diff --git a/kernel/src/arch/x86_64/asm/entry.S b/kernel/src/arch/x86_64/asm/entry.S
index 8df6566cf..9c2c5732c 100644
--- a/kernel/src/arch/x86_64/asm/entry.S
+++ b/kernel/src/arch/x86_64/asm/entry.S
@@ -407,6 +407,11 @@ ENTRY(syscall_64)
     popq %rax
     addq $0x10, %rsp    // 弹出变量FUNC和errcode
 
+    cmpq (%rsp), %rcx
+    jne .L_syscall_must_use_iret
+    cmpq 0x10(%rsp), %r11
+    jne .L_syscall_must_use_iret
+
     popq %rcx           // pop rip到rcx
 
     addq $0x8, %rsp     // 弹出cs
@@ -415,3 +420,9 @@ ENTRY(syscall_64)
 
     swapgs
     sysretq
+
+// 适用于 sigreturn, ptrace, 或任何修改了上下文的情况
+// 此时栈结构完美符合 iretq 要求: [RIP, CS, RFLAGS, RSP, SS]
+.L_syscall_must_use_iret: 
+    swapgs
+    iretq
diff --git a/kernel/src/ipc/syscall/sys_rt_sigtimedwait.rs b/kernel/src/ipc/syscall/sys_rt_sigtimedwait.rs
index 818bd3909..0ac548c41 100644
--- a/kernel/src/ipc/syscall/sys_rt_sigtimedwait.rs
+++ b/kernel/src/ipc/syscall/sys_rt_sigtimedwait.rs
@@ -58,19 +58,12 @@ pub fn do_kernel_rt_sigtimedwait(
         let reader = UserBufferReader::new(uthese, size_of::<SigSet>(), from_user)?;
         let sigset = reader.read_one_from_user::<SigSet>(0)?;
         // 移除不可屏蔽的信号（SIGKILL 和 SIGSTOP）
-        let sigset_val: SigSet = SigSet::from_bits(sigset.bits()).ok_or(SystemError::EINVAL)?;
-        let kill_stop_mask: SigSet =
-            SigSet::from_bits_truncate((Signal::SIGKILL as u64) | (Signal::SIGSTOP as u64));
-        let result = sigset_val & !kill_stop_mask;
-
-        result
+        let mut sigset_val = SigSet::from_bits(sigset.bits()).ok_or(SystemError::EINVAL)?;
+        sigset_val.remove(SigSet::from(Signal::SIGKILL));
+        sigset_val.remove(SigSet::from(Signal::SIGSTOP));
+        sigset_val
     };
 
-    // 如果信号集合为空，直接返回 EINVAL（根据 POSIX 标准）
-    if these.is_empty() {
-        return Err(SystemError::EINVAL);
-    }
-
     // 构造等待/屏蔽语义：与Linux一致
     // - 等待集合 these
     // - 临时屏蔽集合 = 旧blocked ∪ these（将这些信号作为masked的常规语义，但仍由本系统调用专门消费）
@@ -134,13 +127,21 @@ pub fn do_kernel_rt_sigtimedwait(
             }
         }
 
-        // 第四步：释放中断，然后真正进入调度睡眠（窗口期内，线程保持可中断阻塞，发送侧会唤醒）
+        // 第四步：检查是否有其他未屏蔽的待处理信号打断，若被其他信号唤醒了，必须返回 EINTR 让内核去处理那个信号
+        pcb.recalc_sigpending(None);
+        if pcb.has_pending_signal_fast() {
+            drop(preempt_guard);
+            restore_saved_sigmask();
+            return Err(SystemError::EINTR);
+        }
 
+        // 第五步：释放中断，然后真正进入调度睡眠（窗口期内，线程保持可中断阻塞，发送侧会唤醒）
         // 计算剩余等待时间
         let remaining_time = if let Some(deadline) = deadline {
             let now = PosixTimeSpec::now();
             let remaining = deadline.total_nanos() - now.total_nanos();
             if remaining <= 0 {
+                drop(preempt_guard);
                 restore_saved_sigmask();
                 return Err(SystemError::EAGAIN_OR_EWOULDBLOCK);
             }
diff --git a/kernel/src/sched/cputime.rs b/kernel/src/sched/cputime.rs
index f8bec7fcc..0339b499f 100644
--- a/kernel/src/sched/cputime.rs
+++ b/kernel/src/sched/cputime.rs
@@ -88,15 +88,15 @@ impl CpuTimeFunc {
             return;
         }
 
-        if user_tick {
-            pcb.account_utime(cputime);
-        } else {
-            pcb.account_stime(cputime);
-        }
-        pcb.add_sum_exec_runtime(cputime);
+        let accounted_cputime = cputime - other;
+
+        if user_tick {
+            pcb.account_utime(accounted_cputime);
+        } else {
+            pcb.account_stime(accounted_cputime);
+        }
+        pcb.add_sum_exec_runtime(accounted_cputime);
 
-        let cputime_ns = TICK_NESC as u64 * ticks;
-        let accounted_cputime = cputime_ns - other;
         // 检查并处理CPU时间定时器
         let mut itimers = pcb.itimers_irqsave();
         // 处理 ITIMER_VIRTUAL (仅在用户态tick时消耗时间)
diff --git a/user/apps/tests/syscall/gvisor/blocklists/sigreturn_test b/user/apps/tests/syscall/gvisor/blocklists/sigreturn_test
deleted file mode 100644
index 89bd7355d..000000000
--- a/user/apps/tests/syscall/gvisor/blocklists/sigreturn_test
+++ /dev/null
@@ -1,2 +0,0 @@
-# 还在修复中
-SigIretTest.CheckRcxR11
diff --git a/user/apps/tests/syscall/gvisor/blocklists/sigtimedwait_test b/user/apps/tests/syscall/gvisor/blocklists/sigtimedwait_test
new file mode 100644
index 000000000..d46c39df5
--- /dev/null
+++ b/user/apps/tests/syscall/gvisor/blocklists/sigtimedwait_test
@@ -0,0 +1,3 @@
+# getpid() 好像有点问题，还在修
+SigtimedwaitTest.IgnoredUnmaskedSignal
+SigtimedwaitTest.IgnoredMaskedSignal
diff --git a/user/apps/tests/syscall/gvisor/whitelist.txt b/user/apps/tests/syscall/gvisor/whitelist.txt
index bd5bca749..69760d340 100644
--- a/user/apps/tests/syscall/gvisor/whitelist.txt
+++ b/user/apps/tests/syscall/gvisor/whitelist.txt
@@ -57,6 +57,7 @@ sigaction_test
 sigprocmask_test
 sigaltstack_test
 sigreturn_test
+sigtimedwait_test
 
 # 其他测试
 itimer_test