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linux-next/include/linux/kallsyms.h
Arnd Bergmann e4a8ca3baa /proc/module: fix building without kallsyms
As reported by kernelci and other build bots, we now get a link
failure without CONFIG_KALLSYMS:

  module.c:(.text+0xf2c): undefined reference to `kallsyms_show_value'

This adds a dummy helper with the same name that can be used
for compilation. It's not entirely clear to me what this
should return for !CONFIG_KALLSYMS, I picked an unconditional
'false', which leads to the module address being unavailable
to user space.

Link: https://kernelci.org/build/mainline/branch/master/kernel/v4.14-5-g516fb7f2e73d/
Fixes: 516fb7f2e7 ("/proc/module: use the same logic as /proc/kallsyms for address exposure")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-13 09:48:56 -08:00

144 lines
3.7 KiB
C

/* 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/kernel.h>
#include <linux/stddef.h>
#define KSYM_NAME_LEN 128
#define KSYM_SYMBOL_LEN (sizeof("%s+%#lx/%#lx [%s]") + (KSYM_NAME_LEN - 1) + \
2*(BITS_PER_LONG*3/10) + (MODULE_NAME_LEN - 1) + 1)
#ifndef CONFIG_64BIT
# define KALLSYM_FMT "%08lx"
#else
# define KALLSYM_FMT "%016lx"
#endif
struct module;
#ifdef CONFIG_KALLSYMS
/* Lookup the address for a symbol. Returns 0 if not found. */
unsigned long kallsyms_lookup_name(const char *name);
/* Call a function on each kallsyms symbol in the core kernel */
int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *,
unsigned long),
void *data);
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_no_offset(char *buffer, unsigned long address);
extern int sprint_backtrace(char *buffer, unsigned long address);
/* Look up a kernel symbol and print it to the kernel messages. */
extern void __print_symbol(const char *fmt, unsigned long address);
int lookup_symbol_name(unsigned long addr, char *symname);
int lookup_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name);
/* How and when do we show kallsyms values? */
extern int kallsyms_show_value(void);
#else /* !CONFIG_KALLSYMS */
static inline unsigned long kallsyms_lookup_name(const char *name)
{
return 0;
}
static inline int kallsyms_on_each_symbol(int (*fn)(void *, const char *,
struct module *,
unsigned long),
void *data)
{
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_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 lookup_symbol_name(unsigned long addr, char *symname)
{
return -ERANGE;
}
static inline int lookup_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name)
{
return -ERANGE;
}
static inline int kallsyms_show_value(void)
{
return false;
}
/* Stupid that this does nothing, but I didn't create this mess. */
#define __print_symbol(fmt, addr)
#endif /*CONFIG_KALLSYMS*/
/* This macro allows us to keep printk typechecking */
static __printf(1, 2)
void __check_printsym_format(const char *fmt, ...)
{
}
static inline void print_symbol(const char *fmt, unsigned long addr)
{
__check_printsym_format(fmt, "");
__print_symbol(fmt, (unsigned long)
__builtin_extract_return_addr((void *)addr));
}
static inline void print_ip_sym(unsigned long ip)
{
printk("[<%p>] %pS\n", (void *) ip, (void *) ip);
}
#endif /*_LINUX_KALLSYMS_H*/