erts: Fix ASSERT crash in erts_try_seize_code_write_permission

ASSERT(code_writing_process != c_p);

The assert was actually harmless and could be removed as one solution.
But I think it's better to keep it as a way to catch bugs that would
otherwise lead to horrible deadlocks if a thread "forgets" to call
erts_release_code_write_permission().

As a result erts_release_code_write_permission() must be called BEFORE
resuming the suspended process.

1 files changed, 4 insertions, 4 deletions

diff --git a/erts/emulator/beam/beam_bif_load.c b/erts/emulator/beam/beam_bif_load.c
index e0a4f86d2d..73264214ce 100644
--- a/erts/emulator/beam/beam_bif_load.c
+++ b/erts/emulator/beam/beam_bif_load.c
@@ -389,16 +389,16 @@ static void smp_code_ix_commiter(void* null)
     Process* p = commiter_state.stager;
 
     erts_commit_staging_code_ix();
+#ifdef DEBUG
+    commiter_state.stager = NULL;
+#endif
+    erts_release_code_write_permission();
     erts_smp_proc_lock(p, ERTS_PROC_LOCK_STATUS);
     if (!ERTS_PROC_IS_EXITING(p)) {
 	erts_resume(p, ERTS_PROC_LOCK_STATUS);
     }
     erts_smp_proc_unlock(p, ERTS_PROC_LOCK_STATUS);
     erts_smp_proc_dec_refc(p);
-#ifdef DEBUG
-    commiter_state.stager = NULL;
-#endif
-    erts_release_code_write_permission();
 }
 #endif /* ERTS_SMP */