os-xv6/kernel/sysproc.c

#include "types.h"
#include "riscv.h"
#include "defs.h"
#include "param.h"
#include "memlayout.h"
#include "spinlock.h"
#include "proc.h"
#include "sysinfo.h"

uint64
sys_exit(void)
{
  int n;
  argint(0, &n);
  exit(n);
  return 0;  // not reached
}

uint64
sys_getpid(void)
{
  return myproc()->pid;
}

uint64
sys_fork(void)
{
  return fork();
}

uint64
sys_wait(void)
{
  uint64 p;
  argaddr(0, &p);
  return wait(p);
}

uint64
sys_sbrk(void)
{
  uint64 addr;
  int n;

  argint(0, &n);
  addr = myproc()->sz;
  if(growproc(n) < 0)
    return -1;
  return addr;
}

uint64
sys_sleep(void)
{
  int n;
  uint ticks0;

  argint(0, &n);
  if(n < 0)
    n = 0;
  acquire(&tickslock);
  ticks0 = ticks;
  while(ticks - ticks0 < n){
    if(killed(myproc())){
      release(&tickslock);
      return -1;
    }
    sleep(&ticks, &tickslock);
  }
  release(&tickslock);
  return 0;
}

uint64
sys_kill(void)
{
  int pid;

  argint(0, &pid);
  return kill(pid);
}

// return how many clock tick interrupts have occurred
// since start.
uint64
sys_uptime(void)
{
  uint xticks;

  acquire(&tickslock);
  xticks = ticks;
  release(&tickslock);
  return xticks;
}


// 声明 kalloc.c 中的 freemem() 和 proc.c 中的 procinfo()
extern uint64 freemem(void);
extern void procinfo(uint64 *, uint64 *);

uint64
sys_sysinfo(void)
{
  uint64 user_sysinfo_addr;  // 用户态传入的 struct sysinfo 指针（虚拟地址）
  struct sysinfo kinfo;      // 内核态临时结构体（避免直接操作用户态内存）
  uint64 nproc, unused_proc_num;

  // 1. 读取用户态传入的第一个参数：struct sysinfo * 指针
  argaddr(0, &user_sysinfo_addr);  // 参数读取失败，返回错误

  // 2. 收集系统信息
  kinfo.freemem = freemem();  // 统计空闲内存
  procinfo(&nproc, &unused_proc_num);  // 统计进程数
  kinfo.nproc = nproc;
  kinfo.unused_proc_num = unused_proc_num;

  // 3. 将内核态的 kinfo 复制到用户态地址（用户态指针指向的空间）
  // copyout 参数：进程页表、用户态目标地址、内核态源地址、复制字节数
  if (copyout(myproc()->pagetable, user_sysinfo_addr,(char *)&kinfo, sizeof(kinfo)) < 0) {
    return -1;  // 复制失败，返回错误
  }

  return 0;  // 成功返回 0
}


uint64 sys_trace(void){
	int n;
	argint(0, &n);
	struct proc *p = myproc();

	char *mask = p->mask;

	int i = 0;

	while(i < 24 && n > 0){
		if(n % 2){
			mask[i++] = '1';
		}else{
			mask[i++] = '0';
		}
		n >>= 1;
	}

	return 0;
}