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.
> --- 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?
