i386: move kernel
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Thomas Gleixner
951
arch/x86/kernel/process_32.c
Normal file
951
arch/x86/kernel/process_32.c
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@@ -0,0 +1,951 @@
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/*
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* linux/arch/i386/kernel/process.c
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*
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* Copyright (C) 1995 Linus Torvalds
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*
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* Pentium III FXSR, SSE support
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* Gareth Hughes <gareth@valinux.com>, May 2000
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*/
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/*
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* This file handles the architecture-dependent parts of process handling..
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*/
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#include <stdarg.h>
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#include <linux/cpu.h>
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#include <linux/errno.h>
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#include <linux/sched.h>
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#include <linux/fs.h>
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <linux/elfcore.h>
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#include <linux/smp.h>
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#include <linux/stddef.h>
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#include <linux/slab.h>
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#include <linux/vmalloc.h>
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#include <linux/user.h>
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#include <linux/a.out.h>
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#include <linux/interrupt.h>
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#include <linux/utsname.h>
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#include <linux/delay.h>
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#include <linux/reboot.h>
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#include <linux/init.h>
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#include <linux/mc146818rtc.h>
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#include <linux/module.h>
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#include <linux/kallsyms.h>
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#include <linux/ptrace.h>
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#include <linux/random.h>
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#include <linux/personality.h>
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#include <linux/tick.h>
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#include <linux/percpu.h>
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#include <asm/uaccess.h>
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#include <asm/pgtable.h>
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#include <asm/system.h>
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#include <asm/io.h>
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#include <asm/ldt.h>
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#include <asm/processor.h>
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#include <asm/i387.h>
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#include <asm/desc.h>
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#include <asm/vm86.h>
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#ifdef CONFIG_MATH_EMULATION
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#include <asm/math_emu.h>
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#endif
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#include <linux/err.h>
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#include <asm/tlbflush.h>
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#include <asm/cpu.h>
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asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
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static int hlt_counter;
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unsigned long boot_option_idle_override = 0;
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EXPORT_SYMBOL(boot_option_idle_override);
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DEFINE_PER_CPU(struct task_struct *, current_task) = &init_task;
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EXPORT_PER_CPU_SYMBOL(current_task);
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DEFINE_PER_CPU(int, cpu_number);
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EXPORT_PER_CPU_SYMBOL(cpu_number);
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/*
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* Return saved PC of a blocked thread.
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*/
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unsigned long thread_saved_pc(struct task_struct *tsk)
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{
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return ((unsigned long *)tsk->thread.esp)[3];
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}
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/*
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* Powermanagement idle function, if any..
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*/
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void (*pm_idle)(void);
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EXPORT_SYMBOL(pm_idle);
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static DEFINE_PER_CPU(unsigned int, cpu_idle_state);
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void disable_hlt(void)
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{
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hlt_counter++;
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}
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EXPORT_SYMBOL(disable_hlt);
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void enable_hlt(void)
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{
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hlt_counter--;
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}
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EXPORT_SYMBOL(enable_hlt);
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/*
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* We use this if we don't have any better
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* idle routine..
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*/
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void default_idle(void)
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{
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if (!hlt_counter && boot_cpu_data.hlt_works_ok) {
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current_thread_info()->status &= ~TS_POLLING;
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/*
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* TS_POLLING-cleared state must be visible before we
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* test NEED_RESCHED:
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*/
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smp_mb();
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local_irq_disable();
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if (!need_resched())
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safe_halt(); /* enables interrupts racelessly */
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else
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local_irq_enable();
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current_thread_info()->status |= TS_POLLING;
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} else {
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/* loop is done by the caller */
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cpu_relax();
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}
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}
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#ifdef CONFIG_APM_MODULE
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EXPORT_SYMBOL(default_idle);
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#endif
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/*
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* On SMP it's slightly faster (but much more power-consuming!)
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* to poll the ->work.need_resched flag instead of waiting for the
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* cross-CPU IPI to arrive. Use this option with caution.
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*/
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static void poll_idle (void)
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{
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cpu_relax();
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}
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#ifdef CONFIG_HOTPLUG_CPU
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#include <asm/nmi.h>
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/* We don't actually take CPU down, just spin without interrupts. */
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static inline void play_dead(void)
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{
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/* This must be done before dead CPU ack */
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cpu_exit_clear();
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wbinvd();
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mb();
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/* Ack it */
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__get_cpu_var(cpu_state) = CPU_DEAD;
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/*
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* With physical CPU hotplug, we should halt the cpu
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*/
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local_irq_disable();
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while (1)
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halt();
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}
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#else
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static inline void play_dead(void)
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{
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BUG();
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}
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#endif /* CONFIG_HOTPLUG_CPU */
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/*
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* The idle thread. There's no useful work to be
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* done, so just try to conserve power and have a
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* low exit latency (ie sit in a loop waiting for
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* somebody to say that they'd like to reschedule)
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*/
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void cpu_idle(void)
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{
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int cpu = smp_processor_id();
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current_thread_info()->status |= TS_POLLING;
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/* endless idle loop with no priority at all */
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while (1) {
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tick_nohz_stop_sched_tick();
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while (!need_resched()) {
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void (*idle)(void);
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if (__get_cpu_var(cpu_idle_state))
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__get_cpu_var(cpu_idle_state) = 0;
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check_pgt_cache();
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rmb();
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idle = pm_idle;
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if (!idle)
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idle = default_idle;
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if (cpu_is_offline(cpu))
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play_dead();
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__get_cpu_var(irq_stat).idle_timestamp = jiffies;
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idle();
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}
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tick_nohz_restart_sched_tick();
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preempt_enable_no_resched();
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schedule();
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preempt_disable();
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}
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}
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void cpu_idle_wait(void)
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{
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unsigned int cpu, this_cpu = get_cpu();
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cpumask_t map, tmp = current->cpus_allowed;
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set_cpus_allowed(current, cpumask_of_cpu(this_cpu));
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put_cpu();
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cpus_clear(map);
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for_each_online_cpu(cpu) {
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per_cpu(cpu_idle_state, cpu) = 1;
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cpu_set(cpu, map);
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}
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__get_cpu_var(cpu_idle_state) = 0;
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wmb();
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do {
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ssleep(1);
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for_each_online_cpu(cpu) {
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if (cpu_isset(cpu, map) && !per_cpu(cpu_idle_state, cpu))
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cpu_clear(cpu, map);
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}
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cpus_and(map, map, cpu_online_map);
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} while (!cpus_empty(map));
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set_cpus_allowed(current, tmp);
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}
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EXPORT_SYMBOL_GPL(cpu_idle_wait);
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/*
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* This uses new MONITOR/MWAIT instructions on P4 processors with PNI,
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* which can obviate IPI to trigger checking of need_resched.
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* We execute MONITOR against need_resched and enter optimized wait state
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* through MWAIT. Whenever someone changes need_resched, we would be woken
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* up from MWAIT (without an IPI).
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*
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* New with Core Duo processors, MWAIT can take some hints based on CPU
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* capability.
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*/
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void mwait_idle_with_hints(unsigned long eax, unsigned long ecx)
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{
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if (!need_resched()) {
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__monitor((void *)¤t_thread_info()->flags, 0, 0);
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smp_mb();
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if (!need_resched())
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__mwait(eax, ecx);
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}
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}
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/* Default MONITOR/MWAIT with no hints, used for default C1 state */
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static void mwait_idle(void)
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{
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local_irq_enable();
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mwait_idle_with_hints(0, 0);
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}
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void __devinit select_idle_routine(const struct cpuinfo_x86 *c)
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{
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if (cpu_has(c, X86_FEATURE_MWAIT)) {
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printk("monitor/mwait feature present.\n");
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/*
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* Skip, if setup has overridden idle.
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* One CPU supports mwait => All CPUs supports mwait
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*/
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if (!pm_idle) {
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printk("using mwait in idle threads.\n");
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pm_idle = mwait_idle;
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}
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}
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}
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static int __init idle_setup(char *str)
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{
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if (!strcmp(str, "poll")) {
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printk("using polling idle threads.\n");
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pm_idle = poll_idle;
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#ifdef CONFIG_X86_SMP
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if (smp_num_siblings > 1)
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printk("WARNING: polling idle and HT enabled, performance may degrade.\n");
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#endif
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} else if (!strcmp(str, "mwait"))
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force_mwait = 1;
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else
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return -1;
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boot_option_idle_override = 1;
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return 0;
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}
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early_param("idle", idle_setup);
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void show_regs(struct pt_regs * regs)
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{
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unsigned long cr0 = 0L, cr2 = 0L, cr3 = 0L, cr4 = 0L;
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unsigned long d0, d1, d2, d3, d6, d7;
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printk("\n");
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printk("Pid: %d, comm: %20s\n", current->pid, current->comm);
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printk("EIP: %04x:[<%08lx>] CPU: %d\n",0xffff & regs->xcs,regs->eip, smp_processor_id());
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print_symbol("EIP is at %s\n", regs->eip);
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if (user_mode_vm(regs))
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printk(" ESP: %04x:%08lx",0xffff & regs->xss,regs->esp);
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printk(" EFLAGS: %08lx %s (%s %.*s)\n",
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regs->eflags, print_tainted(), init_utsname()->release,
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(int)strcspn(init_utsname()->version, " "),
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init_utsname()->version);
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printk("EAX: %08lx EBX: %08lx ECX: %08lx EDX: %08lx\n",
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regs->eax,regs->ebx,regs->ecx,regs->edx);
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printk("ESI: %08lx EDI: %08lx EBP: %08lx",
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regs->esi, regs->edi, regs->ebp);
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printk(" DS: %04x ES: %04x FS: %04x\n",
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0xffff & regs->xds,0xffff & regs->xes, 0xffff & regs->xfs);
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cr0 = read_cr0();
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cr2 = read_cr2();
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cr3 = read_cr3();
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cr4 = read_cr4_safe();
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printk("CR0: %08lx CR2: %08lx CR3: %08lx CR4: %08lx\n", cr0, cr2, cr3, cr4);
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get_debugreg(d0, 0);
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get_debugreg(d1, 1);
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get_debugreg(d2, 2);
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get_debugreg(d3, 3);
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printk("DR0: %08lx DR1: %08lx DR2: %08lx DR3: %08lx\n",
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d0, d1, d2, d3);
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get_debugreg(d6, 6);
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get_debugreg(d7, 7);
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printk("DR6: %08lx DR7: %08lx\n", d6, d7);
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show_trace(NULL, regs, ®s->esp);
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}
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/*
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* This gets run with %ebx containing the
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* function to call, and %edx containing
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* the "args".
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*/
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extern void kernel_thread_helper(void);
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/*
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* Create a kernel thread
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*/
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int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
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{
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struct pt_regs regs;
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memset(®s, 0, sizeof(regs));
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regs.ebx = (unsigned long) fn;
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regs.edx = (unsigned long) arg;
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regs.xds = __USER_DS;
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regs.xes = __USER_DS;
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regs.xfs = __KERNEL_PERCPU;
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regs.orig_eax = -1;
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regs.eip = (unsigned long) kernel_thread_helper;
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regs.xcs = __KERNEL_CS | get_kernel_rpl();
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regs.eflags = X86_EFLAGS_IF | X86_EFLAGS_SF | X86_EFLAGS_PF | 0x2;
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/* Ok, create the new process.. */
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return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, ®s, 0, NULL, NULL);
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}
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EXPORT_SYMBOL(kernel_thread);
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/*
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* Free current thread data structures etc..
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*/
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void exit_thread(void)
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{
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/* The process may have allocated an io port bitmap... nuke it. */
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if (unlikely(test_thread_flag(TIF_IO_BITMAP))) {
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struct task_struct *tsk = current;
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struct thread_struct *t = &tsk->thread;
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int cpu = get_cpu();
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struct tss_struct *tss = &per_cpu(init_tss, cpu);
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kfree(t->io_bitmap_ptr);
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t->io_bitmap_ptr = NULL;
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clear_thread_flag(TIF_IO_BITMAP);
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/*
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* Careful, clear this in the TSS too:
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*/
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memset(tss->io_bitmap, 0xff, tss->io_bitmap_max);
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t->io_bitmap_max = 0;
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tss->io_bitmap_owner = NULL;
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tss->io_bitmap_max = 0;
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tss->x86_tss.io_bitmap_base = INVALID_IO_BITMAP_OFFSET;
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put_cpu();
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}
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}
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void flush_thread(void)
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{
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struct task_struct *tsk = current;
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memset(tsk->thread.debugreg, 0, sizeof(unsigned long)*8);
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memset(tsk->thread.tls_array, 0, sizeof(tsk->thread.tls_array));
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clear_tsk_thread_flag(tsk, TIF_DEBUG);
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/*
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* Forget coprocessor state..
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*/
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clear_fpu(tsk);
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clear_used_math();
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}
|
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void release_thread(struct task_struct *dead_task)
|
||||
{
|
||||
BUG_ON(dead_task->mm);
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release_vm86_irqs(dead_task);
|
||||
}
|
||||
|
||||
/*
|
||||
* This gets called before we allocate a new thread and copy
|
||||
* the current task into it.
|
||||
*/
|
||||
void prepare_to_copy(struct task_struct *tsk)
|
||||
{
|
||||
unlazy_fpu(tsk);
|
||||
}
|
||||
|
||||
int copy_thread(int nr, unsigned long clone_flags, unsigned long esp,
|
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unsigned long unused,
|
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struct task_struct * p, struct pt_regs * regs)
|
||||
{
|
||||
struct pt_regs * childregs;
|
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struct task_struct *tsk;
|
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int err;
|
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|
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childregs = task_pt_regs(p);
|
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*childregs = *regs;
|
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childregs->eax = 0;
|
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childregs->esp = esp;
|
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|
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p->thread.esp = (unsigned long) childregs;
|
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p->thread.esp0 = (unsigned long) (childregs+1);
|
||||
|
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p->thread.eip = (unsigned long) ret_from_fork;
|
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|
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savesegment(gs,p->thread.gs);
|
||||
|
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tsk = current;
|
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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;
|
||||
}
|
||||
set_tsk_thread_flag(p, TIF_IO_BITMAP);
|
||||
}
|
||||
|
||||
/*
|
||||
* Set a new TLS for the child thread?
|
||||
*/
|
||||
if (clone_flags & CLONE_SETTLS) {
|
||||
struct desc_struct *desc;
|
||||
struct user_desc info;
|
||||
int idx;
|
||||
|
||||
err = -EFAULT;
|
||||
if (copy_from_user(&info, (void __user *)childregs->esi, sizeof(info)))
|
||||
goto out;
|
||||
err = -EINVAL;
|
||||
if (LDT_empty(&info))
|
||||
goto out;
|
||||
|
||||
idx = info.entry_number;
|
||||
if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
|
||||
goto out;
|
||||
|
||||
desc = p->thread.tls_array + idx - GDT_ENTRY_TLS_MIN;
|
||||
desc->a = LDT_entry_a(&info);
|
||||
desc->b = LDT_entry_b(&info);
|
||||
}
|
||||
|
||||
err = 0;
|
||||
out:
|
||||
if (err && p->thread.io_bitmap_ptr) {
|
||||
kfree(p->thread.io_bitmap_ptr);
|
||||
p->thread.io_bitmap_max = 0;
|
||||
}
|
||||
return err;
|
||||
}
|
||||
|
||||
/*
|
||||
* fill in the user structure for a core dump..
|
||||
*/
|
||||
void dump_thread(struct pt_regs * regs, struct user * dump)
|
||||
{
|
||||
int i;
|
||||
|
||||
/* changed the size calculations - should hopefully work better. lbt */
|
||||
dump->magic = CMAGIC;
|
||||
dump->start_code = 0;
|
||||
dump->start_stack = regs->esp & ~(PAGE_SIZE - 1);
|
||||
dump->u_tsize = ((unsigned long) current->mm->end_code) >> PAGE_SHIFT;
|
||||
dump->u_dsize = ((unsigned long) (current->mm->brk + (PAGE_SIZE-1))) >> PAGE_SHIFT;
|
||||
dump->u_dsize -= dump->u_tsize;
|
||||
dump->u_ssize = 0;
|
||||
for (i = 0; i < 8; i++)
|
||||
dump->u_debugreg[i] = current->thread.debugreg[i];
|
||||
|
||||
if (dump->start_stack < TASK_SIZE)
|
||||
dump->u_ssize = ((unsigned long) (TASK_SIZE - dump->start_stack)) >> PAGE_SHIFT;
|
||||
|
||||
dump->regs.ebx = regs->ebx;
|
||||
dump->regs.ecx = regs->ecx;
|
||||
dump->regs.edx = regs->edx;
|
||||
dump->regs.esi = regs->esi;
|
||||
dump->regs.edi = regs->edi;
|
||||
dump->regs.ebp = regs->ebp;
|
||||
dump->regs.eax = regs->eax;
|
||||
dump->regs.ds = regs->xds;
|
||||
dump->regs.es = regs->xes;
|
||||
dump->regs.fs = regs->xfs;
|
||||
savesegment(gs,dump->regs.gs);
|
||||
dump->regs.orig_eax = regs->orig_eax;
|
||||
dump->regs.eip = regs->eip;
|
||||
dump->regs.cs = regs->xcs;
|
||||
dump->regs.eflags = regs->eflags;
|
||||
dump->regs.esp = regs->esp;
|
||||
dump->regs.ss = regs->xss;
|
||||
|
||||
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)
|
||||
*/
|
||||
int dump_task_regs(struct task_struct *tsk, elf_gregset_t *regs)
|
||||
{
|
||||
struct pt_regs ptregs = *task_pt_regs(tsk);
|
||||
ptregs.xcs &= 0xffff;
|
||||
ptregs.xds &= 0xffff;
|
||||
ptregs.xes &= 0xffff;
|
||||
ptregs.xss &= 0xffff;
|
||||
|
||||
elf_core_copy_regs(regs, &ptregs);
|
||||
|
||||
return 1;
|
||||
}
|
||||
|
||||
#ifdef CONFIG_SECCOMP
|
||||
void hard_disable_TSC(void)
|
||||
{
|
||||
write_cr4(read_cr4() | X86_CR4_TSD);
|
||||
}
|
||||
void disable_TSC(void)
|
||||
{
|
||||
preempt_disable();
|
||||
if (!test_and_set_thread_flag(TIF_NOTSC))
|
||||
/*
|
||||
* Must flip the CPU state synchronously with
|
||||
* TIF_NOTSC in the current running context.
|
||||
*/
|
||||
hard_disable_TSC();
|
||||
preempt_enable();
|
||||
}
|
||||
void hard_enable_TSC(void)
|
||||
{
|
||||
write_cr4(read_cr4() & ~X86_CR4_TSD);
|
||||
}
|
||||
#endif /* CONFIG_SECCOMP */
|
||||
|
||||
static noinline void
|
||||
__switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p,
|
||||
struct tss_struct *tss)
|
||||
{
|
||||
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);
|
||||
}
|
||||
|
||||
#ifdef CONFIG_SECCOMP
|
||||
if (test_tsk_thread_flag(prev_p, TIF_NOTSC) ^
|
||||
test_tsk_thread_flag(next_p, TIF_NOTSC)) {
|
||||
/* prev and next are different */
|
||||
if (test_tsk_thread_flag(next_p, TIF_NOTSC))
|
||||
hard_disable_TSC();
|
||||
else
|
||||
hard_enable_TSC();
|
||||
}
|
||||
#endif
|
||||
|
||||
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->x86_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)
|
||||
* matches the next task, we dont have to do anything but
|
||||
* to set a valid offset in the TSS:
|
||||
*/
|
||||
tss->x86_tss.io_bitmap_base = IO_BITMAP_OFFSET;
|
||||
return;
|
||||
}
|
||||
/*
|
||||
* Lazy TSS's I/O bitmap copy. We set an invalid offset here
|
||||
* and we let the task to get a GPF in case an I/O instruction
|
||||
* is performed. The handler of the GPF will verify that the
|
||||
* faulting task has a valid I/O bitmap and, it true, does the
|
||||
* real copy and restart the instruction. This will save us
|
||||
* redundant copies when the currently switched task does not
|
||||
* perform any I/O during its timeslice.
|
||||
*/
|
||||
tss->x86_tss.io_bitmap_base = INVALID_IO_BITMAP_OFFSET_LAZY;
|
||||
}
|
||||
|
||||
/*
|
||||
* switch_to(x,yn) should switch tasks from x to y.
|
||||
*
|
||||
* We fsave/fwait so that an exception goes off at the right time
|
||||
* (as a call from the fsave or fwait in effect) rather than to
|
||||
* the wrong process. Lazy FP saving no longer makes any sense
|
||||
* with modern CPU's, and this simplifies a lot of things (SMP
|
||||
* and UP become the same).
|
||||
*
|
||||
* NOTE! We used to use the x86 hardware context switching. The
|
||||
* reason for not using it any more becomes apparent when you
|
||||
* try to recover gracefully from saved state that is no longer
|
||||
* valid (stale segment register values in particular). With the
|
||||
* hardware task-switch, there is no way to fix up bad state in
|
||||
* a reasonable manner.
|
||||
*
|
||||
* The fact that Intel documents the hardware task-switching to
|
||||
* be slow is a fairly red herring - this code is not noticeably
|
||||
* faster. However, there _is_ some room for improvement here,
|
||||
* so the performance issues may eventually be a valid point.
|
||||
* More important, however, is the fact that this allows us much
|
||||
* more flexibility.
|
||||
*
|
||||
* The return value (in %eax) will be the "prev" task after
|
||||
* the task-switch, and shows up in ret_from_fork in entry.S,
|
||||
* for example.
|
||||
*/
|
||||
struct task_struct fastcall * __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
|
||||
{
|
||||
struct thread_struct *prev = &prev_p->thread,
|
||||
*next = &next_p->thread;
|
||||
int cpu = smp_processor_id();
|
||||
struct tss_struct *tss = &per_cpu(init_tss, cpu);
|
||||
|
||||
/* never put a printk in __switch_to... printk() calls wake_up*() indirectly */
|
||||
|
||||
__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.
|
||||
*/
|
||||
load_esp0(tss, next);
|
||||
|
||||
/*
|
||||
* Save away %gs. No need to save %fs, 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.
|
||||
*/
|
||||
savesegment(gs, prev->gs);
|
||||
|
||||
/*
|
||||
* Load the per-thread Thread-Local Storage descriptor.
|
||||
*/
|
||||
load_TLS(next, cpu);
|
||||
|
||||
/*
|
||||
* Restore IOPL if needed. In normal use, the flags restore
|
||||
* in the switch assembly will handle this. But if the kernel
|
||||
* is running virtualized at a non-zero CPL, the popf will
|
||||
* not restore flags, so it must be done in a separate step.
|
||||
*/
|
||||
if (get_kernel_rpl() && unlikely(prev->iopl != next->iopl))
|
||||
set_iopl_mask(next->iopl);
|
||||
|
||||
/*
|
||||
* Now maybe handle debug registers and/or IO bitmaps
|
||||
*/
|
||||
if (unlikely(task_thread_info(prev_p)->flags & _TIF_WORK_CTXSW_PREV ||
|
||||
task_thread_info(next_p)->flags & _TIF_WORK_CTXSW_NEXT))
|
||||
__switch_to_xtra(prev_p, next_p, tss);
|
||||
|
||||
/*
|
||||
* Leave lazy mode, flushing any hypercalls made here.
|
||||
* This must be done before restoring TLS segments so
|
||||
* the GDT and LDT are properly updated, and must be
|
||||
* done before math_state_restore, so the TS bit is up
|
||||
* to date.
|
||||
*/
|
||||
arch_leave_lazy_cpu_mode();
|
||||
|
||||
/* 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();
|
||||
|
||||
/*
|
||||
* Restore %gs if needed (which is common)
|
||||
*/
|
||||
if (prev->gs | next->gs)
|
||||
loadsegment(gs, next->gs);
|
||||
|
||||
x86_write_percpu(current_task, next_p);
|
||||
|
||||
return prev_p;
|
||||
}
|
||||
|
||||
asmlinkage int sys_fork(struct pt_regs regs)
|
||||
{
|
||||
return do_fork(SIGCHLD, regs.esp, ®s, 0, NULL, NULL);
|
||||
}
|
||||
|
||||
asmlinkage int sys_clone(struct pt_regs regs)
|
||||
{
|
||||
unsigned long clone_flags;
|
||||
unsigned long newsp;
|
||||
int __user *parent_tidptr, *child_tidptr;
|
||||
|
||||
clone_flags = regs.ebx;
|
||||
newsp = regs.ecx;
|
||||
parent_tidptr = (int __user *)regs.edx;
|
||||
child_tidptr = (int __user *)regs.edi;
|
||||
if (!newsp)
|
||||
newsp = regs.esp;
|
||||
return do_fork(clone_flags, newsp, ®s, 0, parent_tidptr, child_tidptr);
|
||||
}
|
||||
|
||||
/*
|
||||
* This is trivial, and on the face of it looks like it
|
||||
* could equally well be done in user mode.
|
||||
*
|
||||
* Not so, for quite unobvious reasons - register pressure.
|
||||
* In user mode vfork() cannot have a stack frame, and if
|
||||
* done by calling the "clone()" system call directly, you
|
||||
* do not have enough call-clobbered registers to hold all
|
||||
* the information you need.
|
||||
*/
|
||||
asmlinkage int sys_vfork(struct pt_regs regs)
|
||||
{
|
||||
return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs.esp, ®s, 0, NULL, NULL);
|
||||
}
|
||||
|
||||
/*
|
||||
* sys_execve() executes a new program.
|
||||
*/
|
||||
asmlinkage int sys_execve(struct pt_regs regs)
|
||||
{
|
||||
int error;
|
||||
char * filename;
|
||||
|
||||
filename = getname((char __user *) regs.ebx);
|
||||
error = PTR_ERR(filename);
|
||||
if (IS_ERR(filename))
|
||||
goto out;
|
||||
error = do_execve(filename,
|
||||
(char __user * __user *) regs.ecx,
|
||||
(char __user * __user *) regs.edx,
|
||||
®s);
|
||||
if (error == 0) {
|
||||
task_lock(current);
|
||||
current->ptrace &= ~PT_DTRACE;
|
||||
task_unlock(current);
|
||||
/* Make sure we don't return using sysenter.. */
|
||||
set_thread_flag(TIF_IRET);
|
||||
}
|
||||
putname(filename);
|
||||
out:
|
||||
return error;
|
||||
}
|
||||
|
||||
#define top_esp (THREAD_SIZE - sizeof(unsigned long))
|
||||
#define top_ebp (THREAD_SIZE - 2*sizeof(unsigned long))
|
||||
|
||||
unsigned long get_wchan(struct task_struct *p)
|
||||
{
|
||||
unsigned long ebp, esp, eip;
|
||||
unsigned long stack_page;
|
||||
int count = 0;
|
||||
if (!p || p == current || p->state == TASK_RUNNING)
|
||||
return 0;
|
||||
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;
|
||||
/* include/asm-i386/system.h:switch_to() pushes ebp last. */
|
||||
ebp = *(unsigned long *) esp;
|
||||
do {
|
||||
if (ebp < stack_page || ebp > top_ebp+stack_page)
|
||||
return 0;
|
||||
eip = *(unsigned long *) (ebp+4);
|
||||
if (!in_sched_functions(eip))
|
||||
return eip;
|
||||
ebp = *(unsigned long *) ebp;
|
||||
} while (count++ < 16);
|
||||
return 0;
|
||||
}
|
||||
|
||||
/*
|
||||
* sys_alloc_thread_area: get a yet unused TLS descriptor index.
|
||||
*/
|
||||
static int get_free_idx(void)
|
||||
{
|
||||
struct thread_struct *t = ¤t->thread;
|
||||
int idx;
|
||||
|
||||
for (idx = 0; idx < GDT_ENTRY_TLS_ENTRIES; idx++)
|
||||
if (desc_empty(t->tls_array + idx))
|
||||
return idx + GDT_ENTRY_TLS_MIN;
|
||||
return -ESRCH;
|
||||
}
|
||||
|
||||
/*
|
||||
* Set a given TLS descriptor:
|
||||
*/
|
||||
asmlinkage int sys_set_thread_area(struct user_desc __user *u_info)
|
||||
{
|
||||
struct thread_struct *t = ¤t->thread;
|
||||
struct user_desc info;
|
||||
struct desc_struct *desc;
|
||||
int cpu, idx;
|
||||
|
||||
if (copy_from_user(&info, u_info, sizeof(info)))
|
||||
return -EFAULT;
|
||||
idx = info.entry_number;
|
||||
|
||||
/*
|
||||
* index -1 means the kernel should try to find and
|
||||
* allocate an empty descriptor:
|
||||
*/
|
||||
if (idx == -1) {
|
||||
idx = get_free_idx();
|
||||
if (idx < 0)
|
||||
return idx;
|
||||
if (put_user(idx, &u_info->entry_number))
|
||||
return -EFAULT;
|
||||
}
|
||||
|
||||
if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
|
||||
return -EINVAL;
|
||||
|
||||
desc = t->tls_array + idx - GDT_ENTRY_TLS_MIN;
|
||||
|
||||
/*
|
||||
* We must not get preempted while modifying the TLS.
|
||||
*/
|
||||
cpu = get_cpu();
|
||||
|
||||
if (LDT_empty(&info)) {
|
||||
desc->a = 0;
|
||||
desc->b = 0;
|
||||
} else {
|
||||
desc->a = LDT_entry_a(&info);
|
||||
desc->b = LDT_entry_b(&info);
|
||||
}
|
||||
load_TLS(t, cpu);
|
||||
|
||||
put_cpu();
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
/*
|
||||
* Get the current Thread-Local Storage area:
|
||||
*/
|
||||
|
||||
#define GET_BASE(desc) ( \
|
||||
(((desc)->a >> 16) & 0x0000ffff) | \
|
||||
(((desc)->b << 16) & 0x00ff0000) | \
|
||||
( (desc)->b & 0xff000000) )
|
||||
|
||||
#define GET_LIMIT(desc) ( \
|
||||
((desc)->a & 0x0ffff) | \
|
||||
((desc)->b & 0xf0000) )
|
||||
|
||||
#define GET_32BIT(desc) (((desc)->b >> 22) & 1)
|
||||
#define GET_CONTENTS(desc) (((desc)->b >> 10) & 3)
|
||||
#define GET_WRITABLE(desc) (((desc)->b >> 9) & 1)
|
||||
#define GET_LIMIT_PAGES(desc) (((desc)->b >> 23) & 1)
|
||||
#define GET_PRESENT(desc) (((desc)->b >> 15) & 1)
|
||||
#define GET_USEABLE(desc) (((desc)->b >> 20) & 1)
|
||||
|
||||
asmlinkage int sys_get_thread_area(struct user_desc __user *u_info)
|
||||
{
|
||||
struct user_desc info;
|
||||
struct desc_struct *desc;
|
||||
int idx;
|
||||
|
||||
if (get_user(idx, &u_info->entry_number))
|
||||
return -EFAULT;
|
||||
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;
|
||||
info.base_addr = GET_BASE(desc);
|
||||
info.limit = GET_LIMIT(desc);
|
||||
info.seg_32bit = GET_32BIT(desc);
|
||||
info.contents = GET_CONTENTS(desc);
|
||||
info.read_exec_only = !GET_WRITABLE(desc);
|
||||
info.limit_in_pages = GET_LIMIT_PAGES(desc);
|
||||
info.seg_not_present = !GET_PRESENT(desc);
|
||||
info.useable = GET_USEABLE(desc);
|
||||
|
||||
if (copy_to_user(u_info, &info, sizeof(info)))
|
||||
return -EFAULT;
|
||||
return 0;
|
||||
}
|
||||
|
||||
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;
|
||||
}
|
||||
Reference in New Issue
Block a user