arch/arm64/include/asm/vdso/vsyscall.h

File Facts

System

Linux kernel

Corpus path

arch/arm64/include/asm/vdso/vsyscall.h

Extension

.h

Size

629 bytes

Lines

28

Domain

Architecture Layer

Bucket

arch/arm64

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.
• Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

• vdso/datapage.h
• asm-generic/vdso/vsyscall.h

Detected Declarations

• function __arch_update_vdso_clock

Annotated Snippet

#ifndef __ASM_VDSO_VSYSCALL_H
#define __ASM_VDSO_VSYSCALL_H

#ifndef __ASSEMBLER__

#include <vdso/datapage.h>

#define VDSO_PRECISION_MASK	~(0xFF00ULL<<48)


/*
 * Update the vDSO data page to keep in sync with kernel timekeeping.
 */
static __always_inline
void __arch_update_vdso_clock(struct vdso_clock *vc)
{
	vc->mask	= VDSO_PRECISION_MASK;
}
#define __arch_update_vdso_clock __arch_update_vdso_clock

/* The asm-generic header needs to be included after the definitions above */
#include <asm-generic/vdso/vsyscall.h>

#endif /* !__ASSEMBLER__ */

#endif /* __ASM_VDSO_VSYSCALL_H */

Annotation

• Immediate include surface: `vdso/datapage.h`, `asm-generic/vdso/vsyscall.h`.
• Detected declarations: `function __arch_update_vdso_clock`.
• Atlas domain: Architecture Layer / arch/arm64.
• 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.