On Fri, Oct 29, 2021 at 11:26:38AM +0800, Muchun Song wrote:
> DEFINE_PROC_SHOW_ATTRIBUTE() is supposed to be used to define a series
> of functions and variables to register proc file easily. And the users
> can use proc_create_data() to pass their own private data and get it
> via seq->private in the callback. Unfortunately, the proc file system
> use PDE_DATA() to get private data instead of inode->i_private. So fix
> it. Fortunately, there only one user of it which does not pass any
> private data, so this bug does not break any in-tree codes.
>
> Fixes: 97a32539b956 ("proc: convert everything to "struct proc_ops"")
> Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
> ---
> include/linux/seq_file.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/include/linux/seq_file.h b/include/linux/seq_file.h
> index 103776e18555..72dbb44a4573 100644
> --- a/include/linux/seq_file.h
> +++ b/include/linux/seq_file.h
> @@ -209,7 +209,7 @@ static const struct file_operations __name ## _fops = { \
> #define DEFINE_PROC_SHOW_ATTRIBUTE(__name) \
> static int __name ## _open(struct inode *inode, struct file *file) \
> { \
> - return single_open(file, __name ## _show, inode->i_private); \
> + return single_open(file, __name ## _show, PDE_DATA(inode)); \
> } \
> \
> static const struct proc_ops __name ## _proc_ops = { \
Hm, after your change DEFINE_SHOW_ATTRIBUTE() and
DEFINE_PROC_SHOW_ATTRIBUTE() macros do exactly the same things, right?:
#define DEFINE_SHOW_ATTRIBUTE(__name) \
static int __name ## _open(struct inode *inode, struct file *file) \
{ \
return single_open(file, __name ## _show, inode->i_private); \
} \
\
static const struct file_operations __name ## _fops = { \
.owner = THIS_MODULE, \
.open = __name ## _open, \
.read = seq_read, \
.llseek = seq_lseek, \
.release = single_release, \
}
#define DEFINE_PROC_SHOW_ATTRIBUTE(__name) \
static int __name ## _open(struct inode *inode, struct file *file) \
{ \
return single_open(file, __name ## _show, inode->i_private); \
} \
Can't you just replace the single instance where
DEFINE_PROC_SHOW_ATTRIBUTE with DEFINE_SHOW_ATTRIBUTE() and remove
DEFINE_PROC_SHOW_ATTRIBUTE completely?
Christian
