[runtime] Unbalanced GC Unsafe transitions before shutdown (mono/mono#17566)

When embedders call mono_runtime_quit or mono_jit_cleanup, we need to do unbalanced transitions to GC Unsafe, because after mini_cleanup runs we don't have GC thread states anymore and MONO_EXIT_GC_UNSAFE will assert.

* [runtime] Do an unbalanced GC Unsafe transition in mono_jit_cleanup

After mini_cleanup, we don't have GC thread states anymore because all that
stuff was cleaned up, so MONO_EXIT_GC_UNSAFE would assert

* [runtime] Mark mono_runtime_quit external only.

Runtime should use mono_runtime_quit_internal.

After we call the quit_function (aka mini_cleanup) we don't have any GC thread
states anymore because all that stuff got cleaned up.  So MONO_EXIT_GC_UNSAFE
can't work.

Commit migrated from https://github.com/mono/mono/commit/0e3caf00df54199be88cfcb53ed847226defebb4

diff --git a/src/mono/mono/metadata/appdomain.c b/src/mono/mono/metadata/appdomain.c
index 63b86b4..d742b92 100644 (file)
--- a/src/mono/mono/metadata/appdomain.c
+++ b/src/mono/mono/metadata/appdomain.c
@@ -547,8 +547,26 @@ mono_install_runtime_cleanup (MonoDomainFunc func)
  * mono_runtime_quit:
  */
 void
-mono_runtime_quit ()
+mono_runtime_quit (void)
 {
+       MONO_STACKDATA (dummy);
+       (void) mono_threads_enter_gc_unsafe_region_unbalanced_internal (&dummy);
+       // after quit_function (in particular, mini_cleanup) everything is
+       // cleaned up so MONO_EXIT_GC_UNSAFE can't work and doesn't make sense.
+       
+       mono_runtime_quit_internal ();
+}
+
+/**
+ * mono_runtime_quit_internal:
+ */
+void
+mono_runtime_quit_internal (void)
+{
+       MONO_REQ_GC_UNSAFE_MODE;
+       // but note that when we return, we're not in GC Unsafe mode anymore.
+       // After clean up threads don't _have_ a thread state anymore.
+       
        if (quit_function != NULL)
                quit_function (mono_get_root_domain (), NULL);
 }

diff --git a/src/mono/mono/metadata/appdomain.h b/src/mono/mono/metadata/appdomain.h
index fc82e19..ab26064 100644 (file)
--- a/src/mono/mono/metadata/appdomain.h
+++ b/src/mono/mono/metadata/appdomain.h
@@ -49,7 +49,7 @@ mono_runtime_cleanup       (MonoDomain *domain);
 MONO_API void
 mono_install_runtime_cleanup (MonoDomainFunc func);
 
-MONO_API void
+MONO_API MONO_RT_EXTERNAL_ONLY void
 mono_runtime_quit (void);
 
 MONO_API void

diff --git a/src/mono/mono/metadata/coree.c b/src/mono/mono/metadata/coree.c
index 4f09ece..cee0560 100644 (file)
--- a/src/mono/mono/metadata/coree.c
+++ b/src/mono/mono/metadata/coree.c
@@ -98,7 +98,7 @@ BOOL STDMETHODCALLTYPE _CorDllMain(HINSTANCE hInst, DWORD dwReason, LPVOID lpRes
                        if (error) {
                                g_free (error);
                                g_free (file_name);
-                               mono_runtime_quit ();
+                               mono_runtime_quit_internal ();
                                return FALSE;
                        }
 
@@ -172,7 +172,7 @@ __int32 STDMETHODCALLTYPE _CorExeMain(void)
                g_free (corlib_version_error);
                g_free (file_name);
                MessageBox (NULL, L"Corlib not in sync with this runtime.", NULL, MB_ICONERROR);
-               mono_runtime_quit ();
+               mono_runtime_quit_internal ();
                ExitProcess (1);
        }
 
@@ -183,7 +183,7 @@ __int32 STDMETHODCALLTYPE _CorExeMain(void)
        if (!assembly) {
                g_free (file_name);
                MessageBox (NULL, L"Cannot open assembly.", NULL, MB_ICONERROR);
-               mono_runtime_quit ();
+               mono_runtime_quit_internal ();
                ExitProcess (1);
        }
 
@@ -192,7 +192,7 @@ __int32 STDMETHODCALLTYPE _CorExeMain(void)
        if (!entry) {
                g_free (file_name);
                MessageBox (NULL, L"Assembly doesn't have an entry point.", NULL, MB_ICONERROR);
-               mono_runtime_quit ();
+               mono_runtime_quit_internal ();
                ExitProcess (1);
        }
 
@@ -201,7 +201,7 @@ __int32 STDMETHODCALLTYPE _CorExeMain(void)
                g_free (file_name);
                mono_error_cleanup (error); /* FIXME don't swallow the error */
                MessageBox (NULL, L"The entry point method could not be loaded.", NULL, MB_ICONERROR);
-               mono_runtime_quit ();
+               mono_runtime_quit_internal ();
                ExitProcess (1);
        }
 
@@ -216,7 +216,7 @@ __int32 STDMETHODCALLTYPE _CorExeMain(void)
        mono_error_raise_exception_deprecated (error); /* OK, triggers unhandled exn handler */
        mono_thread_manage_internal ();
 
-       mono_runtime_quit ();
+       mono_runtime_quit_internal ();
 
        /* return does not terminate the process. */
        ExitProcess (mono_environment_exitcode_get ());
@@ -231,7 +231,7 @@ void STDMETHODCALLTYPE CorExitProcess(int exitCode)
        if (mono_get_root_domain () && !mono_runtime_is_shutting_down ()) {
                mono_runtime_set_shutting_down ();
                mono_thread_suspend_all_other_threads ();
-               mono_runtime_quit ();
+               mono_runtime_quit_internal ();
        }
 #endif
        ExitProcess (exitCode);

diff --git a/src/mono/mono/metadata/domain-internals.h b/src/mono/mono/metadata/domain-internals.h
index 3cd9eb5..e783a27 100644 (file)
--- a/src/mono/mono/metadata/domain-internals.h
+++ b/src/mono/mono/metadata/domain-internals.h
@@ -507,6 +507,9 @@ typedef void (*MonoFreeDomainFunc) (MonoDomain *domain);
 void
 mono_install_free_domain_hook (MonoFreeDomainFunc func);
 
+void
+mono_runtime_quit_internal (void);
+
 void 
 mono_cleanup (void);
 

diff --git a/src/mono/mono/metadata/icall.c b/src/mono/mono/metadata/icall.c
index 07ed114..daca2a9 100644 (file)
--- a/src/mono/mono/metadata/icall.c
+++ b/src/mono/mono/metadata/icall.c
@@ -7670,7 +7670,7 @@ ves_icall_System_Environment_Exit (int result)
        mono_thread_suspend_all_other_threads ();
 #endif
 
-       mono_runtime_quit ();
+       mono_runtime_quit_internal ();
 
        /* we may need to do some cleanup here... */
        exit (result);

diff --git a/src/mono/mono/metadata/runtime.c b/src/mono/mono/metadata/runtime.c
index d779517..36164b8 100644 (file)
--- a/src/mono/mono/metadata/runtime.c
+++ b/src/mono/mono/metadata/runtime.c
@@ -121,7 +121,7 @@ mono_runtime_try_shutdown (void)
        /*TODO move the follow to here:
        mono_thread_suspend_all_other_threads (); OR  mono_thread_wait_all_other_threads
 
-       mono_runtime_quit ();
+       mono_runtime_quit_internal ();
        */
 
        return TRUE;

diff --git a/src/mono/mono/mini/debugger-agent.c b/src/mono/mono/mini/debugger-agent.c
index c1acdbb..d681e25 100644 (file)
--- a/src/mono/mono/mini/debugger-agent.c
+++ b/src/mono/mono/mini/debugger-agent.c
@@ -7001,7 +7001,7 @@ vm_commands (int command, int id, guint8 *p, guint8 *end, Buffer *buf)
                        mono_thread_suspend_all_other_threads ();
 #endif
                        DEBUG_PRINTF (1, "Shutting down the runtime...\n");
-                       mono_runtime_quit ();
+                       mono_runtime_quit_internal ();
                        transport_close2 ();
                        DEBUG_PRINTF (1, "Exiting...\n");
 

diff --git a/src/mono/mono/mini/driver.c b/src/mono/mono/mini/driver.c
index 0adee5f..9b5c3b9 100644 (file)
--- a/src/mono/mono/mini/driver.c
+++ b/src/mono/mono/mini/driver.c
@@ -2798,11 +2798,16 @@ mono_jit_init_version_for_test_only (const char *domain_name, const char *runtim
 void        
 mono_jit_cleanup (MonoDomain *domain)
 {
-       MONO_ENTER_GC_UNSAFE;
+       MONO_STACKDATA (dummy);
+       (void) mono_threads_enter_gc_unsafe_region_unbalanced_internal (&dummy);
+
+       // after mini_cleanup everything is cleaned up so MONO_EXIT_GC_UNSAFE
+       // can't work and doesn't make sense.
+
        mono_thread_manage_internal ();
 
        mini_cleanup (domain);
-       MONO_EXIT_GC_UNSAFE;
+
 }
 
 void