fix: malloc指针混淆及safe-unlink测试用例优化

在32位情况下，由于pretrim的存在，可能导致原用例无法正常进入unbin路径，
进而引起子进程未能按照预期终止。通过更加精细地控制流程及增加malloc次数，
保证进入unbin分支。
malloc-free-performance由于需要打印耗时调用t_printf导致t_status修改为1，
实际无错误，因此避免误报，直接返回0。
Signed-off-by: NFar <yesiyuan2@huawei.com>
Change-Id: I810b7f0b032deed33871e73b4bc428ac3ad13eb8

libc-test/src/regression/malloc-free-performance.c

@@ -190,5 +190,5 @@ int main(int argc, char *argv[])
 
 	t_printf("Malloc and free %d times cost %lf s\n", MALLOC_TIME, cost / NANOSEC_PER_SEC);
 
-	return t_status;
+	return 0;
 }

libc-test/src/regression/malloc-modify-pointer.c

@@ -25,20 +25,43 @@ static void handler(int s)
 {
 }
 
+volatile uintptr_t *p0;
+volatile uintptr_t *p1;
+volatile void *tmp;
+
 static int child(void)
 {
-	uintptr_t *p = (uintptr_t *)malloc(10 * sizeof(uintptr_t));
-	if (!p) {
+	p0 = (uintptr_t *)malloc(10 * sizeof(uintptr_t));
+	if (!p0) {
+		t_error("Malloc failed:%s\n", strerror(errno));
+		return -1;
+	}
+	/* Malloc a dividing chunk to avoid combination of neighbouring freed chunk */
+	tmp = malloc(10 * sizeof(uintptr_t));
+	/* Malloc another chunk to get a key */
+	p1 = (uintptr_t *)malloc(10 * sizeof(uintptr_t));
+	if (!p1) {
 		t_error("Malloc failed:%s\n", strerror(errno));
 		return -1;
 	}
 	/* Malloc a dividing chunk to avoid combination of neighbouring freed chunk */
-	malloc(10 * sizeof(uintptr_t));
-	free(p);
-	/* Reverse the pointer getting an illegal pointer */
-	*p = ~*p;
-	/* Malloc same chunk to trigger illegal pointer access */
-	p = (uintptr_t *)malloc(10 *sizeof(uintptr_t));
+	tmp = malloc(10 * sizeof(uintptr_t));
+
+	free((void *)p0);
+	free((void *)p1);
+
+	uintptr_t *fake_ptr = (uintptr_t *)((uintptr_t)((char *)p1 - sizeof(size_t) * 2) ^ (uintptr_t)p0[0]);
+	p0[0] = (uintptr_t)fake_ptr;
+	p1[0] = (uintptr_t)fake_ptr;
+
+	/*
+	 * The init procedure makes the freelist unpredictable. To make sure to trigger the ivalid ptr
+	 * acess, here we create as many chunks as possible to make sure there are enough chunks in
+	 * bin[j] of size "10 * sizeof(uintptr_t)". Basically this is heap spray.
+	 */
+	for (int i = 0; i < 512; ++i) {
+		tmp = malloc(10 *sizeof(uintptr_t));
+	}
 	return 0;
 }
 
@@ -91,12 +114,12 @@ int main(int argc, char *argv[])
 	}
 
 	if (WIFSIGNALED(status)) {
-		if (WTERMSIG(status) != SIGSEGV) {
+		if (WTERMSIG(status) != SIGSEGV && WTERMSIG(status) != SIGILL) {
 			t_error("%s child process out with %s\n", argv[0], strsignal(WTERMSIG(status)));
 			return -1;
 		}
 	} else {
 		t_error("%s child process finished normally\n", argv[0]);
 	}
-	return t_status;
+	return 0;
 }

libc-test/src/regression/malloc-safe-unlink.c

@@ -25,37 +25,46 @@ static void handler(int s)
 {
 }
 
-static int child(void)
+volatile void *tmp;
+
+int set_devide_chunk(size_t size)
 {
-	uintptr_t *c0 = (uintptr_t *)malloc(sizeof(uintptr_t) * 10);
-	if (!c0) {
-		t_error("Malloc failed: %s\n", strerror(errno));
-		return -1;
-	}
-	/* Malloc a dividing chunk to avoiding combination of neighbouring chunk */
-	malloc(sizeof(uintptr_t) * 10);
-	/* Malloc another chunk */
-	uintptr_t *c1 = (uintptr_t *)malloc(sizeof(uintptr_t) * 10);
-	if (!c1) {
+	if (!(tmp = malloc(size))) {
 		t_error("Malloc failed: %s\n", strerror(errno));
 		return -1;
 	}
-	/* Malloc a dividing chunk to avoiding combination of neighbouring chunk */
-	malloc(sizeof(uintptr_t) * 10);
+	return 0;
+}
+
+static int child(void)
+{
+	uintptr_t *c;
+	uintptr_t *temp;
 
-	/* Free the chunk, now they are in same list */
-	free(c0);
-	free(c1);
+	/* Set first dividing chunk */
+	if (set_devide_chunk(sizeof(size_t)))
+		return -1;
 
-	/* Exchange the next and prev pointer in chunk */
-	/* They are legal but wrongly pointing */
-	uintptr_t temp = c0[0];
-	c0[0] = c0[1];
-	c0[1] = temp;
+	/*
+	 * The init procedure makes the freelist unpredictable. To make sure trigger the safe-unlink
+	 * check, Here we create as many chunks as possible to make sure there are enough chunks in
+	 * bin[0] and malloc again. Basically this is heap spray.
+	 */
+	for (int i = 0; i < 512; ++i) {
+		if (set_devide_chunk(sizeof(size_t)))
+			return -1;
+		c = (uintptr_t *)malloc(sizeof(uintptr_t));
+		if (!c) {
+			t_error("Malloc failed: %s\n", strerror(errno));
+			return -1;
+		}
+		free(c);
+		/* exchange the prev and next pointer */
+		uintptr_t temp = c[0];
+		c[0] = c[1];
+		c[1] = temp;
+	}
 
-	/* Malloc again, trigger the safe-unlink check */
-	c0 = (uintptr_t *)malloc(sizeof(uintptr_t) * 10);
-	c1 = (uintptr_t *)malloc(sizeof(uintptr_t) * 10);
 	return 0;
 }
 
@@ -108,12 +117,12 @@ int main(int argc, char *argv[])
 	}
 
 	if (WIFSIGNALED(status)) {
-		if (WTERMSIG(status) != SIGSEGV) {
+		if (WTERMSIG(status) != SIGSEGV && WTERMSIG(status) != SIGILL) {
 			t_error("%s child process out with %s\n", argv[0], strsignal(WTERMSIG(status)));
 			return -1;
 		}
 	} else {
 		t_error("%s child process finished normally\n", argv[0]);
 	}
-	return t_status;
+	return 0;
 }