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Diffstat (limited to 'arch/x86_64/kernel/process.c')
-rw-r--r--arch/x86_64/kernel/process.c128
1 files changed, 81 insertions, 47 deletions
diff --git a/arch/x86_64/kernel/process.c b/arch/x86_64/kernel/process.c
index fb903e65e079..458006ae19f3 100644
--- a/arch/x86_64/kernel/process.c
+++ b/arch/x86_64/kernel/process.c
@@ -10,7 +10,6 @@
* Andi Kleen.
*
* CPU hotplug support - ashok.raj@intel.com
- * $Id: process.c,v 1.38 2002/01/15 10:08:03 ak Exp $
*/
/*
@@ -64,6 +63,7 @@ EXPORT_SYMBOL(boot_option_idle_override);
* Powermanagement idle function, if any..
*/
void (*pm_idle)(void);
+EXPORT_SYMBOL(pm_idle);
static DEFINE_PER_CPU(unsigned int, cpu_idle_state);
static ATOMIC_NOTIFIER_HEAD(idle_notifier);
@@ -80,25 +80,25 @@ void idle_notifier_unregister(struct notifier_block *n)
}
EXPORT_SYMBOL(idle_notifier_unregister);
-enum idle_state { CPU_IDLE, CPU_NOT_IDLE };
-static DEFINE_PER_CPU(enum idle_state, idle_state) = CPU_NOT_IDLE;
-
void enter_idle(void)
{
- __get_cpu_var(idle_state) = CPU_IDLE;
+ write_pda(isidle, 1);
atomic_notifier_call_chain(&idle_notifier, IDLE_START, NULL);
}
static void __exit_idle(void)
{
- __get_cpu_var(idle_state) = CPU_NOT_IDLE;
+ if (read_pda(isidle) == 0)
+ return;
+ write_pda(isidle, 0);
atomic_notifier_call_chain(&idle_notifier, IDLE_END, NULL);
}
/* Called from interrupts to signify idle end */
void exit_idle(void)
{
- if (current->pid | read_pda(irqcount))
+ /* idle loop has pid 0 */
+ if (current->pid)
return;
__exit_idle();
}
@@ -111,7 +111,7 @@ static void default_idle(void)
{
local_irq_enable();
- clear_thread_flag(TIF_POLLING_NRFLAG);
+ current_thread_info()->status &= ~TS_POLLING;
smp_mb__after_clear_bit();
while (!need_resched()) {
local_irq_disable();
@@ -120,7 +120,7 @@ static void default_idle(void)
else
local_irq_enable();
}
- set_thread_flag(TIF_POLLING_NRFLAG);
+ current_thread_info()->status |= TS_POLLING;
}
/*
@@ -203,8 +203,7 @@ static inline void play_dead(void)
*/
void cpu_idle (void)
{
- set_thread_flag(TIF_POLLING_NRFLAG);
-
+ current_thread_info()->status |= TS_POLLING;
/* endless idle loop with no priority at all */
while (1) {
while (!need_resched()) {
@@ -221,6 +220,9 @@ void cpu_idle (void)
play_dead();
enter_idle();
idle();
+ /* In many cases the interrupt that ended idle
+ has already called exit_idle. But some idle
+ loops can be woken up without interrupt. */
__exit_idle();
}
@@ -297,7 +299,7 @@ void __show_regs(struct pt_regs * regs)
system_utsname.version);
printk("RIP: %04lx:[<%016lx>] ", regs->cs & 0xffff, regs->rip);
printk_address(regs->rip);
- printk("\nRSP: %04lx:%016lx EFLAGS: %08lx\n", regs->ss, regs->rsp,
+ printk("RSP: %04lx:%016lx EFLAGS: %08lx\n", regs->ss, regs->rsp,
regs->eflags);
printk("RAX: %016lx RBX: %016lx RCX: %016lx\n",
regs->rax, regs->rbx, regs->rcx);
@@ -335,7 +337,7 @@ void show_regs(struct pt_regs *regs)
{
printk("CPU %d:", smp_processor_id());
__show_regs(regs);
- show_trace(&regs->rsp);
+ show_trace(NULL, regs, (void *)(regs + 1));
}
/*
@@ -351,6 +353,7 @@ void exit_thread(void)
kfree(t->io_bitmap_ptr);
t->io_bitmap_ptr = NULL;
+ clear_thread_flag(TIF_IO_BITMAP);
/*
* Careful, clear this in the TSS too:
*/
@@ -365,8 +368,12 @@ void flush_thread(void)
struct task_struct *tsk = current;
struct thread_info *t = current_thread_info();
- if (t->flags & _TIF_ABI_PENDING)
+ if (t->flags & _TIF_ABI_PENDING) {
t->flags ^= (_TIF_ABI_PENDING | _TIF_IA32);
+ if (t->flags & _TIF_IA32)
+ current_thread_info()->status |= TS_COMPAT;
+ }
+ t->flags &= ~_TIF_DEBUG;
tsk->thread.debugreg0 = 0;
tsk->thread.debugreg1 = 0;
@@ -459,7 +466,7 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long rsp,
asm("mov %%es,%0" : "=m" (p->thread.es));
asm("mov %%ds,%0" : "=m" (p->thread.ds));
- if (unlikely(me->thread.io_bitmap_ptr != NULL)) {
+ if (unlikely(test_tsk_thread_flag(me, TIF_IO_BITMAP))) {
p->thread.io_bitmap_ptr = kmalloc(IO_BITMAP_BYTES, GFP_KERNEL);
if (!p->thread.io_bitmap_ptr) {
p->thread.io_bitmap_max = 0;
@@ -467,6 +474,7 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long rsp,
}
memcpy(p->thread.io_bitmap_ptr, me->thread.io_bitmap_ptr,
IO_BITMAP_BYTES);
+ set_tsk_thread_flag(p, TIF_IO_BITMAP);
}
/*
@@ -496,6 +504,40 @@ out:
*/
#define loaddebug(thread,r) set_debugreg(thread->debugreg ## r, r)
+static inline void __switch_to_xtra(struct task_struct *prev_p,
+ struct task_struct *next_p,
+ struct tss_struct *tss)
+{
+ struct thread_struct *prev, *next;
+
+ prev = &prev_p->thread,
+ next = &next_p->thread;
+
+ if (test_tsk_thread_flag(next_p, TIF_DEBUG)) {
+ loaddebug(next, 0);
+ loaddebug(next, 1);
+ loaddebug(next, 2);
+ loaddebug(next, 3);
+ /* no 4 and 5 */
+ loaddebug(next, 6);
+ loaddebug(next, 7);
+ }
+
+ if (test_tsk_thread_flag(next_p, 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));
+ } else if (test_tsk_thread_flag(prev_p, TIF_IO_BITMAP)) {
+ /*
+ * Clear any possible leftover bits:
+ */
+ memset(tss->io_bitmap, 0xff, prev->io_bitmap_max);
+ }
+}
+
/*
* switch_to(x,y) should switch tasks from x to y.
*
@@ -513,6 +555,10 @@ __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);
+ /* we're going to use this soon, after a few expensive things */
+ if (next_p->fpu_counter>5)
+ prefetch(&next->i387.fxsave);
+
/*
* Reload esp0, LDT and the page table pointer:
*/
@@ -581,41 +627,29 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
And the AMD workaround requires it to be after DS reload. */
unlazy_fpu(prev_p);
write_pda(kernelstack,
- task_stack_page(next_p) + THREAD_SIZE - PDA_STACKOFFSET);
-
+ (unsigned long)task_stack_page(next_p) + THREAD_SIZE - PDA_STACKOFFSET);
+#ifdef CONFIG_CC_STACKPROTECTOR
+ write_pda(stack_canary, next_p->stack_canary);
/*
- * Now maybe reload the debug registers
+ * Build time only check to make sure the stack_canary is at
+ * offset 40 in the pda; this is a gcc ABI requirement
*/
- if (unlikely(next->debugreg7)) {
- loaddebug(next, 0);
- loaddebug(next, 1);
- loaddebug(next, 2);
- loaddebug(next, 3);
- /* no 4 and 5 */
- loaddebug(next, 6);
- loaddebug(next, 7);
- }
+ BUILD_BUG_ON(offsetof(struct x8664_pda, stack_canary) != 40);
+#endif
+ /*
+ * Now maybe reload the debug registers and handle I/O bitmaps
+ */
+ if (unlikely((task_thread_info(next_p)->flags & _TIF_WORK_CTXSW))
+ || test_tsk_thread_flag(prev_p, TIF_IO_BITMAP))
+ __switch_to_xtra(prev_p, next_p, tss);
- /*
- * Handle the IO bitmap
- */
- if (unlikely(prev->io_bitmap_ptr || next->io_bitmap_ptr)) {
- if (next->io_bitmap_ptr)
- /*
- * 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));
- else {
- /*
- * Clear any possible leftover bits:
- */
- memset(tss->io_bitmap, 0xff, prev->io_bitmap_max);
- }
- }
-
+ /* 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
+ */
+ if (next_p->fpu_counter>5)
+ math_state_restore();
return prev_p;
}
@@ -832,7 +866,7 @@ int dump_task_regs(struct task_struct *tsk, elf_gregset_t *regs)
unsigned long arch_align_stack(unsigned long sp)
{
- if (randomize_va_space)
+ if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
sp -= get_random_int() % 8192;
return sp & ~0xf;
}
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