include/linux/memfd.h

Source file repositories/reference/linux-study-clean/include/linux/memfd.h

File Facts

System
Linux kernel
Corpus path
include/linux/memfd.h
Extension
.h
Size
1431 bytes
Lines
55
Domain
Core OS
Bucket
Core Kernel Interface
Inferred role
Core OS: implementation source
Status
source implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

#ifndef __LINUX_MEMFD_H
#define __LINUX_MEMFD_H

#include <linux/file.h>

#define MEMFD_ANON_NAME "[memfd]"

#ifdef CONFIG_MEMFD_CREATE
extern long memfd_fcntl(struct file *file, unsigned int cmd, unsigned int arg);
struct folio *memfd_alloc_folio(struct file *memfd, pgoff_t idx);
/*
 * Check for any existing seals on mmap, return an error if access is denied due
 * to sealing, or 0 otherwise.
 *
 * We also update VMA flags if appropriate by manipulating the VMA flags pointed
 * to by vm_flags_ptr.
 */
int memfd_check_seals_mmap(struct file *file, vm_flags_t *vm_flags_ptr);
struct file *memfd_alloc_file(const char *name, unsigned int flags);
int memfd_get_seals(struct file *file);
int memfd_add_seals(struct file *file, unsigned int seals);
#else
static inline long memfd_fcntl(struct file *f, unsigned int c, unsigned int a)
{
	return -EINVAL;
}
static inline struct folio *memfd_alloc_folio(struct file *memfd, pgoff_t idx)
{
	return ERR_PTR(-EINVAL);
}
static inline int memfd_check_seals_mmap(struct file *file,
					 vm_flags_t *vm_flags_ptr)
{
	return 0;
}

static inline struct file *memfd_alloc_file(const char *name, unsigned int flags)
{
	return ERR_PTR(-EINVAL);
}

static inline int memfd_get_seals(struct file *file)
{
	return -EINVAL;
}

static inline int memfd_add_seals(struct file *file, unsigned int seals)
{
	return -EINVAL;
}
#endif

#endif /* __LINUX_MEMFD_H */

Annotation

Implementation Notes