mm/gup_test.c

File Facts

System

Linux kernel

Corpus path

mm/gup_test.c

Extension

.c

Size

9213 bytes

Lines

397

Domain

Core OS

Bucket

Memory Management

Inferred role

Core OS: operation-table or driver-model contract

Status

pattern 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 an operation table; this is where Linux turns generic core objects into subsystem-specific behavior.
• 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/kernel.h
• linux/mm.h
• linux/slab.h
• linux/uaccess.h
• linux/ktime.h
• linux/debugfs.h
• linux/highmem.h
• gup_test.h

Detected Declarations

• function put_back_pages
• function verify_dma_pinned
• function WARN
• function dump_pages_test
• function __gup_test_ioctl
• function pin_longterm_test_stop
• function pin_longterm_test_start
• function pin_longterm_test_read
• function pin_longterm_test_ioctl
• function gup_test_ioctl
• function gup_test_release
• function gup_test_init

Annotated Snippet

static const struct file_operations gup_test_fops = {
	.open = nonseekable_open,
	.unlocked_ioctl = gup_test_ioctl,
	.compat_ioctl = compat_ptr_ioctl,
	.release = gup_test_release,
};

static int __init gup_test_init(void)
{
	debugfs_create_file_unsafe("gup_test", 0600, NULL, NULL,
				   &gup_test_fops);

	return 0;
}

late_initcall(gup_test_init);

Annotation

• Immediate include surface: `linux/kernel.h`, `linux/mm.h`, `linux/slab.h`, `linux/uaccess.h`, `linux/ktime.h`, `linux/debugfs.h`, `linux/highmem.h`, `gup_test.h`.
• Detected declarations: `function put_back_pages`, `function verify_dma_pinned`, `function WARN`, `function dump_pages_test`, `function __gup_test_ioctl`, `function pin_longterm_test_stop`, `function pin_longterm_test_start`, `function pin_longterm_test_read`, `function pin_longterm_test_ioctl`, `function gup_test_ioctl`.
• Atlas domain: Core OS / Memory Management.
• Implementation status: pattern 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.