fs/eventfd.c

File Facts

System

Linux kernel

Corpus path

fs/eventfd.c

Extension

.c

Size

11424 bytes

Lines

424

Domain

Core OS

Bucket

VFS And Filesystem Core

Inferred role

Core OS: syscall or user/kernel boundary

Status

core implementation candidate

Why This File Exists

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

• Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.
• Defines or participates in a user/kernel boundary; inspect argument validation, copy_from_user/copy_to_user, credentials, and dispatch target.
• Touches user memory; correctness depends on fault-safe copying and privilege boundary handling.
• Uses kernel synchronization; read lock ordering, sleepability, and interrupt context assumptions before translating.
• Allocates kernel memory; connect allocation flags and lifetime to context constraints.
• Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

• linux/file.h
• linux/poll.h
• linux/init.h
• linux/fs.h
• linux/sched/signal.h
• linux/kernel.h
• linux/slab.h
• linux/list.h
• linux/spinlock.h
• linux/anon_inodes.h
• linux/syscalls.h
• linux/export.h
• linux/kref.h
• linux/eventfd.h
• linux/proc_fs.h
• linux/seq_file.h
• linux/idr.h
• linux/uio.h

Detected Declarations

• syscall eventfd2
• syscall eventfd
• struct eventfd_ctx
• function poll
• function eventfd_free_ctx
• function eventfd_free
• function eventfd_ctx_fdget
• function eventfd_release
• function eventfd_poll
• function eventfd_ctx_do_read
• function eventfd_ctx_remove_wait_queue
• function eventfd_read
• function eventfd_write
• function eventfd_show_fdinfo
• function do_eventfd
• export eventfd_signal_mask
• export eventfd_ctx_put
• export eventfd_ctx_do_read
• export eventfd_ctx_remove_wait_queue
• export eventfd_fget
• export eventfd_ctx_fdget
• export eventfd_ctx_fileget

Annotated Snippet

SYSCALL_DEFINE2(eventfd2, unsigned int, count, int, flags)
{
	return do_eventfd(count, flags);
}

SYSCALL_DEFINE1(eventfd, unsigned int, count)
{
	return do_eventfd(count, 0);
}

Annotation

• Immediate include surface: `linux/file.h`, `linux/poll.h`, `linux/init.h`, `linux/fs.h`, `linux/sched/signal.h`, `linux/kernel.h`, `linux/slab.h`, `linux/list.h`.
• Detected declarations: `syscall eventfd2`, `syscall eventfd`, `struct eventfd_ctx`, `function poll`, `function eventfd_free_ctx`, `function eventfd_free`, `function eventfd_ctx_fdget`, `function eventfd_release`, `function eventfd_poll`, `function eventfd_ctx_do_read`.
• Atlas domain: Core OS / VFS And Filesystem Core.
• Implementation status: core implementation candidate.
• This snippet crosses the user/kernel memory boundary; validate fault handling and access checks before translating the pattern.
• Synchronization appears in or near this file; preserve lock ordering, sleepability, and interrupt-context constraints.

Implementation Notes

• This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
• Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
• Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.