Re: [PATCH] debugfs: Fix !DEBUG_FS debugfs_create_automount

From: Steven Rostedt
Date: Thu Nov 21 2019 - 18:53:44 EST


On Thu, 21 Nov 2019 19:20:21 +0900
Kusanagi Kouichi <slash@xxxxxxxxxxxxxxx> wrote:

> If DEBUG_FS=n, compile fails with the following error:
>
> kernel/trace/trace.c: In function 'tracing_init_dentry':
> kernel/trace/trace.c:8658:9: error: passing argument 3 of 'debugfs_create_automount' from incompatible pointer type [-Werror=incompatible-pointer-types]
> 8658 | trace_automount, NULL);
> | ^~~~~~~~~~~~~~~
> | |
> | struct vfsmount * (*)(struct dentry *, void *)
> In file included from kernel/trace/trace.c:24:
> ./include/linux/debugfs.h:206:25: note: expected 'struct vfsmount * (*)(void *)' but argument is of type 'struct vfsmount * (*)(struct dentry *, void *)'
> 206 | struct vfsmount *(*f)(void *),
> | ~~~~~~~~~~~~~~~~~~~^~~~~~~~~~
>

Please add the tag:

Reported-by: kbuild test robot <lkp@xxxxxxxxx>

You can also add:

Link: https://lore.kernel.org/lkml/201911211354.zYtbB4MD%25lkp@xxxxxxxxx/

-- Steve

> Signed-off-by: Kusanagi Kouichi <slash@xxxxxxxxxxxxxxx>
> ---
> include/linux/debugfs.h | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/include/linux/debugfs.h b/include/linux/debugfs.h
> index 58424eb3b329..798f0b9b43ae 100644
> --- a/include/linux/debugfs.h
> +++ b/include/linux/debugfs.h
> @@ -54,6 +54,8 @@ static const struct file_operations __fops = { \
> .llseek = no_llseek, \
> }
>
> +typedef struct vfsmount *(*debugfs_automount_t)(struct dentry *, void *);
> +
> #if defined(CONFIG_DEBUG_FS)
>
> struct dentry *debugfs_lookup(const char *name, struct dentry *parent);
> @@ -75,7 +77,6 @@ struct dentry *debugfs_create_dir(const char *name, struct dentry *parent);
> struct dentry *debugfs_create_symlink(const char *name, struct dentry *parent,
> const char *dest);
>
> -typedef struct vfsmount *(*debugfs_automount_t)(struct dentry *, void *);
> struct dentry *debugfs_create_automount(const char *name,
> struct dentry *parent,
> debugfs_automount_t f,
> @@ -203,7 +204,7 @@ static inline struct dentry *debugfs_create_symlink(const char *name,
>
> static inline struct dentry *debugfs_create_automount(const char *name,
> struct dentry *parent,
> - struct vfsmount *(*f)(void *),
> + debugfs_automount_t f,
> void *data)
> {
> return ERR_PTR(-ENODEV);