arch/sparc/lib/NGpatch.S

File Facts

System

Linux kernel

Corpus path

arch/sparc/lib/NGpatch.S

Extension

.S

Size

907 bytes

Lines

35

Domain

Architecture Layer

Bucket

arch/sparc

Inferred role

Architecture Layer: arch/sparc

Status

atlas-only

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.

Dependency Surface

• No C-style include directives detected by the generator.

Detected Declarations

• No top-level syscall, struct, function, initcall, or export declaration detected by the generator.

Annotated Snippet

#define BRANCH_ALWAYS	0x10680000
#define NOP		0x01000000
#define NG_DO_PATCH(OLD, NEW)	\
	sethi	%hi(NEW), %g1; \
	or	%g1, %lo(NEW), %g1; \
	sethi	%hi(OLD), %g2; \
	or	%g2, %lo(OLD), %g2; \
	sub	%g1, %g2, %g1; \
	sethi	%hi(BRANCH_ALWAYS), %g3; \
	sll	%g1, 11, %g1; \
	srl	%g1, 11 + 2, %g1; \
	or	%g3, %lo(BRANCH_ALWAYS), %g3; \
	or	%g3, %g1, %g3; \
	stw	%g3, [%g2]; \
	sethi	%hi(NOP), %g3; \
	or	%g3, %lo(NOP), %g3; \
	stw	%g3, [%g2 + 0x4]; \
	flush	%g2;

	.globl	niagara_patch_copyops
	.type	niagara_patch_copyops,#function
niagara_patch_copyops:
	NG_DO_PATCH(memcpy, NGmemcpy)
	NG_DO_PATCH(raw_copy_from_user, NGcopy_from_user)
	NG_DO_PATCH(raw_copy_to_user, NGcopy_to_user)
	retl
	 nop
	.size	niagara_patch_copyops,.-niagara_patch_copyops

Annotation

• Atlas domain: Architecture Layer / arch/sparc.
• Implementation status: atlas-only.
• 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.