linux/kernel/pid_sysctl.h
Joel Granados 1751f872cc treewide: const qualify ctl_tables where applicable
Add the const qualifier to all the ctl_tables in the tree except for
watchdog_hardlockup_sysctl, memory_allocation_profiling_sysctls,
loadpin_sysctl_table and the ones calling register_net_sysctl (./net,
drivers/inifiniband dirs). These are special cases as they use a
registration function with a non-const qualified ctl_table argument or
modify the arrays before passing them on to the registration function.

Constifying ctl_table structs will prevent the modification of
proc_handler function pointers as the arrays would reside in .rodata.
This is made possible after commit 78eb4ea25cd5 ("sysctl: treewide:
constify the ctl_table argument of proc_handlers") constified all the
proc_handlers.

Created this by running an spatch followed by a sed command:
Spatch:
    virtual patch

    @
    depends on !(file in "net")
    disable optional_qualifier
    @

    identifier table_name != {
      watchdog_hardlockup_sysctl,
      iwcm_ctl_table,
      ucma_ctl_table,
      memory_allocation_profiling_sysctls,
      loadpin_sysctl_table
    };
    @@

    + const
    struct ctl_table table_name [] = { ... };

sed:
    sed --in-place \
      -e "s/struct ctl_table .table = &uts_kern/const struct ctl_table *table = \&uts_kern/" \
      kernel/utsname_sysctl.c

Reviewed-by: Song Liu <song@kernel.org>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> # for kernel/trace/
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> # SCSI
Reviewed-by: Darrick J. Wong <djwong@kernel.org> # xfs
Acked-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Corey Minyard <cminyard@mvista.com>
Acked-by: Wei Liu <wei.liu@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Bill O'Donnell <bodonnel@redhat.com>
Acked-by: Baoquan He <bhe@redhat.com>
Acked-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Acked-by: Anna Schumaker <anna.schumaker@oracle.com>
Signed-off-by: Joel Granados <joel.granados@kernel.org>
2025-01-28 13:48:37 +01:00

54 lines
1.5 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 int pid_mfd_noexec_dointvec_minmax(const 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;
int err, scope, parent_scope;
if (write && !ns_capable(ns->user_ns, CAP_SYS_ADMIN))
return -EPERM;
table_copy = *table;
/* You cannot set a lower enforcement value than your parent. */
parent_scope = pidns_memfd_noexec_scope(ns->parent);
/* Equivalent to pidns_memfd_noexec_scope(ns). */
scope = max(READ_ONCE(ns->memfd_noexec_scope), parent_scope);
table_copy.data = &scope;
table_copy.extra1 = &parent_scope;
err = proc_dointvec_minmax(&table_copy, write, buf, lenp, ppos);
if (!err && write)
WRITE_ONCE(ns->memfd_noexec_scope, scope);
return err;
}
static const 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 register_pid_ns_sysctl_table_vm(void) {}
#endif
#endif /* LINUX_PID_SYSCTL_H */