sys_x86_64.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/sys_x86_64.c
 */

#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/sem.h>
#include <linux/msg.h>
#include <linux/shm.h>
#include <linux/stat.h>
#include <linux/mman.h>
#include <linux/file.h>
#include <linux/utsname.h>
#include <linux/personality.h>

#include <asm/uaccess.h>
#include <asm/ipc.h>

/*
 * sys_pipe() is the normal C calling standard for creating
 * a pipe. It's not the way Unix traditionally does this, though.
 */
asmlinkage long sys_pipe(unsigned long * fildes)
{
	int fd[2];
	int error;

	error = do_pipe(fd);
	if (!error) {
		if (copy_to_user(fildes, fd, 2*sizeof(int)))
			error = -EFAULT;
	}
	return error;
}

long sys_mmap(unsigned long addr, unsigned long len, unsigned long prot, unsigned long flags,
	unsigned long fd, unsigned long off)
{
	long error;
	struct file * file;

	error = -EINVAL;
	if (off & ~PAGE_MASK)
		goto out;

	error = -EBADF;
	file = NULL;
	flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
	if (!(flags & MAP_ANONYMOUS)) {
		file = fget(fd);
		if (!file)
			goto out;
	}

	down_write(&current->mm->mmap_sem);
	error = do_mmap_pgoff(file, addr, len, prot, flags, off >> PAGE_SHIFT);
	up_write(&current->mm->mmap_sem);

	if (file)
		fput(file);
out:
	return error;
}


unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags)
{
	struct vm_area_struct *vma;
	unsigned long end = TASK_SIZE;

	if (current->thread.flags & THREAD_IA32) {
		if (!addr) 
			addr = TASK_UNMAPPED_32;
		end = 0xffff0000;
	} else if (flags & MAP_32BIT) { 
		/* This is usually used needed to map code in small
		   model: it needs to be in the first 31bit. Limit it
		   to that.  This means we need to move the unmapped
		   base down for this case.  This may give conflicts
		   with the heap, but we assume that malloc falls back
		   to mmap. Give it 1GB of playground for now. -AK */ 
		if (!addr) 
			addr = 0x40000000; 
		end = 0x80000000;		
	} else { 
		if (!addr) 
			addr = TASK_UNMAPPED_64; 
		end = TASK_SIZE; 
		}

	if (len > end)
		return -ENOMEM;
	addr = PAGE_ALIGN(addr);

	for (vma = find_vma(current->mm, addr); ; vma = vma->vm_next) {
		/* At this point:  (!vma || addr < vma->vm_end). */
		if (end - len < addr)
			return -ENOMEM;
		if (!vma || addr + len <= vma->vm_start)
			return addr;
		addr = vma->vm_end;
	}
}

asmlinkage long sys_uname(struct new_utsname * name)
{
	int err;
	down_read(&uts_sem);
	err=copy_to_user(name, &system_utsname, sizeof (*name));
	up_read(&uts_sem);
	if (personality(current->personality) == PER_LINUX32)
		err = copy_to_user(name->machine, "i686", 5);
	return err?-EFAULT:0;
}


asmlinkage long wrap_sys_shmat(int shmid, char *shmaddr, int shmflg)
{
	unsigned long raddr;
	return sys_shmat(shmid,shmaddr,shmflg,&raddr) ?: raddr;
}