ima: Fix the pathname to relative path when get absolute path failed

euler inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I4L078
CVE: NA

-------------------------------------------------

We backport the
commit 17f4bad3 ("ima: remove usage of filename parameter") to
support absolute path in ima measurement log,when get absolute path
failed, the pathname with NULL value will be passed to the next
measurement processes. Fix the pathname to relative path when get
absolute path failed.
Signed-off-by: NLi Kun <hw.likun@huawei.com>
Signed-off-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: NHui Wang <john.wanghui@huawei.com>
Signed-off-by: NZhang Xiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
Reviewed-by: NJason Yan <yanaijie@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

Conflicts:
	security/integrity/ima/ima_main.c
Signed-off-by: NGuo Zihua <guozihua@huawei.com>
Reviewed-by: NXiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

security/integrity/ima/ima_main.c

@@ -502,6 +502,9 @@ static int process_ns_measurement(struct file *file, const struct cred *cred,
 	if (!pathbuf)	/* ima_rdwr_violation possibly pre-fetched */
 		pathname = ima_d_path(&file->f_path, &pathbuf, filename);
 
+	if (!pathname || strlen(pathname) > IMA_EVENT_NAME_LEN_MAX)
+		pathname = file->f_path.dentry->d_name.name;
+
 	found_digest = ima_lookup_digest(iint->ima_hash->digest, hash_algo,
 					 COMPACT_FILE);