process.c

这个linux源代码是很全面的~基本完整了~使用c编译的~由于时间问题我没有亲自测试~但就算用来做参考资料也是非常好的

/*
 *  linux/arch/x86-64/kernel/process.c
 *
 *  Copyright (C) 1995  Linus Torvalds
 *
 *  Pentium III FXSR, SSE support
 *	Gareth Hughes <[e-mail]>, May 2000
 * 
 *  X86-64 port
 *	Andi Kleen.
 * 
 *  $Id: process.c,v 1.60 2003/01/10 15:16:30 ak Exp $
 */

/*
 * This file handles the architecture-dependent parts of process handling..
 */

#define __KERNEL_SYSCALLS__
#include <stdarg.h>

#include <linux/compiler.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/stddef.h>
#include <linux/unistd.h>
#include <linux/ptrace.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/user.h>
#include <linux/a.out.h>
#include <linux/interrupt.h>
#include <linux/config.h>
#include <linux/delay.h>
#include <linux/reboot.h>
#include <linux/init.h>
#include <linux/ctype.h>
#include <linux/slab.h>

#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/system.h>
#include <asm/io.h>
#include <asm/ldt.h>
#include <asm/processor.h>
#include <asm/i387.h>
#include <asm/desc.h>
#include <asm/mmu_context.h>
#include <asm/pda.h>
#include <asm/prctl.h>
#include <asm/kdebug.h>
#include <asm/proto.h>

#include <linux/irq.h>

asmlinkage extern void ret_from_fork(void);

int hlt_counter;

/*
 * Powermanagement idle function, if any..
 */
void (*pm_idle)(void);

/*
 * Power off function, if any
 */
void (*pm_power_off)(void);

void disable_hlt(void)
{
	hlt_counter++;
}

void enable_hlt(void)
{
	hlt_counter--;
}

/*
 * We use this if we don't have any better
 * idle routine..
 */
static void default_idle(void)
{
	if (!hlt_counter) {
		__cli();
		if (!current->need_resched)
			safe_halt();
		else
			__sti();
	}
}

/*
 * On SMP it's slightly faster (but much more power-consuming!)
 * to poll the ->need_resched flag instead of waiting for the
 * cross-CPU IPI to arrive. Use this option with caution.
 */
static void poll_idle (void)
{
	int oldval;

	__sti();

	/*
	 * Deal with another CPU just having chosen a thread to
	 * run here:
	 */
	oldval = xchg(&current->need_resched, -1);

	if (!oldval)
		asm volatile(
			"2:"
			"cmpl $-1, %0;"
			"rep; nop;"
			"je 2b;"
				: :"m" (current->need_resched));
}

/*
 * 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)
{
	/* endless idle loop with no priority at all */
	init_idle();
	current->nice = 20;
	current->counter = -100;

	while (1) {
		void (*idle)(void) = pm_idle;
		if (!idle)
			idle = default_idle;
		while (!current->need_resched)
			idle();
		schedule();
		check_pgt_cache();
	}
}

static int __init idle_setup (char *str)
{
	if (!strncmp(str, "poll", 4)) {
		printk("using polling idle threads.\n");
		pm_idle = poll_idle;
	}

	return 1;
}

__setup("idle=", idle_setup);

static long no_idt[3];
static int reboot_mode;

#ifdef CONFIG_SMP
int reboot_smp = 0;
static int reboot_cpu = -1;
#endif
static int __init reboot_setup(char *str)
{
	while(1) {
		switch (*str) {
		case 'w': /* "warm" reboot (no memory testing etc) */
			reboot_mode = 0x1234;
			break;
		case 'c': /* "cold" reboot (with memory testing etc) */
			reboot_mode = 0x0;
			break;
#ifdef CONFIG_SMP
		case 's': /* "smp" reboot by executing reset on BSP or other CPU*/
			reboot_smp = 1;
			if (isdigit(str[1]))
				sscanf(str+1, "%d", &reboot_cpu);		
			else if (!strncmp(str,"smp",3))
				sscanf(str+3, "%d", &reboot_cpu); 
			/* we will leave sorting out the final value 
			   when we are ready to reboot, since we might not
 			   have set up boot_cpu_id or smp_num_cpu */
			break;
#endif
		}
		if((str = strchr(str,',')) != NULL)
			str++;
		else
			break;
	}
	return 1;
}

__setup("reboot=", reboot_setup);

static inline void kb_wait(void)
{
	int i;

	for (i=0; i<0x10000; i++)
		if ((inb_p(0x64) & 0x02) == 0)
			break;
}

void machine_restart(char * __unused)
{
#if CONFIG_SMP
	int cpuid;
	
	cpuid = GET_APIC_ID(apic_read(APIC_ID));

	if (reboot_smp) {

		/* check to see if reboot_cpu is valid 
		   if its not, default to the BSP */
		if ((reboot_cpu == -1) ||  
		      (reboot_cpu > (NR_CPUS -1))  || 
		      !(phys_cpu_present_map & (1<<cpuid))) 
			reboot_cpu = boot_cpu_id;

		reboot_smp = 0;  /* use this as a flag to only go through this once*/
		/* re-run this function on the other CPUs
		   it will fall though this section since we have 
		   cleared reboot_smp, and do the reboot if it is the
		   correct CPU, otherwise it halts. */
		if (reboot_cpu != cpuid)
			smp_call_function((void *)machine_restart , NULL, 1, 0);
	}

	/* if reboot_cpu is still -1, then we want a tradional reboot, 
	   and if we are not running on the reboot_cpu,, halt */
	if ((reboot_cpu != -1) && (cpuid != reboot_cpu)) {
		for (;;)
		__asm__ __volatile__ ("hlt");
	}
	/*
	 * Stop all CPUs and turn off local APICs and the IO-APIC, so
	 * other OSs see a clean IRQ state.
	 */
	if (notify_die(DIE_STOP,"cpustop",0,0) != NOTIFY_BAD)
		smp_send_stop();
	disable_IO_APIC();
#endif
	/* Could do reset through the northbridge of the Hammer here. */

	/* rebooting needs to touch the page at absolute addr 0 */
	*((unsigned short *)__va(0x472)) = reboot_mode;
	for (;;) {
		int i;
		/* First fondle with the keyboard controller. */ 
		for (i=0; i<100; i++) {
			kb_wait();
			udelay(50);
			outb(0xfe,0x64);         /* pulse reset low */
			udelay(50);
		}
		/* That didn't work - force a triple fault.. */
		__asm__ __volatile__("lidt %0": :"m" (no_idt));
		__asm__ __volatile__("int3");
	}
}

void machine_halt(void)
{
}

void machine_power_off(void)
{
	if (pm_power_off)
		pm_power_off();
}

extern int printk_address(unsigned long); 

/* Prints also some state that isn't saved in the pt_regs */ 
void show_regs(struct pt_regs * regs)
{
	unsigned long cr0 = 0L, cr2 = 0L, cr3 = 0L, cr4 = 0L, fs, gs, shadowgs;
	unsigned int fsindex,gsindex;
	unsigned int ds,cs,es; 

	printk("\n");
	printk("Pid: %d, comm: %.20s %s\n", current->pid, current->comm, print_tainted());
	printk("RIP: %04lx:", regs->cs & 0xffff);
	printk_address(regs->rip); 
	printk("\nRSP: %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);
	printk("RDX: %016lx RSI: %016lx RDI: %016lx\n",
	       regs->rdx, regs->rsi, regs->rdi); 
	printk("RBP: %016lx R08: %016lx R09: %016lx\n",
	       regs->rbp, regs->r8, regs->r9); 
	printk("R10: %016lx R11: %016lx R12: %016lx\n",
	       regs->r10, regs->r11, regs->r12); 
	printk("R13: %016lx R14: %016lx R15: %016lx\n",
	       regs->r13, regs->r14, regs->r15); 

	asm("movl %%ds,%0" : "=r" (ds)); 
	asm("movl %%cs,%0" : "=r" (cs)); 
	asm("movl %%es,%0" : "=r" (es)); 
	asm("movl %%fs,%0" : "=r" (fsindex));
	asm("movl %%gs,%0" : "=r" (gsindex));

	rdmsrl(MSR_FS_BASE, fs);
	rdmsrl(MSR_GS_BASE, gs); 
	rdmsrl(MSR_KERNEL_GS_BASE, shadowgs); 

	asm("movq %%cr0, %0": "=r" (cr0));
	asm("movq %%cr2, %0": "=r" (cr2));
	asm("movq %%cr3, %0": "=r" (cr3));
	asm("movq %%cr4, %0": "=r" (cr4));

	printk("FS:  %016lx(%04x) GS:%016lx(%04x) knlGS:%016lx\n", 
	       fs,fsindex,gs,gsindex,shadowgs); 
	printk("CS:  %04x DS: %04x ES: %04x CR0: %016lx\n", cs, ds, es, cr0); 
	printk("CR2: %016lx CR3: %016lx CR4: %016lx\n", cr2, cr3, cr4);
}

/*
 * No need to lock the MM as we are the last user
 */
void release_segments(struct mm_struct *mm)
{
	void * ldt = mm->context.segments;

	/*
	 * free the LDT
	 */
	if (ldt) {
		mm->context.segments = NULL;
		clear_LDT();
		vfree(ldt);
	}
}

/* 
 * Free current thread data structures etc..
 */
void exit_thread(void)
{
	struct task_struct *me = current;
	if (me->thread.io_bitmap_ptr) { 
		(init_tss + smp_processor_id())->io_map_base = 
			INVALID_IO_BITMAP_OFFSET;  
		kfree(me->thread.io_bitmap_ptr); 
		me->thread.io_bitmap_ptr = NULL; 		
	} 
}

void flush_thread(void)