Re: [PATCH 11/13] random: simplify sysctl declaration with register_sysctl_subdir()

[Xiaoming Ni]

On 2020/5/29 18:26, Greg KH wrote:
> On Fri, May 29, 2020 at 07:41:06AM +0000, Luis Chamberlain wrote:
> > From: Xiaoming Ni <nixiaoming@xxxxxxxxxx>
> >
> > Move random_table sysctl from kernel/sysctl.c to drivers/char/random.c
> > and use register_sysctl_subdir() to help remove the clutter out of
> > kernel/sysctl.c.
> >
> > Signed-off-by: Xiaoming Ni <nixiaoming@xxxxxxxxxx>
> > Signed-off-by: Luis Chamberlain <mcgrof@xxxxxxxxxx>
> > ---
> >   drivers/char/random.c  | 14 ++++++++++++--
> >   include/linux/sysctl.h |  1 -
> >   kernel/sysctl.c        |  5 -----
> >   3 files changed, 12 insertions(+), 8 deletions(-)
> >
> > diff --git a/drivers/char/random.c b/drivers/char/random.c
> > index a7cf6aa65908..73fd4b6e9c18 100644
> > --- a/drivers/char/random.c
> > +++ b/drivers/char/random.c
> > @@ -2101,8 +2101,7 @@ static int proc_do_entropy(struct ctl_table *table, int write,
> >   }
> >   
> >   static int sysctl_poolsize = INPUT_POOL_WORDS * 32;
> > -extern struct ctl_table random_table[];
> > -struct ctl_table random_table[] = {
> > +static struct ctl_table random_table[] = {
> >   	{
> >   		.procname	= "poolsize",
> >   		.data		= &sysctl_poolsize,
> > @@ -2164,6 +2163,17 @@ struct ctl_table random_table[] = {
> >   #endif
> >   	{ }
> >   };
> > +
> > +/*
> > + * rand_initialize() is called before sysctl_init(),
> > + * so we cannot call register_sysctl_init() in rand_initialize()
> > + */
> > +static int __init random_sysctls_init(void)
> > +{
> > +	register_sysctl_subdir("kernel", "random", random_table);
>
> No error checking?
>
> :(
It was my mistake, I forgot to add a comment here.
Same as the comment of register_sysctl_init(),
There is almost no failure here during the system initialization phase,
and failure in time does not affect the main function.

Thanks
Xiaoming Ni