linux/kernel/pid_sysctl.h
Luis Chamberlain 9e7c73c0b9 kernel: pid_namespace: simplify sysctls with register_sysctl()
register_sysctl_paths() is only required if your child (directories)
have entries and pid_namespace does not. So use register_sysctl_init()
instead where we don't care about the return value and use
register_sysctl() where we do.

Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Acked-by: Jeff Xu <jeffxu@google.com>
Link: https://lore.kernel.org/r/20230302202826.776286-9-mcgrof@kernel.org
2023-05-02 19:23:29 -07:00

60 lines
1.6 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef LINUX_PID_SYSCTL_H
#define LINUX_PID_SYSCTL_H
#include <linux/pid_namespace.h>
#if defined(CONFIG_SYSCTL) && defined(CONFIG_MEMFD_CREATE)
static inline void initialize_memfd_noexec_scope(struct pid_namespace *ns)
{
ns->memfd_noexec_scope =
task_active_pid_ns(current)->memfd_noexec_scope;
}
static int pid_mfd_noexec_dointvec_minmax(struct ctl_table *table,
int write, void *buf, size_t *lenp, loff_t *ppos)
{
struct pid_namespace *ns = task_active_pid_ns(current);
struct ctl_table table_copy;
if (write && !ns_capable(ns->user_ns, CAP_SYS_ADMIN))
return -EPERM;
table_copy = *table;
if (ns != &init_pid_ns)
table_copy.data = &ns->memfd_noexec_scope;
/*
* set minimum to current value, the effect is only bigger
* value is accepted.
*/
if (*(int *)table_copy.data > *(int *)table_copy.extra1)
table_copy.extra1 = table_copy.data;
return proc_dointvec_minmax(&table_copy, write, buf, lenp, ppos);
}
static struct ctl_table pid_ns_ctl_table_vm[] = {
{
.procname = "memfd_noexec",
.data = &init_pid_ns.memfd_noexec_scope,
.maxlen = sizeof(init_pid_ns.memfd_noexec_scope),
.mode = 0644,
.proc_handler = pid_mfd_noexec_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
.extra2 = SYSCTL_TWO,
},
{ }
};
static inline void register_pid_ns_sysctl_table_vm(void)
{
register_sysctl("vm", pid_ns_ctl_table_vm);
}
#else
static inline void initialize_memfd_noexec_scope(struct pid_namespace *ns) {}
static inline void set_memfd_noexec_scope(struct pid_namespace *ns) {}
static inline void register_pid_ns_sysctl_table_vm(void) {}
#endif
#endif /* LINUX_PID_SYSCTL_H */