Files
linux-nf/include/linux/pid_namespace.h
Simon Schuster edd3cb05c0 copy_process: pass clone_flags as u64 across calltree
With the introduction of clone3 in commit 7f192e3cd3 ("fork: add
clone3") the effective bit width of clone_flags on all architectures was
increased from 32-bit to 64-bit, with a new type of u64 for the flags.
However, for most consumers of clone_flags the interface was not
changed from the previous type of unsigned long.

While this works fine as long as none of the new 64-bit flag bits
(CLONE_CLEAR_SIGHAND and CLONE_INTO_CGROUP) are evaluated, this is still
undesirable in terms of the principle of least surprise.

Thus, this commit fixes all relevant interfaces of callees to
sys_clone3/copy_process (excluding the architecture-specific
copy_thread) to consistently pass clone_flags as u64, so that
no truncation to 32-bit integers occurs on 32-bit architectures.

Signed-off-by: Simon Schuster <schuster.simon@siemens-energy.com>
Link: https://lore.kernel.org/20250901-nios2-implement-clone3-v2-2-53fcf5577d57@siemens-energy.com
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-09-01 15:31:34 +02:00

135 lines
3.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_PID_NS_H
#define _LINUX_PID_NS_H
#include <linux/sched.h>
#include <linux/bug.h>
#include <linux/mm.h>
#include <linux/workqueue.h>
#include <linux/threads.h>
#include <linux/nsproxy.h>
#include <linux/ns_common.h>
#include <linux/idr.h>
/* MAX_PID_NS_LEVEL is needed for limiting size of 'struct pid' */
#define MAX_PID_NS_LEVEL 32
struct fs_pin;
#if defined(CONFIG_SYSCTL) && defined(CONFIG_MEMFD_CREATE)
/* modes for vm.memfd_noexec sysctl */
#define MEMFD_NOEXEC_SCOPE_EXEC 0 /* MFD_EXEC implied if unset */
#define MEMFD_NOEXEC_SCOPE_NOEXEC_SEAL 1 /* MFD_NOEXEC_SEAL implied if unset */
#define MEMFD_NOEXEC_SCOPE_NOEXEC_ENFORCED 2 /* same as 1, except MFD_EXEC rejected */
#endif
struct pid_namespace {
struct idr idr;
struct rcu_head rcu;
unsigned int pid_allocated;
struct task_struct *child_reaper;
struct kmem_cache *pid_cachep;
unsigned int level;
int pid_max;
struct pid_namespace *parent;
#ifdef CONFIG_BSD_PROCESS_ACCT
struct fs_pin *bacct;
#endif
struct user_namespace *user_ns;
struct ucounts *ucounts;
int reboot; /* group exit code if this pidns was rebooted */
struct ns_common ns;
struct work_struct work;
#ifdef CONFIG_SYSCTL
struct ctl_table_set set;
struct ctl_table_header *sysctls;
#if defined(CONFIG_MEMFD_CREATE)
int memfd_noexec_scope;
#endif
#endif
} __randomize_layout;
extern struct pid_namespace init_pid_ns;
#define PIDNS_ADDING (1U << 31)
#ifdef CONFIG_PID_NS
static inline struct pid_namespace *get_pid_ns(struct pid_namespace *ns)
{
if (ns != &init_pid_ns)
refcount_inc(&ns->ns.count);
return ns;
}
#if defined(CONFIG_SYSCTL) && defined(CONFIG_MEMFD_CREATE)
static inline int pidns_memfd_noexec_scope(struct pid_namespace *ns)
{
int scope = MEMFD_NOEXEC_SCOPE_EXEC;
for (; ns; ns = ns->parent)
scope = max(scope, READ_ONCE(ns->memfd_noexec_scope));
return scope;
}
#else
static inline int pidns_memfd_noexec_scope(struct pid_namespace *ns)
{
return 0;
}
#endif
extern struct pid_namespace *copy_pid_ns(u64 flags,
struct user_namespace *user_ns, struct pid_namespace *ns);
extern void zap_pid_ns_processes(struct pid_namespace *pid_ns);
extern int reboot_pid_ns(struct pid_namespace *pid_ns, int cmd);
extern void put_pid_ns(struct pid_namespace *ns);
#else /* !CONFIG_PID_NS */
#include <linux/err.h>
static inline struct pid_namespace *get_pid_ns(struct pid_namespace *ns)
{
return ns;
}
static inline int pidns_memfd_noexec_scope(struct pid_namespace *ns)
{
return 0;
}
static inline struct pid_namespace *copy_pid_ns(u64 flags,
struct user_namespace *user_ns, struct pid_namespace *ns)
{
if (flags & CLONE_NEWPID)
ns = ERR_PTR(-EINVAL);
return ns;
}
static inline void put_pid_ns(struct pid_namespace *ns)
{
}
static inline void zap_pid_ns_processes(struct pid_namespace *ns)
{
BUG();
}
static inline int reboot_pid_ns(struct pid_namespace *pid_ns, int cmd)
{
return 0;
}
#endif /* CONFIG_PID_NS */
extern struct pid_namespace *task_active_pid_ns(struct task_struct *tsk);
void pidhash_init(void);
void pid_idr_init(void);
int register_pidns_sysctls(struct pid_namespace *pidns);
void unregister_pidns_sysctls(struct pid_namespace *pidns);
static inline bool task_is_in_init_pid_ns(struct task_struct *tsk)
{
return task_active_pid_ns(tsk) == &init_pid_ns;
}
#endif /* _LINUX_PID_NS_H */