2LS op for handling reflected faults

[akaros.git] / user / pthread / pthread.c

diff --git a/user/pthread/pthread.c b/user/pthread/pthread.c
index af378f9..a1eafb2 100644 (file)
--- a/user/pthread/pthread.c
+++ b/user/pthread/pthread.c
@@ -39,6 +39,8 @@ void pth_thread_runnable(struct uthread *uthread);
 void pth_thread_paused(struct uthread *uthread);
 void pth_thread_blockon_sysc(struct uthread *uthread, void *sysc);
 void pth_thread_has_blocked(struct uthread *uthread, int flags);
+void pth_thread_refl_fault(struct uthread *uthread, unsigned int trap_nr,
+                           unsigned int err, unsigned long aux);
 void pth_preempt_pending(void);
 void pth_spawn_thread(uintptr_t pc_start, void *data);
 
@@ -51,6 +53,7 @@ struct schedule_ops pthread_sched_ops = {
        pth_thread_paused,
        pth_thread_blockon_sysc,
        pth_thread_has_blocked,
+       pth_thread_refl_fault,
        0, /* pth_preempt_pending, */
        0, /* pth_spawn_thread, */
 };
@@ -223,7 +226,6 @@ void pth_thread_blockon_sysc(struct uthread *uthread, void *syscall)
 {
        struct syscall *sysc = (struct syscall*)syscall;
        int old_flags;
-       bool need_to_restart = FALSE;
        uint32_t vcoreid = vcore_id();
        /* rip from the active queue */
        struct pthread_tcb *pthread = (struct pthread_tcb*)uthread;
@@ -256,6 +258,44 @@ void pth_thread_has_blocked(struct uthread *uthread, int flags)
                printf("For great justice!\n");
 }
 
+void pth_thread_refl_fault(struct uthread *uthread, unsigned int trap_nr,
+                           unsigned int err, unsigned long aux)
+{
+       struct pthread_tcb *pthread = (struct pthread_tcb*)uthread;
+       pthread->state = PTH_BLK_SYSC;
+       mcs_pdr_lock(&queue_lock);
+       threads_active--;
+       TAILQ_REMOVE(&active_queue, pthread, next);
+       mcs_pdr_unlock(&queue_lock);
+
+       if (trap_nr != 14) {
+               printf("Pthread has unhandled fault\n");
+               print_user_context(&uthread->u_ctx);
+               exit(-1);
+       }
+
+       if (!(err & PF_VMR_BACKED)) {
+               /* TODO: put your SIGSEGV handling here */
+               printf("Pthread page faulted outside a VMR\n");
+               print_user_context(&uthread->u_ctx);
+               exit(-1);
+       }
+       /* stitching for the event handler.  sysc -> uth, uth -> sysc */
+       uthread->local_sysc.u_data = uthread;
+       uthread->sysc = &uthread->local_sysc;
+       pthread->state = PTH_BLK_SYSC;
+       /* one downside is that we'll never check the return val of the syscall.  if
+        * we errored out, we wouldn't know til we PF'd again, and inspected the old
+        * retval/err and other sysc fields (make sure the PF is on the same addr,
+        * etc).  could run into this issue on truncated files too. */
+       syscall_async(&uthread->local_sysc, SYS_populate_va, aux, 1);
+       if (!register_evq(&uthread->local_sysc, sysc_mgmt[vcore_id()].ev_q)) {
+               /* Lost the race with the call being done.  The kernel won't send the
+                * event.  Just restart him. */
+               restart_thread(&uthread->local_sysc);
+       }
+}
+
 void pth_preempt_pending(void)
 {
 }