Put the task pid in the thread name

kernel/exec.c

@@ -594,11 +594,7 @@ int __do_execve(const char *file, struct exec_args argv, struct exec_args envp)
     strncpy(current->comm, basename, sizeof(current->comm));
     unlock(&current->general_lock);
 
-    // set the thread name
-    char threadname[16];
-    strncpy(threadname, current->comm, sizeof(threadname)-1);
-    threadname[15] = '\0';
-    set_thread_name(threadname);
+    update_thread_name();
 
     // cloexec
     // consider putting this in fd.c?

kernel/task.c

@@ -104,7 +104,7 @@ void task_run_current() {
 
 static void *task_thread(void *task) {
     current = task;
-    set_thread_name(current->comm);
+    update_thread_name();
     task_run_current();
     die("task_thread returned"); // above function call should never return
 }
@@ -125,3 +125,16 @@ int_t sys_sched_yield() {
     sched_yield();
     return 0;
 }
+
+void update_thread_name() {
+    char name[16]; // As long as Linux will let us make this
+    snprintf(name, sizeof(name), "-%d", current->pid);
+    size_t pid_width = strlen(name);
+    size_t name_width = snprintf(name, sizeof(name), "%s", current->comm);
+    sprintf(name + (name_width < sizeof(name) - 1 - pid_width ? name_width : sizeof(name) - 1 - pid_width), "-%d", current->pid);
+#if __APPLE__
+    pthread_setname_np(name);
+#else
+    pthread_setname_np(pthread_self(), name);
+#endif
+}

kernel/task.h

@@ -170,4 +170,8 @@ extern void (*exit_hook)(struct task *task, int code);
 
 #define superuser() (current != NULL && current->euid == 0)
 
+// Update the thread name to match the current task, in the format "comm-pid".
+// Will ensure that the -pid part always fits, then will fit as much of comm as possible.
+void update_thread_name(void);
+
 #endif

util/sync.h

@@ -148,10 +148,4 @@ static inline void sigunwind_end() {
     should_unwind = false;
 }
 
-#if __APPLE__
-#define set_thread_name(threadname) pthread_setname_np(threadname)
-#else
-#define set_thread_name(threadname) pthread_setname_np(pthread_self(), threadname)
-#endif
-
 #endif