1 files changed, 76 insertions, 4 deletions

diff --git a/arch/x86_64/kernel/process.c b/arch/x86_64/kernel/process.c
index 761b6d35e338..7577f9d7a75d 100644
--- a/arch/x86_64/kernel/process.c
+++ b/arch/x86_64/kernel/process.c
@@ -8,7 +8,8 @@
  * 
  *  X86-64 port
  *      Andi Kleen.
- * 
+ *
+ *      CPU hotplug support - ashok.raj@intel.com
  *  $Id: process.c,v 1.38 2002/01/15 10:08:03 ak Exp $
  */
 
@@ -18,6 +19,7 @@
 
 #include <stdarg.h>
 
+#include <linux/cpu.h>
 #include <linux/errno.h>
 #include <linux/sched.h>
 #include <linux/kernel.h>
@@ -34,6 +36,7 @@
 #include <linux/ptrace.h>
 #include <linux/utsname.h>
 #include <linux/random.h>
+#include <linux/kprobes.h>
 
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
@@ -153,6 +156,29 @@ void cpu_idle_wait(void)
 }
 EXPORT_SYMBOL_GPL(cpu_idle_wait);
 
+#ifdef CONFIG_HOTPLUG_CPU
+DECLARE_PER_CPU(int, cpu_state);
+
+#include <asm/nmi.h>
+/* We don't actually take CPU down, just spin without interrupts. */
+static inline void play_dead(void)
+{
+        idle_task_exit();
+        wbinvd();
+        mb();
+        /* Ack it */
+        __get_cpu_var(cpu_state) = CPU_DEAD;
+
+        while (1)
+                safe_halt();
+}
+#else
+static inline void play_dead(void)
+{
+        BUG();
+}
+#endif /* CONFIG_HOTPLUG_CPU */
+
 /*
  * The idle thread. There's no useful work to be
  * done, so just try to conserve power and have a
@@ -173,6 +199,8 @@ void cpu_idle (void)
                         idle = pm_idle;
                         if (!idle)
                                 idle = default_idle;
+                        if (cpu_is_offline(smp_processor_id()))
+                                play_dead();
                         idle();
                 }
 
@@ -203,7 +231,7 @@ static void mwait_idle(void)
         }
 }
 
-void __init select_idle_routine(const struct cpuinfo_x86 *c)
+void __cpuinit select_idle_routine(const struct cpuinfo_x86 *c)
 {
         static int printed;
         if (cpu_has(c, X86_FEATURE_MWAIT)) {
@@ -293,6 +321,14 @@ void exit_thread(void)
 {
         struct task_struct *me = current;
         struct thread_struct *t = &me->thread;
+
+        /*
+         * Remove function-return probe instances associated with this task
+         * and put them back on the free list. Do not insert an exit probe for
+         * this function, it will be disabled by kprobe_flush_task if you do.
+         */
+        kprobe_flush_task(me);
+
         if (me->thread.io_bitmap_ptr) { 
                 struct tss_struct *tss = &per_cpu(init_tss, get_cpu());
 
@@ -312,6 +348,13 @@ void flush_thread(void)
         struct task_struct *tsk = current;
         struct thread_info *t = current_thread_info();
 
+        /*
+         * Remove function-return probe instances associated with this task
+         * and put them back on the free list. Do not insert an exit probe for
+         * this function, it will be disabled by kprobe_flush_task if you do.
+         */
+        kprobe_flush_task(tsk);
+
         if (t->flags & _TIF_ABI_PENDING)
                 t->flags ^= (_TIF_ABI_PENDING | _TIF_IA32);
 
@@ -439,6 +482,33 @@ out:
 }
 
 /*
+ * This function selects if the context switch from prev to next
+ * has to tweak the TSC disable bit in the cr4.
+ */
+static inline void disable_tsc(struct task_struct *prev_p,
+                               struct task_struct *next_p)
+{
+        struct thread_info *prev, *next;
+
+        /*
+         * gcc should eliminate the ->thread_info dereference if
+         * has_secure_computing returns 0 at compile time (SECCOMP=n).
+         */
+        prev = prev_p->thread_info;
+        next = next_p->thread_info;
+
+        if (has_secure_computing(prev) || has_secure_computing(next)) {
+                /* slow path here */
+                if (has_secure_computing(prev) &&
+                    !has_secure_computing(next)) {
+                        write_cr4(read_cr4() & ~X86_CR4_TSD);
+                } else if (!has_secure_computing(prev) &&
+                           has_secure_computing(next))
+                        write_cr4(read_cr4() | X86_CR4_TSD);
+        }
+}
+
+/*
  * This special macro can be used to load a debugging register
  */
 #define loaddebug(thread,r) set_debug(thread->debugreg ## r, r)
@@ -556,6 +626,8 @@ struct task_struct *__switch_to(struct task_struct *prev_p, struct task_struct *
                 }
         }
 
+        disable_tsc(prev_p, next_p);
+
         return prev_p;
 }
 
@@ -656,7 +728,7 @@ long do_arch_prctl(struct task_struct *task, int code, unsigned long addr)
 
         switch (code) { 
         case ARCH_SET_GS:
-                if (addr >= TASK_SIZE) 
+                if (addr >= TASK_SIZE_OF(task))
                         return -EPERM; 
                 cpu = get_cpu();
                 /* handle small bases via the GDT because that's faster to 
@@ -682,7 +754,7 @@ long do_arch_prctl(struct task_struct *task, int code, unsigned long addr)
         case ARCH_SET_FS:
                 /* Not strictly needed for fs, but do it for symmetry
                    with gs */
-                if (addr >= TASK_SIZE)
+                if (addr >= TASK_SIZE_OF(task))
                         return -EPERM; 
                 cpu = get_cpu();
                 /* handle small bases via the GDT because that's faster to