x86: debugctlmsr context switch

[sfrench/cifs-2.6.git] / arch / x86 / kernel / process_64.c

diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 98956555450beff2c49d22eed79a63aecff87175..ae5eca17aa3c945628f122c44f155a53eb9ca78f 100644 (file)
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -1,6 +1,4 @@
 /*
- *  linux/arch/x86-64/kernel/process.c
- *
  *  Copyright (C) 1995  Linus Torvalds
  *
  *  Pentium III FXSR, SSE support
@@ -38,6 +36,7 @@
 #include <linux/notifier.h>
 #include <linux/kprobes.h>
 #include <linux/kdebug.h>
+#include <linux/tick.h>
 
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
@@ -73,13 +72,6 @@ void idle_notifier_register(struct notifier_block *n)
 {
        atomic_notifier_chain_register(&idle_notifier, n);
 }
-EXPORT_SYMBOL_GPL(idle_notifier_register);
-
-void idle_notifier_unregister(struct notifier_block *n)
-{
-       atomic_notifier_chain_unregister(&idle_notifier, n);
-}
-EXPORT_SYMBOL(idle_notifier_unregister);
 
 void enter_idle(void)
 {
@@ -117,11 +109,18 @@ static void default_idle(void)
        smp_mb();
        local_irq_disable();
        if (!need_resched()) {
-               /* Enables interrupts one instruction before HLT.
-                  x86 special cases this so there is no race. */
-               safe_halt();
-       } else
-               local_irq_enable();
+               ktime_t t0, t1;
+               u64 t0n, t1n;
+
+               t0 = ktime_get();
+               t0n = ktime_to_ns(t0);
+               safe_halt();    /* enables interrupts racelessly */
+               local_irq_disable();
+               t1 = ktime_get();
+               t1n = ktime_to_ns(t1);
+               sched_clock_idle_wakeup_event(t1n - t0n);
+       }
+       local_irq_enable();
        current_thread_info()->status |= TS_POLLING;
 }
 
@@ -136,6 +135,10 @@ static void poll_idle (void)
        cpu_relax();
 }
 
+static void do_nothing(void *unused)
+{
+}
+
 void cpu_idle_wait(void)
 {
        unsigned int cpu, this_cpu = get_cpu();
@@ -161,6 +164,13 @@ void cpu_idle_wait(void)
                                cpu_clear(cpu, map);
                }
                cpus_and(map, map, cpu_online_map);
+               /*
+                * We waited 1 sec, if a CPU still did not call idle
+                * it may be because it is in idle and not waking up
+                * because it has nothing to do.
+                * Give all the remaining CPUS a kick.
+                */
+               smp_call_function_mask(map, do_nothing, 0, 0);
        } while (!cpus_empty(map));
 
        set_cpus_allowed(current, tmp);
@@ -197,7 +207,7 @@ static inline void play_dead(void)
  * low exit latency (ie sit in a loop waiting for
  * somebody to say that they'd like to reschedule)
  */
-void cpu_idle (void)
+void cpu_idle(void)
 {
        current_thread_info()->status |= TS_POLLING;
        /* endless idle loop with no priority at all */
@@ -208,6 +218,8 @@ void cpu_idle (void)
                        if (__get_cpu_var(cpu_idle_state))
                                __get_cpu_var(cpu_idle_state) = 0;
 
+                       tick_nohz_stop_sched_tick();
+
                        rmb();
                        idle = pm_idle;
                        if (!idle)
@@ -228,6 +240,7 @@ void cpu_idle (void)
                        __exit_idle();
                }
 
+               tick_nohz_restart_sched_tick();
                preempt_enable_no_resched();
                schedule();
                preempt_disable();
@@ -451,11 +464,7 @@ static inline void set_32bit_tls(struct task_struct *t, int tls, u32 addr)
 
 static inline u32 read_32bit_tls(struct task_struct *t, int tls)
 {
-       struct desc_struct *desc = (void *)t->thread.tls_array;
-       desc += tls;
-       return desc->base0 | 
-               (((u32)desc->base1) << 16) | 
-               (((u32)desc->base2) << 24);
+       return get_desc_base(&t->thread.tls_array[tls]);
 }
 
 /*
@@ -515,7 +524,8 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long rsp,
        if (clone_flags & CLONE_SETTLS) {
 #ifdef CONFIG_IA32_EMULATION
                if (test_thread_flag(TIF_IA32))
-                       err = ia32_child_tls(p, childregs); 
+                       err = do_set_thread_area(p, -1,
+                               (struct user_desc __user *)childregs->rsi, 0);
                else                    
 #endif  
                        err = do_arch_prctl(p, ARCH_SET_FS, childregs->r8); 
@@ -545,6 +555,9 @@ static inline void __switch_to_xtra(struct task_struct *prev_p,
        prev = &prev_p->thread,
        next = &next_p->thread;
 
+       if (next->debugctlmsr != prev->debugctlmsr)
+               wrmsrl(MSR_IA32_DEBUGCTLMSR, next->debugctlmsr);
+
        if (test_tsk_thread_flag(next_p, TIF_DEBUG)) {
                loaddebug(next, 0);
                loaddebug(next, 1);
@@ -579,7 +592,7 @@ static inline void __switch_to_xtra(struct task_struct *prev_p,
  *
  * Kprobes not supported here. Set the probe on schedule instead.
  */
-__kprobes struct task_struct *
+struct task_struct *
 __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
 {
        struct thread_struct *prev = &prev_p->thread,
@@ -699,11 +712,6 @@ long sys_execve(char __user *name, char __user * __user *argv,
        if (IS_ERR(filename)) 
                return error;
        error = do_execve(filename, argv, envp, &regs); 
-       if (error == 0) {
-               task_lock(current);
-               current->ptrace &= ~PT_DTRACE;
-               task_unlock(current);
-       }
        putname(filename);
        return error;
 }
@@ -901,3 +909,10 @@ unsigned long arch_align_stack(unsigned long sp)
                sp -= get_random_int() % 8192;
        return sp & ~0xf;
 }
+
+unsigned long arch_randomize_brk(struct mm_struct *mm)
+{
+       unsigned long range_end = mm->brk + 0x02000000;
+       return randomize_range(mm->brk, range_end, 0) ? : mm->brk;
+}
+