[aot] Avoid `mono_defaults` when creating trampolines. (#32904)

Fixes https://github.com/mono/mono/issues/19009.

https://github.com/mono/mono/pull/18505 made PLT initialization occur at
image load time. When initializing the PLT for mscorlib,
`mono_defaults.corlib` is not yet initialized.

This change works around this by using `mscorlib_aot_module`--which is
initialized relatively early--instead of `mono_defaults.corlib`. PLT
initialization is also moved slightly later: it now happens after
`use_page_trampolines` has been initialized. The `USE_PAGE_TRAMPOLINES`
macro has also been changed to dereference `mscorlib_aot_module`.

This commit also removes an unused parameter from
`mono_aot_create_specific_trampoline`.

Co-authored-by: imhameed <imhameed@microsoft.com>

diff --git a/src/mono/mono/mini/aot-runtime.c b/src/mono/mono/mini/aot-runtime.c
index 3786bb0..ecf3fff 100644 (file)
--- a/src/mono/mono/mini/aot-runtime.c
+++ b/src/mono/mono/mini/aot-runtime.c
@@ -220,7 +220,7 @@ static gsize aot_code_high_addr = 0;
 static gint32 async_jit_info_size;
 
 #ifdef MONOTOUCH
-#define USE_PAGE_TRAMPOLINES (mono_defaults.corlib->aot_module->use_page_trampolines)
+#define USE_PAGE_TRAMPOLINES (mscorlib_aot_module->use_page_trampolines)
 #else
 #define USE_PAGE_TRAMPOLINES 0
 #endif
@@ -2426,10 +2426,6 @@ load_aot_module (MonoAssemblyLoadContext *alc, MonoAssembly *assembly, gpointer
 
        init_amodule_got (amodule, TRUE);
 
-       if (info->flags & MONO_AOT_FILE_FLAG_WITH_LLVM)
-               /* Directly called methods might make calls through the PLT */
-               init_plt (amodule);
-
        if (amodule->jit_code_start)
                mono_jit_info_add_aot_module (assembly->image, amodule->jit_code_start, amodule->jit_code_end);
        if (amodule->llvm_code_start)
@@ -2444,6 +2440,10 @@ load_aot_module (MonoAssemblyLoadContext *alc, MonoAssembly *assembly, gpointer
                /*g_warning ("using page trampolines: %d", amodule->use_page_trampolines);*/
        }
 
+       if (info->flags & MONO_AOT_FILE_FLAG_WITH_LLVM)
+               /* Directly called methods might make calls through the PLT */
+               init_plt (amodule);
+
        /*
         * Register the plt region as a single trampoline so we can unwind from this code
         */
@@ -5537,13 +5537,12 @@ read_page_trampoline_uwinfo (MonoTrampInfo *info, int tramp_type, gboolean is_ge
        else
                g_assert_not_reached ();
 
-       read_unwind_info (mono_defaults.corlib->aot_module, info, symbol_name);
+       read_unwind_info (mscorlib_aot_module, info, symbol_name);
 }
 
 static unsigned char*
 get_new_trampoline_from_page (int tramp_type)
 {
-       MonoAotModule *amodule;
        MonoImage *image;
        TrampolinePage *page;
        int count;
@@ -5565,13 +5564,11 @@ get_new_trampoline_from_page (int tramp_type)
                return code;
        }
        mono_aot_page_unlock ();
-       /* the trampoline template page is in the mscorlib module */
-       image = mono_defaults.corlib;
-       g_assert (image);
 
        psize = MONO_AOT_TRAMP_PAGE_SIZE;
 
-       amodule = image->aot_module;
+       /* the trampoline template page is in the mscorlib module */
+       MonoAotModule *amodule = mscorlib_aot_module;
        g_assert (amodule);
 
        if (tramp_type == MONO_AOT_TRAMP_SPECIFIC)
@@ -5795,7 +5792,7 @@ no_specific_trampoline (void)
  * Return a specific trampoline from the AOT file.
  */
 gpointer
-mono_aot_create_specific_trampoline (MonoImage *image, gpointer arg1, MonoTrampolineType tramp_type, MonoDomain *domain, guint32 *code_len)
+mono_aot_create_specific_trampoline (gpointer arg1, MonoTrampolineType tramp_type, MonoDomain *domain, guint32 *code_len)
 {
        MonoAotModule *amodule;
        guint32 got_offset, tramp_size;
@@ -6024,7 +6021,7 @@ mono_aot_get_lazy_fetch_trampoline (guint32 slot)
 {
        char *symbol;
        gpointer code;
-       MonoAotModule *amodule = mono_defaults.corlib->aot_module;
+       MonoAotModule *amodule = mscorlib_aot_module;
        guint32 index = MONO_RGCTX_SLOT_INDEX (slot);
        static int count = 0;
 
@@ -6046,7 +6043,7 @@ mono_aot_get_lazy_fetch_trampoline (guint32 slot)
        }
 
        symbol = mono_get_rgctx_fetch_trampoline_name (slot);
-       code = load_function (mono_defaults.corlib->aot_module, symbol);
+       code = load_function (amodule, symbol);
        g_free (symbol);
        /* The caller expects an ftnptr */
        return mono_create_ftnptr (mono_domain_get (), code);
@@ -6360,7 +6357,7 @@ mono_aot_get_plt_info_offset (host_mgreg_t *regs, guint8 *code)
 }
 
 gpointer
-mono_aot_create_specific_trampoline (MonoImage *image, gpointer arg1, MonoTrampolineType tramp_type, MonoDomain *domain, guint32 *code_len)
+mono_aot_create_specific_trampoline (gpointer arg1, MonoTrampolineType tramp_type, MonoDomain *domain, guint32 *code_len)
 {
        g_assert_not_reached ();
        return NULL;

diff --git a/src/mono/mono/mini/aot-runtime.h b/src/mono/mono/mini/aot-runtime.h
index 55cd639..1f5537c 100644 (file)
--- a/src/mono/mono/mini/aot-runtime.h
+++ b/src/mono/mono/mini/aot-runtime.h
@@ -247,7 +247,7 @@ MonoJitInfo* mono_aot_find_jit_info         (MonoDomain *domain, MonoImage *imag
 gpointer mono_aot_plt_resolve               (gpointer aot_module, guint32 plt_info_offset, guint8 *code, MonoError *error);
 void     mono_aot_patch_plt_entry           (guint8 *code, guint8 *plt_entry, gpointer *got, host_mgreg_t *regs, guint8 *addr);
 gpointer mono_aot_get_method_from_vt_slot   (MonoDomain *domain, MonoVTable *vtable, int slot, MonoError *error);
-gpointer mono_aot_create_specific_trampoline   (MonoImage *image, gpointer arg1, MonoTrampolineType tramp_type, MonoDomain *domain, guint32 *code_len);
+gpointer mono_aot_create_specific_trampoline   (gpointer arg1, MonoTrampolineType tramp_type, MonoDomain *domain, guint32 *code_len);
 gpointer mono_aot_get_trampoline            (const char *name);
 gpointer mono_aot_get_trampoline_full       (const char *name, MonoTrampInfo **out_tinfo);
 gpointer mono_aot_get_unbox_trampoline      (MonoMethod *method, gpointer addr);

diff --git a/src/mono/mono/mini/mini-trampolines.c b/src/mono/mono/mini/mini-trampolines.c
index 0b17c84..55834cd 100644 (file)
--- a/src/mono/mono/mini/mini-trampolines.c
+++ b/src/mono/mono/mini/mini-trampolines.c
@@ -1326,7 +1326,7 @@ mono_create_specific_trampoline (gpointer arg1, MonoTrampolineType tramp_type, M
        guint32 len;
 
        if (mono_aot_only)
-               code = mono_aot_create_specific_trampoline (mono_defaults.corlib, arg1, tramp_type, domain, &len);
+               code = mono_aot_create_specific_trampoline (arg1, tramp_type, domain, &len);
        else
                code = mono_arch_create_specific_trampoline (arg1, tramp_type, domain, &len);
        mono_lldb_save_specific_trampoline_info (arg1, tramp_type, domain, code, len);