kernel: exit: Handle killings of kernel threads

Signed-off-by: Ian Moffett <ian@osmora.org>

4 files changed, 19 insertions, 10 deletions

diff --git a/sys/include/sys/proc.h b/sys/include/sys/proc.h
index 1b59de9..7b03672 100644
--- a/sys/include/sys/proc.h
+++ b/sys/include/sys/proc.h
@@ -84,6 +84,11 @@ struct proc {
 #define PROC_LEAFQ      BIT(3)  /* Leaf queue is active */
 #define PROC_WAITED     BIT(4)  /* Being waited on by parent */
 
+/*
+ * Flags for exit1()
+ */
+#define EXIT_KTD     BIT(0)  /* Kill a kernel thread */
+
 struct proc *this_td(void);
 struct proc *get_child(struct proc *cur, pid_t pid);
 int md_spawn(struct proc *p, struct proc *parent, uintptr_t ip);
@@ -95,7 +100,7 @@ void md_td_stackinit(struct proc *td, void *stack_top, struct exec_prog *prog);
 __dead void md_td_kick(struct proc *td);
 
 int fork1(struct proc *cur, int flags, void(*ip)(void), struct proc **newprocp);
-int exit1(struct proc *td);
+int exit1(struct proc *td, int flags);
 __dead scret_t sys_exit(struct syscall_args *scargs);
 
 #endif  /* _KERNEL */
diff --git a/sys/kern/kern_exit.c b/sys/kern/kern_exit.c
index d6c9168..da1e3cf 100644
--- a/sys/kern/kern_exit.c
+++ b/sys/kern/kern_exit.c
@@ -40,7 +40,7 @@
 #define pr_error(...) pr_trace(__VA_ARGS__)
 
 static void
-unload_td(struct proc *td)
+unload_td(struct proc *td, int flags)
 {
     const struct auxval *auxvalp;
     struct exec_prog *execp;
@@ -49,6 +49,10 @@ unload_td(struct proc *td)
     size_t len;
 
     sched_detach(td);
+    if (ISSET(flags, EXIT_KTD)) {
+        return;
+    }
+
     execp = &td->exec;
     auxvalp = &execp->auxval;
     pcbp = &td->pcb;
@@ -79,7 +83,7 @@ unload_td(struct proc *td)
  * @td: Thread to exit
  */
 int
-exit1(struct proc *td)
+exit1(struct proc *td, int flags)
 {
     struct pcb *pcbp;
     struct proc *curtd, *procp;
@@ -97,7 +101,7 @@ exit1(struct proc *td)
     /* If we have any children, kill them too */
     if (td->nleaves > 0) {
         TAILQ_FOREACH(procp, &td->leafq, leaf_link) {
-            exit1(procp);
+            exit1(procp, flags);
         }
     }
 
@@ -110,7 +114,7 @@ exit1(struct proc *td)
         stack -= VM_HIGHER_HALF;
     }
 
-    unload_td(td);
+    unload_td(td, flags);
     vm_unmap(pcbp->addrsp, td->stack_base, PROC_STACK_SIZE);
     vm_free_frame(stack, PROC_STACK_PAGES);
     pmap_destroy_vas(pcbp->addrsp);
@@ -145,6 +149,6 @@ sys_exit(struct syscall_args *scargs)
     struct proc *td = this_td();
 
     td->exit_status = scargs->arg0;
-    exit1(td);
+    exit1(td, 0);
     __builtin_unreachable();
 }
diff --git a/sys/kern/kern_spawn.c b/sys/kern/kern_spawn.c
index cb898dc..032ba24 100644
--- a/sys/kern/kern_spawn.c
+++ b/sys/kern/kern_spawn.c
@@ -84,7 +84,7 @@ spawn_thunk(void)
 
     if (execve(cur, &execve_args) != 0) {
         pr_error("execve failed, aborting\n");
-        exit1(this_td());
+        exit1(this_td(), 0);
     }
     __builtin_unreachable();
 }
diff --git a/sys/kern/kern_stub.c b/sys/kern/kern_stub.c
index 1a5fb0e..fa1be65 100644
--- a/sys/kern/kern_stub.c
+++ b/sys/kern/kern_stub.c
@@ -41,7 +41,7 @@ sigfpe_default(int signo)
 
     td = this_td();
     kprintf("Floating point exception (pid=%d)\n", td->pid);
-    exit1(td);
+    exit1(td, 0);
 }
 
 void
@@ -51,7 +51,7 @@ sigkill_default(int signo)
 
     td = this_td();
     kprintf("Terminated (pid=%d)\n", td->pid);
-    exit1(td);
+    exit1(td, 0);
 }
 
 void
@@ -61,7 +61,7 @@ sigsegv_default(int signo)
 
     td = this_td();
     kprintf("Segmentation fault (pid=%d)\n", td->pid);
-    exit1(td);
+    exit1(td, 0);
 }
 
 int