#include <stdarg.h>
+#include <linux/cpu.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/fs.h>
#include <linux/kallsyms.h>
#include <linux/ptrace.h>
#include <linux/random.h>
+#include <linux/kprobes.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <linux/irq.h>
#include <linux/err.h>
+#include <asm/tlbflush.h>
+#include <asm/cpu.h>
+
asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
static int hlt_counter;
* Powermanagement idle function, if any..
*/
void (*pm_idle)(void);
+EXPORT_SYMBOL(pm_idle);
static DEFINE_PER_CPU(unsigned int, cpu_idle_state);
void disable_hlt(void)
cpu_relax();
}
}
+#ifdef CONFIG_APM_MODULE
+EXPORT_SYMBOL(default_idle);
+#endif
/*
* On SMP it's slightly faster (but much more power-consuming!)
}
}
+#ifdef CONFIG_HOTPLUG_CPU
+#include <asm/nmi.h>
+/* We don't actually take CPU down, just spin without interrupts. */
+static inline void play_dead(void)
+{
+ /* This must be done before dead CPU ack */
+ cpu_exit_clear();
+ wbinvd();
+ mb();
+ /* Ack it */
+ __get_cpu_var(cpu_state) = CPU_DEAD;
+
+ /*
+ * With physical CPU hotplug, we should halt the cpu
+ */
+ local_irq_disable();
+ while (1)
+ __asm__ __volatile__("hlt":::"memory");
+}
+#else
+static inline void play_dead(void)
+{
+ BUG();
+}
+#endif /* CONFIG_HOTPLUG_CPU */
+
/*
* The idle thread. There's no useful work to be
* done, so just try to conserve power and have a
* 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)
{
+ int cpu = raw_smp_processor_id();
+
/* endless idle loop with no priority at all */
while (1) {
while (!need_resched()) {
if (!idle)
idle = default_idle;
+ if (cpu_is_offline(cpu))
+ play_dead();
+
__get_cpu_var(irq_stat).idle_timestamp = jiffies;
idle();
}
}
}
-void __init select_idle_routine(const struct cpuinfo_x86 *c)
+void __devinit select_idle_routine(const struct cpuinfo_x86 *c)
{
if (cpu_has(c, X86_FEATURE_MWAIT)) {
printk("monitor/mwait feature present.\n");
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 (regs->xcs & 3)
+ if (user_mode(regs))
printk(" ESP: %04x:%08lx",0xffff & regs->xss,regs->esp);
printk(" EFLAGS: %08lx %s (%s)\n",
regs->eflags, print_tainted(), system_utsname.release);
/* Ok, create the new process.. */
return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, ®s, 0, NULL, NULL);
}
+EXPORT_SYMBOL(kernel_thread);
/*
* Free current thread data structures etc..
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)) {
int cpu = get_cpu();
{
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));
/*
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;
dump->u_fpvalid = dump_fpu (regs, &dump->i387);
}
+EXPORT_SYMBOL(dump_thread);
/*
* Capture the user space registers if the task is not running (in user space)
*/
tss->io_bitmap_base = INVALID_IO_BITMAP_OFFSET_LAZY;
}
+
/*
- * This special macro can be used to load a debugging register
+ * This function selects if the context switch from prev to next
+ * has to tweak the TSC disable bit in the cr4.
*/
-#define loaddebug(thread,register) \
- __asm__("movl %0,%%db" #register \
- : /* no output */ \
- :"r" (thread->debugreg[register]))
+static inline void disable_tsc(struct task_struct *prev_p,
+ struct task_struct *next_p)
+{
+ struct thread_info *prev, *next;
+
+ /*
+ * 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;
+
+ if (has_secure_computing(prev) || has_secure_computing(next)) {
+ /* slow path here */
+ if (has_secure_computing(prev) &&
+ !has_secure_computing(next)) {
+ write_cr4(read_cr4() & ~X86_CR4_TSD);
+ } else if (!has_secure_computing(prev) &&
+ has_secure_computing(next))
+ write_cr4(read_cr4() | X86_CR4_TSD);
+ }
+}
/*
* switch_to(x,yn) should switch tasks from x to y.
* 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.
+ *
+ * Glibc normally makes %fs be zero, and %gs is one of
+ * the TLS segments.
*/
- if (unlikely(prev->fs | prev->gs | next->fs | next->gs)) {
+ if (unlikely(prev->fs | next->fs))
loadsegment(fs, next->fs);
+
+ if (prev->gs | next->gs)
loadsegment(gs, next->gs);
- }
/*
* Now maybe reload the debug registers
*/
if (unlikely(next->debugreg[7])) {
- loaddebug(next, 0);
- loaddebug(next, 1);
- loaddebug(next, 2);
- loaddebug(next, 3);
+ 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 */
- loaddebug(next, 6);
- loaddebug(next, 7);
+ 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);
+ disable_tsc(prev_p, next_p);
+
return prev_p;
}
} while (count++ < 16);
return 0;
}
+EXPORT_SYMBOL(get_wchan);
/*
* sys_alloc_thread_area: get a yet unused TLS descriptor index.
if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
return -EINVAL;
+ memset(&info, 0, sizeof(info));
+
desc = current->thread.tls_array + idx - GDT_ENTRY_TLS_MIN;
info.entry_number = idx;
projects / linux-2.6 / blobdiff