mirror of
https://github.com/torvalds/linux.git
synced 2024-12-02 00:51:44 +00:00
7aba5dcc23
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
63 lines
1.8 KiB
C
63 lines
1.8 KiB
C
/* SPDX-License-Identifier: GPL-2.0-or-later */
|
|
/*
|
|
* Copyright (C) International Business Machines Corp., 2000-2002
|
|
*/
|
|
|
|
#ifndef H_JFS_XATTR
|
|
#define H_JFS_XATTR
|
|
|
|
#include <linux/xattr.h>
|
|
|
|
/*
|
|
* jfs_ea_list describe the on-disk format of the extended attributes.
|
|
* I know the null-terminator is redundant since namelen is stored, but
|
|
* I am maintaining compatibility with OS/2 where possible.
|
|
*/
|
|
struct jfs_ea {
|
|
u8 flag; /* Unused? */
|
|
u8 namelen; /* Length of name */
|
|
__le16 valuelen; /* Length of value */
|
|
char name[]; /* Attribute name (includes null-terminator) */
|
|
}; /* Value immediately follows name */
|
|
|
|
struct jfs_ea_list {
|
|
__le32 size; /* overall size */
|
|
struct jfs_ea ea[]; /* Variable length list */
|
|
};
|
|
|
|
/* Macros for defining maxiumum number of bytes supported for EAs */
|
|
#define MAXEASIZE 65535
|
|
#define MAXEALISTSIZE MAXEASIZE
|
|
|
|
/*
|
|
* some macros for dealing with variable length EA lists.
|
|
*/
|
|
#define EA_SIZE(ea) \
|
|
(sizeof (struct jfs_ea) + (ea)->namelen + 1 + \
|
|
le16_to_cpu((ea)->valuelen))
|
|
#define NEXT_EA(ea) ((struct jfs_ea *) (((char *) (ea)) + (EA_SIZE (ea))))
|
|
#define FIRST_EA(ealist) ((ealist)->ea)
|
|
#define EALIST_SIZE(ealist) le32_to_cpu((ealist)->size)
|
|
#define END_EALIST(ealist) \
|
|
((struct jfs_ea *) (((char *) (ealist)) + EALIST_SIZE(ealist)))
|
|
|
|
extern int __jfs_setxattr(tid_t, struct inode *, const char *, const void *,
|
|
size_t, int);
|
|
extern ssize_t __jfs_getxattr(struct inode *, const char *, void *, size_t);
|
|
extern ssize_t jfs_listxattr(struct dentry *, char *, size_t);
|
|
|
|
extern const struct xattr_handler *jfs_xattr_handlers[];
|
|
|
|
#ifdef CONFIG_JFS_SECURITY
|
|
extern int jfs_init_security(tid_t, struct inode *, struct inode *,
|
|
const struct qstr *);
|
|
#else
|
|
static inline int jfs_init_security(tid_t tid, struct inode *inode,
|
|
struct inode *dir, const struct qstr *qstr)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
#endif /* H_JFS_XATTR */
|