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| author | Maíra Canal <maira.canal@usp.br> | 2022-01-31 21:22:42 +0300 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2022-02-01 19:31:55 +0300 |
| commit | 90b2433edb6d995bd23d6adde753095b4ab26104 (patch) | |
| tree | 808609b1f7efc50d00639b0b0754008f821c1274 | |
| parent | 6692531df62d812de5d22c8bca0d90edc163aa84 (diff) | |
| download | linux-90b2433edb6d995bd23d6adde753095b4ab26104.tar.xz | |
seq_file: fix NULL pointer arithmetic warning
Implement conditional logic in order to replace NULL pointer arithmetic.
The use of NULL pointer arithmetic was pointed out by clang with the
following warning:
fs/kernfs/file.c:128:15: warning: performing pointer arithmetic on a
null pointer has undefined behavior [-Wnull-pointer-arithmetic]
return NULL + !*ppos;
~~~~ ^
fs/seq_file.c:559:14: warning: performing pointer arithmetic on a
null pointer has undefined behavior [-Wnull-pointer-arithmetic]
return NULL + (*pos == 0);
Signed-off-by: Maíra Canal <maira.canal@usp.br>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| -rw-r--r-- | fs/kernfs/file.c | 7 | ||||
| -rw-r--r-- | fs/seq_file.c | 4 | ||||
| -rw-r--r-- | include/linux/seq_file.h | 1 |
3 files changed, 4 insertions, 8 deletions
diff --git a/fs/kernfs/file.c b/fs/kernfs/file.c index 9414a7a60a9f..7aefaca876a0 100644 --- a/fs/kernfs/file.c +++ b/fs/kernfs/file.c @@ -120,13 +120,8 @@ static void *kernfs_seq_start(struct seq_file *sf, loff_t *ppos) if (next == ERR_PTR(-ENODEV)) kernfs_seq_stop_active(sf, next); return next; - } else { - /* - * The same behavior and code as single_open(). Returns - * !NULL if pos is at the beginning; otherwise, NULL. - */ - return NULL + !*ppos; } + return single_start(sf, ppos); } static void *kernfs_seq_next(struct seq_file *sf, void *v, loff_t *ppos) diff --git a/fs/seq_file.c b/fs/seq_file.c index f8e1f4ee87ff..7ab8a58c29b6 100644 --- a/fs/seq_file.c +++ b/fs/seq_file.c @@ -554,9 +554,9 @@ int seq_dentry(struct seq_file *m, struct dentry *dentry, const char *esc) } EXPORT_SYMBOL(seq_dentry); -static void *single_start(struct seq_file *p, loff_t *pos) +void *single_start(struct seq_file *p, loff_t *pos) { - return NULL + (*pos == 0); + return *pos ? NULL : SEQ_START_TOKEN; } static void *single_next(struct seq_file *p, void *v, loff_t *pos) diff --git a/include/linux/seq_file.h b/include/linux/seq_file.h index 88cc16444b43..60820ab511d2 100644 --- a/include/linux/seq_file.h +++ b/include/linux/seq_file.h @@ -162,6 +162,7 @@ int seq_dentry(struct seq_file *, struct dentry *, const char *); int seq_path_root(struct seq_file *m, const struct path *path, const struct path *root, const char *esc); +void *single_start(struct seq_file *, loff_t *); int single_open(struct file *, int (*)(struct seq_file *, void *), void *); int single_open_size(struct file *, int (*)(struct seq_file *, void *), void *, size_t); int single_release(struct inode *, struct file *); |