]);
+}
+
+static int __init nospectre_v1_cmdline(char *str)
+{
+ spectre_v1_mitigation = SPECTRE_V1_MITIGATION_NONE;
+ return 0;
+}
+early_param("nospectre_v1", nospectre_v1_cmdline);
+
+#undef pr_fmt
#define pr_fmt(fmt) "Spectre V2 : " fmt
static enum spectre_v2_mitigation spectre_v2_enabled __ro_after_init =
@@ -213,7 +491,7 @@
static enum spectre_v2_user_mitigation spectre_v2_user __ro_after_init =
SPECTRE_V2_USER_NONE;
-#ifdef RETPOLINE
+#ifdef CONFIG_RETPOLINE
static bool spectre_v2_bad_module;
bool retpoline_module_ok(bool has_retpoline)
@@ -262,17 +540,18 @@
};
static const char * const spectre_v2_user_strings[] = {
- [SPECTRE_V2_USER_NONE] = "User space: Vulnerable",
- [SPECTRE_V2_USER_STRICT] = "User space: Mitigation: STIBP protection",
- [SPECTRE_V2_USER_PRCTL] = "User space: Mitigation: STIBP via prctl",
- [SPECTRE_V2_USER_SECCOMP] = "User space: Mitigation: STIBP via seccomp and prctl",
+ [SPECTRE_V2_USER_NONE] = "User space: Vulnerable",
+ [SPECTRE_V2_USER_STRICT] = "User space: Mitigation: STIBP protection",
+ [SPECTRE_V2_USER_STRICT_PREFERRED] = "User space: Mitigation: STIBP always-on protection",
+ [SPECTRE_V2_USER_PRCTL] = "User space: Mitigation: STIBP via prctl",
+ [SPECTRE_V2_USER_SECCOMP] = "User space: Mitigation: STIBP via seccomp and prctl",
};
static const struct {
const char *option;
enum spectre_v2_user_cmd cmd;
bool secure;
-} v2_user_options[] __initdata = {
+} v2_user_options[] __initconst = {
{ "auto", SPECTRE_V2_USER_CMD_AUTO, false },
{ "off", SPECTRE_V2_USER_CMD_NONE, false },
{ "on", SPECTRE_V2_USER_CMD_FORCE, true },
@@ -355,6 +634,15 @@
break;
}
+ /*
+ * At this point, an STIBP mode other than "off" has been set.
+ * If STIBP support is not being forced, check if STIBP always-on
+ * is preferred.
+ */
+ if (mode != SPECTRE_V2_USER_STRICT &&
+ boot_cpu_has(X86_FEATURE_AMD_STIBP_ALWAYS_ON))
+ mode = SPECTRE_V2_USER_STRICT_PREFERRED;
+
/* Initialize Indirect Branch Prediction Barrier */
if (boot_cpu_has(X86_FEATURE_IBPB)) {
setup_force_cpu_cap(X86_FEATURE_USE_IBPB);
@@ -379,12 +667,12 @@
"always-on" : "conditional");
}
- /* If enhanced IBRS is enabled no STIPB required */
+ /* If enhanced IBRS is enabled no STIBP required */
if (spectre_v2_enabled == SPECTRE_V2_IBRS_ENHANCED)
return;
/*
- * If SMT is not possible or STIBP is not available clear the STIPB
+ * If SMT is not possible or STIBP is not available clear the STIBP
* mode.
*/
if (!smt_possible || !boot_cpu_has(X86_FEATURE_STIBP))
@@ -407,7 +695,7 @@
const char *option;
enum spectre_v2_mitigation_cmd cmd;
bool secure;
-} mitigation_options[] __initdata = {
+} mitigation_options[] __initconst = {
{ "off", SPECTRE_V2_CMD_NONE, false },
{ "on", SPECTRE_V2_CMD_FORCE, true },
{ "retpoline", SPECTRE_V2_CMD_RETPOLINE, false },
@@ -428,7 +716,8 @@
char arg[20];
int ret, i;
- if (cmdline_find_option_bool(boot_command_line, "nospectre_v2"))
+ if (cmdline_find_option_bool(boot_command_line, "nospectre_v2") ||
+ cpu_mitigations_off())
return SPECTRE_V2_CMD_NONE;
ret = cmdline_find_option(boot_command_line, "spectre_v2", arg, sizeof(arg));
@@ -456,6 +745,7 @@
}
if (cmd == SPECTRE_V2_CMD_RETPOLINE_AMD &&
+ boot_cpu_data.x86_vendor != X86_VENDOR_HYGON &&
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;
@@ -512,7 +802,8 @@
return;
retpoline_auto:
- if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD) {
+ if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD ||
+ boot_cpu_data.x86_vendor == X86_VENDOR_HYGON) {
retpoline_amd:
if (!boot_cpu_has(X86_FEATURE_LFENCE_RDTSC)) {
pr_err("Spectre mitigation: LFENCE not serializing, switching to generic retpoline\n");
@@ -560,9 +851,6 @@
/* Set up IBPB and STIBP depending on the general spectre V2 command */
spectre_v2_user_select_mitigation(cmd);
-
- /* Enable STIBP if appropriate */
- arch_smt_update();
}
static void update_stibp_msr(void * __unused)
@@ -596,18 +884,41 @@
static_branch_disable(&switch_to_cond_stibp);
}
-void arch_smt_update(void)
+#undef pr_fmt
+#define pr_fmt(fmt) fmt
+
+/* Update the static key controlling the MDS CPU buffer clear in idle */
+static void update_mds_branch_idle(void)
{
- /* Enhanced IBRS implies STIBP. No update required. */
- if (spectre_v2_enabled == SPECTRE_V2_IBRS_ENHANCED)
+ /*
+ * Enable the idle clearing if SMT is active on CPUs which are
+ * affected only by MSBDS and not any other MDS variant.
+ *
+ * The other variants cannot be mitigated when SMT is enabled, so
+ * clearing the buffers on idle just to prevent the Store Buffer
+ * repartitioning leak would be a window dressing exercise.
+ */
+ if (!boot_cpu_has_bug(X86_BUG_MSBDS_ONLY))
return;
+ if (sched_smt_active())
+ static_branch_enable(&mds_idle_clear);
+ else
+ static_branch_disable(&mds_idle_clear);
+}
+
+#define MDS_MSG_SMT "MDS CPU bug present and SMT on, data leak possible. See https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/mds.html for more details.\n"
+#define TAA_MSG_SMT "TAA CPU bug present and SMT on, data leak possible. See https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/tsx_async_abort.html for more details.\n"
+
+void cpu_bugs_smt_update(void)
+{
mutex_lock(&spec_ctrl_mutex);
switch (spectre_v2_user) {
case SPECTRE_V2_USER_NONE:
break;
case SPECTRE_V2_USER_STRICT:
+ case SPECTRE_V2_USER_STRICT_PREFERRED:
update_stibp_strict();
break;
case SPECTRE_V2_USER_PRCTL:
@@ -616,6 +927,28 @@
break;
}
+ switch (mds_mitigation) {
+ case MDS_MITIGATION_FULL:
+ case MDS_MITIGATION_VMWERV:
+ if (sched_smt_active() && !boot_cpu_has(X86_BUG_MSBDS_ONLY))
+ pr_warn_once(MDS_MSG_SMT);
+ update_mds_branch_idle();
+ break;
+ case MDS_MITIGATION_OFF:
+ break;
+ }
+
+ switch (taa_mitigation) {
+ case TAA_MITIGATION_VERW:
+ case TAA_MITIGATION_UCODE_NEEDED:
+ if (sched_smt_active())
+ pr_warn_once(TAA_MSG_SMT);
+ break;
+ case TAA_MITIGATION_TSX_DISABLED:
+ case TAA_MITIGATION_OFF:
+ break;
+ }
+
mutex_unlock(&spec_ctrl_mutex);
}
@@ -643,7 +976,7 @@
static const struct {
const char *option;
enum ssb_mitigation_cmd cmd;
-} ssb_mitigation_options[] __initdata = {
+} ssb_mitigation_options[] __initconst = {
{ "auto", SPEC_STORE_BYPASS_CMD_AUTO }, /* Platform decides */
{ "on", SPEC_STORE_BYPASS_CMD_ON }, /* Disable Speculative Store Bypass */
{ "off", SPEC_STORE_BYPASS_CMD_NONE }, /* Don't touch Speculative Store Bypass */
@@ -657,7 +990,8 @@
char arg[20];
int ret, i;
- if (cmdline_find_option_bool(boot_command_line, "nospec_store_bypass_disable")) {
+ if (cmdline_find_option_bool(boot_command_line, "nospec_store_bypass_disable") ||
+ cpu_mitigations_off()) {
return SPEC_STORE_BYPASS_CMD_NONE;
} else {
ret = cmdline_find_option(boot_command_line, "spec_store_bypass_disable",
@@ -719,6 +1053,16 @@
}
/*
+ * If SSBD is controlled by the SPEC_CTRL MSR, then set the proper
+ * bit in the mask to allow guests to use the mitigation even in the
+ * case where the host does not enable it.
+ */
+ if (static_cpu_has(X86_FEATURE_SPEC_CTRL_SSBD) ||
+ static_cpu_has(X86_FEATURE_AMD_SSBD)) {
+ x86_spec_ctrl_mask |= SPEC_CTRL_SSBD;
+ }
+
+ /*
* We have three CPU feature flags that are in play here:
* - X86_BUG_SPEC_STORE_BYPASS - CPU is susceptible.
* - X86_FEATURE_SSBD - CPU is able to turn off speculative store bypass
@@ -735,7 +1079,6 @@
x86_amd_ssb_disable();
} else {
x86_spec_ctrl_base |= SPEC_CTRL_SSBD;
- x86_spec_ctrl_mask |= SPEC_CTRL_SSBD;
wrmsrl(MSR_IA32_SPEC_CTRL, x86_spec_ctrl_base);
}
}
@@ -783,15 +1126,25 @@
if (task_spec_ssb_force_disable(task))
return -EPERM;
task_clear_spec_ssb_disable(task);
+ task_clear_spec_ssb_noexec(task);
task_update_spec_tif(task);
break;
case PR_SPEC_DISABLE:
task_set_spec_ssb_disable(task);
+ task_clear_spec_ssb_noexec(task);
task_update_spec_tif(task);
break;
case PR_SPEC_FORCE_DISABLE:
task_set_spec_ssb_disable(task);
task_set_spec_ssb_force_disable(task);
+ task_clear_spec_ssb_noexec(task);
+ task_update_spec_tif(task);
+ break;
+ case PR_SPEC_DISABLE_NOEXEC:
+ if (task_spec_ssb_force_disable(task))
+ return -EPERM;
+ task_set_spec_ssb_disable(task);
+ task_set_spec_ssb_noexec(task);
task_update_spec_tif(task);
break;
default:
@@ -810,7 +1163,8 @@
* Indirect branch speculation is always disabled in strict
* mode.
*/
- if (spectre_v2_user == SPECTRE_V2_USER_STRICT)
+ if (spectre_v2_user == SPECTRE_V2_USER_STRICT ||
+ spectre_v2_user == SPECTRE_V2_USER_STRICT_PREFERRED)
return -EPERM;
task_clear_spec_ib_disable(task);
task_update_spec_tif(task);
@@ -823,7 +1177,8 @@
*/
if (spectre_v2_user == SPECTRE_V2_USER_NONE)
return -EPERM;
- if (spectre_v2_user == SPECTRE_V2_USER_STRICT)
+ if (spectre_v2_user == SPECTRE_V2_USER_STRICT ||
+ spectre_v2_user == SPECTRE_V2_USER_STRICT_PREFERRED)
return 0;
task_set_spec_ib_disable(task);
if (ctrl == PR_SPEC_FORCE_DISABLE)
@@ -868,6 +1223,8 @@
case SPEC_STORE_BYPASS_PRCTL:
if (task_spec_ssb_force_disable(task))
return PR_SPEC_PRCTL | PR_SPEC_FORCE_DISABLE;
+ if (task_spec_ssb_noexec(task))
+ return PR_SPEC_PRCTL | PR_SPEC_DISABLE_NOEXEC;
if (task_spec_ssb_disable(task))
return PR_SPEC_PRCTL | PR_SPEC_DISABLE;
return PR_SPEC_PRCTL | PR_SPEC_ENABLE;
@@ -894,6 +1251,7 @@
return PR_SPEC_PRCTL | PR_SPEC_DISABLE;
return PR_SPEC_PRCTL | PR_SPEC_ENABLE;
case SPECTRE_V2_USER_STRICT:
+ case SPECTRE_V2_USER_STRICT_PREFERRED:
return PR_SPEC_DISABLE;
default:
return PR_SPEC_NOT_AFFECTED;
@@ -921,6 +1279,9 @@
x86_amd_ssb_disable();
}
+bool itlb_multihit_kvm_mitigation;
+EXPORT_SYMBOL_GPL(itlb_multihit_kvm_mitigation);
+
#undef pr_fmt
#define pr_fmt(fmt) "L1TF: " fmt
@@ -956,15 +1317,15 @@
case INTEL_FAM6_WESTMERE:
case INTEL_FAM6_SANDYBRIDGE:
case INTEL_FAM6_IVYBRIDGE:
- case INTEL_FAM6_HASWELL_CORE:
- case INTEL_FAM6_HASWELL_ULT:
- case INTEL_FAM6_HASWELL_GT3E:
- case INTEL_FAM6_BROADWELL_CORE:
- case INTEL_FAM6_BROADWELL_GT3E:
- case INTEL_FAM6_SKYLAKE_MOBILE:
- case INTEL_FAM6_SKYLAKE_DESKTOP:
- case INTEL_FAM6_KABYLAKE_MOBILE:
- case INTEL_FAM6_KABYLAKE_DESKTOP:
+ case INTEL_FAM6_HASWELL:
+ case INTEL_FAM6_HASWELL_L:
+ case INTEL_FAM6_HASWELL_G:
+ case INTEL_FAM6_BROADWELL:
+ case INTEL_FAM6_BROADWELL_G:
+ case INTEL_FAM6_SKYLAKE_L:
+ case INTEL_FAM6_SKYLAKE:
+ case INTEL_FAM6_KABYLAKE_L:
+ case INTEL_FAM6_KABYLAKE:
if (c->x86_cache_bits < 44)
c->x86_cache_bits = 44;
break;
@@ -978,6 +1339,11 @@
if (!boot_cpu_has_bug(X86_BUG_L1TF))
return;
+ if (cpu_mitigations_off())
+ l1tf_mitigation = L1TF_MITIGATION_OFF;
+ else if (cpu_mitigations_auto_nosmt())
+ l1tf_mitigation = L1TF_MITIGATION_FLUSH_NOSMT;
+
override_cache_bits(&boot_cpu_data);
switch (l1tf_mitigation) {
@@ -1000,12 +1366,13 @@
#endif
half_pa = (u64)l1tf_pfn_limit() << PAGE_SHIFT;
- if (e820__mapped_any(half_pa, ULLONG_MAX - half_pa, E820_TYPE_RAM)) {
+ if (l1tf_mitigation != L1TF_MITIGATION_OFF &&
+ e820__mapped_any(half_pa, ULLONG_MAX - half_pa, E820_TYPE_RAM)) {
pr_warn("System has more than MAX_PA/2 memory. L1TF mitigation not effective.\n");
pr_info("You may make it effective by booting the kernel with mem=%llu parameter.\n",
half_pa);
pr_info("However, doing so will make a part of your RAM unusable.\n");
- pr_info("Reading https://www.kernel.org/doc/html/latest/admin-guide/l1tf.html might help you decide.\n");
+ pr_info("Reading https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/l1tf.html might help you decide.\n");
return;
}
@@ -1038,6 +1405,7 @@
early_param("l1tf", l1tf_cmdline);
#undef pr_fmt
+#define pr_fmt(fmt) fmt
#ifdef CONFIG_SYSFS
@@ -1069,13 +1437,58 @@
l1tf_vmx_states[l1tf_vmx_mitigation],
sched_smt_active() ? "vulnerable" : "disabled");
}
+
+static ssize_t itlb_multihit_show_state(char *buf)
+{
+ if (itlb_multihit_kvm_mitigation)
+ return sprintf(buf, "KVM: Mitigation: Split huge pages\n");
+ else
+ return sprintf(buf, "KVM: Vulnerable\n");
+}
#else
static ssize_t l1tf_show_state(char *buf)
{
return sprintf(buf, "%s\n", L1TF_DEFAULT_MSG);
}
+
+static ssize_t itlb_multihit_show_state(char *buf)
+{
+ return sprintf(buf, "Processor vulnerable\n");
+}
#endif
+static ssize_t mds_show_state(char *buf)
+{
+ if (boot_cpu_has(X86_FEATURE_HYPERVISOR)) {
+ return sprintf(buf, "%s; SMT Host state unknown\n",
+ mds_strings[mds_mitigation]);
+ }
+
+ if (boot_cpu_has(X86_BUG_MSBDS_ONLY)) {
+ return sprintf(buf, "%s; SMT %s\n", mds_strings[mds_mitigation],
+ (mds_mitigation == MDS_MITIGATION_OFF ? "vulnerable" :
+ sched_smt_active() ? "mitigated" : "disabled"));
+ }
+
+ return sprintf(buf, "%s; SMT %s\n", mds_strings[mds_mitigation],
+ sched_smt_active() ? "vulnerable" : "disabled");
+}
+
+static ssize_t tsx_async_abort_show_state(char *buf)
+{
+ if ((taa_mitigation == TAA_MITIGATION_TSX_DISABLED) ||
+ (taa_mitigation == TAA_MITIGATION_OFF))
+ return sprintf(buf, "%s\n", taa_strings[taa_mitigation]);
+
+ if (boot_cpu_has(X86_FEATURE_HYPERVISOR)) {
+ return sprintf(buf, "%s; SMT Host state unknown\n",
+ taa_strings[taa_mitigation]);
+ }
+
+ return sprintf(buf, "%s; SMT %s\n", taa_strings[taa_mitigation],
+ sched_smt_active() ? "vulnerable" : "disabled");
+}
+
static char *stibp_state(void)
{
if (spectre_v2_enabled == SPECTRE_V2_IBRS_ENHANCED)
@@ -1086,6 +1499,8 @@
return ", STIBP: disabled";
case SPECTRE_V2_USER_STRICT:
return ", STIBP: forced";
+ case SPECTRE_V2_USER_STRICT_PREFERRED:
+ return ", STIBP: always-on";
case SPECTRE_V2_USER_PRCTL:
case SPECTRE_V2_USER_SECCOMP:
if (static_key_enabled(&switch_to_cond_stibp))
@@ -1123,7 +1538,7 @@
break;
case X86_BUG_SPECTRE_V1:
- return sprintf(buf, "Mitigation: __user pointer sanitization\n");
+ return sprintf(buf, "%s\n", spectre_v1_strings[spectre_v1_mitigation]);
case X86_BUG_SPECTRE_V2:
return sprintf(buf, "%s%s%s%s%s%s\n", spectre_v2_strings[spectre_v2_enabled],
@@ -1140,6 +1555,16 @@
if (boot_cpu_has(X86_FEATURE_L1TF_PTEINV))
return l1tf_show_state(buf);
break;
+
+ case X86_BUG_MDS:
+ return mds_show_state(buf);
+
+ case X86_BUG_TAA:
+ return tsx_async_abort_show_state(buf);
+
+ case X86_BUG_ITLB_MULTIHIT:
+ return itlb_multihit_show_state(buf);
+
default:
break;
}
@@ -1171,4 +1596,19 @@
{
return cpu_show_common(dev, attr, buf, X86_BUG_L1TF);
}
+
+ssize_t cpu_show_mds(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ return cpu_show_common(dev, attr, buf, X86_BUG_MDS);
+}
+
+ssize_t cpu_show_tsx_async_abort(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ return cpu_show_common(dev, attr, buf, X86_BUG_TAA);
+}
+
+ssize_t cpu_show_itlb_multihit(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ return cpu_show_common(dev, attr, buf, X86_BUG_ITLB_MULTIHIT);
+}
#endif