include/linux/kallsyms.h

Source file repositories/reference/linux-study-clean/include/linux/kallsyms.h

File Facts

System
Linux kernel
Corpus path
include/linux/kallsyms.h
Extension
.h
Size
4342 bytes
Lines
175
Domain
Core OS
Bucket
Core Kernel Interface
Inferred role
Core OS: implementation source
Status
source implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

#ifndef _LINUX_KALLSYMS_H
#define _LINUX_KALLSYMS_H

#include <linux/errno.h>
#include <linux/buildid.h>
#include <linux/kernel.h>
#include <linux/stddef.h>
#include <linux/mm.h>
#include <linux/module.h>

#include <asm/sections.h>

#define KSYM_NAME_LEN 512
#define KSYM_SYMBOL_LEN (sizeof("%s+%#lx/%#lx [%s %s]") + \
			(KSYM_NAME_LEN - 1) + \
			2*(BITS_PER_LONG*3/10) + (MODULE_NAME_LEN - 1) + \
			(BUILD_ID_SIZE_MAX * 2) + 1)

struct cred;
struct module;

static inline int is_kernel_text(unsigned long addr)
{
	if (__is_kernel_text(addr))
		return 1;
	return in_gate_area_no_mm(addr);
}

static inline int is_kernel(unsigned long addr)
{
	if (__is_kernel(addr))
		return 1;
	return in_gate_area_no_mm(addr);
}

static inline int is_ksym_addr(unsigned long addr)
{
	if (IS_ENABLED(CONFIG_KALLSYMS_ALL))
		return is_kernel(addr);

	return is_kernel_text(addr) || is_kernel_inittext(addr);
}

static inline void *dereference_symbol_descriptor(void *ptr)
{
#ifdef CONFIG_HAVE_FUNCTION_DESCRIPTORS
	struct module *mod;

	ptr = dereference_kernel_function_descriptor(ptr);
	if (is_ksym_addr((unsigned long)ptr))
		return ptr;

	guard(rcu)();
	mod = __module_address((unsigned long)ptr);

	if (mod)
		ptr = dereference_module_function_descriptor(mod, ptr);
#endif
	return ptr;
}

/* How and when do we show kallsyms values? */
extern bool kallsyms_show_value(const struct cred *cred);

#ifdef CONFIG_KALLSYMS
unsigned long kallsyms_sym_address(int idx);
int kallsyms_on_each_symbol(int (*fn)(void *, const char *, unsigned long),
			    void *data);
int kallsyms_on_each_match_symbol(int (*fn)(void *, unsigned long),
				  const char *name, void *data);

/* Lookup the address for a symbol. Returns 0 if not found. */
unsigned long kallsyms_lookup_name(const char *name);

extern int kallsyms_lookup_size_offset(unsigned long addr,
				  unsigned long *symbolsize,
				  unsigned long *offset);

/* Lookup an address.  modname is set to NULL if it's in the kernel. */
const char *kallsyms_lookup(unsigned long addr,
			    unsigned long *symbolsize,
			    unsigned long *offset,
			    char **modname, char *namebuf);

/* Look up a kernel symbol and return it in a text buffer. */
extern int sprint_symbol(char *buffer, unsigned long address);
extern int sprint_symbol_build_id(char *buffer, unsigned long address);
extern int sprint_symbol_no_offset(char *buffer, unsigned long address);
extern int sprint_backtrace(char *buffer, unsigned long address);
extern int sprint_backtrace_build_id(char *buffer, unsigned long address);

Annotation

Implementation Notes