arch/x86/entry/vsyscall/vsyscall_emu_64.S

File Facts

System

Linux kernel

Corpus path

arch/x86/entry/vsyscall/vsyscall_emu_64.S

Extension

.S

Size

600 bytes

Lines

40

Domain

Architecture Layer

Bucket

arch/x86

Inferred role

Architecture Layer: syscall or user/kernel boundary

Status

core implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

• CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.
• Defines or participates in a user/kernel boundary; inspect argument validation, copy_from_user/copy_to_user, credentials, and dispatch target.

Dependency Surface

• linux/linkage.h
• asm/irq_vectors.h
• asm/page_types.h
• asm/unistd_64.h

Detected Declarations

• No top-level syscall, struct, function, initcall, or export declaration detected by the generator.

Annotated Snippet

#include <linux/linkage.h>

#include <asm/irq_vectors.h>
#include <asm/page_types.h>
#include <asm/unistd_64.h>

__PAGE_ALIGNED_DATA
	.globl __vsyscall_page
	.balign PAGE_SIZE, 0xcc
	.type __vsyscall_page, @object
__vsyscall_page:

	mov $__NR_gettimeofday, %rax
	syscall
	ret
	int3

	.balign 1024, 0xcc
	mov $__NR_time, %rax
	syscall
	ret
	int3

	.balign 1024, 0xcc
	mov $__NR_getcpu, %rax
	syscall
	ret
	int3

	.balign 4096, 0xcc

	.size __vsyscall_page, 4096

Annotation

• Immediate include surface: `linux/linkage.h`, `asm/irq_vectors.h`, `asm/page_types.h`, `asm/unistd_64.h`.
• Atlas domain: Architecture Layer / arch/x86.
• Implementation status: core implementation candidate.

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.