/*
* Called when a thread receives an async exception while executing unmanaged code.
* Instead of checking for this exception in the managed-to-native wrapper, we hijack
* the return address on the stack to point to a helper routine which throws the
* exception.
*/
void
mono_arch_notify_pending_exc (MonoThreadInfo *info)
{
MonoLMF *lmf = mono_get_lmf ();
if (!info) {
lmf = mono_get_lmf ();
} else {
g_assert (info->thread_saved_state [ASYNC_SUSPEND_STATE_INDEX].valid);
lmf = info->thread_saved_state [ASYNC_SUSPEND_STATE_INDEX].unwind_data [MONO_UNWIND_DATA_LMF];
}
if (!lmf)
/* Not yet started */
return;
if (lmf->rsp == 0)
/* Initial LMF */
return;
if ((guint64)lmf->previous_lmf & 1)
/* Already hijacked or trampoline LMF entry */
return;
/* lmf->rsp is set just before making the call which transitions to unmanaged code */
lmf->rip = *(guint64*)(lmf->rsp - 8);
/* Signal that lmf->rip is set */
lmf->previous_lmf = (gpointer)((guint64)lmf->previous_lmf | 1);
*(gpointer*)(lmf->rsp - 8) = throw_pending_exception;
}
guint64
mono_amd64_get_original_ip (void)
{
MonoLMF *lmf = mono_get_lmf ();
g_assert (lmf);
/* Reset the change to previous_lmf */
lmf->previous_lmf = (gpointer)((guint64)lmf->previous_lmf & ~1);
return lmf->rip;
}
static int
continuation_store (MonoContinuation *cont, int state, MonoException **e)
{
MonoLMF *lmf = mono_get_lmf ();
gsize num_bytes;
if (!cont->domain) {
*e = mono_get_exception_argument ("cont", "Continuation not initialized");
return 0;
}
if (cont->domain != mono_domain_get () || cont->thread_id != GetCurrentThreadId ()) {
*e = mono_get_exception_argument ("cont", "Continuation from another thread or domain");
return 0;
}
cont->lmf = lmf;
cont->return_ip = __builtin_return_address (0);
cont->return_sp = __builtin_frame_address (0);
num_bytes = (char*)cont->top_sp - (char*)cont->return_sp;
/*g_print ("store: %d bytes, sp: %p, ip: %p, lmf: %p\n", num_bytes, cont->return_sp, cont->return_ip, lmf);*/
if (cont->saved_stack && num_bytes <= cont->stack_alloc_size) {
/* clear to avoid GC retention */
if (num_bytes < cont->stack_used_size) {
memset ((char*)cont->saved_stack + num_bytes, 0, cont->stack_used_size - num_bytes);
}
cont->stack_used_size = num_bytes;
} else {
tasklets_lock ();
internal_init ();
if (cont->saved_stack) {
mono_g_hash_table_remove (keepalive_stacks, cont->saved_stack);
mono_gc_free_fixed (cont->saved_stack);
}
cont->stack_used_size = num_bytes;
cont->stack_alloc_size = num_bytes * 1.1;
cont->saved_stack = mono_gc_alloc_fixed (cont->stack_alloc_size, NULL);
mono_g_hash_table_insert (keepalive_stacks, cont->saved_stack, cont->saved_stack);
tasklets_unlock ();
}
memcpy (cont->saved_stack, cont->return_sp, num_bytes);
return state;
}
static int
continuation_store (MonoContinuation *cont, int state, MonoException **e)
{
MonoLMF *lmf = mono_get_lmf ();
gsize num_bytes;
if (!cont->domain) {
*e = mono_get_exception_argument ("cont", "Continuation not initialized");
return 0;
}
if (cont->domain != mono_domain_get () || !mono_native_thread_id_equals (cont->thread_id, mono_native_thread_id_get ())) {
*e = mono_get_exception_argument ("cont", "Continuation from another thread or domain");
return 0;
}
cont->lmf = lmf;
cont->return_ip = __builtin_extract_return_addr (__builtin_return_address (0));
cont->return_sp = __builtin_frame_address (0);
num_bytes = (char*)cont->top_sp - (char*)cont->return_sp;
/*g_print ("store: %d bytes, sp: %p, ip: %p, lmf: %p\n", num_bytes, cont->return_sp, cont->return_ip, lmf);*/
if (cont->saved_stack && num_bytes <= cont->stack_alloc_size) {
/* clear to avoid GC retention */
if (num_bytes < cont->stack_used_size) {
memset ((char*)cont->saved_stack + num_bytes, 0, cont->stack_used_size - num_bytes);
}
cont->stack_used_size = num_bytes;
} else {
tasklets_lock ();
internal_init ();
if (cont->saved_stack)
mono_gc_free_fixed (cont->saved_stack);
cont->stack_used_size = num_bytes;
cont->stack_alloc_size = num_bytes * 1.1;
cont->saved_stack = mono_gc_alloc_fixed (cont->stack_alloc_size, NULL, MONO_ROOT_SOURCE_THREADING, "saved tasklet stack");
tasklets_unlock ();
}
memcpy (cont->saved_stack, cont->return_sp, num_bytes);
return state;
}
static MonoException*
continuation_mark_frame (MonoContinuation *cont)
{
MonoJitTlsData *jit_tls;
MonoLMF *lmf;
MonoContext ctx, new_ctx;
MonoJitInfo *ji, rji;
int endloop = FALSE;
if (cont->domain)
return mono_get_exception_argument ("cont", "Already marked");
jit_tls = (MonoJitTlsData *)mono_native_tls_get_value (mono_jit_tls_id);
lmf = mono_get_lmf();
cont->domain = mono_domain_get ();
cont->thread_id = mono_native_thread_id_get ();
/* get to the frame that called Mark () */
memset (&rji, 0, sizeof (rji));
memset (&ctx, 0, sizeof (ctx));
do {
ji = mono_find_jit_info (cont->domain, jit_tls, &rji, NULL, &ctx, &new_ctx, NULL, &lmf, NULL, NULL);
if (!ji || ji == (gpointer)-1) {
return mono_get_exception_not_supported ("Invalid stack frame");
}
ctx = new_ctx;
if (endloop)
break;
if (!ji->is_trampoline && strcmp (jinfo_get_method (ji)->name, "Mark") == 0)
endloop = TRUE;
} while (1);
cont->top_sp = MONO_CONTEXT_GET_SP (&ctx);
/*g_print ("method: %s, sp: %p\n", jinfo_get_method (ji)->name, cont->top_sp);*/
return NULL;
}
/*
* Called when a thread receives an async exception while executing unmanaged code.
* Instead of checking for this exception in the managed-to-native wrapper, we hijack
* the return address on the stack to point to a helper routine which throws the
* exception.
*/
void
mono_arch_notify_pending_exc (void)
{
MonoLMF *lmf = mono_get_lmf ();
if (!lmf)
/* Not yet started */
return;
if (lmf->rsp == 0)
/* Initial LMF */
return;
if ((guint64)lmf->previous_lmf & 1)
/* Already hijacked or trampoline LMF entry */
return;
/* lmf->rsp is set just before making the call which transitions to unmanaged code */
lmf->rip = *(guint64*)(lmf->rsp - 8);
/* Signal that lmf->rip is set */
lmf->previous_lmf = (gpointer)((guint64)lmf->previous_lmf | 1);
*(gpointer*)(lmf->rsp - 8) = throw_pending_exception;
}
