JIT: add missing endbr

PR php#8774 added IBT support for jitted code and passed all built-in tests in
"ext/opcache/tests/jit". However, we found several "missing ENDBR" issues
recently when running some real world workloads.

Such workloads introduce new code path and thus more "indirect branch target"
are in jited code. This fix adds missing endbr correspondingly.

Signed-off-by: PeterYang12 <yuhan.yang@intel.com>
Reviewed-by:   chen-hu-97  <hu1.chen@intel.com>
Reviewed-by:   bjzhjing    <cathy.zhang@intel.com>

Author: PeterYang12

ext/opcache/jit/zend_jit_x86.dasc

@@ -1640,8 +1640,14 @@ static size_t tsrm_tls_offset;
 
 #if defined (__CET__) && (__CET__ & 1) != 0
 # define ENDBR_PADDING 4
+/* Keep 16 exit points in a single code block */
+#	define ZEND_JIT_EXIT_POINTS_SPACING   8  // endbr + push byte + short jmp = bytes
+#	define ZEND_JIT_EXIT_POINTS_PER_GROUP 16 // number of continuous exit points
 #else
 # define ENDBR_PADDING 0
+/* Keep 32 exit points in a single code block */
+#	define ZEND_JIT_EXIT_POINTS_SPACING   4  // push byte + short jmp = bytes
+#	define ZEND_JIT_EXIT_POINTS_PER_GROUP 32 // number of continuous exit points
 #endif
 
 static bool reuse_ip = 0;
@@ -2605,18 +2611,16 @@ static int zend_jit_trace_escape_stub(dasm_State **Dst)
 	return 1;
 }
 
-/* Keep 32 exit points in a single code block */
-#define ZEND_JIT_EXIT_POINTS_SPACING   4  // push byte + short jmp = bytes
-#define ZEND_JIT_EXIT_POINTS_PER_GROUP 32 // number of continuous exit points
-
 static int zend_jit_trace_exit_group_stub(dasm_State **Dst, uint32_t n)
 {
 	uint32_t i;
 
 	for (i = 0; i < ZEND_JIT_EXIT_POINTS_PER_GROUP - 1; i++) {
+		|	ENDBR
 		|	push byte i
-		|	.byte 0xeb, (4*(ZEND_JIT_EXIT_POINTS_PER_GROUP-i)-6) // jmp >1
+		|	.byte 0xeb, (ZEND_JIT_EXIT_POINTS_SPACING*(ZEND_JIT_EXIT_POINTS_PER_GROUP-i)-ZEND_JIT_EXIT_POINTS_SPACING -2) // jmp >1
 	}
+	|	ENDBR
 	|	push byte i
 	|// 1:
 	|	add aword [r4], n
@@ -3126,6 +3130,7 @@ static int zend_jit_set_ip(dasm_State **Dst, const zend_op *opline)
 
 static int zend_jit_set_ip_ex(dasm_State **Dst, const zend_op *opline, bool set_ip_reg)
 {
+	|	ENDBR
 	if (last_valid_opline == opline) {
 		zend_jit_use_last_valid_opline();
 	} else if (GCC_GLOBAL_REGS && last_valid_opline) {
@@ -3214,6 +3219,7 @@ static int zend_jit_check_exception_undef_result(dasm_State **Dst, const zend_op
 
 static int zend_jit_trace_begin(dasm_State **Dst, uint32_t trace_num, zend_jit_trace_info *parent, uint32_t exit_num)
 {
+	|	ENDBR
 	zend_regset regset = ZEND_REGSET_SCRATCH;
 
 #if ZTS
@@ -15026,13 +15032,15 @@ static int zend_jit_switch(dasm_State **Dst, const zend_op *opline, const zend_o
 					} while (count);
 					|.code
 					|3:
+					|	ENDBR
 				} else {
 					|	LOAD_ADDR FCARG1a, jumptable
 					|	EXT_CALL zend_hash_index_find, r0
 					if (!zend_jit_hash_jmp(Dst, opline, op_array, ssa, jumptable, default_b, default_label, next_opline, trace_info)) {
 						return 0;
 					}
 					|3:
+					|	ENDBR
 				}
 			}
 		} else if (opline->opcode == ZEND_SWITCH_STRING) {
@@ -15074,6 +15082,7 @@ static int zend_jit_switch(dasm_State **Dst, const zend_op *opline, const zend_o
 					return 0;
 				}
 				|3:
+				|	ENDBR
 			}
 		} else if (opline->opcode == ZEND_MATCH) {
 			if (op1_info & (MAY_BE_LONG|MAY_BE_STRING)) {