user_access从指定地址写入数据到用户空间时kernel panic

[val213]

描述错误
内核panic（崩溃）。从日志中可以看出，崩溃发生在src/syscall/user_access.rs文件的第299行，第13列。错误信息表明，源切片的长度（4）与目标切片的长度（1）不匹配。

   /// 从指定地址写入数据到用户空间
    ///
    /// @param data 要写入的数据地址
    /// @param offset 在UserBuffer中的字节偏移量
    /// @return 返回写入元素的数量
    ///
    pub fn copy_to_user<T: core::marker::Copy>(
        &'a mut self,
        src: &[T],
        offset: usize,
    ) -> Result<usize, SystemError> {
        let dst = Self::convert_with_offset(self.buffer, offset)?;
        dst.copy_from_slice(src);
        return Ok(src.len());
    }

这是一个典型的数组越界错误，意味着在程序中尝试将一个长度为4的切片复制到一个长度为1的切片中，这显然是不可能的，因此导致了内核panic。解决这个问题的方法可能是检查代码中负责复制切片的地方，确保源切片的索引不会超出其长度，并且目标切片的空间足够存放源切片的数据。

重现步骤
执行dog example.com --tls @dns.google或者执行dog example.com --https @https://cloudflare-dns.com/dns-query。

期望行为
正常得到返回的结果。

屏幕截图

其他上下文

dog支持 DoT (DNS-over-TLS) 传输系统。 默认情况下，使用DoT的查询将通过端口853发送。通过TLS通信通道发送DNS查询的目的是防止在查询或响应在公共Internet上传输时被窃听或修改。

dog支持 DoH (DNS-over-HTTPS) 传输系统。 默认情况下，使用DoH的查询将通过端口443(标准HTTPS端口)发送。像 DNS-over-tls 一样，通过HTTPS发送DNS查询的目的是防止在公共互联网上传输的查询或响应被窃听或修改。 通过与Web使用的HTTPS流量使用相同的端口和协议，可以实现DNS流量的融合，避免被检测到或阻断。与其他传输类型不同，HTTPS协议需要一个完整的URL，包括路径和协议，作为名称服务器。注意:查找名称服务器的IP地址是由操作系统执行的，而不是由dog执行的。

系统日志

�[41m[ ERROR ] �[0m(src/lib.rs:109)	 Kernel Panic Occurred.
Location:
	File: src/syscall/user_access.rs
	Line: 299, Column: 13
Message:
	source slice length (4) does not match destination slice length (1)
Rust Panic Backtrace:
function:rust_begin_unwind() 	(+) 0754 address:0xffff800001043f92
function:ore::panicking::panic_fmt() 	(+) 0049 address:0xffff80000121b431
function:ore::slice::<impl [T]>::copy_from_slice::len_mismatch_fail() 	(+) 0112 address:0xffff800001219920
function:dragonos_kernel::syscall::misc::<impl dragonos_kernel::syscall::Syscall>::get_random() 	(+) 0679 address:0xffff800001028327
function:dragonos_kernel::syscall::Syscall::handle() 	(+) 6178 address:0xffff800001029da2
function:syscall_handler() 	(+) 0262 address:0xffff8000010ceb46
Current PCB:
	ProcessControlBlock { pid: Pid(20), tgid: Pid(20), basic: RwLock { lock: 0, data: UnsafeCell { .. } }, preempt_count: 0, flags: LockFreeFlags { inner: (empty) }, worker_private: SpinLock { lock: false, data: UnsafeCell { .. } }, kernel_stack: RwLock { lock: 0, data: UnsafeCell { .. } }, syscall_stack: RwLock { lock: 0, data: UnsafeCell { .. } }, sched_info: ProcessSchedulerInfo { on_cpu: AtomicProcessorId { container: 0 }, migrate_to: AtomicProcessorId { container: 0 }, inner_locked: RwLock { lock: 0, data: UnsafeCell { .. } }, priority: SchedPriority(100), virtual_runtime: 61092, rt_time_slice: 0 }, arch_info: SpinLock { lock: false, data: UnsafeCell { .. } }, sig_info: RwLock { lock: 0, data: UnsafeCell { .. } }, sig_struct: SpinLock { lock: false, data: UnsafeCell { .. } }, exit_signal: SIGCHLD, parent_pcb: RwLock { lock: 0, data: UnsafeCell { .. } }, real_parent_pcb: RwLock { lock: 0, data: UnsafeCell { .. } }, children: RwLock { lock: 0, data: UnsafeCell { .. } }, wait_queue: WaitQueue(SpinLock { lock: false, data: UnsafeCell { .. } }), thread: RwLock { lock: 0, data: UnsafeCell { .. } } }
�[92mroot@DragonOS�[0m:�[96m/�[0m$ �[18G�[18Gdog example.com --https @https://cloudflare-dns.com/dns-query�[18Gdog banana                                                   �[28G�[18Gdog non-exist  --short�[18Gdog example.com A AAAA MX TXT --json�[18Gdog example.com --https @https://cloudflare-dns.com/dns-query�[18Gdog example.com --tls @dns.google                            �[51G
�[1;33m[ WARN ] �[0m(src/syscall/mod.rs:794)	 SYS_POLL has not yet been implemented
�[1;33m[ WARN ] �[0m(src/syscall/mod.rs:804)	 SYS_RT_SIGPROCMASK has not yet been implemented
�[1;33m[ WARN ] �[0m(src/syscall/mod.rs:814)	 SYS_SIGALTSTACK has not yet been implemented
�[1;33m[ WARN ] �[0m(src/syscall/mod.rs:804)	 SYS_RT_SIGPROCMASK has not yet been implemented
�[1;33m[ WARN ] �[0m(src/syscall/mod.rs:804)	 SYS_RT_SIGPROCMASK has not yet been implemented

�[41m[ ERROR ] �[0m(src/lib.rs:109)	 Kernel Panic Occurred.
Location:
	File: src/syscall/user_access.rs
	Line: 299, Column: 13
Message:
	source slice length (4) does not match destination slice length (1)
Rust Panic Backtrace:
function:rust_begin_unwind() 	(+) 0754 address:0xffff800001043f92
function:ore::panicking::panic_fmt() 	(+) 0049 address:0xffff80000121b431
function:ore::slice::<impl [T]>::copy_from_slice::len_mismatch_fail() 	(+) 0112 address:0xffff800001219920
function:dragonos_kernel::syscall::misc::<impl dragonos_kernel::syscall::Syscall>::get_random() 	(+) 0679 address:0xffff800001028327
function:dragonos_kernel::syscall::Syscall::handle() 	(+) 6178 address:0xffff800001029da2
function:syscall_handler() 	(+) 0262 address:0xffff8000010ceb46
Current PCB:
	ProcessControlBlock { pid: Pid(21), tgid: Pid(21), basic: RwLock { lock: 0, data: UnsafeCell { .. } }, preempt_count: 0, flags: LockFreeFlags { inner: (empty) }, worker_private: SpinLock { lock: false, data: UnsafeCell { .. } }, kernel_stack: RwLock { lock: 0, data: UnsafeCell { .. } }, syscall_stack: RwLock { lock: 0, data: UnsafeCell { .. } }, sched_info: ProcessSchedulerInfo { on_cpu: AtomicProcessorId { container: 0 }, migrate_to: AtomicProcessorId { container: 0 }, inner_locked: RwLock { lock: 0, data: UnsafeCell { .. } }, priority: SchedPriority(100), virtual_runtime: 61700, rt_time_slice: 0 }, arch_info: SpinLock { lock: false, data: UnsafeCell { .. } }, sig_info: RwLock { lock: 0, data: UnsafeCell { .. } }, sig_struct: SpinLock { lock: false, data: UnsafeCell { .. } }, exit_signal: SIGCHLD, parent_pcb: RwLock { lock: 0, data: UnsafeCell { .. } }, real_parent_pcb: RwLock { lock: 0, data: UnsafeCell { .. } }, children: RwLock { lock: 0, data: UnsafeCell { .. } }, wait_queue: WaitQueue(SpinLock { lock: false, data: UnsafeCell { .. } }), thread: RwLock { lock: 0, data: UnsafeCell { .. } } }
�[92mroot@DragonOS�[0m:�[96m/�[0m$ �[18G

[fslongjin]

放一下你仓库版本的那个git日志，可能是你本地的太老了，因为这个问题之前一个多两星期左右的时候已经修了

[val213]

放一下你仓库版本的那个git日志，可能是你本地的太老了，因为这个问题之前一个多两星期左右的时候已经修了

已经同步了最新的commit了，还是kernel panic

[fslongjin]

这个是get_random函数的。可以看看那边，debug一下