Report fatal error if JIT cannot be enabled

Closes GH-12403

Author: danog

NEWS

@@ -26,6 +26,8 @@ MBString:
 
 Opcache:
   . Added large shared segments support for FreeBSD. (David Carlier)
+  . If JIT is enabled, PHP will now exit with a fatal error on startup in case
+    of JIT startup initialization issues. (danog)
 
 PDO_PGSQL:
   . Fixed GH-12423, DSN credentials being prioritized over the user/password

UPGRADING

@@ -163,6 +163,10 @@ PHP 8.4 UPGRADE NOTES
   . Added mb_trim, mb_ltrim and mb_rtrim functions.
     RFC: https://wiki.php.net/rfc/mb_trim
 
+- Opcache:
+  . If JIT is enabled, PHP will now exit with a fatal error on startup in case
+    of JIT startup initialization issues.
+
 ========================================
 7. New Classes and Interfaces
 ========================================

ext/opcache/ZendAccelerator.c

@@ -3248,16 +3248,13 @@ static zend_result accel_post_startup(void)
 		zend_shared_alloc_lock();
 #ifdef HAVE_JIT
 		if (JIT_G(enabled)) {
-			if (JIT_G(buffer_size) == 0
-		     || !ZSMMG(reserved)
-			 || zend_jit_startup(ZSMMG(reserved), jit_size, reattached) != SUCCESS) {
+			if (JIT_G(buffer_size) == 0) {
 				JIT_G(enabled) = false;
 				JIT_G(on) = false;
-				/* The JIT is implicitly disabled with opcache.jit_buffer_size=0, so we don't want to
-				 * emit a warning here. */
-				if (JIT_G(buffer_size) != 0) {
-					zend_accel_error(ACCEL_LOG_WARNING, "Could not enable JIT!");
-				}
+			} else if (!ZSMMG(reserved)) {
+				zend_accel_error_noreturn(ACCEL_LOG_FATAL, "Could not enable JIT: could not use reserved buffer!");
+			} else {
+				zend_jit_startup(ZSMMG(reserved), jit_size, reattached);
 			}
 		}
 #endif

ext/opcache/jit/zend_jit.c

@@ -3419,7 +3419,7 @@ ZEND_EXT_API int zend_jit_check_support(void)
 	return SUCCESS;
 }
 
-ZEND_EXT_API int zend_jit_startup(void *buf, size_t size, bool reattached)
+ZEND_EXT_API void zend_jit_startup(void *buf, size_t size, bool reattached)
 {
 	zend_jit_halt_op = zend_get_halt_op();
 	zend_jit_profile_counter_rid = zend_get_op_array_extension_handle(ACCELERATOR_PRODUCT_NAME);
@@ -3494,24 +3494,16 @@ ZEND_EXT_API int zend_jit_startup(void *buf, size_t size, bool reattached)
 	}
 
 	zend_jit_unprotect();
-	if (zend_jit_setup() != SUCCESS) {
-		zend_jit_protect();
-		// TODO: error reporting and cleanup ???
-		return FAILURE;
-	}
+	zend_jit_setup();
 	zend_jit_protect();
 	zend_jit_init_handlers();
 
-	if (zend_jit_trace_startup(reattached) != SUCCESS) {
-		return FAILURE;
-	}
+	zend_jit_trace_startup(reattached);
 
 	zend_jit_unprotect();
 	/* save JIT buffer pos */
 	dasm_ptr[1] = dasm_ptr[0];
 	zend_jit_protect();
-
-	return SUCCESS;
 }
 
 ZEND_EXT_API void zend_jit_shutdown(void)

ext/opcache/jit/zend_jit.h

@@ -158,7 +158,7 @@ ZEND_EXT_API void zend_jit_init(void);
 ZEND_EXT_API int  zend_jit_config(zend_string *jit_options, int stage);
 ZEND_EXT_API int  zend_jit_debug_config(zend_long old_val, zend_long new_val, int stage);
 ZEND_EXT_API int  zend_jit_check_support(void);
-ZEND_EXT_API int  zend_jit_startup(void *jit_buffer, size_t size, bool reattached);
+ZEND_EXT_API void zend_jit_startup(void *jit_buffer, size_t size, bool reattached);
 ZEND_EXT_API void zend_jit_shutdown(void);
 ZEND_EXT_API void zend_jit_activate(void);
 ZEND_EXT_API void zend_jit_deactivate(void);

ext/opcache/jit/zend_jit_ir.c

@@ -2869,7 +2869,7 @@ static void *zend_jit_ir_compile(ir_ctx *ctx, size_t *size, const char *name)
 	return entry;
 }
 
-static int zend_jit_setup_stubs(void)
+static void zend_jit_setup_stubs(void)
 {
 	zend_jit_ctx jit;
 	void *entry;
@@ -2888,7 +2888,7 @@ static int zend_jit_setup_stubs(void)
 		entry = zend_jit_ir_compile(&jit.ctx, &size, zend_jit_stubs[i].name);
 		if (!entry) {
 			zend_jit_free_ctx(&jit);
-			return 0;
+			zend_accel_error_noreturn(ACCEL_LOG_FATAL, "Could not enable JIT: could not compile stub");
 		}
 
 		zend_jit_stub_handlers[i] = entry;
@@ -2920,7 +2920,6 @@ static int zend_jit_setup_stubs(void)
 		}
 		zend_jit_free_ctx(&jit);
 	}
-	return 1;
 }
 
 #define REGISTER_HELPER(n)  \
@@ -3121,7 +3120,7 @@ static void zend_jit_setup_disasm(void)
 #endif
 }
 
-static int zend_jit_calc_trace_prologue_size(void)
+static void zend_jit_calc_trace_prologue_size(void)
 {
 	zend_jit_ctx jit_ctx;
 	zend_jit_ctx *jit = &jit_ctx;
@@ -3142,11 +3141,10 @@ static int zend_jit_calc_trace_prologue_size(void)
 	zend_jit_free_ctx(jit);
 
 	if (!entry) {
-		return 0;
+		zend_accel_error_noreturn(ACCEL_LOG_FATAL, "Could not enable JIT: could not compile prologue");
 	}
 
 	zend_jit_trace_prologue_size = size;
-	return 1;
 }
 
 #if !ZEND_WIN32 && !defined(IR_TARGET_AARCH64)
@@ -3197,12 +3195,11 @@ static zend_never_inline void zend_jit_set_sp_adj_vm(void)
 }
 #endif
 
-static int zend_jit_setup(void)
+static void zend_jit_setup(void)
 {
 #if defined(IR_TARGET_X86)
 	if (!zend_cpu_supports_sse2()) {
-		zend_error(E_CORE_ERROR, "CPU doesn't support SSE2");
-		return FAILURE;
+		zend_accel_error_noreturn(ACCEL_LOG_FATAL, "Could not enable JIT: CPU doesn't support SSE2");
 	}
 #endif
 #if defined(IR_TARGET_X86) || defined(IR_TARGET_X64)
@@ -3235,8 +3232,7 @@ static int zend_jit_setup(void)
 			offset += sizeof(void*);
 		}
 		if (offset >= size) {
-			// TODO: error message ???
-			return FAILURE;
+			zend_accel_error_noreturn(ACCEL_LOG_FATAL, "Could not enable JIT: offset >= size");
 		}
 	} while(0);
 # elif ZEND_WIN32
@@ -3259,8 +3255,7 @@ static int zend_jit_setup(void)
 			offset += sizeof(void*);
 		}
 		if (offset >= size) {
-			// TODO: error message ???
-			return FAILURE;
+			zend_accel_error_noreturn(ACCEL_LOG_FATAL, "Could not enable JIT: offset >= size");
 		}
 	} while(0);
 # elif defined(__APPLE__) && defined(__x86_64__)
@@ -3345,17 +3340,9 @@ static int zend_jit_setup(void)
 			ZEND_JIT_DEBUG_IR_AFTER_SCCP|ZEND_JIT_DEBUG_IR_AFTER_SCHEDULE|ZEND_JIT_DEBUG_IR_AFTER_REGS);
 	}
 
-	if (!zend_jit_calc_trace_prologue_size()) {
-	    JIT_G(debug) = debug;
-		return FAILURE;
-	}
-	if (!zend_jit_setup_stubs()) {
-	    JIT_G(debug) = debug;
-		return FAILURE;
-	}
+	zend_jit_calc_trace_prologue_size();
+	zend_jit_setup_stubs();
 	JIT_G(debug) = debug;
-
-	return SUCCESS;
 }
 
 static void zend_jit_shutdown_ir(void)

ext/opcache/jit/zend_jit_trace.c

@@ -46,16 +46,16 @@ static zend_always_inline const char *zend_jit_trace_star_desc(uint8_t trace_fla
 	}
 }
 
-static int zend_jit_trace_startup(bool reattached)
+static void zend_jit_trace_startup(bool reattached)
 {
 	if (!reattached) {
 		zend_jit_traces = (zend_jit_trace_info*)zend_shared_alloc(sizeof(zend_jit_trace_info) * JIT_G(max_root_traces));
 		if (!zend_jit_traces) {
-			return FAILURE;
+			zend_accel_error_noreturn(ACCEL_LOG_FATAL, "Could not allocate JIT root traces buffer!");
 		}
 		zend_jit_exit_groups = (const void**)zend_shared_alloc(sizeof(void*) * (ZEND_JIT_TRACE_MAX_EXITS/ZEND_JIT_EXIT_POINTS_PER_GROUP));
 		if (!zend_jit_exit_groups) {
-			return FAILURE;
+			zend_accel_error_noreturn(ACCEL_LOG_FATAL, "Could not allocate JIT exit groups buffer!");
 		}
 		ZEND_JIT_TRACE_NUM = 1;
 		ZEND_JIT_COUNTER_NUM = 0;
@@ -67,11 +67,11 @@ static int zend_jit_trace_startup(bool reattached)
 	} else {
 		zend_jit_traces = ZCSG(jit_traces);
 		if (!zend_jit_traces) {
-			return FAILURE;
+			zend_accel_error_noreturn(ACCEL_LOG_FATAL, "Could not obtain JIT traces buffer!");
 		}
 		zend_jit_exit_groups = ZCSG(jit_exit_groups);
 		if (!zend_jit_exit_groups) {
-			return FAILURE;
+			zend_accel_error_noreturn(ACCEL_LOG_FATAL, "Could not obtain JIT exit groups buffer!");
 		}
 	}
 
@@ -80,10 +80,8 @@ static int zend_jit_trace_startup(bool reattached)
 
 	JIT_G(exit_counters) = calloc(JIT_G(max_exit_counters), 1);
 	if (JIT_G(exit_counters) == NULL) {
-		return FAILURE;
+		zend_accel_error_noreturn(ACCEL_LOG_FATAL, "Could not allocate JIT exit counters buffer!");
 	}
-
-	return SUCCESS;
 }
 
 static const void *zend_jit_trace_allocate_exit_point(uint32_t n)