On Fri, 08 Jun 2018 23:16:59 +0200,
Andrew Morton wrote:
>
> On Fri, 8 Jun 2018 15:49:49 +0200 Takashi Iwai <ti...@suse.de> wrote:
>
> > Currently shmmni proc entry accepts all entered integer values, but
> > the practical limit is IPCMNI (32768). This confuses user as if a
> > bigger value were accepted but not applied correctly.
> >
> > This patch changes the proc entry to use *_minmax variant to limit the
> > accepted values accordingly.
>
> Waiman Long was working on a (vastly more complicated) patchset to
> address this.
That's great. Any patch available for testing?
> > --- a/ipc/ipc_sysctl.c
> > +++ b/ipc/ipc_sysctl.c
> > @@ -99,6 +99,7 @@ static int proc_ipc_auto_msgmni(struct ctl_table *table,
> > int write,
> > static int zero;
> > static int one = 1;
> > static int int_max = INT_MAX;
> > +static int ipcmni = IPCMNI;
> >
> > static struct ctl_table ipc_kern_table[] = {
> > {
> > @@ -120,7 +121,9 @@ static struct ctl_table ipc_kern_table[] = {
> > .data = &init_ipc_ns.shm_ctlmni,
> > .maxlen = sizeof(init_ipc_ns.shm_ctlmni),
> > .mode = 0644,
> > - .proc_handler = proc_ipc_dointvec,
> > + .proc_handler = proc_ipc_dointvec_minmax,
> > + .extra1 = &zero,
> > + .extra2 = &ipcmni,
> > },
> > {
> > .procname = "shm_rmid_forced",
>
> What is the back-compatibility situation here?
It's obviously an error to set such a high value and suppose that it
were accepted. So relying on that behavior must be broken in
anyway...
thanks,
Takashi
