[PATCH] tracefs: Annotate tracefs_ops with __ro_after_init

[PATCH] tracefs: Annotate tracefs_ops with __ro_after_init

[Zubin Mithra]

tracefs_ops is initialized inside tracefs_create_instance_dir and not
modified after. tracefs_create_instance_dir allows for initialization
only once, and is called from create_trace_instances(marked __init),
which is called from tracer_init_tracefs(marked __init).

Signed-off-by: Zubin Mithra <zsm@chromium.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
---
 fs/tracefs/inode.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/tracefs/inode.c b/fs/tracefs/inode.c
index bea8ad876bf9..20e965873f27 100644
--- a/fs/tracefs/inode.c
+++ b/fs/tracefs/inode.c
@@ -53,7 +53,7 @@ static const struct file_operations tracefs_file_operations = {
 static struct tracefs_dir_ops {
 	int (*mkdir)(const char *name);
 	int (*rmdir)(const char *name);
-} tracefs_ops;
+} tracefs_ops __ro_after_init;
 
 static char *get_dname(struct dentry *dentry)
 {
-- 
2.18.0.233.g985f88cf7e-goog

Re: [PATCH] tracefs: Annotate tracefs_ops with __ro_after_init

[Kees Cook]

Adding Steven (maintainer) and Al (fs) to CC...

On Tue, Jul 24, 2018 at 1:02 PM, Zubin Mithra <zsm@chromium.org> wrote:
> tracefs_ops is initialized inside tracefs_create_instance_dir and not
> modified after. tracefs_create_instance_dir allows for initialization
> only once, and is called from create_trace_instances(marked __init),
> which is called from tracer_init_tracefs(marked __init).
>
> Signed-off-by: Zubin Mithra <zsm@chromium.org>
> Reviewed-by: Kees Cook <keescook@chromium.org>

Who's tree should this go through?

Thanks!

-Kees

> ---
>  fs/tracefs/inode.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/tracefs/inode.c b/fs/tracefs/inode.c
> index bea8ad876bf9..20e965873f27 100644
> --- a/fs/tracefs/inode.c
> +++ b/fs/tracefs/inode.c
> @@ -53,7 +53,7 @@ static const struct file_operations tracefs_file_operations = {
>  static struct tracefs_dir_ops {
>         int (*mkdir)(const char *name);
>         int (*rmdir)(const char *name);
> -} tracefs_ops;
> +} tracefs_ops __ro_after_init;
>
>  static char *get_dname(struct dentry *dentry)
>  {
> --
> 2.18.0.233.g985f88cf7e-goog
>



-- 
Kees Cook
Pixel Security

Re: [PATCH] tracefs: Annotate tracefs_ops with __ro_after_init

[Steven Rostedt]

On Tue, 24 Jul 2018 15:07:18 -0700
Kees Cook <keescook@chromium.org> wrote:

> Adding Steven (maintainer) and Al (fs) to CC...

Thanks, first I've seen of this.

> 
> On Tue, Jul 24, 2018 at 1:02 PM, Zubin Mithra <zsm@chromium.org> wrote:
> > tracefs_ops is initialized inside tracefs_create_instance_dir and not
> > modified after. tracefs_create_instance_dir allows for initialization
> > only once, and is called from create_trace_instances(marked __init),
> > which is called from tracer_init_tracefs(marked __init).

Then, especially with this change, we should mark
tracefs_create_instance_dir() as init, as it would fail any other time.

> >
> > Signed-off-by: Zubin Mithra <zsm@chromium.org>
> > Reviewed-by: Kees Cook <keescook@chromium.org>  
> 
> Who's tree should this go through?

I can take it or someone else can, and I'll ack it if need be.

-- Steve


> 
> Thanks!
> 
> -Kees
> 
> > ---
> >  fs/tracefs/inode.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/fs/tracefs/inode.c b/fs/tracefs/inode.c
> > index bea8ad876bf9..20e965873f27 100644
> > --- a/fs/tracefs/inode.c
> > +++ b/fs/tracefs/inode.c
> > @@ -53,7 +53,7 @@ static const struct file_operations tracefs_file_operations = {
> >  static struct tracefs_dir_ops {
> >         int (*mkdir)(const char *name);
> >         int (*rmdir)(const char *name);
> > -} tracefs_ops;
> > +} tracefs_ops __ro_after_init;
> >
> >  static char *get_dname(struct dentry *dentry)
> >  {
> > --
> > 2.18.0.233.g985f88cf7e-goog
> >  
> 
> 
>