feat(syscall): 实现syscall restart

能够在系统调用返回ERESTARTSYS时,信号处理结束后,自动重启系统调用. TODO: 实现wait等需要restart_block的系统调用的重启 Signed-off-by: longjin <[email protected]>
DragonOS-Community · Dec 10, 2024 · 6868946 · 6868946
1 parent 72423f9
commit 6868946
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diff --git a/kernel/Cargo.toml b/kernel/Cargo.toml
@@ -76,6 +76,7 @@ unwinding = { git = "https://git.mirrors.dragonos.org.cn/DragonOS-Community/unwi
     "panic",
     "personality"
 ]}
+defer = "0.2.1"
 
 # target为x86_64时，使用下面的依赖
 [target.'cfg(target_arch = "x86_64")'.dependencies]
@@ -106,4 +107,4 @@ debug = true   # Controls whether the compiler passes `-g`
 
 # The release profile, used for `cargo build --release`
 [profile.release]
-debug = false
+debug = true
diff --git a/kernel/crates/system_error/Cargo.toml b/kernel/crates/system_error/Cargo.toml
@@ -7,4 +7,4 @@ edition = "2021"
 
 [dependencies]
 num-traits = { git = "https://git.mirrors.dragonos.org.cn/DragonOS-Community/num-traits.git", rev="1597c1c", default-features = false }
-num-derive = "0.3"
+num-derive = "0.3"
diff --git a/kernel/crates/system_error/src/lib.rs b/kernel/crates/system_error/src/lib.rs
@@ -277,31 +277,51 @@ pub enum SystemError {
 
     // === 以下错误码不应该被用户态程序使用 ===
     ERESTARTSYS = 512,
+    ERESTARTNOINTR = 513,
+    /// restart if no handler
+    ERESTARTNOHAND = 514,
+
+    /// 没有对应的ioctlcmd
+    ENOIOCTLCMD = 515,
+    /// restart by calling sys restart syscall
+    ERESTART_RESTARTBLOCK = 516,
+
+    // === TODO: 这几个KVM的错误码不要放在这里 ===
+
     // VMX on 虚拟化开启指令出错
-    EVMXONFailed = 513,
+    EVMXONFailed = 1513,
     // VMX off 虚拟化关闭指令出错
-    EVMXOFFFailed = 514,
+    EVMXOFFFailed = 1514,
     // VMX VMWRITE 写入虚拟化VMCS内存出错
-    EVMWRITEFailed = 515,
-    EVMREADFailed = 516,
-    EVMPRTLDFailed = 517,
-    EVMLAUNCHFailed = 518,
-    KVM_HVA_ERR_BAD = 519,
-    /// 没有对应的ioctlcmd
-    ENOIOCTLCMD = 520,
+    EVMWRITEFailed = 1515,
+    EVMREADFailed = 1516,
+    EVMPRTLDFailed = 1517,
+    EVMLAUNCHFailed = 1518,
+    KVM_HVA_ERR_BAD = 1519,
+
+    MAXERRNO = 4095,
 }
 
 impl SystemError {
-    /// @brief 把posix错误码转换为系统错误枚举类型。
+    /// 判断一个值是否是有效的posix错误码。
+    pub fn is_valid_posix_errno<T>(val: T) -> bool
+    where
+        T: PartialOrd + From<i32>,
+    {
+        let max_errno = T::from(-(Self::MAXERRNO as i32));
+        val < T::from(0) && val >= max_errno
+    }
+
+    /// 尝试把posix错误码转换为系统错误枚举类型。
     pub fn from_posix_errno(errno: i32) -> Option<SystemError> {
         // posix 错误码是小于0的
-        if errno >= 0 {
+        if !Self::is_valid_posix_errno(errno) {
             return None;
         }
         return <Self as num_traits::FromPrimitive>::from_i32(-errno);
     }
 
-    /// @brief 把系统错误枚举类型转换为负数posix错误码。
+    /// 把系统错误枚举类型转换为负数posix错误码。
     pub fn to_posix_errno(&self) -> i32 {
         return -<Self as num_traits::ToPrimitive>::to_i32(self).unwrap();
     }

diff --git a/kernel/src/arch/x86_64/asm/entry.S b/kernel/src/arch/x86_64/asm/entry.S
@@ -64,9 +64,9 @@ ENTRY(ret_from_intr)
     // 进入信号处理流程
     cli
 
-    // 将原本要返回的栈帧的栈指针传入do_signal的第一个参数
+    // 将原本要返回的栈帧的栈指针传入irqentry_exit的第一个参数
     movq %rsp, %rdi
-    callq do_signal
+    callq irqentry_exit
     cli
 
 __entry_ret_from_intr_before_gs_check_2:
@@ -375,10 +375,10 @@ ENTRY(syscall_64)
     sti
     callq *%rdx //调用服务程序
 
-    // 将原本要返回的栈帧的栈指针传入do_signal的第一个参数
+    // 将原本要返回的栈帧的栈指针传入 irqentry_exit 的第一个参数
     movq %rsp, %rdi
 
-    callq do_signal
+    callq irqentry_exit
 
     cli
 

diff --git a/kernel/src/arch/x86_64/interrupt/mod.rs b/kernel/src/arch/x86_64/interrupt/mod.rs
@@ -125,6 +125,8 @@ pub struct TrapFrame {
     pub es: ::core::ffi::c_ulong,
     pub rax: ::core::ffi::c_ulong,
     pub func: ::core::ffi::c_ulong,
+    /// - 该字段在异常发生时，保存的是错误码
+    /// - 在系统调用时，由系统调用入口函数将其设置为系统调用号
     pub errcode: ::core::ffi::c_ulong,
     pub rip: ::core::ffi::c_ulong,
     pub cs: ::core::ffi::c_ulong,
@@ -182,6 +184,31 @@ impl TrapFrame {
     pub fn set_pc(&mut self, pc: usize) {
         self.rip = pc as u64;
     }
+
+    /// 获取系统调用号
+    ///
+    /// # Safety
+    /// 该函数只能在系统调用上下文中调用，
+    /// 在其他上下文中，该函数返回值未定义
+    pub unsafe fn syscall_nr(&self) -> Option<usize> {
+        if self.errcode == u64::MAX {
+            return None;
+        }
+        Some(self.errcode as usize)
+    }
+
+    /// 获取系统调用错误码
+    ///
+    /// # Safety
+    /// 该函数只能在系统调用上下文中调用，
+    /// 在其他上下文中，该函数返回值未定义
+    ///
+    /// # Returns
+    /// 返回一个 `Option<SystemError>`，表示系统调用的错误码。
+    pub unsafe fn syscall_error(&self) -> Option<SystemError> {
+        let val = self.rax as i32;
+        SystemError::from_posix_errno(val)
+    }
 }
 
 impl ProbeArgs for TrapFrame {