arch/arm64/include/asm/gcs.h

File Facts

System

Linux kernel

Corpus path

arch/arm64/include/asm/gcs.h

Extension

.h

Size

4223 bytes

Lines

197

Domain

Architecture Layer

Bucket

arch/arm64

Inferred role

Architecture Layer: implementation source

Status

source 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.
• Touches user memory; correctness depends on fault-safe copying and privilege boundary handling.
• Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

• asm/types.h
• asm/uaccess.h

Detected Declarations

• struct kernel_clone_args
• struct ksignal
• function gcsb_dsync
• function gcsstr
• function gcsss1
• function gcsss2
• function task_gcs_el0_enabled
• function gcs_check_locked
• function gcssttr
• function put_user_gcs
• function push_user_gcs
• function get_user_gcs
• function pop_user_gcs
• function task_gcs_el0_enabled
• function gcs_set_el0_mode
• function gcs_check_locked
• function get_user_gcs
• function pop_user_gcs

Annotated Snippet

static inline void gcs_set_el0_mode(struct task_struct *task) { }
static inline void gcs_free(struct task_struct *task) { }
static inline void gcs_preserve_current_state(void) { }
static inline void put_user_gcs(unsigned long val, unsigned long __user *addr,
				int *err) { }
static inline void push_user_gcs(unsigned long val, int *err) { }

static inline unsigned long gcs_alloc_thread_stack(struct task_struct *tsk,
						   const struct kernel_clone_args *args)
{
	return -ENOTSUPP;
}
static inline int gcs_check_locked(struct task_struct *task,
				   unsigned long new_val)
{
	return 0;
}
static inline u64 get_user_gcs(unsigned long __user *addr, int *err)
{
	*err = -EFAULT;
	return 0;
}
static inline u64 pop_user_gcs(int *err)
{
	return 0;
}

#endif

#endif

Annotation

• Immediate include surface: `asm/types.h`, `asm/uaccess.h`.
• Detected declarations: `struct kernel_clone_args`, `struct ksignal`, `function gcsb_dsync`, `function gcsstr`, `function gcsss1`, `function gcsss2`, `function task_gcs_el0_enabled`, `function gcs_check_locked`, `function gcssttr`, `function put_user_gcs`.
• Atlas domain: Architecture Layer / arch/arm64.
• Implementation status: source implementation candidate.
• This snippet crosses the user/kernel memory boundary; validate fault handling and access checks before translating the pattern.

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.