[PATCH 5.4 43/65] samples/vfs: avoid warning in statx override

[Greg Kroah-Hartman]

From: Kees Cook <keescook@xxxxxxxxxxxx>

[ Upstream commit c3eeaae9fd736b7f2afbda8d3cbb1cbae06decf3 ]

Something changed recently to uncover this warning:

  samples/vfs/test-statx.c:24:15: warning: `struct foo' declared inside parameter list will not be visible outside of this definition or declaration
     24 | #define statx foo
        |               ^~~

Which is due the use of "struct statx" (here, "struct foo") in a function
prototype argument list before it has been defined:

 int
 # 56 "/usr/include/x86_64-linux-gnu/bits/statx-generic.h"
    foo
 # 56 "/usr/include/x86_64-linux-gnu/bits/statx-generic.h" 3 4
          (int __dirfd, const char *__restrict __path, int __flags,
            unsigned int __mask, struct
 # 57 "/usr/include/x86_64-linux-gnu/bits/statx-generic.h"
                                       foo
 # 57 "/usr/include/x86_64-linux-gnu/bits/statx-generic.h" 3 4
                                             *__restrict __buf)
   __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (2, 5)));

Add explicit struct before #include to avoid warning.

Fixes: f1b5618e013a ("vfs: Add a sample program for the new mount API")
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Miklos Szeredi <mszeredi@xxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: David Howells <dhowells@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/202006282213.C516EA6@keescook
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 samples/vfs/test-statx.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/samples/vfs/test-statx.c b/samples/vfs/test-statx.c
index a3d68159fb510..507f09c38b49f 100644
--- a/samples/vfs/test-statx.c
+++ b/samples/vfs/test-statx.c
@@ -23,6 +23,8 @@
 #include <linux/fcntl.h>
 #define statx foo
 #define statx_timestamp foo_timestamp
+struct statx;
+struct statx_timestamp;
 #include <sys/stat.h>
 #undef statx
 #undef statx_timestamp
-- 
2.25.1