#include <linux/user.h>
#include <linux/a.out.h>
#include <linux/interrupt.h>
-#include <linux/config.h>
#include <linux/utsname.h>
#include <linux/delay.h>
#include <linux/reboot.h>
#include <linux/kallsyms.h>
#include <linux/ptrace.h>
#include <linux/random.h>
-#include <linux/kprobes.h>
+#include <linux/personality.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/ldt.h>
#include <asm/processor.h>
#include <asm/i387.h>
-#include <asm/irq.h>
#include <asm/desc.h>
+#include <asm/vm86.h>
#ifdef CONFIG_MATH_EMULATION
#include <asm/math_emu.h>
#endif
-#include <linux/irq.h>
#include <linux/err.h>
#include <asm/tlbflush.h>
#include <asm/cpu.h>
+#include <asm/pda.h>
asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
void default_idle(void)
{
if (!hlt_counter && boot_cpu_data.hlt_works_ok) {
+ current_thread_info()->status &= ~TS_POLLING;
+ smp_mb__after_clear_bit();
local_irq_disable();
if (!need_resched())
- safe_halt();
+ safe_halt(); /* enables interrupts racelessly */
else
local_irq_enable();
+ current_thread_info()->status |= TS_POLLING;
} else {
+ /* loop is done by the caller */
cpu_relax();
}
}
*/
static void poll_idle (void)
{
- int oldval;
-
- local_irq_enable();
-
- /*
- * Deal with another CPU just having chosen a thread to
- * run here:
- */
- oldval = test_and_clear_thread_flag(TIF_NEED_RESCHED);
-
- if (!oldval) {
- set_thread_flag(TIF_POLLING_NRFLAG);
- asm volatile(
- "2:"
- "testl %0, %1;"
- "rep; nop;"
- "je 2b;"
- : : "i"(_TIF_NEED_RESCHED), "m" (current_thread_info()->flags));
-
- clear_thread_flag(TIF_POLLING_NRFLAG);
- } else {
- set_need_resched();
- }
+ cpu_relax();
}
#ifdef CONFIG_HOTPLUG_CPU
*/
local_irq_disable();
while (1)
- __asm__ __volatile__("hlt":::"memory");
+ halt();
}
#else
static inline void play_dead(void)
*/
void cpu_idle(void)
{
- int cpu = raw_smp_processor_id();
+ int cpu = smp_processor_id();
+
+ current_thread_info()->status |= TS_POLLING;
/* endless idle loop with no priority at all */
while (1) {
__get_cpu_var(irq_stat).idle_timestamp = jiffies;
idle();
}
+ preempt_enable_no_resched();
schedule();
+ preempt_disable();
}
}
void cpu_idle_wait(void)
{
unsigned int cpu, this_cpu = get_cpu();
- cpumask_t map;
+ cpumask_t map, tmp = current->cpus_allowed;
set_cpus_allowed(current, cpumask_of_cpu(this_cpu));
put_cpu();
}
cpus_and(map, map, cpu_online_map);
} while (!cpus_empty(map));
+
+ set_cpus_allowed(current, tmp);
}
EXPORT_SYMBOL_GPL(cpu_idle_wait);
* We execute MONITOR against need_resched and enter optimized wait state
* through MWAIT. Whenever someone changes need_resched, we would be woken
* up from MWAIT (without an IPI).
+ *
+ * New with Core Duo processors, MWAIT can take some hints based on CPU
+ * capability.
*/
-static void mwait_idle(void)
+void mwait_idle_with_hints(unsigned long eax, unsigned long ecx)
{
- local_irq_enable();
-
if (!need_resched()) {
- set_thread_flag(TIF_POLLING_NRFLAG);
- do {
- __monitor((void *)¤t_thread_info()->flags, 0, 0);
- if (need_resched())
- break;
- __mwait(0, 0);
- } while (!need_resched());
- clear_thread_flag(TIF_POLLING_NRFLAG);
+ __monitor((void *)¤t_thread_info()->flags, 0, 0);
+ smp_mb();
+ if (!need_resched())
+ __mwait(eax, ecx);
}
}
+/* Default MONITOR/MWAIT with no hints, used for default C1 state */
+static void mwait_idle(void)
+{
+ local_irq_enable();
+ mwait_idle_with_hints(0, 0);
+}
+
void __devinit select_idle_routine(const struct cpuinfo_x86 *c)
{
if (cpu_has(c, X86_FEATURE_MWAIT)) {
printk("EIP: %04x:[<%08lx>] CPU: %d\n",0xffff & regs->xcs,regs->eip, smp_processor_id());
print_symbol("EIP is at %s\n", regs->eip);
- if (user_mode(regs))
+ if (user_mode_vm(regs))
printk(" ESP: %04x:%08lx",0xffff & regs->xss,regs->esp);
- printk(" EFLAGS: %08lx %s (%s)\n",
- regs->eflags, print_tainted(), system_utsname.release);
+ printk(" EFLAGS: %08lx %s (%s %.*s)\n",
+ regs->eflags, print_tainted(), init_utsname()->release,
+ (int)strcspn(init_utsname()->version, " "),
+ init_utsname()->version);
printk("EAX: %08lx EBX: %08lx ECX: %08lx EDX: %08lx\n",
regs->eax,regs->ebx,regs->ecx,regs->edx);
printk("ESI: %08lx EDI: %08lx EBP: %08lx",
regs->esi, regs->edi, regs->ebp);
- printk(" DS: %04x ES: %04x\n",
- 0xffff & regs->xds,0xffff & regs->xes);
+ printk(" DS: %04x ES: %04x GS: %04x\n",
+ 0xffff & regs->xds,0xffff & regs->xes, 0xffff & regs->xgs);
cr0 = read_cr0();
cr2 = read_cr2();
cr3 = read_cr3();
- if (current_cpu_data.x86 > 4) {
- cr4 = read_cr4();
- }
+ cr4 = read_cr4_safe();
printk("CR0: %08lx CR2: %08lx CR3: %08lx CR4: %08lx\n", cr0, cr2, cr3, cr4);
- show_trace(NULL, ®s->esp);
+ show_trace(NULL, regs, ®s->esp);
}
/*
* the "args".
*/
extern void kernel_thread_helper(void);
-__asm__(".section .text\n"
- ".align 4\n"
- "kernel_thread_helper:\n\t"
- "movl %edx,%eax\n\t"
- "pushl %edx\n\t"
- "call *%ebx\n\t"
- "pushl %eax\n\t"
- "call do_exit\n"
- ".previous");
/*
* Create a kernel thread
regs.xds = __USER_DS;
regs.xes = __USER_DS;
+ regs.xgs = __KERNEL_PDA;
regs.orig_eax = -1;
regs.eip = (unsigned long) kernel_thread_helper;
- regs.xcs = __KERNEL_CS;
+ regs.xcs = __KERNEL_CS | get_kernel_rpl();
regs.eflags = X86_EFLAGS_IF | X86_EFLAGS_SF | X86_EFLAGS_PF | 0x2;
/* Ok, create the new process.. */
*/
void exit_thread(void)
{
- struct task_struct *tsk = current;
- struct thread_struct *t = &tsk->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(tsk);
-
/* The process may have allocated an io port bitmap... nuke it. */
- if (unlikely(NULL != t->io_bitmap_ptr)) {
+ if (unlikely(test_thread_flag(TIF_IO_BITMAP))) {
+ struct task_struct *tsk = current;
+ struct thread_struct *t = &tsk->thread;
int cpu = get_cpu();
struct tss_struct *tss = &per_cpu(init_tss, cpu);
kfree(t->io_bitmap_ptr);
t->io_bitmap_ptr = NULL;
+ clear_thread_flag(TIF_IO_BITMAP);
/*
* Careful, clear this in the TSS too:
*/
{
struct task_struct *tsk = current;
- /*
- * 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);
-
memset(tsk->thread.debugreg, 0, sizeof(unsigned long)*8);
memset(tsk->thread.tls_array, 0, sizeof(tsk->thread.tls_array));
+ clear_tsk_thread_flag(tsk, TIF_DEBUG);
/*
* Forget coprocessor state..
*/
void release_thread(struct task_struct *dead_task)
{
- if (dead_task->mm) {
- // temporary debugging check
- if (dead_task->mm->context.size) {
- printk("WARNING: dead process %8s still has LDT? <%p/%d>\n",
- dead_task->comm,
- dead_task->mm->context.ldt,
- dead_task->mm->context.size);
- BUG();
- }
- }
-
+ BUG_ON(dead_task->mm);
release_vm86_irqs(dead_task);
}
struct task_struct *tsk;
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 = task_pt_regs(p);
*childregs = *regs;
childregs->eax = 0;
childregs->esp = esp;
p->thread.eip = (unsigned long) ret_from_fork;
savesegment(fs,p->thread.fs);
- savesegment(gs,p->thread.gs);
tsk = current;
- if (unlikely(NULL != tsk->thread.io_bitmap_ptr)) {
- p->thread.io_bitmap_ptr = kmalloc(IO_BITMAP_BYTES, GFP_KERNEL);
+ if (unlikely(test_tsk_thread_flag(tsk, TIF_IO_BITMAP))) {
+ p->thread.io_bitmap_ptr = kmemdup(tsk->thread.io_bitmap_ptr,
+ IO_BITMAP_BYTES, GFP_KERNEL);
if (!p->thread.io_bitmap_ptr) {
p->thread.io_bitmap_max = 0;
return -ENOMEM;
}
- memcpy(p->thread.io_bitmap_ptr, tsk->thread.io_bitmap_ptr,
- IO_BITMAP_BYTES);
+ set_tsk_thread_flag(p, TIF_IO_BITMAP);
}
/*
dump->regs.ds = regs->xds;
dump->regs.es = regs->xes;
savesegment(fs,dump->regs.fs);
- savesegment(gs,dump->regs.gs);
+ dump->regs.gs = regs->xgs;
dump->regs.orig_eax = regs->orig_eax;
dump->regs.eip = regs->eip;
dump->regs.cs = regs->xcs;
*/
int dump_task_regs(struct task_struct *tsk, elf_gregset_t *regs)
{
- struct pt_regs ptregs;
-
- ptregs = *(struct pt_regs *)
- ((unsigned long)tsk->thread_info+THREAD_SIZE - sizeof(ptregs));
+ struct pt_regs ptregs = *task_pt_regs(tsk);
ptregs.xcs &= 0xffff;
ptregs.xds &= 0xffff;
ptregs.xes &= 0xffff;
return 1;
}
-static inline void
-handle_io_bitmap(struct thread_struct *next, struct tss_struct *tss)
+static noinline void __switch_to_xtra(struct task_struct *next_p,
+ struct tss_struct *tss)
{
- if (!next->io_bitmap_ptr) {
+ struct thread_struct *next;
+
+ next = &next_p->thread;
+
+ if (test_tsk_thread_flag(next_p, TIF_DEBUG)) {
+ set_debugreg(next->debugreg[0], 0);
+ set_debugreg(next->debugreg[1], 1);
+ set_debugreg(next->debugreg[2], 2);
+ set_debugreg(next->debugreg[3], 3);
+ /* no 4 and 5 */
+ set_debugreg(next->debugreg[6], 6);
+ set_debugreg(next->debugreg[7], 7);
+ }
+
+ if (!test_tsk_thread_flag(next_p, TIF_IO_BITMAP)) {
/*
* Disable the bitmap via an invalid offset. We still cache
* the previous bitmap owner and the IO bitmap contents:
tss->io_bitmap_base = INVALID_IO_BITMAP_OFFSET;
return;
}
+
if (likely(next == tss->io_bitmap_owner)) {
/*
* Previous owner of the bitmap (hence the bitmap content)
* 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;
+ prev = task_thread_info(prev_p);
+ next = task_thread_info(next_p);
if (has_secure_computing(prev) || has_secure_computing(next)) {
/* slow path here */
__unlazy_fpu(prev_p);
+
+ /* 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:
+ * Reload esp0.
*/
load_esp0(tss, next);
/*
- * Load the per-thread Thread-Local Storage descriptor.
+ * Save away %fs. No need to save %gs, as it was saved on the
+ * stack on entry. No need to save %es and %ds, as those are
+ * always kernel segments while inside the kernel. Doing this
+ * before setting the new TLS descriptors avoids the situation
+ * where we temporarily have non-reloadable segments in %fs
+ * and %gs. This could be an issue if the NMI handler ever
+ * used %fs or %gs (it does not today), or if the kernel is
+ * running inside of a hypervisor layer.
*/
- load_TLS(next, cpu);
+ savesegment(fs, prev->fs);
/*
- * Save away %fs and %gs. No need to save %es and %ds, as
- * those are always kernel segments while inside the kernel.
+ * Load the per-thread Thread-Local Storage descriptor.
*/
- asm volatile("mov %%fs,%0":"=m" (prev->fs));
- asm volatile("mov %%gs,%0":"=m" (prev->gs));
+ load_TLS(next, cpu);
/*
- * Restore %fs and %gs if needed.
+ * Restore %fs if needed.
*
- * Glibc normally makes %fs be zero, and %gs is one of
- * the TLS segments.
+ * Glibc normally makes %fs be zero.
*/
if (unlikely(prev->fs | next->fs))
loadsegment(fs, next->fs);
- if (prev->gs | next->gs)
- loadsegment(gs, next->gs);
+ write_pda(pcurrent, next_p);
/*
- * Now maybe reload the debug registers
+ * Now maybe handle debug registers and/or IO bitmaps
*/
- if (unlikely(next->debugreg[7])) {
- set_debugreg(next->debugreg[0], 0);
- set_debugreg(next->debugreg[1], 1);
- set_debugreg(next->debugreg[2], 2);
- set_debugreg(next->debugreg[3], 3);
- /* no 4 and 5 */
- set_debugreg(next->debugreg[6], 6);
- set_debugreg(next->debugreg[7], 7);
- }
-
- if (unlikely(prev->io_bitmap_ptr || next->io_bitmap_ptr))
- handle_io_bitmap(next, tss);
+ if (unlikely((task_thread_info(next_p)->flags & _TIF_WORK_CTXSW)
+ || test_tsk_thread_flag(prev_p, TIF_IO_BITMAP)))
+ __switch_to_xtra(next_p, tss);
disable_tsc(prev_p, next_p);
+ /* 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;
}
int count = 0;
if (!p || p == current || p->state == TASK_RUNNING)
return 0;
- stack_page = (unsigned long)p->thread_info;
+ stack_page = (unsigned long)task_stack_page(p);
esp = p->thread.esp;
if (!stack_page || esp < stack_page || esp > top_esp+stack_page)
return 0;
} while (count++ < 16);
return 0;
}
-EXPORT_SYMBOL(get_wchan);
/*
* sys_alloc_thread_area: get a yet unused TLS descriptor index.
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;
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff