Fix phpGH-13232: Segmentation fault will be reported when JIT is off but JIT_debug is still on

Closes phpGH-13234.

Author: nielsdos

NEWS

@@ -20,6 +20,10 @@ PHP                                                                        NEWS
   . Fixed bug GH-12107 (When running a stored procedure (that returns a result
     set) twice, PHP crashes). (nielsdos)
 
+- Opcache:
+  . Fixed bug GH-13232 (Segmentation fault will be reported when JIT is off but
+    JIT_debug is still on). (nielsdos)
+
 - OpenSSL:
   . Fixed LibreSSL undefined reference when OPENSSL_NO_ENGINE not set.
    (David Carlier).

ext/opcache/jit/zend_jit.c

@@ -5040,7 +5040,7 @@ ZEND_EXT_API int zend_jit_startup(void *buf, size_t size, bool reattached)
 
 ZEND_EXT_API void zend_jit_shutdown(void)
 {
-	if (JIT_G(debug) & ZEND_JIT_DEBUG_SIZE) {
+	if (JIT_G(debug) & ZEND_JIT_DEBUG_SIZE && dasm_ptr != NULL) {
 		fprintf(stderr, "\nJIT memory usage: %td\n", (ptrdiff_t)((char*)*dasm_ptr - (char*)dasm_buf));
 	}
 

ext/opcache/tests/jit/gh13232.phpt

@@ -0,0 +1,13 @@
+--TEST--
+GH-13232 (Segmentation fault will be reported when JIT is off but JIT_debug is still on)
+--INI--
+opcache.enable=1
+opcache.enable_cli=1
+opcache.jit=disable
+opcache.jit_debug=0xfffff
+--FILE--
+<?php
+echo "Done\n";
+?>
+--EXPECT--
+Done