v4.19.13 snapshot.
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
new file mode 100644
index 0000000..7d31192
--- /dev/null
+++ b/arch/x86/kernel/process.c
@@ -0,0 +1,858 @@
+// SPDX-License-Identifier: GPL-2.0
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/prctl.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/sched/idle.h>
+#include <linux/sched/debug.h>
+#include <linux/sched/task.h>
+#include <linux/sched/task_stack.h>
+#include <linux/init.h>
+#include <linux/export.h>
+#include <linux/pm.h>
+#include <linux/tick.h>
+#include <linux/random.h>
+#include <linux/user-return-notifier.h>
+#include <linux/dmi.h>
+#include <linux/utsname.h>
+#include <linux/stackprotector.h>
+#include <linux/cpuidle.h>
+#include <trace/events/power.h>
+#include <linux/hw_breakpoint.h>
+#include <asm/cpu.h>
+#include <asm/apic.h>
+#include <asm/syscalls.h>
+#include <linux/uaccess.h>
+#include <asm/mwait.h>
+#include <asm/fpu/internal.h>
+#include <asm/debugreg.h>
+#include <asm/nmi.h>
+#include <asm/tlbflush.h>
+#include <asm/mce.h>
+#include <asm/vm86.h>
+#include <asm/switch_to.h>
+#include <asm/desc.h>
+#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
+ * so they are allowed to end up in the .data..cacheline_aligned
+ * section. Since TSS's are completely CPU-local, we want them
+ * on exact cacheline boundaries, to eliminate cacheline ping-pong.
+ */
+__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
+ * privilege level. Since the init task never runs anything
+ * but ring 0 code, there is no need for a valid value here.
+ * Poison it.
+ */
+ .sp0 = (1UL << (BITS_PER_LONG-1)) + 1,
+
+ /*
+ * .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,
+
+#ifdef CONFIG_X86_32
+ .ss0 = __KERNEL_DS,
+ .ss1 = __KERNEL_CS,
+ .io_bitmap_base = INVALID_IO_BITMAP_OFFSET,
+#endif
+ },
+#ifdef CONFIG_X86_32
+ /*
+ * Note that the .io_bitmap member must be extra-big. This is because
+ * the CPU will access an additional byte beyond the end of the IO
+ * permission bitmap. The extra byte must be all 1 bits, and must
+ * be within the limit.
+ */
+ .io_bitmap = { [0 ... IO_BITMAP_LONGS] = ~0 },
+#endif
+};
+EXPORT_PER_CPU_SYMBOL(cpu_tss_rw);
+
+DEFINE_PER_CPU(bool, __tss_limit_invalid);
+EXPORT_PER_CPU_SYMBOL_GPL(__tss_limit_invalid);
+
+/*
+ * this gets called so that we can store lazy state into memory and copy the
+ * current task into the new thread.
+ */
+int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
+{
+ memcpy(dst, src, arch_task_struct_size);
+#ifdef CONFIG_VM86
+ dst->thread.vm86 = NULL;
+#endif
+
+ return fpu__copy(&dst->thread.fpu, &src->thread.fpu);
+}
+
+/*
+ * Free current thread data structures etc..
+ */
+void exit_thread(struct task_struct *tsk)
+{
+ struct thread_struct *t = &tsk->thread;
+ unsigned long *bp = t->io_bitmap_ptr;
+ struct fpu *fpu = &t->fpu;
+
+ if (bp) {
+ struct tss_struct *tss = &per_cpu(cpu_tss_rw, get_cpu());
+
+ t->io_bitmap_ptr = NULL;
+ clear_thread_flag(TIF_IO_BITMAP);
+ /*
+ * Careful, clear this in the TSS too:
+ */
+ memset(tss->io_bitmap, 0xff, t->io_bitmap_max);
+ t->io_bitmap_max = 0;
+ put_cpu();
+ kfree(bp);
+ }
+
+ free_vm86(t);
+
+ fpu__drop(fpu);
+}
+
+void flush_thread(void)
+{
+ struct task_struct *tsk = current;
+
+ flush_ptrace_hw_breakpoint(tsk);
+ memset(tsk->thread.tls_array, 0, sizeof(tsk->thread.tls_array));
+
+ fpu__clear(&tsk->thread.fpu);
+}
+
+void disable_TSC(void)
+{
+ preempt_disable();
+ if (!test_and_set_thread_flag(TIF_NOTSC))
+ /*
+ * Must flip the CPU state synchronously with
+ * TIF_NOTSC in the current running context.
+ */
+ cr4_set_bits(X86_CR4_TSD);
+ preempt_enable();
+}
+
+static void enable_TSC(void)
+{
+ preempt_disable();
+ if (test_and_clear_thread_flag(TIF_NOTSC))
+ /*
+ * Must flip the CPU state synchronously with
+ * TIF_NOTSC in the current running context.
+ */
+ cr4_clear_bits(X86_CR4_TSD);
+ preempt_enable();
+}
+
+int get_tsc_mode(unsigned long adr)
+{
+ unsigned int val;
+
+ if (test_thread_flag(TIF_NOTSC))
+ val = PR_TSC_SIGSEGV;
+ else
+ val = PR_TSC_ENABLE;
+
+ return put_user(val, (unsigned int __user *)adr);
+}
+
+int set_tsc_mode(unsigned int val)
+{
+ if (val == PR_TSC_SIGSEGV)
+ disable_TSC();
+ else if (val == PR_TSC_ENABLE)
+ enable_TSC();
+ else
+ return -EINVAL;
+
+ return 0;
+}
+
+DEFINE_PER_CPU(u64, msr_misc_features_shadow);
+
+static void set_cpuid_faulting(bool on)
+{
+ u64 msrval;
+
+ msrval = this_cpu_read(msr_misc_features_shadow);
+ msrval &= ~MSR_MISC_FEATURES_ENABLES_CPUID_FAULT;
+ msrval |= (on << MSR_MISC_FEATURES_ENABLES_CPUID_FAULT_BIT);
+ this_cpu_write(msr_misc_features_shadow, msrval);
+ wrmsrl(MSR_MISC_FEATURES_ENABLES, msrval);
+}
+
+static void disable_cpuid(void)
+{
+ preempt_disable();
+ if (!test_and_set_thread_flag(TIF_NOCPUID)) {
+ /*
+ * Must flip the CPU state synchronously with
+ * TIF_NOCPUID in the current running context.
+ */
+ set_cpuid_faulting(true);
+ }
+ preempt_enable();
+}
+
+static void enable_cpuid(void)
+{
+ preempt_disable();
+ if (test_and_clear_thread_flag(TIF_NOCPUID)) {
+ /*
+ * Must flip the CPU state synchronously with
+ * TIF_NOCPUID in the current running context.
+ */
+ set_cpuid_faulting(false);
+ }
+ preempt_enable();
+}
+
+static int get_cpuid_mode(void)
+{
+ return !test_thread_flag(TIF_NOCPUID);
+}
+
+static int set_cpuid_mode(struct task_struct *task, unsigned long cpuid_enabled)
+{
+ if (!static_cpu_has(X86_FEATURE_CPUID_FAULT))
+ return -ENODEV;
+
+ if (cpuid_enabled)
+ enable_cpuid();
+ else
+ disable_cpuid();
+
+ return 0;
+}
+
+/*
+ * Called immediately after a successful exec.
+ */
+void arch_setup_new_exec(void)
+{
+ /* If cpuid was previously disabled for this task, re-enable it. */
+ if (test_thread_flag(TIF_NOCPUID))
+ enable_cpuid();
+}
+
+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.
+ * Normally this is 128 bytes or less:
+ */
+ memcpy(tss->io_bitmap, next->io_bitmap_ptr,
+ max(prev->io_bitmap_max, next->io_bitmap_max));
+ /*
+ * Make sure that the TSS limit is correct for the CPU
+ * to notice the IO bitmap.
+ */
+ refresh_tss_limit();
+ } else if (tifp & _TIF_IO_BITMAP) {
+ /*
+ * Clear any possible leftover bits:
+ */
+ memset(tss->io_bitmap, 0xff, prev->io_bitmap_max);
+ }
+}
+
+#ifdef CONFIG_SMP
+
+struct ssb_state {
+ struct ssb_state *shared_state;
+ raw_spinlock_t lock;
+ unsigned int disable_state;
+ unsigned long local_state;
+};
+
+#define LSTATE_SSB 0
+
+static DEFINE_PER_CPU(struct ssb_state, ssb_state);
+
+void speculative_store_bypass_ht_init(void)
+{
+ struct ssb_state *st = this_cpu_ptr(&ssb_state);
+ unsigned int this_cpu = smp_processor_id();
+ unsigned int cpu;
+
+ st->local_state = 0;
+
+ /*
+ * Shared state setup happens once on the first bringup
+ * of the CPU. It's not destroyed on CPU hotunplug.
+ */
+ if (st->shared_state)
+ return;
+
+ raw_spin_lock_init(&st->lock);
+
+ /*
+ * Go over HT siblings and check whether one of them has set up the
+ * shared state pointer already.
+ */
+ for_each_cpu(cpu, topology_sibling_cpumask(this_cpu)) {
+ if (cpu == this_cpu)
+ continue;
+
+ if (!per_cpu(ssb_state, cpu).shared_state)
+ continue;
+
+ /* Link it to the state of the sibling: */
+ st->shared_state = per_cpu(ssb_state, cpu).shared_state;
+ return;
+ }
+
+ /*
+ * First HT sibling to come up on the core. Link shared state of
+ * the first HT sibling to itself. The siblings on the same core
+ * which come up later will see the shared state pointer and link
+ * themself to the state of this CPU.
+ */
+ st->shared_state = st;
+}
+
+/*
+ * Logic is: First HT sibling enables SSBD for both siblings in the core
+ * and last sibling to disable it, disables it for the whole core. This how
+ * MSR_SPEC_CTRL works in "hardware":
+ *
+ * CORE_SPEC_CTRL = THREAD0_SPEC_CTRL | THREAD1_SPEC_CTRL
+ */
+static __always_inline void amd_set_core_ssb_state(unsigned long tifn)
+{
+ struct ssb_state *st = this_cpu_ptr(&ssb_state);
+ u64 msr = x86_amd_ls_cfg_base;
+
+ if (!static_cpu_has(X86_FEATURE_ZEN)) {
+ msr |= ssbd_tif_to_amd_ls_cfg(tifn);
+ wrmsrl(MSR_AMD64_LS_CFG, msr);
+ return;
+ }
+
+ if (tifn & _TIF_SSBD) {
+ /*
+ * Since this can race with prctl(), block reentry on the
+ * same CPU.
+ */
+ if (__test_and_set_bit(LSTATE_SSB, &st->local_state))
+ return;
+
+ msr |= x86_amd_ls_cfg_ssbd_mask;
+
+ raw_spin_lock(&st->shared_state->lock);
+ /* First sibling enables SSBD: */
+ if (!st->shared_state->disable_state)
+ wrmsrl(MSR_AMD64_LS_CFG, msr);
+ st->shared_state->disable_state++;
+ raw_spin_unlock(&st->shared_state->lock);
+ } else {
+ if (!__test_and_clear_bit(LSTATE_SSB, &st->local_state))
+ return;
+
+ raw_spin_lock(&st->shared_state->lock);
+ st->shared_state->disable_state--;
+ if (!st->shared_state->disable_state)
+ wrmsrl(MSR_AMD64_LS_CFG, msr);
+ raw_spin_unlock(&st->shared_state->lock);
+ }
+}
+#else
+static __always_inline void amd_set_core_ssb_state(unsigned long tifn)
+{
+ u64 msr = x86_amd_ls_cfg_base | ssbd_tif_to_amd_ls_cfg(tifn);
+
+ wrmsrl(MSR_AMD64_LS_CFG, msr);
+}
+#endif
+
+static __always_inline void amd_set_ssb_virt_state(unsigned long tifn)
+{
+ /*
+ * SSBD has the same definition in SPEC_CTRL and VIRT_SPEC_CTRL,
+ * so ssbd_tif_to_spec_ctrl() just works.
+ */
+ wrmsrl(MSR_AMD64_VIRT_SPEC_CTRL, ssbd_tif_to_spec_ctrl(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)
+{
+ 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);
+ }
+
+ if (updmsr)
+ wrmsrl(MSR_IA32_SPEC_CTRL, msr);
+}
+
+static unsigned long speculation_ctrl_update_tif(struct task_struct *tsk)
+{
+ 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 speculation_ctrl_update(unsigned long tif)
+{
+ /* Forced update. Make sure all relevant TIF flags are different */
+ preempt_disable();
+ __speculation_ctrl_update(~tif, tif);
+ preempt_enable();
+}
+
+/* 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;
+
+ prev = &prev_p->thread;
+ next = &next_p->thread;
+
+ tifn = READ_ONCE(task_thread_info(next_p)->flags);
+ tifp = READ_ONCE(task_thread_info(prev_p)->flags);
+ switch_to_bitmap(prev, next, tifp, tifn);
+
+ propagate_user_return_notify(prev_p, next_p);
+
+ if ((tifp & _TIF_BLOCKSTEP || tifn & _TIF_BLOCKSTEP) &&
+ arch_has_block_step()) {
+ unsigned long debugctl, msk;
+
+ rdmsrl(MSR_IA32_DEBUGCTLMSR, debugctl);
+ debugctl &= ~DEBUGCTLMSR_BTF;
+ msk = tifn & _TIF_BLOCKSTEP;
+ debugctl |= (msk >> TIF_BLOCKSTEP) << DEBUGCTLMSR_BTF_SHIFT;
+ wrmsrl(MSR_IA32_DEBUGCTLMSR, debugctl);
+ }
+
+ if ((tifp ^ tifn) & _TIF_NOTSC)
+ cr4_toggle_bits_irqsoff(X86_CR4_TSD);
+
+ if ((tifp ^ tifn) & _TIF_NOCPUID)
+ set_cpuid_faulting(!!(tifn & _TIF_NOCPUID));
+
+ 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);
+ }
+}
+
+/*
+ * Idle related variables and functions
+ */
+unsigned long boot_option_idle_override = IDLE_NO_OVERRIDE;
+EXPORT_SYMBOL(boot_option_idle_override);
+
+static void (*x86_idle)(void);
+
+#ifndef CONFIG_SMP
+static inline void play_dead(void)
+{
+ BUG();
+}
+#endif
+
+void arch_cpu_idle_enter(void)
+{
+ tsc_verify_tsc_adjust(false);
+ local_touch_nmi();
+}
+
+void arch_cpu_idle_dead(void)
+{
+ play_dead();
+}
+
+/*
+ * Called from the generic idle code.
+ */
+void arch_cpu_idle(void)
+{
+ x86_idle();
+}
+
+/*
+ * We use this if we don't have any better idle routine..
+ */
+void __cpuidle default_idle(void)
+{
+ trace_cpu_idle_rcuidle(1, smp_processor_id());
+ safe_halt();
+ trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
+}
+#ifdef CONFIG_APM_MODULE
+EXPORT_SYMBOL(default_idle);
+#endif
+
+#ifdef CONFIG_XEN
+bool xen_set_default_idle(void)
+{
+ bool ret = !!x86_idle;
+
+ x86_idle = default_idle;
+
+ return ret;
+}
+#endif
+
+void stop_this_cpu(void *dummy)
+{
+ local_irq_disable();
+ /*
+ * Remove this CPU:
+ */
+ set_cpu_online(smp_processor_id(), false);
+ 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 native_halt() so that memory contents don't change
+ * (stack usage and variables) after possibly issuing the
+ * native_wbinvd() above.
+ */
+ native_halt();
+ }
+}
+
+/*
+ * AMD Erratum 400 aware idle routine. We handle it the same way as C3 power
+ * states (local apic timer and TSC stop).
+ */
+static void amd_e400_idle(void)
+{
+ /*
+ * We cannot use static_cpu_has_bug() here because X86_BUG_AMD_APIC_C1E
+ * gets set after static_cpu_has() places have been converted via
+ * alternatives.
+ */
+ if (!boot_cpu_has_bug(X86_BUG_AMD_APIC_C1E)) {
+ default_idle();
+ return;
+ }
+
+ tick_broadcast_enter();
+
+ default_idle();
+
+ /*
+ * The switch back from broadcast mode needs to be called with
+ * interrupts disabled.
+ */
+ local_irq_disable();
+ tick_broadcast_exit();
+ local_irq_enable();
+}
+
+/*
+ * Intel Core2 and older machines prefer MWAIT over HALT for C1.
+ * We can't rely on cpuidle installing MWAIT, because it will not load
+ * on systems that support only C1 -- so the boot default must be MWAIT.
+ *
+ * Some AMD machines are the opposite, they depend on using HALT.
+ *
+ * So for default C1, which is used during boot until cpuidle loads,
+ * use MWAIT-C1 on Intel HW that has it, else use HALT.
+ */
+static int prefer_mwait_c1_over_halt(const struct cpuinfo_x86 *c)
+{
+ if (c->x86_vendor != X86_VENDOR_INTEL)
+ return 0;
+
+ if (!cpu_has(c, X86_FEATURE_MWAIT) || static_cpu_has_bug(X86_BUG_MONITOR))
+ return 0;
+
+ return 1;
+}
+
+/*
+ * MONITOR/MWAIT with no hints, used for default C1 state. This invokes MWAIT
+ * with interrupts enabled and no flags, which is backwards compatible with the
+ * original MWAIT implementation.
+ */
+static __cpuidle void mwait_idle(void)
+{
+ if (!current_set_polling_and_test()) {
+ trace_cpu_idle_rcuidle(1, smp_processor_id());
+ if (this_cpu_has(X86_BUG_CLFLUSH_MONITOR)) {
+ mb(); /* quirk */
+ clflush((void *)¤t_thread_info()->flags);
+ mb(); /* quirk */
+ }
+
+ __monitor((void *)¤t_thread_info()->flags, 0, 0);
+ if (!need_resched())
+ __sti_mwait(0, 0);
+ else
+ local_irq_enable();
+ trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
+ } else {
+ local_irq_enable();
+ }
+ __current_clr_polling();
+}
+
+void select_idle_routine(const struct cpuinfo_x86 *c)
+{
+#ifdef CONFIG_SMP
+ if (boot_option_idle_override == IDLE_POLL && smp_num_siblings > 1)
+ pr_warn_once("WARNING: polling idle and HT enabled, performance may degrade\n");
+#endif
+ if (x86_idle || boot_option_idle_override == IDLE_POLL)
+ return;
+
+ if (boot_cpu_has_bug(X86_BUG_AMD_E400)) {
+ pr_info("using AMD E400 aware idle routine\n");
+ x86_idle = amd_e400_idle;
+ } else if (prefer_mwait_c1_over_halt(c)) {
+ pr_info("using mwait in idle threads\n");
+ x86_idle = mwait_idle;
+ } else
+ x86_idle = default_idle;
+}
+
+void amd_e400_c1e_apic_setup(void)
+{
+ if (boot_cpu_has_bug(X86_BUG_AMD_APIC_C1E)) {
+ pr_info("Switch to broadcast mode on CPU%d\n", smp_processor_id());
+ local_irq_disable();
+ tick_broadcast_force();
+ local_irq_enable();
+ }
+}
+
+void __init arch_post_acpi_subsys_init(void)
+{
+ u32 lo, hi;
+
+ if (!boot_cpu_has_bug(X86_BUG_AMD_E400))
+ return;
+
+ /*
+ * AMD E400 detection needs to happen after ACPI has been enabled. If
+ * the machine is affected K8_INTP_C1E_ACTIVE_MASK bits are set in
+ * MSR_K8_INT_PENDING_MSG.
+ */
+ rdmsr(MSR_K8_INT_PENDING_MSG, lo, hi);
+ if (!(lo & K8_INTP_C1E_ACTIVE_MASK))
+ return;
+
+ boot_cpu_set_bug(X86_BUG_AMD_APIC_C1E);
+
+ if (!boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
+ mark_tsc_unstable("TSC halt in AMD C1E");
+ pr_info("System has AMD C1E enabled\n");
+}
+
+static int __init idle_setup(char *str)
+{
+ if (!str)
+ return -EINVAL;
+
+ if (!strcmp(str, "poll")) {
+ pr_info("using polling idle threads\n");
+ boot_option_idle_override = IDLE_POLL;
+ cpu_idle_poll_ctrl(true);
+ } else if (!strcmp(str, "halt")) {
+ /*
+ * When the boot option of idle=halt is added, halt is
+ * forced to be used for CPU idle. In such case CPU C2/C3
+ * won't be used again.
+ * To continue to load the CPU idle driver, don't touch
+ * the boot_option_idle_override.
+ */
+ x86_idle = default_idle;
+ boot_option_idle_override = IDLE_HALT;
+ } else if (!strcmp(str, "nomwait")) {
+ /*
+ * If the boot option of "idle=nomwait" is added,
+ * it means that mwait will be disabled for CPU C2/C3
+ * states. In such case it won't touch the variable
+ * of boot_option_idle_override.
+ */
+ boot_option_idle_override = IDLE_NOMWAIT;
+ } else
+ return -1;
+
+ return 0;
+}
+early_param("idle", idle_setup);
+
+unsigned long arch_align_stack(unsigned long sp)
+{
+ if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
+ sp -= get_random_int() % 8192;
+ return sp & ~0xf;
+}
+
+unsigned long arch_randomize_brk(struct mm_struct *mm)
+{
+ return randomize_page(mm->brk, 0x02000000);
+}
+
+/*
+ * Called from fs/proc with a reference on @p to find the function
+ * which called into schedule(). This needs to be done carefully
+ * because the task might wake up and we might look at a stack
+ * changing under us.
+ */
+unsigned long get_wchan(struct task_struct *p)
+{
+ unsigned long start, bottom, top, sp, fp, ip, ret = 0;
+ int count = 0;
+
+ if (!p || p == current || p->state == TASK_RUNNING)
+ return 0;
+
+ if (!try_get_task_stack(p))
+ return 0;
+
+ start = (unsigned long)task_stack_page(p);
+ if (!start)
+ goto out;
+
+ /*
+ * Layout of the stack page:
+ *
+ * ----------- topmax = start + THREAD_SIZE - sizeof(unsigned long)
+ * PADDING
+ * ----------- top = topmax - TOP_OF_KERNEL_STACK_PADDING
+ * stack
+ * ----------- bottom = start
+ *
+ * The tasks stack pointer points at the location where the
+ * framepointer is stored. The data on the stack is:
+ * ... IP FP ... IP FP
+ *
+ * We need to read FP and IP, so we need to adjust the upper
+ * bound by another unsigned long.
+ */
+ top = start + THREAD_SIZE - TOP_OF_KERNEL_STACK_PADDING;
+ top -= 2 * sizeof(unsigned long);
+ bottom = start;
+
+ sp = READ_ONCE(p->thread.sp);
+ if (sp < bottom || sp > top)
+ goto out;
+
+ fp = READ_ONCE_NOCHECK(((struct inactive_task_frame *)sp)->bp);
+ do {
+ if (fp < bottom || fp > top)
+ goto out;
+ ip = READ_ONCE_NOCHECK(*(unsigned long *)(fp + sizeof(unsigned long)));
+ if (!in_sched_functions(ip)) {
+ ret = ip;
+ goto out;
+ }
+ fp = READ_ONCE_NOCHECK(*(unsigned long *)fp);
+ } while (count++ < 16 && p->state != TASK_RUNNING);
+
+out:
+ put_task_stack(p);
+ return ret;
+}
+
+long do_arch_prctl_common(struct task_struct *task, int option,
+ unsigned long cpuid_enabled)
+{
+ switch (option) {
+ case ARCH_GET_CPUID:
+ return get_cpuid_mode();
+ case ARCH_SET_CPUID:
+ return set_cpuid_mode(task, cpuid_enabled);
+ }
+
+ return -EINVAL;
+}