vserver 2.0 rc7

[linux-2.6.git] / arch / i386 / kernel / process.c

diff --git a/arch/i386/kernel/process.c b/arch/i386/kernel/process.c
index 28b0d7b..96e3ea6 100644 (file)
--- a/arch/i386/kernel/process.c
+++ b/arch/i386/kernel/process.c
@@ -36,6 +36,7 @@
 #include <linux/module.h>
 #include <linux/kallsyms.h>
 #include <linux/ptrace.h>
+#include <linux/random.h>
 
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
@@ -55,7 +56,7 @@
 
 asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
 
-int hlt_counter;
+static int hlt_counter;
 
 unsigned long boot_option_idle_override = 0;
 EXPORT_SYMBOL(boot_option_idle_override);
@@ -72,7 +73,7 @@ unsigned long thread_saved_pc(struct task_struct *tsk)
  * Powermanagement idle function, if any..
  */
 void (*pm_idle)(void);
-static cpumask_t cpu_idle_map;
+static DEFINE_PER_CPU(unsigned int, cpu_idle_state);
 
 void disable_hlt(void)
 {
@@ -145,22 +146,21 @@ static void poll_idle (void)
  */
 void cpu_idle (void)
 {
-       int cpu = _smp_processor_id();
-
        /* endless idle loop with no priority at all */
        while (1) {
                while (!need_resched()) {
                        void (*idle)(void);
 
-                       if (cpu_isset(cpu, cpu_idle_map))
-                               cpu_clear(cpu, cpu_idle_map);
+                       if (__get_cpu_var(cpu_idle_state))
+                               __get_cpu_var(cpu_idle_state) = 0;
+
                        rmb();
                        idle = pm_idle;
 
                        if (!idle)
                                idle = default_idle;
 
-                       irq_stat[cpu].idle_timestamp = jiffies;
+                       __get_cpu_var(irq_stat).idle_timestamp = jiffies;
                        idle();
                }
                schedule();
@@ -169,16 +169,28 @@ void cpu_idle (void)
 
 void cpu_idle_wait(void)
 {
-       int cpu;
+       unsigned int cpu, this_cpu = get_cpu();
        cpumask_t map;
 
-       for_each_online_cpu(cpu)
-               cpu_set(cpu, cpu_idle_map);
+       set_cpus_allowed(current, cpumask_of_cpu(this_cpu));
+       put_cpu();
+
+       cpus_clear(map);
+       for_each_online_cpu(cpu) {
+               per_cpu(cpu_idle_state, cpu) = 1;
+               cpu_set(cpu, map);
+       }
+
+       __get_cpu_var(cpu_idle_state) = 0;
 
        wmb();
        do {
                ssleep(1);
-               cpus_and(map, cpu_idle_map, cpu_online_map);
+               for_each_online_cpu(cpu) {
+                       if (cpu_isset(cpu, map) && !per_cpu(cpu_idle_state, cpu))
+                               cpu_clear(cpu, map);
+               }
+               cpus_and(map, map, cpu_online_map);
        } while (!cpus_empty(map));
 }
 EXPORT_SYMBOL_GPL(cpu_idle_wait);
@@ -388,6 +400,17 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long esp,
        int err;
 
        childregs = ((struct pt_regs *) (THREAD_SIZE + (unsigned long) p->thread_info)) - 1;
+       /*
+        * The below -8 is to reserve 8 bytes on top of the ring0 stack.
+        * This is necessary to guarantee that the entire "struct pt_regs"
+        * is accessable even if the CPU haven't stored the SS/ESP registers
+        * on the stack (interrupt gate does not save these registers
+        * when switching to the same priv ring).
+        * Therefore beware: accessing the xss/esp fields of the
+        * "struct pt_regs" is possible, but they may contain the
+        * completely wrong values.
+        */
+       childregs = (struct pt_regs *) ((unsigned long) childregs - 8);
        *childregs = *regs;
        childregs->eax = 0;
        childregs->esp = esp;
@@ -536,13 +559,6 @@ handle_io_bitmap(struct thread_struct *next, struct tss_struct *tss)
         */
        tss->io_bitmap_base = INVALID_IO_BITMAP_OFFSET_LAZY;
 }
-/*
- * This special macro can be used to load a debugging register
- */
-#define loaddebug(thread,register) \
-               __asm__("movl %0,%%db" #register  \
-                       : /* no output */ \
-                       :"r" (thread->debugreg[register]))
 
 /*
  *     switch_to(x,yn) should switch tasks from x to y.
@@ -596,8 +612,8 @@ struct task_struct fastcall * __switch_to(struct task_struct *prev_p, struct tas
         * Save away %fs and %gs. No need to save %es and %ds, as
         * those are always kernel segments while inside the kernel.
         */
-       asm volatile("movl %%fs,%0":"=m" (*(int *)&prev->fs));
-       asm volatile("movl %%gs,%0":"=m" (*(int *)&prev->gs));
+       asm volatile("mov %%fs,%0":"=m" (prev->fs));
+       asm volatile("mov %%gs,%0":"=m" (prev->gs));
 
        /*
         * Restore %fs and %gs if needed.
@@ -828,3 +844,9 @@ asmlinkage int sys_get_thread_area(struct user_desc __user *u_info)
        return 0;
 }
 
+unsigned long arch_align_stack(unsigned long sp)
+{
+       if (randomize_va_space)
+               sp -= get_random_int() % 8192;
+       return sp & ~0xf;
+}