Modify signal.rs and sys_kill to support more signals

os/src/syscall/process.rs

@@ -107,7 +107,12 @@ pub fn sys_waitpid(pid: isize, exit_code_ptr: *mut i32) -> isize {
 pub fn sys_kill(pid: usize, signal: u32) -> isize {
     if let Some(task) = pid2task(pid) {
         if let Some(flag) = SignalFlags::from_bits(signal) {
-            task.inner_exclusive_access().signals |= flag;
+            // insert the signal if legal
+            let mut task_ref = task.inner_exclusive_access();
+            if task_ref.pending_signals.contains(flag) {
+                return -1;
+            }
+            task_ref.pending_signals.insert(flag);
             0
         } else {
             -1

os/src/task/signal.rs

@@ -2,11 +2,37 @@ use bitflags::*;
 
 bitflags! {
     pub struct SignalFlags: u32 {
-        const SIGINT    = 1 << 2;
-        const SIGILL    = 1 << 4;
-        const SIGABRT   = 1 << 6;
-        const SIGFPE    = 1 << 8;
-        const SIGSEGV   = 1 << 11;
+        const SIGHUP = 1 << 1;
+        const SIGINT = 1 << 2;
+        const SIGQUIT = 1 << 3;
+        const SIGILL = 1 << 4;
+        const SIGTRAP = 1 << 5;
+        const SIGABRT = 1 << 6;
+        const SIGBUS = 1 << 7;
+        const SIGFPE = 1 << 8;
+        const SIGKILL = 1 << 9;
+        const SIGUSR1 = 1 << 10;
+        const SIGSEGV = 1 << 11;
+        const SIGUSR2 = 1 << 12;
+        const SIGPIPE = 1 << 13;
+        const SIGALRM = 1 << 14;
+        const SIGTERM = 1 << 15;
+        const SIGSTKFLT = 1 << 16;
+        const SIGCHLD = 1 << 17;
+        const SIGCONT = 1 << 18;
+        const SIGSTOP = 1 << 19;
+        const SIGTSTP = 1 << 20;
+        const SIGTTIN = 1 << 21;
+        const SIGTTOU = 1 << 22;
+        const SIGURG = 1 << 23;
+        const SIGXCPU = 1 << 24;
+        const SIGXFSZ = 1 << 25;
+        const SIGVTALRM = 1 << 26;
+        const SIGPROF = 1 << 27;
+        const SIGWINCH = 1 << 28;
+        const SIGIO = 1 << 29;
+        const SIGPWR = 1 << 30;
+        const SIGSYS = 1 << 31;
     }
 }
 

os/src/task/task.rs

@@ -30,6 +30,7 @@ pub struct TaskControlBlockInner {
     pub exit_code: i32,
     pub fd_table: Vec<Option<Arc<dyn File + Send + Sync>>>,
     pub signals: SignalFlags,
+    pub pending_signals: SignalFlags
 }
 
 impl TaskControlBlockInner {
@@ -92,6 +93,7 @@ impl TaskControlBlock {
                         Some(Arc::new(Stdout)),
                     ],
                     signals: SignalFlags::empty(),
+                    pending_signals: SignalFlags::empty()
                 })
             },
         };
@@ -194,6 +196,7 @@ impl TaskControlBlock {
                     exit_code: 0,
                     fd_table: new_fd_table,
                     signals: SignalFlags::empty(),
+                    pending_signals: SignalFlags::empty()
                 })
             },
         });