From: Xu Kuohai <redacted>

To be consistent with most LSM hooks, convert the return value of
hook inode_getsecurity to 0 or a negative error code.

Before:
- Hook inode_getsecurity returns size of buffer on success or a
  negative error code on failure.

After:
- Hook inode_getsecurity returns 0 on success or a negative error
  code on failure. An output parameter @len is introduced to hold
  the buffer size on success.

Signed-off-by: Xu Kuohai <redacted>
---
 fs/xattr.c                    | 19 ++++++++++---------
 include/linux/lsm_hook_defs.h |  3 ++-
 include/linux/security.h      | 12 ++++++------
 security/commoncap.c          |  9 ++++++---
 security/security.c           | 11 ++++++-----
 security/selinux/hooks.c      | 16 ++++++----------
 security/smack/smack_lsm.c    | 14 +++++++-------
 7 files changed, 43 insertions(+), 41 deletions(-)

diff --git a/fs/xattr.c b/fs/xattr.c
index f8b643f91a98..f4e3bedf7272 100644
--- a/fs/xattr.c
+++ b/fs/xattr.c

@@ -339,27 +339,28 @@ xattr_getsecurity(struct mnt_idmap *idmap, struct inode *inode,
 		  const char *name, void *value, size_t size)
 {
 	void *buffer = NULL;
-	ssize_t len;
+	int error;
+	u32 len;
 
 	if (!value || !size) {
-		len = security_inode_getsecurity(idmap, inode, name,
-						 &buffer, false);
+		error = security_inode_getsecurity(idmap, inode, name,
+						   false, &buffer, &len);
 		goto out_noalloc;
 	}
 
-	len = security_inode_getsecurity(idmap, inode, name, &buffer,
-					 true);
-	if (len < 0)
-		return len;
+	error = security_inode_getsecurity(idmap, inode, name, true,
+					   &buffer, &len);
+	if (error)
+		return error;
 	if (size < len) {
-		len = -ERANGE;
+		error = -ERANGE;
 		goto out;
 	}
 	memcpy(value, buffer, len);
 out:
 	kfree(buffer);
 out_noalloc:
-	return len;
+	return error < 0 ? error : len;