diff --git a/porting/liteos_a/user/src/exit/exit.c b/porting/liteos_a/user/src/exit/exit.c
new file mode 100644
index 0000000000000000000000000000000000000000..5001bf12b86f5a29aa073f9f84bac7e1ed38b17f
--- /dev/null
+++ b/porting/liteos_a/user/src/exit/exit.c
@@ -0,0 +1,40 @@
+#include <stdlib.h>
+#include <stdint.h>
+#include <signal.h>
+#include <atomic.h>
+#include "libc.h"
+
+static void dummy()
+{
+}
+
+/* atexit.c and __stdio_exit.c override these. the latter is linked
+ * as a consequence of linking either __toread.c or __towrite.c. */
+weak_alias(dummy, __funcs_on_exit);
+weak_alias(dummy, __stdio_exit);
+weak_alias(dummy, _fini);
+
+extern weak hidden void (*const __fini_array_start)(void), (*const __fini_array_end)(void);
+
+static void libc_exit_fini(void)
+{
+	uintptr_t a = (uintptr_t)&__fini_array_end;
+	for (; a>(uintptr_t)&__fini_array_start; a-=sizeof(void(*)()))
+		(*(void (**)())(a-sizeof(void(*)())))();
+	_fini();
+}
+
+weak_alias(libc_exit_fini, __libc_exit_fini);
+
+_Noreturn void exit(int code)
+{
+	sigset_t set;
+	if (a_cas(&libc.exit, 0, 1) != 0) {
+		return;
+	}
+	__block_app_sigs(&set);
+	__funcs_on_exit();
+	__libc_exit_fini();
+	__stdio_exit();
+	_Exit(code);
+}
diff --git a/porting/liteos_a/user/src/internal/libc.h b/porting/liteos_a/user/src/internal/libc.h
index da237ed147e38cea0ac2188e54d5df775fe71187..759f5b8a79d3afe3efc8f6915544dfb1883a439c 100644
--- a/porting/liteos_a/user/src/internal/libc.h
+++ b/porting/liteos_a/user/src/internal/libc.h
@@ -27,6 +27,7 @@ struct __libc {
 	size_t tls_size, tls_align, tls_cnt;
 	size_t page_size;
 	struct __locale_struct global_locale;
+	int exit;
 };
 
 #ifndef PAGE_SIZE
diff --git a/porting/liteos_a/user/src/process/fork.c b/porting/liteos_a/user/src/process/fork.c
index b5b8dca0abf6bd31541729086781d05692ade9d1..160ef5d2c19c3756b0e8dfe95fa1ee7d358e004e 100644
--- a/porting/liteos_a/user/src/process/fork.c
+++ b/porting/liteos_a/user/src/process/fork.c
@@ -30,6 +30,7 @@ pid_t fork(void)
 		self->next = self->prev = self;
 		__thread_list_lock = 0;
 		libc.threads_minus_1 = 0;
+		libc.exit = 0;
 		signal(SIGSYS, arm_do_signal);
 	}
 	__restore_sigs(&set);
diff --git a/porting/liteos_a/user_debug/src/exit/exit.c b/porting/liteos_a/user_debug/src/exit/exit.c
index 5d2d00a33b1b05a73f9bfdda58cf443d49f1645b..945da5206bf748e8837cd08009efbb09273c0d4d 100644
--- a/porting/liteos_a/user_debug/src/exit/exit.c
+++ b/porting/liteos_a/user_debug/src/exit/exit.c
@@ -2,6 +2,8 @@
 #include <stdint.h>
 #include <stdbool.h>
 #include <debug.h>
+#include <signal.h>
+#include <atomic.h>
 #include "libc.h"
 
 extern bool g_enable_check;
@@ -32,6 +34,11 @@ weak_alias(libc_exit_fini, __libc_exit_fini);
 
 _Noreturn void exit(int code)
 {
+	sigset_t set;
+	if (a_cas(&libc.exit, 0, 1) != 0) {
+		return;
+	}
+	__block_app_sigs(&set);
 	if (g_enable_check) {
 		check_leak();
 		check_heap_integrity();