Merge master.kernel.org:/home/rmk/linux-2.6-arm

[safe/jmp/linux-2.6] / arch / x86 / kernel / process_64.c

diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index e8a9aaf..eb62cbc 100644 (file)
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -14,8 +14,6 @@
  * This file handles the architecture-dependent parts of process handling..
  */
 
-#include <stdarg.h>
-
 #include <linux/stackprotector.h>
 #include <linux/cpu.h>
 #include <linux/errno.h>
@@ -32,7 +30,6 @@
 #include <linux/delay.h>
 #include <linux/module.h>
 #include <linux/ptrace.h>
-#include <linux/random.h>
 #include <linux/notifier.h>
 #include <linux/kprobes.h>
 #include <linux/kdebug.h>
@@ -58,9 +55,6 @@
 
 asmlinkage extern void ret_from_fork(void);
 
-DEFINE_PER_CPU(struct task_struct *, current_task) = &init_task;
-EXPORT_PER_CPU_SYMBOL(current_task);
-
 DEFINE_PER_CPU(unsigned long, old_rsp);
 static DEFINE_PER_CPU(unsigned char, is_idle);
 
@@ -278,7 +272,7 @@ void prepare_to_copy(struct task_struct *tsk)
        unlazy_fpu(tsk);
 }
 
-int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
+int copy_thread(unsigned long clone_flags, unsigned long sp,
                unsigned long unused,
        struct task_struct *p, struct pt_regs *regs)
 {
@@ -335,7 +329,8 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
                        goto out;
        }
 
-       ds_copy_thread(p, me);
+       clear_tsk_thread_flag(p, TIF_DS_AREA_MSR);
+       p->thread.ds_ctx = NULL;
 
        clear_tsk_thread_flag(p, TIF_DEBUGCTLMSR);
        p->thread.debugctlmsr = 0;
@@ -388,9 +383,17 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
        int cpu = smp_processor_id();
        struct tss_struct *tss = &per_cpu(init_tss, cpu);
        unsigned fsindex, gsindex;
+       bool preload_fpu;
+
+       /*
+        * If the task has used fpu the last 5 timeslices, just do a full
+        * restore of the math state immediately to avoid the trap; the
+        * chances of needing FPU soon are obviously high now
+        */
+       preload_fpu = tsk_used_math(next_p) && next_p->fpu_counter > 5;
 
        /* we're going to use this soon, after a few expensive things */
-       if (next_p->fpu_counter > 5)
+       if (preload_fpu)
                prefetch(next->xstate);
 
        /*
@@ -421,6 +424,13 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
 
        load_TLS(next, cpu);
 
+       /* Must be after DS reload */
+       unlazy_fpu(prev_p);
+
+       /* Make sure cpu is ready for new context */
+       if (preload_fpu)
+               clts();
+
        /*
         * Leave lazy mode, flushing any hypercalls made here.
         * This must be done before restoring TLS segments so
@@ -461,9 +471,6 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
                wrmsrl(MSR_KERNEL_GS_BASE, next->gs);
        prev->gsindex = gsindex;
 
-       /* Must be after DS reload */
-       unlazy_fpu(prev_p);
-
        /*
         * Switch the PDA and FPU contexts.
         */
@@ -482,15 +489,12 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
                     task_thread_info(prev_p)->flags & _TIF_WORK_CTXSW_PREV))
                __switch_to_xtra(prev_p, next_p, tss);
 
-       /* If the task has used fpu the last 5 timeslices, just do a full
-        * restore of the math state immediately to avoid the trap; the
-        * chances of needing FPU soon are obviously high now
-        *
-        * tsk_used_math() checks prevent calling math_state_restore(),
-        * which can sleep in the case of !tsk_used_math()
+       /*
+        * Preload the FPU context, now that we've determined that the
+        * task is likely to be using it. 
         */
-       if (tsk_used_math(next_p) && next_p->fpu_counter > 5)
-               math_state_restore();
+       if (preload_fpu)
+               __math_state_restore();
        return prev_p;
 }
 
@@ -660,15 +664,8 @@ long sys_arch_prctl(int code, unsigned long addr)
        return do_arch_prctl(current, code, addr);
 }
 
-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)
+unsigned long KSTK_ESP(struct task_struct *task)
 {
-       unsigned long range_end = mm->brk + 0x02000000;
-       return randomize_range(mm->brk, range_end, 0) ? : mm->brk;
+       return (test_tsk_thread_flag(task, TIF_IA32)) ?
+                       (task_pt_regs(task)->sp) : ((task)->thread.usersp);
 }