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-rw-r--r--arch/x86/kernel/acpi/boot.c2
-rw-r--r--arch/x86/kernel/cpu/bugs.c525
-rw-r--r--arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c4
-rw-r--r--arch/x86/kernel/cpu/mcheck/mce.c6
-rw-r--r--arch/x86/kernel/cpu/mcheck/mce_amd.c19
-rw-r--r--arch/x86/kernel/cpu/mshyperv.c11
-rw-r--r--arch/x86/kernel/cpu/mtrr/if.c2
-rw-r--r--arch/x86/kernel/cpu/vmware.c2
-rw-r--r--arch/x86/kernel/fpu/signal.c4
-rw-r--r--arch/x86/kernel/ftrace.c15
-rw-r--r--arch/x86/kernel/head32.c1
-rw-r--r--arch/x86/kernel/head64.c2
-rw-r--r--arch/x86/kernel/kprobes/opt.c2
-rw-r--r--arch/x86/kernel/ldt.c59
-rw-r--r--arch/x86/kernel/macros.S16
-rw-r--r--arch/x86/kernel/process.c101
-rw-r--r--arch/x86/kernel/process.h39
-rw-r--r--arch/x86/kernel/process_32.c10
-rw-r--r--arch/x86/kernel/process_64.c109
-rw-r--r--arch/x86/kernel/ptrace.c9
-rw-r--r--arch/x86/kernel/setup.c17
-rw-r--r--arch/x86/kernel/vsmp_64.c84
22 files changed, 653 insertions, 386 deletions
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 92c76bf97ad8..06635fbca81c 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -1776,5 +1776,5 @@ void __init arch_reserve_mem_area(acpi_physical_address addr, size_t size)
u64 x86_default_get_root_pointer(void)
{
- return boot_params.hdr.acpi_rsdp_addr;
+ return boot_params.acpi_rsdp_addr;
}
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index c37e66e493bf..500278f5308e 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -14,6 +14,7 @@
#include <linux/module.h>
#include <linux/nospec.h>
#include <linux/prctl.h>
+#include <linux/sched/smt.h>
#include <asm/spec-ctrl.h>
#include <asm/cmdline.h>
@@ -53,6 +54,13 @@ static u64 __ro_after_init x86_spec_ctrl_mask = SPEC_CTRL_IBRS;
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() */
+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);
+
void __init check_bugs(void)
{
identify_boot_cpu();
@@ -123,31 +131,6 @@ void __init check_bugs(void)
#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",
- [SPECTRE_V2_IBRS_ENHANCED] = "Mitigation: Enhanced IBRS",
-};
-
-#undef pr_fmt
-#define pr_fmt(fmt) "Spectre V2 : " fmt
-
-static enum spectre_v2_mitigation spectre_v2_enabled __ro_after_init =
- SPECTRE_V2_NONE;
-
void
x86_virt_spec_ctrl(u64 guest_spec_ctrl, u64 guest_virt_spec_ctrl, bool setguest)
{
@@ -169,6 +152,10 @@ x86_virt_spec_ctrl(u64 guest_spec_ctrl, u64 guest_virt_spec_ctrl, bool setguest)
static_cpu_has(X86_FEATURE_AMD_SSBD))
hostval |= ssbd_tif_to_spec_ctrl(ti->flags);
+ /* Conditional STIBP enabled? */
+ if (static_branch_unlikely(&switch_to_cond_stibp))
+ hostval |= stibp_tif_to_spec_ctrl(ti->flags);
+
if (hostval != guestval) {
msrval = setguest ? guestval : hostval;
wrmsrl(MSR_IA32_SPEC_CTRL, msrval);
@@ -202,7 +189,7 @@ x86_virt_spec_ctrl(u64 guest_spec_ctrl, u64 guest_virt_spec_ctrl, bool setguest)
tif = setguest ? ssbd_spec_ctrl_to_tif(guestval) :
ssbd_spec_ctrl_to_tif(hostval);
- speculative_store_bypass_update(tif);
+ speculation_ctrl_update(tif);
}
}
EXPORT_SYMBOL_GPL(x86_virt_spec_ctrl);
@@ -217,6 +204,15 @@ static void x86_amd_ssb_disable(void)
wrmsrl(MSR_AMD64_LS_CFG, msrval);
}
+#undef pr_fmt
+#define pr_fmt(fmt) "Spectre V2 : " fmt
+
+static enum spectre_v2_mitigation spectre_v2_enabled __ro_after_init =
+ SPECTRE_V2_NONE;
+
+static enum spectre_v2_user_mitigation spectre_v2_user __ro_after_init =
+ SPECTRE_V2_USER_NONE;
+
#ifdef RETPOLINE
static bool spectre_v2_bad_module;
@@ -238,67 +234,217 @@ static inline const char *spectre_v2_module_string(void)
static inline const char *spectre_v2_module_string(void) { return ""; }
#endif
-static void __init spec2_print_if_insecure(const char *reason)
+static inline bool match_option(const char *arg, int arglen, const char *opt)
{
- if (boot_cpu_has_bug(X86_BUG_SPECTRE_V2))
- pr_info("%s selected on command line.\n", reason);
+ int len = strlen(opt);
+
+ return len == arglen && !strncmp(arg, opt, len);
}
-static void __init spec2_print_if_secure(const char *reason)
+/* The kernel command line selection for spectre v2 */
+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,
+};
+
+enum spectre_v2_user_cmd {
+ SPECTRE_V2_USER_CMD_NONE,
+ SPECTRE_V2_USER_CMD_AUTO,
+ SPECTRE_V2_USER_CMD_FORCE,
+ SPECTRE_V2_USER_CMD_PRCTL,
+ SPECTRE_V2_USER_CMD_PRCTL_IBPB,
+ SPECTRE_V2_USER_CMD_SECCOMP,
+ SPECTRE_V2_USER_CMD_SECCOMP_IBPB,
+};
+
+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",
+};
+
+static const struct {
+ const char *option;
+ enum spectre_v2_user_cmd cmd;
+ bool secure;
+} v2_user_options[] __initdata = {
+ { "auto", SPECTRE_V2_USER_CMD_AUTO, false },
+ { "off", SPECTRE_V2_USER_CMD_NONE, false },
+ { "on", SPECTRE_V2_USER_CMD_FORCE, true },
+ { "prctl", SPECTRE_V2_USER_CMD_PRCTL, false },
+ { "prctl,ibpb", SPECTRE_V2_USER_CMD_PRCTL_IBPB, false },
+ { "seccomp", SPECTRE_V2_USER_CMD_SECCOMP, false },
+ { "seccomp,ibpb", SPECTRE_V2_USER_CMD_SECCOMP_IBPB, false },
+};
+
+static void __init spec_v2_user_print_cond(const char *reason, bool secure)
{
- if (!boot_cpu_has_bug(X86_BUG_SPECTRE_V2))
- pr_info("%s selected on command line.\n", reason);
+ if (boot_cpu_has_bug(X86_BUG_SPECTRE_V2) != secure)
+ pr_info("spectre_v2_user=%s forced on command line.\n", reason);
}
-static inline bool retp_compiler(void)
+static enum spectre_v2_user_cmd __init
+spectre_v2_parse_user_cmdline(enum spectre_v2_mitigation_cmd v2_cmd)
{
- return __is_defined(RETPOLINE);
+ char arg[20];
+ int ret, i;
+
+ switch (v2_cmd) {
+ case SPECTRE_V2_CMD_NONE:
+ return SPECTRE_V2_USER_CMD_NONE;
+ case SPECTRE_V2_CMD_FORCE:
+ return SPECTRE_V2_USER_CMD_FORCE;
+ default:
+ break;
+ }
+
+ ret = cmdline_find_option(boot_command_line, "spectre_v2_user",
+ arg, sizeof(arg));
+ if (ret < 0)
+ return SPECTRE_V2_USER_CMD_AUTO;
+
+ for (i = 0; i < ARRAY_SIZE(v2_user_options); i++) {
+ if (match_option(arg, ret, v2_user_options[i].option)) {
+ spec_v2_user_print_cond(v2_user_options[i].option,
+ v2_user_options[i].secure);
+ return v2_user_options[i].cmd;
+ }
+ }
+
+ pr_err("Unknown user space protection option (%s). Switching to AUTO select\n", arg);
+ return SPECTRE_V2_USER_CMD_AUTO;
}
-static inline bool match_option(const char *arg, int arglen, const char *opt)
+static void __init
+spectre_v2_user_select_mitigation(enum spectre_v2_mitigation_cmd v2_cmd)
{
- int len = strlen(opt);
+ enum spectre_v2_user_mitigation mode = SPECTRE_V2_USER_NONE;
+ bool smt_possible = IS_ENABLED(CONFIG_SMP);
+ enum spectre_v2_user_cmd cmd;
- return len == arglen && !strncmp(arg, opt, len);
+ if (!boot_cpu_has(X86_FEATURE_IBPB) && !boot_cpu_has(X86_FEATURE_STIBP))
+ return;
+
+ if (cpu_smt_control == CPU_SMT_FORCE_DISABLED ||
+ cpu_smt_control == CPU_SMT_NOT_SUPPORTED)
+ smt_possible = false;
+
+ cmd = spectre_v2_parse_user_cmdline(v2_cmd);
+ switch (cmd) {
+ case SPECTRE_V2_USER_CMD_NONE:
+ goto set_mode;
+ case SPECTRE_V2_USER_CMD_FORCE:
+ mode = SPECTRE_V2_USER_STRICT;
+ break;
+ case SPECTRE_V2_USER_CMD_PRCTL:
+ case SPECTRE_V2_USER_CMD_PRCTL_IBPB:
+ mode = SPECTRE_V2_USER_PRCTL;
+ break;
+ case SPECTRE_V2_USER_CMD_AUTO:
+ case SPECTRE_V2_USER_CMD_SECCOMP:
+ case SPECTRE_V2_USER_CMD_SECCOMP_IBPB:
+ if (IS_ENABLED(CONFIG_SECCOMP))
+ mode = SPECTRE_V2_USER_SECCOMP;
+ else
+ mode = SPECTRE_V2_USER_PRCTL;
+ break;
+ }
+
+ /* Initialize Indirect Branch Prediction Barrier */
+ if (boot_cpu_has(X86_FEATURE_IBPB)) {
+ setup_force_cpu_cap(X86_FEATURE_USE_IBPB);
+
+ switch (cmd) {
+ case SPECTRE_V2_USER_CMD_FORCE:
+ case SPECTRE_V2_USER_CMD_PRCTL_IBPB:
+ case SPECTRE_V2_USER_CMD_SECCOMP_IBPB:
+ static_branch_enable(&switch_mm_always_ibpb);
+ break;
+ case SPECTRE_V2_USER_CMD_PRCTL:
+ case SPECTRE_V2_USER_CMD_AUTO:
+ case SPECTRE_V2_USER_CMD_SECCOMP:
+ static_branch_enable(&switch_mm_cond_ibpb);
+ break;
+ default:
+ break;
+ }
+
+ pr_info("mitigation: Enabling %s Indirect Branch Prediction Barrier\n",
+ static_key_enabled(&switch_mm_always_ibpb) ?
+ "always-on" : "conditional");
+ }
+
+ /* If enhanced IBRS is enabled no STIPB required */
+ if (spectre_v2_enabled == SPECTRE_V2_IBRS_ENHANCED)
+ return;
+
+ /*
+ * If SMT is not possible or STIBP is not available clear the STIPB
+ * mode.
+ */
+ if (!smt_possible || !boot_cpu_has(X86_FEATURE_STIBP))
+ mode = SPECTRE_V2_USER_NONE;
+set_mode:
+ spectre_v2_user = mode;
+ /* Only print the STIBP mode when SMT possible */
+ if (smt_possible)
+ pr_info("%s\n", spectre_v2_user_strings[mode]);
}
+static const char * const spectre_v2_strings[] = {
+ [SPECTRE_V2_NONE] = "Vulnerable",
+ [SPECTRE_V2_RETPOLINE_GENERIC] = "Mitigation: Full generic retpoline",
+ [SPECTRE_V2_RETPOLINE_AMD] = "Mitigation: Full AMD retpoline",
+ [SPECTRE_V2_IBRS_ENHANCED] = "Mitigation: Enhanced IBRS",
+};
+
static const struct {
const char *option;
enum spectre_v2_mitigation_cmd cmd;
bool secure;
-} mitigation_options[] = {
- { "off", SPECTRE_V2_CMD_NONE, false },
- { "on", SPECTRE_V2_CMD_FORCE, true },
- { "retpoline", SPECTRE_V2_CMD_RETPOLINE, false },
- { "retpoline,amd", SPECTRE_V2_CMD_RETPOLINE_AMD, false },
- { "retpoline,generic", SPECTRE_V2_CMD_RETPOLINE_GENERIC, false },
- { "auto", SPECTRE_V2_CMD_AUTO, false },
+} mitigation_options[] __initdata = {
+ { "off", SPECTRE_V2_CMD_NONE, false },
+ { "on", SPECTRE_V2_CMD_FORCE, true },
+ { "retpoline", SPECTRE_V2_CMD_RETPOLINE, false },
+ { "retpoline,amd", SPECTRE_V2_CMD_RETPOLINE_AMD, false },
+ { "retpoline,generic", SPECTRE_V2_CMD_RETPOLINE_GENERIC, false },
+ { "auto", SPECTRE_V2_CMD_AUTO, false },
};
+static void __init spec_v2_print_cond(const char *reason, bool secure)
+{
+ if (boot_cpu_has_bug(X86_BUG_SPECTRE_V2) != secure)
+ pr_info("%s selected on command line.\n", reason);
+}
+
static enum spectre_v2_mitigation_cmd __init spectre_v2_parse_cmdline(void)
{
+ enum spectre_v2_mitigation_cmd cmd = SPECTRE_V2_CMD_AUTO;
char arg[20];
int ret, i;
- enum spectre_v2_mitigation_cmd cmd = SPECTRE_V2_CMD_AUTO;
if (cmdline_find_option_bool(boot_command_line, "nospectre_v2"))
return SPECTRE_V2_CMD_NONE;
- else {
- ret = cmdline_find_option(boot_command_line, "spectre_v2", arg, sizeof(arg));
- if (ret < 0)
- return SPECTRE_V2_CMD_AUTO;
- for (i = 0; i < ARRAY_SIZE(mitigation_options); i++) {
- if (!match_option(arg, ret, mitigation_options[i].option))
- continue;
- cmd = mitigation_options[i].cmd;
- break;
- }
+ ret = cmdline_find_option(boot_command_line, "spectre_v2", arg, sizeof(arg));
+ if (ret < 0)
+ return SPECTRE_V2_CMD_AUTO;
- if (i >= ARRAY_SIZE(mitigation_options)) {
- pr_err("unknown option (%s). Switching to AUTO select\n", arg);
- return SPECTRE_V2_CMD_AUTO;
- }
+ for (i = 0; i < ARRAY_SIZE(mitigation_options); i++) {
+ if (!match_option(arg, ret, mitigation_options[i].option))
+ continue;
+ cmd = mitigation_options[i].cmd;
+ break;
+ }
+
+ if (i >= ARRAY_SIZE(mitigation_options)) {
+ pr_err("unknown option (%s). Switching to AUTO select\n", arg);
+ return SPECTRE_V2_CMD_AUTO;
}
if ((cmd == SPECTRE_V2_CMD_RETPOLINE ||
@@ -316,54 +462,11 @@ static enum spectre_v2_mitigation_cmd __init spectre_v2_parse_cmdline(void)
return SPECTRE_V2_CMD_AUTO;
}
- if (mitigation_options[i].secure)
- spec2_print_if_secure(mitigation_options[i].option);
- else
- spec2_print_if_insecure(mitigation_options[i].option);
-
+ spec_v2_print_cond(mitigation_options[i].option,
+ mitigation_options[i].secure);
return cmd;
}
-static bool stibp_needed(void)
-{
- if (spectre_v2_enabled == SPECTRE_V2_NONE)
- return false;
-
- if (!boot_cpu_has(X86_FEATURE_STIBP))
- return false;
-
- return true;
-}
-
-static void update_stibp_msr(void *info)
-{
- wrmsrl(MSR_IA32_SPEC_CTRL, x86_spec_ctrl_base);
-}
-
-void arch_smt_update(void)
-{
- u64 mask;
-
- if (!stibp_needed())
- return;
-
- mutex_lock(&spec_ctrl_mutex);
- mask = x86_spec_ctrl_base;
- if (cpu_smt_control == CPU_SMT_ENABLED)
- mask |= SPEC_CTRL_STIBP;
- else
- mask &= ~SPEC_CTRL_STIBP;
-
- if (mask != x86_spec_ctrl_base) {
- pr_info("Spectre v2 cross-process SMT mitigation: %s STIBP\n",
- cpu_smt_control == CPU_SMT_ENABLED ?
- "Enabling" : "Disabling");
- x86_spec_ctrl_base = mask;
- on_each_cpu(update_stibp_msr, NULL, 1);
- }
- mutex_unlock(&spec_ctrl_mutex);
-}
-
static void __init spectre_v2_select_mitigation(void)
{
enum spectre_v2_mitigation_cmd cmd = spectre_v2_parse_cmdline();
@@ -417,14 +520,12 @@ retpoline_auto:
pr_err("Spectre mitigation: LFENCE not serializing, switching to generic retpoline\n");
goto retpoline_generic;
}
- mode = retp_compiler() ? SPECTRE_V2_RETPOLINE_AMD :
- SPECTRE_V2_RETPOLINE_MINIMAL_AMD;
+ mode = SPECTRE_V2_RETPOLINE_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;
+ mode = SPECTRE_V2_RETPOLINE_GENERIC;
setup_force_cpu_cap(X86_FEATURE_RETPOLINE);
}
@@ -443,12 +544,6 @@ specv2_set_mode:
setup_force_cpu_cap(X86_FEATURE_RSB_CTXSW);
pr_info("Spectre v2 / SpectreRSB mitigation: Filling RSB on context switch\n");
- /* Initialize Indirect Branch Prediction Barrier if supported */
- if (boot_cpu_has(X86_FEATURE_IBPB)) {
- setup_force_cpu_cap(X86_FEATURE_USE_IBPB);
- pr_info("Spectre v2 mitigation: Enabling Indirect Branch Prediction Barrier\n");
- }
-
/*
* Retpoline means the kernel is safe because it has no indirect
* branches. Enhanced IBRS protects firmware too, so, enable restricted
@@ -465,10 +560,67 @@ specv2_set_mode:
pr_info("Enabling Restricted Speculation for firmware calls\n");
}
+ /* 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)
+{
+ wrmsrl(MSR_IA32_SPEC_CTRL, x86_spec_ctrl_base);
+}
+
+/* Update x86_spec_ctrl_base in case SMT state changed. */
+static void update_stibp_strict(void)
+{
+ u64 mask = x86_spec_ctrl_base & ~SPEC_CTRL_STIBP;
+
+ if (sched_smt_active())
+ mask |= SPEC_CTRL_STIBP;
+
+ if (mask == x86_spec_ctrl_base)
+ return;
+
+ pr_info("Update user space SMT mitigation: STIBP %s\n",
+ mask & SPEC_CTRL_STIBP ? "always-on" : "off");
+ x86_spec_ctrl_base = mask;
+ on_each_cpu(update_stibp_msr, NULL, 1);
+}
+
+/* Update the static key controlling the evaluation of TIF_SPEC_IB */
+static void update_indir_branch_cond(void)
+{
+ if (sched_smt_active())
+ static_branch_enable(&switch_to_cond_stibp);
+ else
+ static_branch_disable(&switch_to_cond_stibp);
+}
+
+void arch_smt_update(void)
+{
+ /* Enhanced IBRS implies STIBP. No update required. */
+ if (spectre_v2_enabled == SPECTRE_V2_IBRS_ENHANCED)
+ return;
+
+ mutex_lock(&spec_ctrl_mutex);
+
+ switch (spectre_v2_user) {
+ case SPECTRE_V2_USER_NONE:
+ break;
+ case SPECTRE_V2_USER_STRICT:
+ update_stibp_strict();
+ break;
+ case SPECTRE_V2_USER_PRCTL:
+ case SPECTRE_V2_USER_SECCOMP:
+ update_indir_branch_cond();
+ break;
+ }
+
+ mutex_unlock(&spec_ctrl_mutex);
+}
+
#undef pr_fmt
#define pr_fmt(fmt) "Speculative Store Bypass: " fmt
@@ -483,7 +635,7 @@ enum ssb_mitigation_cmd {
SPEC_STORE_BYPASS_CMD_SECCOMP,
};
-static const char *ssb_strings[] = {
+static const char * const ssb_strings[] = {
[SPEC_STORE_BYPASS_NONE] = "Vulnerable",
[SPEC_STORE_BYPASS_DISABLE] = "Mitigation: Speculative Store Bypass disabled",
[SPEC_STORE_BYPASS_PRCTL] = "Mitigation: Speculative Store Bypass disabled via prctl",
@@ -493,7 +645,7 @@ static const char *ssb_strings[] = {
static const struct {
const char *option;
enum ssb_mitigation_cmd cmd;
-} ssb_mitigation_options[] = {
+} ssb_mitigation_options[] __initdata = {
{ "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 */
@@ -604,10 +756,25 @@ static void ssb_select_mitigation(void)
#undef pr_fmt
#define pr_fmt(fmt) "Speculation prctl: " fmt
-static int ssb_prctl_set(struct task_struct *task, unsigned long ctrl)
+static void task_update_spec_tif(struct task_struct *tsk)
{
- bool update;
+ /* Force the update of the real TIF bits */
+ set_tsk_thread_flag(tsk, TIF_SPEC_FORCE_UPDATE);
+ /*
+ * Immediately update the speculation control MSRs for the current
+ * task, but for a non-current task delay setting the CPU
+ * mitigation until it is scheduled next.
+ *
+ * This can only happen for SECCOMP mitigation. For PRCTL it's
+ * always the current task.
+ */
+ if (tsk == current)
+ speculation_ctrl_update_current();
+}
+
+static int ssb_prctl_set(struct task_struct *task, unsigned long ctrl)
+{
if (ssb_mode != SPEC_STORE_BYPASS_PRCTL &&
ssb_mode != SPEC_STORE_BYPASS_SECCOMP)
return -ENXIO;
@@ -618,28 +785,56 @@ static int ssb_prctl_set(struct task_struct *task, unsigned long ctrl)
if (task_spec_ssb_force_disable(task))
return -EPERM;
task_clear_spec_ssb_disable(task);
- update = test_and_clear_tsk_thread_flag(task, TIF_SSBD);
+ task_update_spec_tif(task);
break;
case PR_SPEC_DISABLE:
task_set_spec_ssb_disable(task);
- update = !test_and_set_tsk_thread_flag(task, TIF_SSBD);
+ task_update_spec_tif(task);
break;
case PR_SPEC_FORCE_DISABLE:
task_set_spec_ssb_disable(task);
task_set_spec_ssb_force_disable(task);
- update = !test_and_set_tsk_thread_flag(task, TIF_SSBD);
+ task_update_spec_tif(task);
break;
default:
return -ERANGE;
}
+ return 0;
+}
- /*
- * If being set on non-current task, delay setting the CPU
- * mitigation until it is next scheduled.
- */
- if (task == current && update)
- speculative_store_bypass_update_current();
-
+static int ib_prctl_set(struct task_struct *task, unsigned long ctrl)
+{
+ switch (ctrl) {
+ case PR_SPEC_ENABLE:
+ if (spectre_v2_user == SPECTRE_V2_USER_NONE)
+ return 0;
+ /*
+ * Indirect branch speculation is always disabled in strict
+ * mode.
+ */
+ if (spectre_v2_user == SPECTRE_V2_USER_STRICT)
+ return -EPERM;
+ task_clear_spec_ib_disable(task);
+ task_update_spec_tif(task);
+ break;
+ case PR_SPEC_DISABLE:
+ case PR_SPEC_FORCE_DISABLE:
+ /*
+ * Indirect branch speculation is always allowed when
+ * mitigation is force disabled.
+ */
+ if (spectre_v2_user == SPECTRE_V2_USER_NONE)
+ return -EPERM;
+ if (spectre_v2_user == SPECTRE_V2_USER_STRICT)
+ return 0;
+ task_set_spec_ib_disable(task);
+ if (ctrl == PR_SPEC_FORCE_DISABLE)
+ task_set_spec_ib_force_disable(task);
+ task_update_spec_tif(task);
+ break;
+ default:
+ return -ERANGE;
+ }
return 0;
}
@@ -649,6 +844,8 @@ int arch_prctl_spec_ctrl_set(struct task_struct *task, unsigned long which,
switch (which) {
case PR_SPEC_STORE_BYPASS:
return ssb_prctl_set(task, ctrl);
+ case PR_SPEC_INDIRECT_BRANCH:
+ return ib_prctl_set(task, ctrl);
default:
return -ENODEV;
}
@@ -659,6 +856,8 @@ void arch_seccomp_spec_mitigate(struct task_struct *task)
{
if (ssb_mode == SPEC_STORE_BYPASS_SECCOMP)
ssb_prctl_set(task, PR_SPEC_FORCE_DISABLE);
+ if (spectre_v2_user == SPECTRE_V2_USER_SECCOMP)
+ ib_prctl_set(task, PR_SPEC_FORCE_DISABLE);
}
#endif
@@ -681,11 +880,35 @@ static int ssb_prctl_get(struct task_struct *task)
}
}
+static int ib_prctl_get(struct task_struct *task)
+{
+ if (!boot_cpu_has_bug(X86_BUG_SPECTRE_V2))
+ return PR_SPEC_NOT_AFFECTED;
+
+ switch (spectre_v2_user) {
+ case SPECTRE_V2_USER_NONE:
+ return PR_SPEC_ENABLE;
+ case SPECTRE_V2_USER_PRCTL:
+ case SPECTRE_V2_USER_SECCOMP:
+ if (task_spec_ib_force_disable(task))
+ return PR_SPEC_PRCTL | PR_SPEC_FORCE_DISABLE;
+ if (task_spec_ib_disable(task))
+ return PR_SPEC_PRCTL | PR_SPEC_DISABLE;
+ return PR_SPEC_PRCTL | PR_SPEC_ENABLE;
+ case SPECTRE_V2_USER_STRICT:
+ return PR_SPEC_DISABLE;
+ default:
+ return PR_SPEC_NOT_AFFECTED;
+ }
+}
+
int arch_prctl_spec_ctrl_get(struct task_struct *task, unsigned long which)
{
switch (which) {
case PR_SPEC_STORE_BYPASS:
return ssb_prctl_get(task);
+ case PR_SPEC_INDIRECT_BRANCH:
+ return ib_prctl_get(task);
default:
return -ENODEV;
}
@@ -823,7 +1046,7 @@ early_param("l1tf", l1tf_cmdline);
#define L1TF_DEFAULT_MSG "Mitigation: PTE Inversion"
#if IS_ENABLED(CONFIG_KVM_INTEL)
-static const char *l1tf_vmx_states[] = {
+static const char * const l1tf_vmx_states[] = {
[VMENTER_L1D_FLUSH_AUTO] = "auto",
[VMENTER_L1D_FLUSH_NEVER] = "vulnerable",
[VMENTER_L1D_FLUSH_COND] = "conditional cache flushes",
@@ -839,13 +1062,14 @@ static ssize_t l1tf_show_state(char *buf)
if (l1tf_vmx_mitigation == VMENTER_L1D_FLUSH_EPT_DISABLED ||
(l1tf_vmx_mitigation == VMENTER_L1D_FLUSH_NEVER &&
- cpu_smt_control == CPU_SMT_ENABLED))
+ sched_smt_active())) {
return sprintf(buf, "%s; VMX: %s\n", L1TF_DEFAULT_MSG,
l1tf_vmx_states[l1tf_vmx_mitigation]);
+ }
return sprintf(buf, "%s; VMX: %s, SMT %s\n", L1TF_DEFAULT_MSG,
l1tf_vmx_states[l1tf_vmx_mitigation],
- cpu_smt_control == CPU_SMT_ENABLED ? "vulnerable" : "disabled");
+ sched_smt_active() ? "vulnerable" : "disabled");
}
#else
static ssize_t l1tf_show_state(char *buf)
@@ -854,11 +1078,39 @@ static ssize_t l1tf_show_state(char *buf)
}
#endif
+static char *stibp_state(void)
+{
+ if (spectre_v2_enabled == SPECTRE_V2_IBRS_ENHANCED)
+ return "";
+
+ switch (spectre_v2_user) {
+ case SPECTRE_V2_USER_NONE:
+ return ", STIBP: disabled";
+ case SPECTRE_V2_USER_STRICT:
+ return ", STIBP: forced";
+ case SPECTRE_V2_USER_PRCTL:
+ case SPECTRE_V2_USER_SECCOMP:
+ if (static_key_enabled(&switch_to_cond_stibp))
+ return ", STIBP: conditional";
+ }
+ return "";
+}
+
+static char *ibpb_state(void)
+{
+ if (boot_cpu_has(X86_FEATURE_IBPB)) {
+ if (static_key_enabled(&switch_mm_always_ibpb))
+ return ", IBPB: always-on";
+ if (static_key_enabled(&switch_mm_cond_ibpb))
+ return ", IBPB: conditional";
+ return ", IBPB: disabled";
+ }
+ return "";
+}
+
static ssize_t cpu_show_common(struct device *dev, struct device_attribute *attr,
char *buf, unsigned int bug)
{
- int ret;
-
if (!boot_cpu_has_bug(bug))
return sprintf(buf, "Not affected\n");
@@ -876,13 +1128,12 @@ static ssize_t cpu_show_common(struct device *dev, struct device_attribute *attr
return sprintf(buf, "Mitigation: __user pointer sanitization\n");
case X86_BUG_SPECTRE_V2:
- ret = sprintf(buf, "%s%s%s%s%s%s\n", spectre_v2_strings[spectre_v2_enabled],
- boot_cpu_has(X86_FEATURE_USE_IBPB) ? ", IBPB" : "",
+ return sprintf(buf, "%s%s%s%s%s%s\n", spectre_v2_strings[spectre_v2_enabled],
+ ibpb_state(),
boot_cpu_has(X86_FEATURE_USE_IBRS_FW) ? ", IBRS_FW" : "",
- (x86_spec_ctrl_base & SPEC_CTRL_STIBP) ? ", STIBP" : "",
+ stibp_state(),
boot_cpu_has(X86_FEATURE_RSB_CTXSW) ? ", RSB filling" : "",
spectre_v2_module_string());
- return ret;
case X86_BUG_SPEC_STORE_BYPASS:
return sprintf(buf, "%s\n", ssb_strings[ssb_mode]);
diff --git a/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c b/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c
index 27937458c231..efa4a519f5e5 100644
--- a/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c
+++ b/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c
@@ -23,6 +23,7 @@
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/cpu.h>
#include <linux/kernfs.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
@@ -310,9 +311,11 @@ ssize_t rdtgroup_schemata_write(struct kernfs_open_file *of,
return -EINVAL;
buf[nbytes - 1] = '\0';
+ cpus_read_lock();
rdtgrp = rdtgroup_kn_lock_live(of->kn);
if (!rdtgrp) {
rdtgroup_kn_unlock(of->kn);
+ cpus_read_unlock();
return -ENOENT;
}
rdt_last_cmd_clear();
@@ -367,6 +370,7 @@ ssize_t rdtgroup_schemata_write(struct kernfs_open_file *of,
out:
rdtgroup_kn_unlock(of->kn);
+ cpus_read_unlock();
return ret ?: nbytes;
}
diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index 8c66d2fc8f81..36d2696c9563 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -485,7 +485,7 @@ static void mce_report_event(struct pt_regs *regs)
* be somewhat complicated (e.g. segment offset would require an instruction
* parser). So only support physical addresses up to page granuality for now.
*/
-static int mce_usable_address(struct mce *m)
+int mce_usable_address(struct mce *m)
{
if (!(m->status & MCI_STATUS_ADDRV))
return 0;
@@ -505,6 +505,7 @@ static int mce_usable_address(struct mce *m)
return 1;
}
+EXPORT_SYMBOL_GPL(mce_usable_address);
bool mce_is_memory_error(struct mce *m)
{
@@ -534,7 +535,7 @@ bool mce_is_memory_error(struct mce *m)
}
EXPORT_SYMBOL_GPL(mce_is_memory_error);
-static bool mce_is_correctable(struct mce *m)
+bool mce_is_correctable(struct mce *m)
{
if (m->cpuvendor == X86_VENDOR_AMD && m->status & MCI_STATUS_DEFERRED)
return false;
@@ -547,6 +548,7 @@ static bool mce_is_correctable(struct mce *m)
return true;
}
+EXPORT_SYMBOL_GPL(mce_is_correctable);
static bool cec_add_mce(struct mce *m)
{
diff --git a/arch/x86/kernel/cpu/mcheck/mce_amd.c b/arch/x86/kernel/cpu/mcheck/mce_amd.c
index dd33c357548f..e12454e21b8a 100644
--- a/arch/x86/kernel/cpu/mcheck/mce_amd.c
+++ b/arch/x86/kernel/cpu/mcheck/mce_amd.c
@@ -56,7 +56,7 @@
/* Threshold LVT offset is at MSR0xC0000410[15:12] */
#define SMCA_THR_LVT_OFF 0xF000
-static bool thresholding_en;
+static bool thresholding_irq_en;
static const char * const th_names[] = {
"load_store",
@@ -534,9 +534,8 @@ prepare_threshold_block(unsigned int bank, unsigned int block, u32 addr,
set_offset:
offset = setup_APIC_mce_threshold(offset, new);
-
- if ((offset == new) && (mce_threshold_vector != amd_threshold_interrupt))
- mce_threshold_vector = amd_threshold_interrupt;
+ if (offset == new)
+ thresholding_irq_en = true;
done:
mce_threshold_block_init(&b, offset);
@@ -1357,9 +1356,6 @@ int mce_threshold_remove_device(unsigned int cpu)
{
unsigned int bank;
- if (!thresholding_en)
- return 0;
-
for (bank = 0; bank < mca_cfg.banks; ++bank) {
if (!(per_cpu(bank_map, cpu) & (1 << bank)))
continue;
@@ -1377,9 +1373,6 @@ int mce_threshold_create_device(unsigned int cpu)
struct threshold_bank **bp;
int err = 0;
- if (!thresholding_en)
- return 0;
-
bp = per_cpu(threshold_banks, cpu);
if (bp)
return 0;
@@ -1408,9 +1401,6 @@ static __init int threshold_init_device(void)
{
unsigned lcpu = 0;
- if (mce_threshold_vector == amd_threshold_interrupt)
- thresholding_en = true;
-
/* to hit CPUs online before the notifier is up */
for_each_online_cpu(lcpu) {
int err = mce_threshold_create_device(lcpu);
@@ -1419,6 +1409,9 @@ static __init int threshold_init_device(void)
return err;
}
+ if (thresholding_irq_en)
+ mce_threshold_vector = amd_threshold_interrupt;
+
return 0;
}
/*
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index 1c72f3819eb1..e81a2db42df7 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -20,6 +20,7 @@
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/kexec.h>
+#include <linux/i8253.h>
#include <asm/processor.h>
#include <asm/hypervisor.h>
#include <asm/hyperv-tlfs.h>
@@ -295,6 +296,16 @@ static void __init ms_hyperv_init_platform(void)
if (efi_enabled(EFI_BOOT))
x86_platform.get_nmi_reason = hv_get_nmi_reason;
+ /*
+ * Hyper-V VMs have a PIT emulation quirk such that zeroing the
+ * counter register during PIT shutdown restarts the PIT. So it
+ * continues to interrupt @18.2 HZ. Setting i8253_clear_counter
+ * to false tells pit_shutdown() not to zero the counter so that
+ * the PIT really is shutdown. Generation 2 VMs don't have a PIT,
+ * and setting this value has no effect.
+ */
+ i8253_clear_counter_on_shutdown = false;
+
#if IS_ENABLED(CONFIG_HYPERV)
/*
* Setup the hook to get control post apic initialization.
diff --git a/arch/x86/kernel/cpu/mtrr/if.c b/arch/x86/kernel/cpu/mtrr/if.c
index 2e173d47b450..4d36dcc1cf87 100644
--- a/arch/x86/kernel/cpu/mtrr/if.c
+++ b/arch/x86/kernel/cpu/mtrr/if.c
@@ -165,6 +165,8 @@ mtrr_ioctl(struct file *file, unsigned int cmd, unsigned long __arg)
struct mtrr_gentry gentry;
void __user *arg = (void __user *) __arg;
+ memset(&gentry, 0, sizeof(gentry));
+
switch (cmd) {
case MTRRIOC_ADD_ENTRY:
case MTRRIOC_SET_ENTRY:
diff --git a/arch/x86/kernel/cpu/vmware.c b/arch/x86/kernel/cpu/vmware.c
index d9ab49bed8af..0eda91f8eeac 100644
--- a/arch/x86/kernel/cpu/vmware.c
+++ b/arch/x86/kernel/cpu/vmware.c
@@ -77,7 +77,7 @@ static __init int setup_vmw_sched_clock(char *s)
}
early_param("no-vmw-sched-clock", setup_vmw_sched_clock);
-static unsigned long long vmware_sched_clock(void)
+static unsigned long long notrace vmware_sched_clock(void)
{
unsigned long long ns;
diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c
index 61a949d84dfa..d99a8ee9e185 100644
--- a/arch/x86/kernel/fpu/signal.c
+++ b/arch/x86/kernel/fpu/signal.c
@@ -344,10 +344,10 @@ static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size)
sanitize_restored_xstate(tsk, &env, xfeatures, fx_only);
}
+ local_bh_disable();
fpu->initialized = 1;
- preempt_disable();
fpu__restore(fpu);
- preempt_enable();
+ local_bh_enable();
return err;
} else {
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index 01ebcb6f263e..7ee8067cbf45 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -994,7 +994,6 @@ void prepare_ftrace_return(unsigned long self_addr, unsigned long *parent,
{
unsigned long old;
int faulted;
- struct ftrace_graph_ent trace;
unsigned long return_hooker = (unsigned long)
&return_to_handler;
@@ -1046,19 +1045,7 @@ void prepare_ftrace_return(unsigned long self_addr, unsigned long *parent,
return;
}
- trace.func = self_addr;
- trace.depth = current->curr_ret_stack + 1;
-
- /* Only trace if the calling function expects to */
- if (!ftrace_graph_entry(&trace)) {
+ if (function_graph_enter(old, self_addr, frame_pointer, parent))
*parent = old;
- return;
- }
-
- if (ftrace_push_return_trace(old, self_addr, &trace.depth,
- frame_pointer, parent) == -EBUSY) {
- *parent = old;
- return;
- }
}
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
diff --git a/arch/x86/kernel/head32.c b/arch/x86/kernel/head32.c
index 76fa3b836598..ec6fefbfd3c0 100644
--- a/arch/x86/kernel/head32.c
+++ b/arch/x86/kernel/head32.c
@@ -37,7 +37,6 @@ asmlinkage __visible void __init i386_start_kernel(void)
cr4_init_shadow();
sanitize_boot_params(&boot_params);
- x86_verify_bootdata_version();
x86_early_init_platform_quirks();
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index 7663a8eb602b..16b1cbd3a61e 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -457,8 +457,6 @@ void __init x86_64_start_reservations(char *real_mode_data)
if (!boot_params.hdr.version)
copy_bootdata(__va(real_mode_data));
- x86_verify_bootdata_version();
-
x86_early_init_platform_quirks();
switch (boot_params.hdr.hardware_subarch) {
diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c
index 40b16b270656..6adf6e6c2933 100644
--- a/arch/x86/kernel/kprobes/opt.c
+++ b/arch/x86/kernel/kprobes/opt.c
@@ -189,7 +189,7 @@ static int copy_optimized_instructions(u8 *dest, u8 *src, u8 *real)
int len = 0, ret;
while (len < RELATIVEJUMP_SIZE) {
- ret = __copy_instruction(dest + len, src + len, real, &insn);
+ ret = __copy_instruction(dest + len, src + len, real + len, &insn);
if (!ret || !can_boost(&insn, src + len))
return -EINVAL;
len += ret;
diff --git a/arch/x86/kernel/ldt.c b/arch/x86/kernel/ldt.c
index ab18e0884dc6..6135ae8ce036 100644
--- a/arch/x86/kernel/ldt.c
+++ b/arch/x86/kernel/ldt.c
@@ -199,14 +199,6 @@ static void sanity_check_ldt_mapping(struct mm_struct *mm)
/*
* 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)
@@ -214,8 +206,7 @@ map_ldt_struct(struct mm_struct *mm, struct ldt_struct *ldt, int slot)
unsigned long va;
bool is_vmalloc;
spinlock_t *ptl;
- pgd_t *pgd;
- int i;
+ int i, nr_pages;
if (!static_cpu_has(X86_FEATURE_PTI))
return 0;
@@ -229,16 +220,11 @@ map_ldt_struct(struct mm_struct *mm, struct ldt_struct *ldt, int slot)
/* Check if the current mappings are sane */
sanity_check_ldt_mapping(mm);
- /*
- * 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);
-
is_vmalloc = is_vmalloc_addr(ldt->entries);
- for (i = 0; i * PAGE_SIZE < ldt->nr_entries * LDT_ENTRY_SIZE; i++) {
+ nr_pages = DIV_ROUND_UP(ldt->nr_entries * LDT_ENTRY_SIZE, PAGE_SIZE);
+
+ for (i = 0; i < nr_pages; i++) {
unsigned long offset = i << PAGE_SHIFT;
const void *src = (char *)ldt->entries + offset;
unsigned long pfn;
@@ -272,13 +258,39 @@ map_ldt_struct(struct mm_struct *mm, struct ldt_struct *ldt, int slot)
/* Propagate LDT mapping to the user page-table */
map_ldt_struct_to_user(mm);
- va = (unsigned long)ldt_slot_va(slot);
- flush_tlb_mm_range(mm, va, va + LDT_SLOT_STRIDE, PAGE_SHIFT, false);
-
ldt->slot = slot;
return 0;
}
+static void unmap_ldt_struct(struct mm_struct *mm, struct ldt_struct *ldt)
+{
+ unsigned long va;
+ int i, nr_pages;
+
+ if (!ldt)
+ return;
+
+ /* LDT map/unmap is only required for PTI */
+ if (!static_cpu_has(X86_FEATURE_PTI))
+ return;
+
+ nr_pages = DIV_ROUND_UP(ldt->nr_entries * LDT_ENTRY_SIZE, PAGE_SIZE);
+
+ for (i = 0; i < nr_pages; i++) {
+ unsigned long offset = i << PAGE_SHIFT;
+ spinlock_t *ptl;
+ pte_t *ptep;
+
+ va = (unsigned long)ldt_slot_va(ldt->slot) + offset;
+ ptep = get_locked_pte(mm, va, &ptl);
+ pte_clear(mm, va, ptep);
+ pte_unmap_unlock(ptep, ptl);
+ }
+
+ va = (unsigned long)ldt_slot_va(ldt->slot);
+ flush_tlb_mm_range(mm, va, va + nr_pages * PAGE_SIZE, PAGE_SHIFT, false);
+}
+
#else /* !CONFIG_PAGE_TABLE_ISOLATION */
static int
@@ -286,6 +298,10 @@ map_ldt_struct(struct mm_struct *mm, struct ldt_struct *ldt, int slot)
{
return 0;
}
+
+static void unmap_ldt_struct(struct mm_struct *mm, struct ldt_struct *ldt)
+{
+}
#endif /* CONFIG_PAGE_TABLE_ISOLATION */
static void free_ldt_pgtables(struct mm_struct *mm)
@@ -524,6 +540,7 @@ static int write_ldt(void __user *ptr, unsigned long bytecount, int oldmode)
}
install_ldt(mm, new_ldt);
+ unmap_ldt_struct(mm, old_ldt);
free_ldt_struct(old_ldt);
error = 0;
diff --git a/arch/x86/kernel/macros.S b/arch/x86/kernel/macros.S
deleted file mode 100644
index 161c95059044..000000000000
--- a/arch/x86/kernel/macros.S
+++ /dev/null
@@ -1,16 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-
-/*
- * This file includes headers whose assembly part includes macros which are
- * commonly used. The macros are precompiled into assmebly file which is later
- * assembled together with each compiled file.
- */
-
-#include <linux/compiler.h>
-#include <asm/refcount.h>
-#include <asm/alternative-asm.h>
-#include <asm/bug.h>
-#include <asm/paravirt.h>
-#include <asm/asm.h>
-#include <asm/cpufeature.h>
-#include <asm/jump_label.h>
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index c93fcfdf1673..7d31192296a8 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -40,6 +40,8 @@
#include <asm/prctl.h>
#include <asm/spec-ctrl.h>
+#include "process.h"
+
/*
* per-CPU TSS segments. Threads are completely 'soft' on Linux,
* no more per-task TSS's. The TSS size is kept cacheline-aligned
@@ -252,11 +254,12 @@ void arch_setup_new_exec(void)
enable_cpuid();
}
-static inline void switch_to_bitmap(struct tss_struct *tss,
- struct thread_struct *prev,
+static inline void switch_to_bitmap(struct thread_struct *prev,
struct thread_struct *next,
unsigned long tifp, unsigned long tifn)
{
+ struct tss_struct *tss = this_cpu_ptr(&cpu_tss_rw);
+
if (tifn & _TIF_IO_BITMAP) {
/*
* Copy the relevant range of the IO bitmap.
@@ -395,32 +398,85 @@ static __always_inline void amd_set_ssb_virt_state(unsigned long tifn)
wrmsrl(MSR_AMD64_VIRT_SPEC_CTRL, ssbd_tif_to_spec_ctrl(tifn));
}
-static __always_inline void intel_set_ssb_state(unsigned long tifn)
+/*
+ * Update the MSRs managing speculation control, during context switch.
+ *
+ * tifp: Previous task's thread flags
+ * tifn: Next task's thread flags
+ */
+static __always_inline void __speculation_ctrl_update(unsigned long tifp,
+ unsigned long tifn)
{
- u64 msr = x86_spec_ctrl_base | ssbd_tif_to_spec_ctrl(tifn);
+ unsigned long tif_diff = tifp ^ tifn;
+ u64 msr = x86_spec_ctrl_base;
+ bool updmsr = false;
+
+ /*
+ * If TIF_SSBD is different, select the proper mitigation
+ * method. Note that if SSBD mitigation is disabled or permanentely
+ * enabled this branch can't be taken because nothing can set
+ * TIF_SSBD.
+ */
+ if (tif_diff & _TIF_SSBD) {
+ if (static_cpu_has(X86_FEATURE_VIRT_SSBD)) {
+ amd_set_ssb_virt_state(tifn);
+ } else if (static_cpu_has(X86_FEATURE_LS_CFG_SSBD)) {
+ amd_set_core_ssb_state(tifn);
+ } else if (static_cpu_has(X86_FEATURE_SPEC_CTRL_SSBD) ||
+ static_cpu_has(X86_FEATURE_AMD_SSBD)) {
+ msr |= ssbd_tif_to_spec_ctrl(tifn);
+ updmsr = true;
+ }
+ }
+
+ /*
+ * Only evaluate TIF_SPEC_IB if conditional STIBP is enabled,
+ * otherwise avoid the MSR write.
+ */
+ if (IS_ENABLED(CONFIG_SMP) &&
+ static_branch_unlikely(&switch_to_cond_stibp)) {
+ updmsr |= !!(tif_diff & _TIF_SPEC_IB);
+ msr |= stibp_tif_to_spec_ctrl(tifn);
+ }
- wrmsrl(MSR_IA32_SPEC_CTRL, msr);
+ if (updmsr)
+ wrmsrl(MSR_IA32_SPEC_CTRL, msr);
}
-static __always_inline void __speculative_store_bypass_update(unsigned long tifn)
+static unsigned long speculation_ctrl_update_tif(struct task_struct *tsk)
{
- if (static_cpu_has(X86_FEATURE_VIRT_SSBD))
- amd_set_ssb_virt_state(tifn);
- else if (static_cpu_has(X86_FEATURE_LS_CFG_SSBD))
- amd_set_core_ssb_state(tifn);
- else
- intel_set_ssb_state(tifn);
+ if (test_and_clear_tsk_thread_flag(tsk, TIF_SPEC_FORCE_UPDATE)) {
+ if (task_spec_ssb_disable(tsk))
+ set_tsk_thread_flag(tsk, TIF_SSBD);
+ else
+ clear_tsk_thread_flag(tsk, TIF_SSBD);
+
+ if (task_spec_ib_disable(tsk))
+ set_tsk_thread_flag(tsk, TIF_SPEC_IB);
+ else
+ clear_tsk_thread_flag(tsk, TIF_SPEC_IB);
+ }
+ /* Return the updated threadinfo flags*/
+ return task_thread_info(tsk)->flags;
}
-void speculative_store_bypass_update(unsigned long tif)
+void speculation_ctrl_update(unsigned long tif)
{
+ /* Forced update. Make sure all relevant TIF flags are different */
preempt_disable();
- __speculative_store_bypass_update(tif);
+ __speculation_ctrl_update(~tif, tif);
preempt_enable();
}
-void __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p,
- struct tss_struct *tss)
+/* Called from seccomp/prctl update */
+void speculation_ctrl_update_current(void)
+{
+ preempt_disable();
+ speculation_ctrl_update(speculation_ctrl_update_tif(current));
+ preempt_enable();
+}
+
+void __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p)
{
struct thread_struct *prev, *next;
unsigned long tifp, tifn;
@@ -430,7 +486,7 @@ void __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p,
tifn = READ_ONCE(task_thread_info(next_p)->flags);
tifp = READ_ONCE(task_thread_info(prev_p)->flags);
- switch_to_bitmap(tss, prev, next, tifp, tifn);
+ switch_to_bitmap(prev, next, tifp, tifn);
propagate_user_return_notify(prev_p, next_p);
@@ -451,8 +507,15 @@ void __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p,
if ((tifp ^ tifn) & _TIF_NOCPUID)
set_cpuid_faulting(!!(tifn & _TIF_NOCPUID));
- if ((tifp ^ tifn) & _TIF_SSBD)
- __speculative_store_bypass_update(tifn);
+ if (likely(!((tifp | tifn) & _TIF_SPEC_FORCE_UPDATE))) {
+ __speculation_ctrl_update(tifp, tifn);
+ } else {
+ speculation_ctrl_update_tif(prev_p);
+ tifn = speculation_ctrl_update_tif(next_p);
+
+ /* Enforce MSR update to ensure consistent state */
+ __speculation_ctrl_update(~tifn, tifn);
+ }
}
/*
diff --git a/arch/x86/kernel/process.h b/arch/x86/kernel/process.h
new file mode 100644
index 000000000000..898e97cf6629
--- /dev/null
+++ b/arch/x86/kernel/process.h
@@ -0,0 +1,39 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Code shared between 32 and 64 bit
+
+#include <asm/spec-ctrl.h>
+
+void __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p);
+
+/*
+ * This needs to be inline to optimize for the common case where no extra
+ * work needs to be done.
+ */
+static inline void switch_to_extra(struct task_struct *prev,
+ struct task_struct *next)
+{
+ unsigned long next_tif = task_thread_info(next)->flags;
+ unsigned long prev_tif = task_thread_info(prev)->flags;
+
+ if (IS_ENABLED(CONFIG_SMP)) {
+ /*
+ * Avoid __switch_to_xtra() invocation when conditional
+ * STIPB is disabled and the only different bit is
+ * TIF_SPEC_IB. For CONFIG_SMP=n TIF_SPEC_IB is not
+ * in the TIF_WORK_CTXSW masks.
+ */
+ if (!static_branch_likely(&switch_to_cond_stibp)) {
+ prev_tif &= ~_TIF_SPEC_IB;
+ next_tif &= ~_TIF_SPEC_IB;
+ }
+ }
+
+ /*
+ * __switch_to_xtra() handles debug registers, i/o bitmaps,
+ * speculation mitigations etc.
+ */
+ if (unlikely(next_tif & _TIF_WORK_CTXSW_NEXT ||
+ prev_tif & _TIF_WORK_CTXSW_PREV))
+ __switch_to_xtra(prev, next);
+}
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index 5046a3c9dec2..d3e593eb189f 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -59,6 +59,8 @@
#include <asm/intel_rdt_sched.h>
#include <asm/proto.h>
+#include "process.h"
+
void __show_regs(struct pt_regs *regs, enum show_regs_mode mode)
{
unsigned long cr0 = 0L, cr2 = 0L, cr3 = 0L, cr4 = 0L;
@@ -232,7 +234,6 @@ __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_rw, cpu);
/* never put a printk in __switch_to... printk() calls wake_up*() indirectly */
@@ -264,12 +265,7 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
if (get_kernel_rpl() && unlikely(prev->iopl != next->iopl))
set_iopl_mask(next->iopl);
- /*
- * Now maybe handle debug registers and/or IO bitmaps
- */
- if (unlikely(task_thread_info(prev_p)->flags & _TIF_WORK_CTXSW_PREV ||
- task_thread_info(next_p)->flags & _TIF_WORK_CTXSW_NEXT))
- __switch_to_xtra(prev_p, next_p, tss);
+ switch_to_extra(prev_p, next_p);
/*
* Leave lazy mode, flushing any hypercalls made here.
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 0e0b4288a4b2..ddd4fa718c43 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -60,6 +60,8 @@
#include <asm/unistd_32_ia32.h>
#endif
+#include "process.h"
+
/* Prints also some state that isn't saved in the pt_regs */
void __show_regs(struct pt_regs *regs, enum show_regs_mode mode)
{
@@ -337,24 +339,6 @@ static unsigned long x86_fsgsbase_read_task(struct task_struct *task,
return base;
}
-void x86_fsbase_write_cpu(unsigned long fsbase)
-{
- /*
- * Set the selector to 0 as a notion, that the segment base is
- * overwritten, which will be checked for skipping the segment load
- * during context switch.
- */
- loadseg(FS, 0);
- wrmsrl(MSR_FS_BASE, fsbase);
-}
-
-void x86_gsbase_write_cpu_inactive(unsigned long gsbase)
-{
- /* Set the selector to 0 for the same reason as %fs above. */
- loadseg(GS, 0);
- wrmsrl(MSR_KERNEL_GS_BASE, gsbase);
-}
-
unsigned long x86_fsbase_read_task(struct task_struct *task)
{
unsigned long fsbase;
@@ -383,38 +367,18 @@ unsigned long x86_gsbase_read_task(struct task_struct *task)
return gsbase;
}
-int x86_fsbase_write_task(struct task_struct *task, unsigned long fsbase)
+void x86_fsbase_write_task(struct task_struct *task, unsigned long fsbase)
{
- /*
- * Not strictly needed for %fs, but do it for symmetry
- * with %gs
- */
- if (unlikely(fsbase >= TASK_SIZE_MAX))
- return -EPERM;
+ WARN_ON_ONCE(task == current);
- preempt_disable();
task->thread.fsbase = fsbase;
- if (task == current)
- x86_fsbase_write_cpu(fsbase);
- task->thread.fsindex = 0;
- preempt_enable();
-
- return 0;
}
-int x86_gsbase_write_task(struct task_struct *task, unsigned long gsbase)
+void x86_gsbase_write_task(struct task_struct *task, unsigned long gsbase)
{
- if (unlikely(gsbase >= TASK_SIZE_MAX))
- return -EPERM;
+ WARN_ON_ONCE(task == current);
- preempt_disable();
task->thread.gsbase = gsbase;
- if (task == current)
- x86_gsbase_write_cpu_inactive(gsbase);
- task->thread.gsindex = 0;
- preempt_enable();
-
- return 0;
}
int copy_thread_tls(unsigned long clone_flags, unsigned long sp,
@@ -553,7 +517,6 @@ __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_rw, cpu);
WARN_ON_ONCE(IS_ENABLED(CONFIG_DEBUG_ENTRY) &&
this_cpu_read(irq_count) != -1);
@@ -617,12 +580,7 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
/* Reload sp0. */
update_task_stack(next_p);
- /*
- * Now maybe reload the debug registers and handle I/O bitmaps
- */
- if (unlikely(task_thread_info(next_p)->flags & _TIF_WORK_CTXSW_NEXT ||
- task_thread_info(prev_p)->flags & _TIF_WORK_CTXSW_PREV))
- __switch_to_xtra(prev_p, next_p, tss);
+ switch_to_extra(prev_p, next_p);
#ifdef CONFIG_XEN_PV
/*
@@ -758,11 +716,60 @@ long do_arch_prctl_64(struct task_struct *task, int option, unsigned long arg2)
switch (option) {
case ARCH_SET_GS: {
- ret = x86_gsbase_write_task(task, arg2);
+ if (unlikely(arg2 >= TASK_SIZE_MAX))
+ return -EPERM;
+
+ preempt_disable();
+ /*
+ * ARCH_SET_GS has always overwritten the index
+ * and the base. Zero is the most sensible value
+ * to put in the index, and is the only value that
+ * makes any sense if FSGSBASE is unavailable.
+ */
+ if (task == current) {
+ loadseg(GS, 0);
+ x86_gsbase_write_cpu_inactive(arg2);
+
+ /*
+ * On non-FSGSBASE systems, save_base_legacy() expects
+ * that we also fill in thread.gsbase.
+ */
+ task->thread.gsbase = arg2;
+
+ } else {
+ task->thread.gsindex = 0;
+ x86_gsbase_write_task(task, arg2);
+ }
+ preempt_enable();
break;
}
case ARCH_SET_FS: {
- ret = x86_fsbase_write_task(task, arg2);
+ /*
+ * Not strictly needed for %fs, but do it for symmetry
+ * with %gs
+ */
+ if (unlikely(arg2 >= TASK_SIZE_MAX))
+ return -EPERM;
+
+ preempt_disable();
+ /*
+ * Set the selector to 0 for the same reason
+ * as %gs above.
+ */
+ if (task == current) {
+ loadseg(FS, 0);
+ x86_fsbase_write_cpu(arg2);
+
+ /*
+ * On non-FSGSBASE systems, save_base_legacy() expects
+ * that we also fill in thread.fsbase.
+ */
+ task->thread.fsbase = arg2;
+ } else {
+ task->thread.fsindex = 0;
+ x86_fsbase_write_task(task, arg2);
+ }
+ preempt_enable();
break;
}
case ARCH_GET_FS: {
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index ffae9b9740fd..4b8ee05dd6ad 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -397,11 +397,12 @@ static int putreg(struct task_struct *child,
if (value >= TASK_SIZE_MAX)
return -EIO;
/*
- * When changing the FS base, use the same
- * mechanism as for do_arch_prctl_64().
+ * When changing the FS base, use do_arch_prctl_64()
+ * to set the index to zero and to set the base
+ * as requested.
*/
if (child->thread.fsbase != value)
- return x86_fsbase_write_task(child, value);
+ return do_arch_prctl_64(child, ARCH_SET_FS, value);
return 0;
case offsetof(struct user_regs_struct,gs_base):
/*
@@ -410,7 +411,7 @@ static int putreg(struct task_struct *child,
if (value >= TASK_SIZE_MAX)
return -EIO;
if (child->thread.gsbase != value)
- return x86_gsbase_write_task(child, value);
+ return do_arch_prctl_64(child, ARCH_SET_GS, value);
return 0;
#endif
}
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index b74e7bfed6ab..d494b9bfe618 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -1280,23 +1280,6 @@ void __init setup_arch(char **cmdline_p)
unwind_init();
}
-/*
- * From boot protocol 2.14 onwards we expect the bootloader to set the
- * version to "0x8000 | <used version>". In case we find a version >= 2.14
- * without the 0x8000 we assume the boot loader supports 2.13 only and
- * reset the version accordingly. The 0x8000 flag is removed in any case.
- */
-void __init x86_verify_bootdata_version(void)
-{
- if (boot_params.hdr.version & VERSION_WRITTEN)
- boot_params.hdr.version &= ~VERSION_WRITTEN;
- else if (boot_params.hdr.version >= 0x020e)
- boot_params.hdr.version = 0x020d;
-
- if (boot_params.hdr.version < 0x020e)
- boot_params.hdr.acpi_rsdp_addr = 0;
-}
-
#ifdef CONFIG_X86_32
static struct resource video_ram_resource = {
diff --git a/arch/x86/kernel/vsmp_64.c b/arch/x86/kernel/vsmp_64.c
index 1eae5af491c2..891a75dbc131 100644
--- a/arch/x86/kernel/vsmp_64.c
+++ b/arch/x86/kernel/vsmp_64.c
@@ -26,65 +26,8 @@
#define TOPOLOGY_REGISTER_OFFSET 0x10
-#if defined CONFIG_PCI && defined CONFIG_PARAVIRT_XXL
-/*
- * Interrupt control on vSMPowered systems:
- * ~AC is a shadow of IF. If IF is 'on' AC should be 'off'
- * and vice versa.
- */
-
-asmlinkage __visible unsigned long vsmp_save_fl(void)
-{
- unsigned long flags = native_save_fl();
-
- if (!(flags & X86_EFLAGS_IF) || (flags & X86_EFLAGS_AC))
- flags &= ~X86_EFLAGS_IF;
- return flags;
-}
-PV_CALLEE_SAVE_REGS_THUNK(vsmp_save_fl);
-
-__visible void vsmp_restore_fl(unsigned long flags)
-{
- if (flags & X86_EFLAGS_IF)
- flags &= ~X86_EFLAGS_AC;
- else
- flags |= X86_EFLAGS_AC;
- native_restore_fl(flags);
-}
-PV_CALLEE_SAVE_REGS_THUNK(vsmp_restore_fl);
-
-asmlinkage __visible void vsmp_irq_disable(void)
-{
- unsigned long flags = native_save_fl();
-
- native_restore_fl((flags & ~X86_EFLAGS_IF) | X86_EFLAGS_AC);
-}
-PV_CALLEE_SAVE_REGS_THUNK(vsmp_irq_disable);
-
-asmlinkage __visible void vsmp_irq_enable(void)
-{
- unsigned long flags = native_save_fl();
-
- native_restore_fl((flags | X86_EFLAGS_IF) & (~X86_EFLAGS_AC));
-}
-PV_CALLEE_SAVE_REGS_THUNK(vsmp_irq_enable);
-
-static unsigned __init vsmp_patch(u8 type, void *ibuf,
- unsigned long addr, unsigned len)
-{
- switch (type) {
- case PARAVIRT_PATCH(irq.irq_enable):
- case PARAVIRT_PATCH(irq.irq_disable):
- case PARAVIRT_PATCH(irq.save_fl):
- case PARAVIRT_PATCH(irq.restore_fl):
- return paravirt_patch_default(type, ibuf, addr, len);
- default:
- return native_patch(type, ibuf, addr, len);
- }
-
-}
-
-static void __init set_vsmp_pv_ops(void)
+#ifdef CONFIG_PCI
+static void __init set_vsmp_ctl(void)
{
void __iomem *address;
unsigned int cap, ctl, cfg;
@@ -109,28 +52,12 @@ static void __init set_vsmp_pv_ops(void)
}
#endif
- if (cap & ctl & (1 << 4)) {
- /* Setup irq ops and turn on vSMP IRQ fastpath handling */
- pv_ops.irq.irq_disable = PV_CALLEE_SAVE(vsmp_irq_disable);
- pv_ops.irq.irq_enable = PV_CALLEE_SAVE(vsmp_irq_enable);
- pv_ops.irq.save_fl = PV_CALLEE_SAVE(vsmp_save_fl);
- pv_ops.irq.restore_fl = PV_CALLEE_SAVE(vsmp_restore_fl);
- pv_ops.init.patch = vsmp_patch;
- ctl &= ~(1 << 4);
- }
writel(ctl, address + 4);
ctl = readl(address + 4);
pr_info("vSMP CTL: control set to:0x%08x\n", ctl);
early_iounmap(address, 8);
}
-#else
-static void __init set_vsmp_pv_ops(void)
-{
-}
-#endif
-
-#ifdef CONFIG_PCI
static int is_vsmp = -1;
static void __init detect_vsmp_box(void)
@@ -164,11 +91,14 @@ static int is_vsmp_box(void)
{
return 0;
}
+static void __init set_vsmp_ctl(void)
+{
+}
#endif
static void __init vsmp_cap_cpus(void)
{
-#if !defined(CONFIG_X86_VSMP) && defined(CONFIG_SMP)
+#if !defined(CONFIG_X86_VSMP) && defined(CONFIG_SMP) && defined(CONFIG_PCI)
void __iomem *address;
unsigned int cfg, topology, node_shift, maxcpus;
@@ -221,6 +151,6 @@ void __init vsmp_init(void)
vsmp_cap_cpus();
- set_vsmp_pv_ops();
+ set_vsmp_ctl();
return;
}