Disable LSan tls

LSan crashes a lot recently, and it seems to be caused by tls. Since we're not
actually making use of C11s _Thread_local we can set the use_tls=0 option. This
causes a false positive in dlopen() that apprently uses thread locals. We
suppress this with __lsan_disable()/__lsan_enable().

Co-authored-by: ju1ius <[email protected]>

Author: 2 people

Zend/zend_portability.h

@@ -159,18 +159,47 @@
 #  define PHP_RTLD_MODE  RTLD_LAZY
 # endif
 
+# ifdef __SANITIZE_ADDRESS__
+#  include "sanitizer/lsan_interface.h"
+# endif
+
+/* dl uses a thread local variable internally. Due to LSan crashing we're setting use_tls=0, which
+ * will report a leak inside dlopen() that we need to suppress. */
+static inline void *zend_dlopen(const char *file, int mode)
+{
+# ifdef __SANITIZE_ADDRESS__
+	__lsan_disable();
+# endif
+	void *ptr = dlopen(file, mode);
+# ifdef __SANITIZE_ADDRESS__
+	__lsan_enable();
+# endif
+	return ptr;
+}
 # if defined(RTLD_GROUP) && defined(RTLD_WORLD) && defined(RTLD_PARENT)
-#  define DL_LOAD(libname)			dlopen(libname, PHP_RTLD_MODE | RTLD_GLOBAL | RTLD_GROUP | RTLD_WORLD | RTLD_PARENT)
+#  define DL_LOAD(libname)			zend_dlopen(libname, PHP_RTLD_MODE | RTLD_GLOBAL | RTLD_GROUP | RTLD_WORLD | RTLD_PARENT)
 # elif defined(RTLD_DEEPBIND) && !defined(__SANITIZE_ADDRESS__) && !__has_feature(memory_sanitizer)
-#  define DL_LOAD(libname)			dlopen(libname, PHP_RTLD_MODE | RTLD_GLOBAL | RTLD_DEEPBIND)
+#  define DL_LOAD(libname)			zend_dlopen(libname, PHP_RTLD_MODE | RTLD_GLOBAL | RTLD_DEEPBIND)
 # else
-#  define DL_LOAD(libname)			dlopen(libname, PHP_RTLD_MODE | RTLD_GLOBAL)
+#  define DL_LOAD(libname)			zend_dlopen(libname, PHP_RTLD_MODE | RTLD_GLOBAL)
 # endif
+
+static inline void *zend_dlsym(void *__restrict handle, const char *__restrict name)
+{
+# ifdef __SANITIZE_ADDRESS__
+	__lsan_disable();
+# endif
+	void *ptr = dlsym(handle, name);
+# ifdef __SANITIZE_ADDRESS__
+	__lsan_enable();
+# endif
+	return ptr;
+}
 # define DL_UNLOAD					dlclose
 # if defined(DLSYM_NEEDS_UNDERSCORE)
-#  define DL_FETCH_SYMBOL(h,s)		dlsym((h), "_" s)
+#  define DL_FETCH_SYMBOL(h,s)		zend_dlsym((h), "_" s)
 # else
-#  define DL_FETCH_SYMBOL			dlsym
+#  define DL_FETCH_SYMBOL			zend_dlsym
 # endif
 # define DL_ERROR					dlerror
 # define DL_HANDLE					void *

ext/readline/readline_cli.c

@@ -754,7 +754,7 @@ this extension sharedto offer compatibility.
 	do { \
 		(cb) = NULL; \
 		cli_shell_callbacks_t *(*get_callbacks)(void); \
-		get_callbacks = dlsym(RTLD_DEFAULT, "php_cli_get_shell_callbacks"); \
+		get_callbacks = DL_FETCH_SYMBOL(RTLD_DEFAULT, "php_cli_get_shell_callbacks"); \
 		if (get_callbacks) { \
 			(cb) = get_callbacks(); \
 		} \

run-tests.php

@@ -586,7 +586,7 @@ function main(): void
                     $lsanSuppressions = __DIR__ . '/.github/lsan-suppressions.txt';
                     if (file_exists($lsanSuppressions)) {
                         $environment['LSAN_OPTIONS'] = 'suppressions=' . $lsanSuppressions
-                            . ':print_suppressions=0';
+                            . ':print_suppressions=0:use_tls=0:fast_unwind_on_malloc=false';
                     }
                     break;
                 case '--repeat':