arch/um/include/shared/kern_util.h

File Facts

System

Linux kernel

Corpus path

arch/um/include/shared/kern_util.h

Extension

.h

Size

1975 bytes

Lines

71

Domain

Architecture Layer

Bucket

arch/um

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.
• 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

• sysdep/ptrace.h
• sysdep/faultinfo.h

Detected Declarations

• struct siginfo
• struct pt_regs

Annotated Snippet

#ifndef __KERN_UTIL_H__
#define __KERN_UTIL_H__

#include <sysdep/ptrace.h>
#include <sysdep/faultinfo.h>

struct siginfo;

extern int uml_exitcode;

extern int kmalloc_ok;

extern unsigned long alloc_stack(int order, int atomic);
extern void free_stack(unsigned long stack, int order);

struct pt_regs;
extern void do_signal(struct pt_regs *regs);
extern void interrupt_end(void);
extern void relay_signal(int sig, struct siginfo *si, struct uml_pt_regs *regs,
			 void *mc);

extern unsigned long segv(struct faultinfo fi, unsigned long ip,
			  int is_user, struct uml_pt_regs *regs,
			  void *mc);
extern int handle_page_fault(unsigned long address, unsigned long ip,
			     int is_write, int is_user, int *code_out);

extern unsigned int do_IRQ(int irq, struct uml_pt_regs *regs);
extern void initial_thread_cb(void (*proc)(void *), void *arg);

extern void timer_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs);

extern void uml_pm_wake(void);

extern int start_uml(void);

extern void uml_cleanup(void);
extern void do_uml_exitcalls(void);

/*
 * Are we disallowed to sleep? Used to choose between GFP_KERNEL and
 * GFP_ATOMIC.
 */
extern int __uml_cant_sleep(void);
extern int get_current_pid(void);
extern int copy_from_user_proc(void *to, void *from, int size);
extern char *uml_strdup(const char *string);
int uml_need_resched(void);

extern unsigned long to_irq_stack(unsigned long *mask_out);
extern unsigned long from_irq_stack(int nested);

extern int singlestepping(void);

extern void segv_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs,
			 void *mc);
extern void winch(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs,
		  void *mc);
extern void fatal_sigsegv(void) __attribute__ ((noreturn));

void um_idle_sleep(void);

void kasan_map_memory(void *start, size_t len);

#endif

Annotation

• Immediate include surface: `sysdep/ptrace.h`, `sysdep/faultinfo.h`.
• Detected declarations: `struct siginfo`, `struct pt_regs`.
• Atlas domain: Architecture Layer / arch/um.
• 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.