arch/um/drivers/harddog_kern.c

File Facts

System

Linux kernel

Corpus path

arch/um/drivers/harddog_kern.c

Extension

.c

Size

4101 bytes

Lines

175

Domain

Architecture Layer

Bucket

arch/um

Inferred role

Architecture Layer: operation-table or driver-model contract

Status

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

Dependency Surface

• linux/module.h
• linux/types.h
• linux/kernel.h
• linux/fs.h
• linux/mm.h
• linux/miscdevice.h
• linux/watchdog.h
• linux/reboot.h
• linux/mutex.h
• linux/init.h
• linux/spinlock.h
• linux/uaccess.h
• mconsole.h
• harddog.h

Detected Declarations

• function harddog_open
• function harddog_release
• function harddog_write
• function harddog_ioctl_unlocked
• function harddog_ioctl

Annotated Snippet

static const struct file_operations harddog_fops = {
	.owner		= THIS_MODULE,
	.write		= harddog_write,
	.unlocked_ioctl	= harddog_ioctl,
	.compat_ioctl	= compat_ptr_ioctl,
	.open		= harddog_open,
	.release	= harddog_release,
};

static struct miscdevice harddog_miscdev = {
	.minor		= WATCHDOG_MINOR,
	.name		= "watchdog",
	.fops		= &harddog_fops,
};
module_misc_device(harddog_miscdev);

Annotation

• Immediate include surface: `linux/module.h`, `linux/types.h`, `linux/kernel.h`, `linux/fs.h`, `linux/mm.h`, `linux/miscdevice.h`, `linux/watchdog.h`, `linux/reboot.h`.
• Detected declarations: `function harddog_open`, `function harddog_release`, `function harddog_write`, `function harddog_ioctl_unlocked`, `function harddog_ioctl`.
• Atlas domain: Architecture Layer / arch/um.
• 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.