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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 */
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/*
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* Copyright (C) International Business Machines Corp., 2000-2002
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*/
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#ifndef H_JFS_XATTR
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#define H_JFS_XATTR
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#include <linux/xattr.h>
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/*
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* jfs_ea_list describe the on-disk format of the extended attributes.
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* I know the null-terminator is redundant since namelen is stored, but
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* I am maintaining compatibility with OS/2 where possible.
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*/
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struct jfs_ea {
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u8 flag; /* Unused? */
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u8 namelen; /* Length of name */
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__le16 valuelen; /* Length of value */
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char name[]; /* Attribute name (includes null-terminator) */
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}; /* Value immediately follows name */
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struct jfs_ea_list {
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__le32 size; /* overall size */
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struct jfs_ea ea[]; /* Variable length list */
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};
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/* Macros for defining maxiumum number of bytes supported for EAs */
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#define MAXEASIZE 65535
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#define MAXEALISTSIZE MAXEASIZE
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/*
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* some macros for dealing with variable length EA lists.
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*/
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#define EA_SIZE(ea) \
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(sizeof (struct jfs_ea) + (ea)->namelen + 1 + \
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le16_to_cpu((ea)->valuelen))
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#define NEXT_EA(ea) ((struct jfs_ea *) (((char *) (ea)) + (EA_SIZE (ea))))
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#define FIRST_EA(ealist) ((ealist)->ea)
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#define EALIST_SIZE(ealist) le32_to_cpu((ealist)->size)
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#define END_EALIST(ealist) \
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((struct jfs_ea *) (((char *) (ealist)) + EALIST_SIZE(ealist)))
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extern int __jfs_setxattr(tid_t, struct inode *, const char *, const void *,
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size_t, int);
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extern ssize_t __jfs_getxattr(struct inode *, const char *, void *, size_t);
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extern ssize_t jfs_listxattr(struct dentry *, char *, size_t);
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extern const struct xattr_handler *jfs_xattr_handlers[];
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#ifdef CONFIG_JFS_SECURITY
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extern int jfs_init_security(tid_t, struct inode *, struct inode *,
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const struct qstr *);
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#else
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static inline int jfs_init_security(tid_t tid, struct inode *inode,
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struct inode *dir, const struct qstr *qstr)
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{
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return 0;
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}
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#endif
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#endif /* H_JFS_XATTR */
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