Fix kill deadlock.

Cargo.lock

@@ -226,7 +226,7 @@ checksum = "64072665120942deff5fd5425d6c1811b854f4939e7f1c01ce755f64432bbea7"
 
 [[package]]
 name = "redox_syscall"
-version = "0.5.2"
+version = "0.5.3"
 dependencies = [
  "bitflags 2.4.2",
 ]

src/scheme/proc.rs

@@ -1,7 +1,12 @@
 use crate::{
     arch::paging::{Page, RmmA, RmmArch, VirtualAddress},
     context::{
-        self, context::{HardBlockedReason, SignalState}, file::{FileDescriptor, InternalFlags}, memory::{handle_notify_files, AddrSpaceWrapper, Grant, PageSpan}, process::{self, Process, ProcessId, ProcessInfo}, Context, ContextRef, Status
+        self,
+        context::{HardBlockedReason, SignalState},
+        file::{FileDescriptor, InternalFlags},
+        memory::{handle_notify_files, AddrSpaceWrapper, Grant, PageSpan},
+        process::{self, Process, ProcessId, ProcessInfo},
+        Context, ContextRef, Status,
     },
     memory::PAGE_SIZE,
     ptrace,
@@ -1419,7 +1424,11 @@ impl ContextHandle {
                 {
                     let process = Arc::clone(&context.read().process);
                     let mut process = process.write();
-                    if let Some(pos) = process.threads.iter().position(|p| Weak::as_ptr(p) == Arc::as_ptr(&context)) {
+                    if let Some(pos) = process
+                        .threads
+                        .iter()
+                        .position(|p| Weak::as_ptr(p) == Arc::as_ptr(&context))
+                    {
                         process.threads.remove(pos);
                     }
                 }

src/syscall/process.rs

@@ -7,7 +7,9 @@ use rmm::Arch;
 use spin::RwLock;
 
 use crate::context::{
-    memory::{AddrSpace, Grant, PageSpan}, process::{self, Process, ProcessId, ProcessInfo, ProcessStatus}, Context, ContextRef, WaitpidKey
+    memory::{AddrSpace, Grant, PageSpan},
+    process::{self, Process, ProcessId, ProcessInfo, ProcessStatus},
+    Context, ContextRef, WaitpidKey,
 };
 
 use crate::{
@@ -234,6 +236,7 @@ pub fn kill(pid: ProcessId, sig: usize, parent_sigchld: bool) -> Result<usize> {
                     pgid: proc_info.pgid,
                 };
             }
+            drop(process_guard);
             let mut context_guard = context_lock.write();
             if sig == SIGSTOP
                 || (matches!(sig, SIGTTIN | SIGTTOU | SIGTSTP)