arch/sh/include/asm/futex.h

File Facts

System

Linux kernel

Corpus path

arch/sh/include/asm/futex.h

Extension

.h

Size

1381 bytes

Lines

73

Domain

Architecture Layer

Bucket

arch/sh

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.
• Uses kernel synchronization; read lock ordering, sleepability, and interrupt context assumptions before translating.

Dependency Surface

• linux/futex.h
• linux/uaccess.h
• asm/errno.h
• asm/futex-irq.h
• asm/futex-cas.h
• asm/futex-llsc.h

Detected Declarations

• function futex_atomic_cmpxchg_inatomic
• function arch_futex_atomic_op_inuser

Annotated Snippet

switch (op) {
		case FUTEX_OP_SET:
			newval = oparg;
			break;
		case FUTEX_OP_ADD:
			newval = oldval + oparg;
			break;
		case FUTEX_OP_OR:
			newval = oldval | oparg;
			break;
		case FUTEX_OP_ANDN:
			newval = oldval & ~oparg;
			break;
		case FUTEX_OP_XOR:
			newval = oldval ^ oparg;
			break;
		default:
			ret = -ENOSYS;
			break;
		}

		if (ret) break;

		ret = futex_atomic_cmpxchg_inatomic(&prev, uaddr, oldval, newval);
	} while (!ret && prev != oldval);

	if (!ret)
		*oval = oldval;

	return ret;
}

#endif /* __ASM_SH_FUTEX_H */

Annotation

• Immediate include surface: `linux/futex.h`, `linux/uaccess.h`, `asm/errno.h`, `asm/futex-irq.h`, `asm/futex-cas.h`, `asm/futex-llsc.h`.
• Detected declarations: `function futex_atomic_cmpxchg_inatomic`, `function arch_futex_atomic_op_inuser`.
• Atlas domain: Architecture Layer / arch/sh.
• Implementation status: source 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.