Fix JIT handling of interrupts

Before, opcode handlers would handle an interrupt and return the next opline to
execute. Now they return interrupt_op so we must execute it to fetch the next
opline.

We cannot call interrupt_op->handler directly as this doesn't return: we need to
call the non-tailcalling helper instead.

Author: arnaud-lb

Zend/zend_vm.h

@@ -32,13 +32,18 @@ ZEND_API void ZEND_FASTCALL zend_serialize_opcode_handler(zend_op *op);
 ZEND_API void ZEND_FASTCALL zend_deserialize_opcode_handler(zend_op *op);
 ZEND_API const void* ZEND_FASTCALL zend_get_opcode_handler_func(const zend_op *op);
 ZEND_API const zend_op *zend_get_halt_op(void);
+ZEND_API const zend_op *zend_get_interrupt_op(void);
 ZEND_API int ZEND_FASTCALL zend_vm_call_opcode_handler(zend_execute_data *ex);
 ZEND_API int zend_vm_kind(void);
 ZEND_API bool zend_gcc_global_regs(void);
 
 void zend_vm_init(void);
 void zend_vm_dtor(void);
 
+#if ZEND_VM_KIND == ZEND_VM_KIND_TAILCALL
+const struct _zend_op *zend_vm_handle_interrupt(struct _zend_execute_data *execute_data, const struct _zend_op *opline);
+#endif
+
 END_EXTERN_C()
 
 #define ZEND_VM_SET_OPCODE_HANDLER(opline) zend_vm_set_opcode_handler(opline)

Zend/zend_vm_execute.h

@@ -161,6 +161,22 @@ ZEND_API const zend_op *zend_get_halt_op(void)
 #endif
 }
 
+ZEND_API const zend_op *zend_get_interrupt_op(void)
+{
+#if ZEND_VM_KIND == ZEND_VM_KIND_TAILCALL
+	return &call_interrupt_op;
+#else
+	return NULL;
+#endif
+}
+
+#if ZEND_VM_KIND == ZEND_VM_KIND_TAILCALL
+ZEND_OPCODE_HANDLER_RET ZEND_OPCODE_HANDLER_FUNC_CCONV zend_vm_handle_interrupt(ZEND_OPCODE_HANDLER_ARGS)
+{
+	return zend_interrupt_helper_SPEC(ZEND_OPCODE_HANDLER_ARGS_PASSTHRU);
+}
+#endif
+
 ZEND_API int zend_vm_kind(void)
 {
 	return ZEND_VM_KIND;

Zend/zend_vm_execute.skl

@@ -78,6 +78,7 @@ int zend_jit_profile_counter_rid = -1;
 int16_t zend_jit_hot_counters[ZEND_HOT_COUNTERS_COUNT];
 
 const zend_op *zend_jit_halt_op = NULL;
+const zend_op *zend_jit_interrupt_op = NULL;
 #ifdef HAVE_PTHREAD_JIT_WRITE_PROTECT_NP
 static int zend_write_protect = 1;
 #endif
@@ -3777,6 +3778,7 @@ int zend_jit_check_support(void)
 void zend_jit_startup(void *buf, size_t size, bool reattached)
 {
 	zend_jit_halt_op = zend_get_halt_op();
+	zend_jit_interrupt_op = zend_get_interrupt_op();
 	zend_jit_profile_counter_rid = zend_get_op_array_extension_handle(ACCELERATOR_PRODUCT_NAME);
 
 #ifdef HAVE_PTHREAD_JIT_WRITE_PROTECT_NP

ext/opcache/jit/zend_jit.c

@@ -177,6 +177,7 @@ typedef struct _zend_jit_op_array_hot_extension {
 	zend_jit_hash((op_array)->opcodes)
 
 extern const zend_op *zend_jit_halt_op;
+extern const zend_op *zend_jit_interrupt_op;
 
 #ifdef HAVE_GCC_GLOBAL_REGS
 # define EXECUTE_DATA_D                       void

ext/opcache/jit/zend_jit_internal.h

@@ -1072,6 +1072,11 @@ zend_jit_trace_stop ZEND_FASTCALL zend_jit_trace_execute(zend_execute_data  *ex,
 		if (UNEXPECTED(opline == zend_jit_halt_op)) {
 #else
 		opline = handler(ZEND_OPCODE_HANDLER_ARGS_PASSTHRU);
+# if ZEND_VM_KIND == ZEND_VM_KIND_TAILCALL
+		while (UNEXPECTED(opline == zend_jit_interrupt_op)) {
+			opline = zend_vm_handle_interrupt(ZEND_OPCODE_HANDLER_ARGS_PASSTHRU);
+		}
+# endif
 		if (UNEXPECTED(((uintptr_t)opline & ~ZEND_VM_ENTER_BIT) == 0)) {
 #endif
 			if (prev_opline->opcode == ZEND_YIELD || prev_opline->opcode == ZEND_YIELD_FROM) {