[linux-block.git] / include / linux / kallsyms.h

/* SPDX-License-Identifier: GPL-2.0 */
/* Rewritten and vastly simplified by Rusty Russell for in-kernel
 * module loader:
 *   Copyright 2002 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation
 */
#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);

int lookup_symbol_name(unsigned long addr, char *symname);

#else /* !CONFIG_KALLSYMS */

static inline unsigned long kallsyms_lookup_name(const char *name)
{
	return 0;
}

static inline int kallsyms_lookup_size_offset(unsigned long addr,
					      unsigned long *symbolsize,
					      unsigned long *offset)
{
	return 0;
}

static inline const char *kallsyms_lookup(unsigned long addr,
					  unsigned long *symbolsize,
					  unsigned long *offset,
					  char **modname, char *namebuf)
{
	return NULL;
}

static inline int sprint_symbol(char *buffer, unsigned long addr)
{
	*buffer = '\0';
	return 0;
}

static inline int sprint_symbol_build_id(char *buffer, unsigned long address)
{
	*buffer = '\0';
	return 0;
}

static inline int sprint_symbol_no_offset(char *buffer, unsigned long addr)
{
	*buffer = '\0';
	return 0;
}

static inline int sprint_backtrace(char *buffer, unsigned long addr)
{
	*buffer = '\0';
	return 0;
}

static inline int sprint_backtrace_build_id(char *buffer, unsigned long addr)
{
	*buffer = '\0';
	return 0;
}

static inline int lookup_symbol_name(unsigned long addr, char *symname)
{
	return -ERANGE;
}

static inline int kallsyms_on_each_symbol(int (*fn)(void *, const char *, unsigned long),
					  void *data)
{
	return -EOPNOTSUPP;
}

static inline int kallsyms_on_each_match_symbol(int (*fn)(void *, unsigned long),
						const char *name, void *data)
{
	return -EOPNOTSUPP;
}
#endif /*CONFIG_KALLSYMS*/

static inline void print_ip_sym(const char *loglvl, unsigned long ip)
{
	printk("%s[<%px>] %pS\n", loglvl, (void *) ip, (void *) ip);
}

#endif /*_LINUX_KALLSYMS_H*/
Commit	Line	Data
	1	/* SPDX-License-Identifier: GPL-2.0 */
	2	/* Rewritten and vastly simplified by Rusty Russell for in-kernel
	3	* module loader:
	4	* Copyright 2002 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation
	5	*/
	6	#ifndef _LINUX_KALLSYMS_H
	7	#define _LINUX_KALLSYMS_H
	8
	9	#include <linux/errno.h>
	10	#include <linux/buildid.h>
	11	#include <linux/kernel.h>
	12	#include <linux/stddef.h>
	13	#include <linux/mm.h>
	14	#include <linux/module.h>
	15
	16	#include <asm/sections.h>
	17
	18	#define KSYM_NAME_LEN 512
	19	#define KSYM_SYMBOL_LEN (sizeof("%s+%#lx/%#lx [%s %s]") + \
	20	(KSYM_NAME_LEN - 1) + \
	21	2(BITS_PER_LONG3/10) + (MODULE_NAME_LEN - 1) + \
	22	(BUILD_ID_SIZE_MAX * 2) + 1)
	23
	24	struct cred;
	25	struct module;
	26
	27	static inline int is_kernel_text(unsigned long addr)
	28	{
	29	if (__is_kernel_text(addr))
	30	return 1;
	31	return in_gate_area_no_mm(addr);
	32	}
	33
	34	static inline int is_kernel(unsigned long addr)
	35	{
	36	if (__is_kernel(addr))
	37	return 1;
	38	return in_gate_area_no_mm(addr);
	39	}
	40
	41	static inline int is_ksym_addr(unsigned long addr)
	42	{
	43	if (IS_ENABLED(CONFIG_KALLSYMS_ALL))
	44	return is_kernel(addr);
	45
	46	return is_kernel_text(addr) \|\| is_kernel_inittext(addr);
	47	}
	48
	49	static inline void dereference_symbol_descriptor(void ptr)
	50	{
	51	#ifdef CONFIG_HAVE_FUNCTION_DESCRIPTORS
	52	struct module *mod;
	53
	54	ptr = dereference_kernel_function_descriptor(ptr);
	55	if (is_ksym_addr((unsigned long)ptr))
	56	return ptr;
	57
	58	guard(rcu)();
	59	mod = __module_address((unsigned long)ptr);
	60
	61	if (mod)
	62	ptr = dereference_module_function_descriptor(mod, ptr);
	63	#endif
	64	return ptr;
	65	}
	66
	67	/* How and when do we show kallsyms values? */
	68	extern bool kallsyms_show_value(const struct cred *cred);
	69
	70	#ifdef CONFIG_KALLSYMS
	71	unsigned long kallsyms_sym_address(int idx);
	72	int kallsyms_on_each_symbol(int (fn)(void , const char *, unsigned long),
	73	void *data);
	74	int kallsyms_on_each_match_symbol(int (fn)(void , unsigned long),
	75	const char name, void data);
	76
	77	/* Lookup the address for a symbol. Returns 0 if not found. */
	78	unsigned long kallsyms_lookup_name(const char *name);
	79
	80	extern int kallsyms_lookup_size_offset(unsigned long addr,
	81	unsigned long *symbolsize,
	82	unsigned long *offset);
	83
	84	/* Lookup an address. modname is set to NULL if it's in the kernel. */
	85	const char *kallsyms_lookup(unsigned long addr,
	86	unsigned long *symbolsize,
	87	unsigned long *offset,
	88	char *modname, char namebuf);
	89
	90	/* Look up a kernel symbol and return it in a text buffer. */
	91	extern int sprint_symbol(char *buffer, unsigned long address);
	92	extern int sprint_symbol_build_id(char *buffer, unsigned long address);
	93	extern int sprint_symbol_no_offset(char *buffer, unsigned long address);
	94	extern int sprint_backtrace(char *buffer, unsigned long address);
	95	extern int sprint_backtrace_build_id(char *buffer, unsigned long address);
	96
	97	int lookup_symbol_name(unsigned long addr, char *symname);
	98
	99	#else /* !CONFIG_KALLSYMS */
	100
	101	static inline unsigned long kallsyms_lookup_name(const char *name)
	102	{
	103	return 0;
	104	}
	105
	106	static inline int kallsyms_lookup_size_offset(unsigned long addr,
	107	unsigned long *symbolsize,
	108	unsigned long *offset)
	109	{
	110	return 0;
	111	}
	112
	113	static inline const char *kallsyms_lookup(unsigned long addr,
	114	unsigned long *symbolsize,
	115	unsigned long *offset,
	116	char *modname, char namebuf)
	117	{
	118	return NULL;
	119	}
	120
	121	static inline int sprint_symbol(char *buffer, unsigned long addr)
	122	{
	123	*buffer = '\0';
	124	return 0;
	125	}
	126
	127	static inline int sprint_symbol_build_id(char *buffer, unsigned long address)
	128	{
	129	*buffer = '\0';
	130	return 0;
	131	}
	132
	133	static inline int sprint_symbol_no_offset(char *buffer, unsigned long addr)
	134	{
	135	*buffer = '\0';
	136	return 0;
	137	}
	138
	139	static inline int sprint_backtrace(char *buffer, unsigned long addr)
	140	{
	141	*buffer = '\0';
	142	return 0;
	143	}
	144
	145	static inline int sprint_backtrace_build_id(char *buffer, unsigned long addr)
	146	{
	147	*buffer = '\0';
	148	return 0;
	149	}
	150
	151	static inline int lookup_symbol_name(unsigned long addr, char *symname)
	152	{
	153	return -ERANGE;
	154	}
	155
	156	static inline int kallsyms_on_each_symbol(int (fn)(void , const char *, unsigned long),
	157	void *data)
	158	{
	159	return -EOPNOTSUPP;
	160	}
	161
	162	static inline int kallsyms_on_each_match_symbol(int (fn)(void , unsigned long),
	163	const char name, void data)
	164	{
	165	return -EOPNOTSUPP;
	166	}
	167	#endif /CONFIG_KALLSYMS/
	168
	169	static inline void print_ip_sym(const char *loglvl, unsigned long ip)
	170	{
	171	printk("%s[<%px>] %pS\n", loglvl, (void ) ip, (void ) ip);
	172	}
	173
	174	#endif /_LINUX_KALLSYMS_H/